biology07

Transcription

biology07

biology07
The Annual Meeting of the Swiss Zoological,
Botanical and Mycological Societies
February 15–16, 2007, ETH Zurich
Abstracts
The annual two-day scientific meeting of organismic and
integrative biology
The forum for PhD students and postdocs to present their
research
Sponsors
Editor:
Swiss Federal Research Institute WSL, Birmensdorf, Switzerland, 2007
Organizers:
Werner Suter, Beatrice Senn, Kurt Bollmann, Simon Egli, Felix Gugerli, Rolf Holderegger, Daniel Rigling,
Christoph Scheidegger, Martin Schütz, Josef Senn, Beat Wermelinger, Tom Wohlgemuth
Swiss Federal Research Institute WSL
Zürcherstrasse 111
CH-8903 Birmensdorf
Switzerland
Recommended form of citation:
Swiss Federal Research Institute WSL (ed) 2007: biology07 – The Annual Meeting of the Swiss Zoological,
Botanical and Mycological Societies. ETH Zurich, February 15–16, 2007. Abstracts. 72 pp.
Authors, 2007: Title. In: biology07 – The Annual Meeting of the Swiss Zoological, Botanical and Mycological
Societies. ETH Zurich, February 15–16, 2007. Abstracts. page number.
Available from http://www.wsl.ch/biology07/index_EN?redir=1&
biology07
The Annual Meeting of the Swiss Zoological, Botanical and
Mycological Societies
The annual two-day scientific meeting of organismic and integrative biology
The forum for PhD students and postdocs to present their research
The scientific meeting: Thursday 15 February to Friday 16 February 2007
ETH Zürich, Zentrum, main building (Rämistrasse 101), in the Auditorium Maximum (HG F30)
Keynote speakers:
Jaboury Ghazoul: Eidg. Technische Hochschule Zürich, Switzerland
The Paradox of ecosystem services: ecology, economics and the pollination crisis
Han Olff: University of Groningen, The Netherlands
Plant-herbivore interactions and biodiversity
Tord Snäll: Swedisch University of Agricultural Sciences, Uppsala, Sweden
Epiphyte metapopulation dynamics in a dynamic forest landscape
Alan R. Templeton: Washington University, St. Louis, USA
Integrating landscape genetics with Phylogeography: lessons from naked mole rats
Darwin’s Birthday Party: Thursday night, 15 February 2007
Swiss Federal Research Institute WSL, Zürcherstrasse 111, 8903 Birmensdorf
Keynote speaker
Jurgen Tack: Institute of Nature Conservation, Brussels, Belgium
Having dinner with Darwin: Biodiversity on the menu
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Content
Templeton, Alan R.
Aebi, Alexandre; Schönrogge, Karsten; Hayward, Alexander; Stone, Graham N.
Fink, Sabine; Excoffier, Laurent; Heckel, Gerald
Burri, Reto; Niculita, Hélène; Roulin, Alexandre; Fumagalli, Luca
Braaker, Sonja; Excoffier, Laurent; Heckel, Gerald
Dépraz, Aline; Pfenninger, Markus; Hausser, Jacques
Gehrke, Berit; Linder, Peter
Machado, Marlon C.; Eggli, Urs; Nyffeler, Reto
Thiel-Egenter, Conny; Holderegger, Rolf; Englisch, Thorsten; Wohlgemuth, Thomas; Linder, Peter;
Gugerli, Felix; IntraBioDiv-Consortium
Snäll, Tord
Biebach, Iris; Keller, Lukas
Signorell, Natalina; Patthey, Patrick; Rotelli, Luca; Arlettaz, Raphaël
Meunier, Joël; Chapuisat, Michel
Reber, Anabelle; Castella, Grégoire; Christe, Philippe; Chapuisat, Michel
Hangartner, Sandra B.; Garner, T.W.J.
Turnbull, Lindsay A.; Paul-Victor, Cloé; Schmid, Bernhard; Purves, Drew W.
Galley, Chloé; Zimmermann, Niklaus; Linder, H. Peter
Nusbaumer, Louis; Ranirison, Patrick; Gautier, Laurent; Spichiger, Rodolphe
Guggisberg, Alessia; Mansion, Guilhem; Conti, Elena
Colard, Alexandre; Corradi, Nicolas; Sanders, Ian R.
Ghazoul, Jaboury
Oehl, Fritz; Sieverding, Ewald; Bogenrieder, Arno; Stahr, Karl; Laczko, Endre; Mäder, Paul; Kuss, Patrick;
Ineichen, Kurt; Wiemken, Andres
Kaiser, Christopher N.; Müller, Christine B.
Steinebrunner, Fabrizio; Schiestl, Florian; Twel, Robert; Francke, Wittko; Leuchtmann, Adrian
Vojtech, Eva; Turnbull, Lindsay A.; Hector, Andy
Jourdie, Violaine; Alvarez, Nadir; Turlings, Ted C.J.
Bergmüller, R.; Pinto, A.; Bshary, R.
Tanner, Marion; Kölliker, Mathias; Richner, Heinz
Thüler, Karin; Ward, Paul
Piault, Romain; Gasparini, Julien; Paulet, Mariane; Bize, Pierre; McGraw, Kevin; Roulin, Alexandre
Olff, Han
Moretti, Marco; Legg, Colin
Elzinga, Jelmer A.; Bernasconi, Giorgina
Bagchi, Robert; Philipson, Christopher P.; Slade, Eleanor; Phillips, Sam; Villeneuva, Jerôme; Hector,
Andrew; Lewis, Owen T.; Scholes, Julie D.; Press, Malcolm C.
Naisbit, Russell E.; Aerni, Gilles; Margraf, Nicolas; Rahier, Martine
Thiel, Dominik; Jenni-Eiermann, Susi; Jenni, Lukas
Müller, Claudia; Jenni-Eiermann, Susi; Jenni, Lukas
Haemmerli, Marc
Aebischer, Adrian; Koch, Silvia; Nyffeler, Peter; Arlettaz, Raphael
Aeschbacher, Simon; Biebach, Iris
Alvarez, Miguel; Deil, Ulrich; Ramírez, Carlos
Angelone, Sonia; Holderegger, Rolf
Ashrafi, Sohrab; Bontadina, Fabio; Kiefer, Andreas; Pavlinic, Igor; Arlettaz, Raphaël
Biedermann, Peter H.W.; Taborsky, Michael
Bischoff, Linda L.; Tschirren, Barbara; Saladin, Verena; Richner, Heinz
Broennimann, Olivier; Treier, U.A.; Müller-Schärer, H.; Thuiller, W.; Peterson, A.T.; Guisan, A.
Bruintjes, Rick; Taborsky, Michael
Brunner, Patrick C.; Schürch, Stephanie
Bruyndonckx, Nadia; Devevey, Godefroy; Keller, Laurent; Christe, Philippe
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biology07 – oral presentations
Danisman, Evin
Fischer, Martin C.; Excoffier, Laurent; Heckel, Gerald
Frei, Eva S.; Nyffeler, Reto
Furrer, Roman D.; Manser, Marta B.
Gallizzi, Katharina; Gern, Lise; Richner, Heinz
Gegenschatz, Silvan E.; Ribi, Georg
Gerber, Esther; Schaffner, U.; Krebs, C.; Murrell, C.; Moretti, M.
Grossen, Christine; Biebach, Iris; Keller, Lukas
Hennig, Ernest; Ghazoul, J.
Herrmann, Doris; Poncet, Bénédicte; Manel, Stéphanie; Holderegger, Rolf; Taberlet, Pierre; Thuiller,
Wilfried; Gielly, Ludovic; Rioux, Delphine; Aubert, Serge; Gugerli, Felix; IntraBioDiv Consortium
Internicola, Antonina I.; Gigord, Luc D.B.; Bernasconi, Giorgina
Kamm, Urs; Gugerli, Felix; Holderegger, Rolf; Rotach, Peter; Ewards, Peter
Kehrli, Patrik; Bersier, Louis-Félix
Kotrschal, A.; Ilmonen, P., Penn D.J.
Lendel, Anita; Eggli, U.; Nyffeler, R.
Martinez, Nicolas
Müller, Corsin A.; Manser, Marta B.
Neuenschwander, Samuel
Patthey, Patrick; Wirthner, Sven; Signorell, Natalina; Arlettaz, Raphaël
Pluess, Andrea R.
Pohl, Mandy; Rixen, Ch.; Körner, Ch.
Ragettli, Gian Andraia; Bontadina, Fabio; Schaub, Michael; Zoephel, Ulrich; Arlettaz, Raphaël
Ranirison, Patrick; Nusbaumer, Louis; Gautier, Laurent
Raveh S.; Tonetti N.; Betschart B.; Dobson S.F.; Neuhaus P.
Reichlin, Thomas S.; Hobson, Keith A.; Schaub, Michael; Jenni Lukas; Arlettaz, Raphaël
Rixen, Christian; Haag, Susanne; Kulakowski, Dominik; Bebi, Peter
Rytz, Raphael; Heckel, Gerald
Sattler, T.; Duelli, P.; Wirz, P.; Siegwart, R.; Schulz, A.; Obrist, M.K.; Milani, L.; Kindermann, M.;
Bontadina, F.; Albin, V.; Arlettaz, R.; Moretti, M.
Sattler, T.; Bontadina, F.; Arlettaz, R.
Sbilordo, Sonja H.; Ribi, Georg
Sieber, Yasemin; Wirth, L.; Erhardt, A.; Reyer, U.; Holderegger, R.
Staerkle, Michael; Kölliker, Mathias
Szentkuti, Susanne; Bontadina, Fabio; Moretti, Marco; Spada, Martina; Zambelli, Nicola; Martinoli,
Adriano; Arlettaz, Raphaël
von Felten, Stefanie; Buchmann, N.; Hector, A.; Niklaus, P.; Scherer-Lorenzen, M.; Schmid, B.
Weinberger, Irene; Bontadina, Fabio; Arlettaz, Raphaël
Wipf, Sonja
Wittwer, Gregor; Patthey, Patrick; Arlettaz, Raphaël; Marin, Stéphane; Magnani, Yann
Wurm, Yannick; Wang, John; Jemielity, Stephanie; Keller, Laurent
Zbinden, Judith A.; Largiadèr, Carlo R.; Leippert, Fabio; Margaritoulis, Dimitris; Arlettaz, Raphaël
Balmer, Oliver; Caccone, Adalgisa
Moretti, Marco; Patocchi, Nicola; Schaffner, Urs; Gerber, Esther
Tack, Jürgen
Dobbertin, Matthias; Rigling, Andreas; Wohlgemutz, Thomas
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Landscape genetics on different scales of space and time
Templeton, Alan R.
Department of Biology, Washington University, St. Louis, Missouri 63130-4899 USA
Correspondence: [email protected]
A new genetic variant initially exists in only one place at one time. DNA replication allows this variant to
travel from one generation to the next and to spread through space. The strategies that work best in
revealing how genes spread through space and time depend upon the spatial/temporal scale of the study.
At small spatial scales, high levels of pre-existing genetic variation, such as those provided by
microsatellites, are needed because the mutational process is not a major factor on a short time scale.
Insight into the movement of genes through the landscape can be achieved by coupling microsatellite
surveys with traditional population ecology studies. As the geographical and temporal scale of the study
goes up, the mutational process becomes important, and phylogeographic approaches become
increasingly informative. At intermediate spatial and temporal scales, both phylogeographic and
microsatellite approaches are informative and complement each other. At the largest temporal scales,
phylogeographic and coalescent approaches become the primary tools for analysis.
Phylogeography of oak gallwasp parasitoids
Aebi, Alexandre1; Schönrogge, Karsten2; Hayward, Alexander1;Stone, Graham N1
1
The University of Edinburgh, Institute of Evolutionary biology, King’s Buildings, EH9 3JT West Mains road,
Edinburgh, UK
2
Centre for Ecology and Hydrology, CEH Dorset, Winfrith Technology Centre, Dorchester, DT2 8ZD, UK
The western paleartic oak gallwasp community contains 170 species of gallwasps (Hymenoptera:
Cynipidae) 145 species of inquilines (Hymenoptera: Cynipidae) and 104 species of parasitoids
(Hymenoptera: Chalcidoidea) and thus represent a model system for the study of community ecology,
invasion biology and phylogeography.
The evolution of Western Palaearctic oak gallwasp communities shows similar phylogeographic histories
for several widespread gallwasp species. In each case, allele frequency and haplotype sequence data
strongly support an eastern origin, followed by westwards range expansion. Oak gallwaps are attacked by
a rich guild of chalcid parasitoids often specialized on different gallwasp hosts. To understand the
evolution of this community, we are constructing the phylogeographic histories of a selection of species
to be able to compare the results obtained for different trophic levels.
Here we present the phylogeography of two parasitoids, Eurytoma brunniventris (Hymenoptera:
Eurytomidae) Sycophila biguttata (Hymenoptera: Eurytomidae). Analysis of haplotype mt-DNA
sequence data revealed that E. brunniventris and S. biguttata actually consist of an assemblage of several
cryptic species with very different biology. Moreover species of the genus Eurytoma were described on
the base of their host plant but our data shoes evidence of multiple host shift between oak gall wasps and
other Cynipids on alternative host-plants. Our results highlighted the importance of molecular tool for the
detection of cryptic taxon in this biological system but also have an importance to understand the
evolution of widespread communities. The extent to which such enemies are truly generalist (rather than
being divided into cryptic species or host races, attacking part of the observed host or prey range) is
central to major issues in ecology, such as food-web stability.
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Mammalian monogamy is not controlled by a single gene
Computational and Molecular Population Genetics (CMPG), Zoological Institute, University of Bern,
Baltzerstrasse 6, CH-3012 Bern, Switzerland
Complex social behavior in Microtus voles and other mammals has been postulated to be under the direct
genetic control of a single locus, the arginine-vasopressin 1a receptor (avpr1a) gene. By using a
phylogenetic approach, we show that a repetitive element in the promoter region reportedly causing
monogamy is actually widespread in non-monogamous Microtus and other rodents. There was no
evidence for intraspecific polymorphism in regard to the presence of the repetitive element, and its
absence in two closely related non-monogamous species is apparently the result of an evolutionarily
recent loss. Our analyses demonstrate further that similar repetitive structures upstream of the avpr1a
gene in humans and primates which have been associated with social bonding are evolutionarily distinct
from those in rodents. Our evolutionary analysis reveals that monogamy in rodents is not controlled by a
single polymorphism in the promoter region of the avpr1a gene. We thus resolve the contradiction
between the claims for an evolutionary conserved genetic programming of social behavior in mammals,
and the vast evidence for highly complex and flexible mating systems.
The slow and the furious – MHC class II b exons 2 and 3 tell
different stories in owls
Burri, Reto; Niculita, Hélène; Roulin, Alexandre; Fumagalli, Luca
Laboratoire de Biologie de la Conservation, Département d’Ecologie et Evolution, Université de Lausanne, 1015
Lausanne, Switzerland.
The major histocompatibility complex (MHC) is a highly variable multi-gene family critical to the
vertebrate immune system. In most taxa, including mammals, genes of related species form orthologous
clusters, following a birth-and-death model of evolution. In birds however, so far orthologous
relationships have been revealed only twice, indicating elevated rates of concerted evolution or recent
duplication. To shed light on the time scale at which the diversification and homogenization of avian
MHC genes occur, studies considering a monophyletic group of closely related species are called for.
In the present study we isolated exon 2 and exon 3 sequences of MHC class II B genes in twelve
European and one African owl species. Exon 2 encodes the 1-domain involved in antigen binding and is
supposed to be under balancing selection, while exon 3 contains the 2-domain involved in T-cell
binding. Our analyses reveal that in owls, these two exons tell different stories. Exon 3 traces back
duplication history. In contrast, exon 2 shows a complex phylogeny revealing effects of positive
selection. Our data represent the first example in the avian MHC in which ancestral polymorphisms have
been retained in coding sequences over multiple successive speciation events for nearly 40 MYA.
Moreover, they show that the MHC of owls is the closest to the ancestral MHC state and particularly
different from other taxa already described.
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Complex postglacial recolonization of the Alps by the common vole
(Microtus arvalis)
Braaker, Sonja; Excoffier, Laurent; Heckel, Gerald
Computational and Molecular Population Genetics (CMPG) Laboratory, Zoological Institute, University of Bern,
Mountain ranges like the Alps or the Pyrenees are often seen as important barriers to recolonization of
habitats after glaciations. However, it is obvious that the effectiveness of topographical structures on
recolonizations depends to a large extent on biological parameters like the dispersal capacity of
organisms. In this study, we examine genetic variation in the common vole (Microtus arvalis) in Europe
to infer the colonization history of the Alps after the last glacial maximum (LGM) and the location of
zones of secondary contact between highly diverged evolutionary lineages. We analyzed 1 kb of the
mitochondrial cytochrome b gene (cytb) of 217 individuals from 104 locations throughout and
surrounding the Alps. This allowed us to considerably refine the probable locations of the LGM refugia
compared to previous suggestions, and to locate the contact zones between the four major evolutionary
lineages in European M. arvalis. The improved coverage of the old evolutionary lineage in Western
Europe revealed a deep split into a northern and a southern lineage which diverged before the LGM.
Postglacial recolonization of the Alps occurred from various directions by three different lineages. In
particular the transalpine distribution of the Italian lineage challenged a major barrier effect of the
mountain ridge. The locations of the contact zones between evolutionary lineages in the Alps and patterns
of genetic similarity within lineages in regard to topographical structures demonstrate a complex
recolonization history with a likely crossing of the main mountain ridge by these small rodents. This
result questions the effectiveness of the Alps as the main barrier for postglacial recolonization of similar
or larger animals and stresses the importance of the onset and speed of recolonization processes for the
formation of phylogeographic patterns.
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Postglacial history of Trochulus villosus
(Hygromiidae, Gastropoda): the Alps at a snail’s pace
Dépraz, Aline1; Pfenninger, Markus2; Hausser, Jacques1
1
Dep. of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland
Abt. Ökologie & Evolution, JW Goethe-Universität, BioCampus Sysmayerstrasse, 60054 Frankfurt am Main,
Germany
2
How did species recolonise the empty spaces left by the retreating quaternary glaciers and where did they
come from? Such questions have mainly been addressed using species with moderate to high dispersal
capacities, usually at the scale of continents. A panel of different species with respect to their ecologies,
distributions and dispersal abilities might prove useful to refine the picture. The hairy land snail,
Trochulus villosus, dwells calcareous forested habitats at altitudes between 500 and 2200m. Its rather
small distribution is centered on the swiss Alps and Jura, little extending to Austria and France. Such a
restricted range allows for an intensive sampling: 52 populations were sampled, covering the whole
distribution of T. villosus. In each population, an average of 8.75 individuals were sequenced for 2
mitochondrial genes (16SrRNA and COX1). A selection of populations were further genotyped for
microsatellite markers. Two divergent mtDNA clades emerge: one with a central distribution, the other
being peripheral. Both groups seem to have expanded soon after the last glacial maximum, but the central
one earlier (Bayesian analyses). These results suggest two origins of recolonisation, whose exact
locations remain uncertain. The recolonisation of the present day distribution is linked to a population
expansion in 2 phases, where the second “late” population might have been restricted to a marginal
distribution.
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Temperate plant elements in Africa – a case study of Carex
(Cyperaceae)
Gehrke, Berit; Linder, Peter
Institute for Systematic Botany, University of Zurich, 8008 Zurich, Switzerland
The temperate – upper montane and alpine – floras of tropical and southern Africa contain a large number
floral elements from different floral regions. One of the regions of origin are the temperate and boreal
areas of the Northern Hemisphere. These Northern Hemisphere plant elements are taxa that evolved and
diversified mainly north of the Sahara, but have a few species in the high and temperate mountains in
Africa. In these regions, climate conditions such as average temperature, annual precipitation,
temperature fluctuation during a day and soil types resemble those of temperate or boreal areas.
One of these plant groups is Carex (the ‘sedges’) a large genus in the Cyperaceae with more than 1700
species distributed throughout the world. Although most species are found in the Northern Hemisphere,
about 55 taxa are found in the Mounatins of the Afrotemperate Regions. These mountains are widely
separated from each other, and are disconnected from the northern temperate occurrences of Carex. In our
study we address questions of origin and diversification of Carex in Africa through a phylogenetic and
biogeographical approach. We analysed DNA sequences from 35 of the 55 African taxa, as well as 300
taxa representing most sections of the tribe Cariceae, and most of its geographical distribution.
Results of the molecular phylogenetic study indicate that there have been several dispersal events of
Carex from Eurasia into Africa. While some of the dispersal events were followed by diversification,
others were not but these have nevertheless resulted in taxa distributed over widely seperated areas. We
will use these phylogenetic data combined with species distributions and habitat ranges to construct a
model for the evolution of the distribution of Carex in the Afrotemperate regions.
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Phylogenetic relationships in the genus Parodia Spegazzini
(Cactaceae-Notocacteae)
Machado, Marlon C.1; Eggli, Urs2; Nyffeler, Reto1
1
Institut für Systematische Botanik, Universität Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
Sukkulenten-Sammlung Zürich, Mythenquai 88, CH-8002 Zürich, Switzerland
2
Parodia Spegazzini comprises about 60 to 70 species of globular to rarely subcolumnar cacti with
occurrence in the eastern portion of central South America. The species are distributed in two centers of
diversity; one center is located in the eastern slopes of the Andes in northwestern Argentina and eastern
Bolivia, and a second center is found in the lowland pampas regions of northeastern Argentina, southern
Brazil, eastern Paraguay, and Uruguay. Many species have very limited ranges, and the majority is
threatened by grazing, agriculture, and habitat modification. In this study we investigate the phylogenetic
relationships among 32 exemplars representing all subgroups of Parodia s.l. with the use of nuclear and
plastid molecular markers (ITS from the nuclear ribosomal DNA and six cpDNA markers). The
monophyly of Parodia s.l. is tested with the inclusion of five species from other genera of tribe
Notocacteae. Four species from tribes Cereeae and Trichocereeae are added as secondary outgroups. The
data matrix with the aligned sequences is 7814 characters long, 875 of which are informative. We
analyzed the data matrix with cladistic and bayesian inference methods. The different analyses resulted in
well resolved consensus trees with a similar topology and high statistical support values for the majority
of the clades. Parodia is resolved as a monophyletic group, and nine well-supported clades are identified,
some of which correspond to groups previously classified as segregate genera. However, the relationships
among these clades do not agree with any of the hypotheses of relationships proposed previously. The
pampas regions harbor the majority of the Parodia subgroups, and includes the earlier diverging (i.e.,
more basal) lineages within the genus, often ocurring in specialized, restricted habitats. There is also
evidence for multiple colonization events from the pampas regions to the eastern Andean foothills.
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Congruence of phylogeographic and biogeographic breaks in the
European Alps
Thiel-Egenter, Conny1; Holderegger, Rolf1; Englisch, Thorsten2; Wohlgemuth, Thomas1; Linder, Peter3; Gugerli,
Felix1; IntraBioDiv-Consortium4
1
Swiss Federal Research Institute WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland
Department of Biogeography, University of Vienna, Rennweg 14, 1030 Vienna, Austria
3
Institute of Systematic Botany, Zollikerstrasse 107, 8008 Zurich, Switzerland
4
http://intrabiodiv.vitamib.com
2
There is a long history of studying the flora in the European Alps and its biogeography. Since the early
19th century, scientists have attempted to localize floristically similar regions and its delimitations and to
explain these with geological or climatic factors. A most widely discussed biogeographic break is the one
between the eastern and western Alps. However, this hypothesized break between the two flora regions
has never been statistically tested. Here, we propose a new approach to geographically identify
biogeographic breaks. We use an exhaustive dataset of the distribution of alpine plant species, compiled
in the frame of the project IntraBioDiv. Data on species occurrences refer to a regular spatial grid laid
over the whole range of the European Alps. On the same grid, we assessed the genetic structure of several
widely distributed alpine plant species to identify common phylogeographic breaks in the Alps. We
expect that biogeographic and phylogeographic breaks are largely congruent in the Alps due to historical
processes acting at both the genetic and the species level in the same direction. Such processes, e.g.
isolation, regional extinction or range-expansion are related to Quaternary ice ages, which had a
substantial influence on present alpine biota.
[Epiphyte metapopulation dynamics in a dynamic forest landscape
Snäll, Tord
Swedish University of Agriculture Sciences, Uppsala, Sweden
Metapopulation dynamics have received much attention in population biology and conservation. Most
studies have dealt with species whose turnover rates are much higher than the rate of turnover of their
habitat patches. Models for such dynamics have assumed a static patch landscape. However, the
dynamics of many species is affected by the dynamics of their patches. I will talk about the relative
importance of local conditions, spatial connectivity and host tree dynamics on the metapopulation
dynamics of epiphytes. I will show a large effect of connectivity in explaining colonisation events. The
diameter of trees explains the distribution pattern of epiphytes but does not necessarily explain dynamic
colonisation events. Local extinctions from standing trees very rarely occur. Using simulations, I will
show that future metapopulation size can be overestimated unless one accounts for the increased local
extinction rate imposed by the dynamics of the trees. I will put forth the low rate of local extinction from
standing trees as the mechanism behind the large effect of the historic landscape in explaining today‚s
pattern of epiphytes in the landscape.]
As the author was unable to attend, this keynote speech was replaced by an address given by Matthias
Dobbertin from WSL – see page 72.
12
Genetics reflects reintroduction in alpine ibex
Biebach, Iris1; Keller, Lukas1
1
Zoological Museum, University of Zurich, 8057 Zurich, Switzerland
Many species that were extirpated in the last two centuries have been successfully reintroduced to parts of
their former range. However, such reintroductions were usually associated with low number of founders,
which may have long term genetic consequences. Here we investigate these genetic consequences, loss of
genetic diversity due to genetic drift and inbreeding, in the reintroduced Alpine ibex. In the early 19th
century only one population of Alpine ibex survived in the Gran Paradiso National Park in Italy. The
subsequent reintroductions with multiple bottlenecks are well documented for many populations. We
genotyped 14 populations at 45 microsatellite loci distributed across the genome. Among these14
populations, there are three founder populations first established in the wild in Switzerland, 9 daughter
populations later derived from these and two are located in the Gran Paradiso region. The observed
genetic structure clearly reflects the reintroduction history with low genetic differentiation between the
initially reintroduced populations and their daughter populations. This suggests that mainly genetic drift
lead to the genetic structure in Alpine ibex. However, it is difficult to quantify the influence of possible
gene flow from these data alone. We addressed this question in a related study. Inbreeding was estimated
from genetic data at the population level. All ibex populations showed high levels of inbreeding but we
also found variation between populations. This variation can be attributed again to the founding history:
Inbreeding was negatively correlated with the number of source populations. These results are important
for understanding the genetic effects in small ungulate populations and for an adaptive management of
Alpine ibex.
13
Microhabitat selection in the alpine black grouse (Tetrao tetrix)
during the breeding period: implications for species’ preservation
via habitat management – first results
Signorell, Natalina1; Patthey, Patrick1; Rotelli, Luca2; Arlettaz, Raphaël1,3
1
Zoological Institute, Division of Conservation Biology, University of Berne, Erlachstrasse 9a, CH-3012 Bern,
Switzerland
2
Parco Naturale Veglia-Devero, Viale Pieri 27, I-28868 Varzo, Italy
3
Swiss Ornithological Institute, Valais Field Station, Nature Centre, CH-3970 Salgesch, Switzerland
Alpine environments experience substantial changes since spreading winter and summer leisure activities
have caused increased habitat alterations and disturbances in these habitats. However, to what extent
these changes are detrimental to the fauna of Alpine ecosystems remains ill-understood. We focused on
the black grouse as a model species, a characteristic native, endangered species of Alpine high elevation
coniferous forests and the timberline. Because reproductive success is an essential component of black
grouse life history and therefore population dynamics, and since females, especially when they lead
chicks, are very sensitive to changes in their breeding habitats and/or disturbances, we focused on
microhabitat selection during the breeding period. We ran habitat selection analyses with radio-tracked
males, breeding and non-breeding females. We compared habitat features at radio-bearing points with
those at randomly chosen locations within the individual home ranges. To investigate whether individuals
select or avoid certain microhabitat features in their home range, we constructed logistic regressions
(mixed generalized linear models) with “visited” and “non-visited” as response variable and the measured
microhabitat variables as independent variables. We also ran logistic regressions to test for differences in
microhabitat selection between males and females. Results show that females, especially chick-rearing
hens, show a distinct preference for drier and warmer, more open and multifaceted microhabitats than
males. Additionally, the niche width of females is narrower than that of males. Analysing the selected
variables on a larger scale with GIS will allow constructing accurate habitat suitability maps for the entire
Swiss Alps. This would be a first step for developing appropriate, spatially-explicit habitat management
plans.
14
The inheritance of queen size and queen number in ants
Meunier, Joël; Chapuisat, Michel
Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
Social insect colonies can be headed by one or several queens, and the genetic or environmental causes of
this variation in social structure remain poorly understood. Changes in queen number are often associated
with differences in the body size of gynes (new winged queens). Queens produced by single-queen
colonies are usually heavier and have more energetic reserves in order to disperse and found colonies
independently. In contrast, queens produced by multiple-queen colonies are often smaller, as they stay in
the mother colony and found colonies with the help of workers. We study a socially polymorphic
population of the ant Formica selysi in which there is no genetic differentiation between single and
multiple-queen colonies. In the field, gynes produced by single-queen colonies are heavier than gynes
produced by multiple-queen ones. Here, we test whether this difference in gyne weight is influenced by
genetic and/or maternal factors in the egg that covary with the social structure, or whether it is influenced
by the social structure of the workers that raise the brood. We cross-fostered eggs among laboratory
colonies, so that eggs collected from either single- or multiple-queen colonies were raised by workers
originating from either single- or multiple-queen colonies. Eggs from single-queen colonies developed
into heavier gynes than eggs from multiple-queen ones, with a larger head width and higher lipid content.
In contrast the origin of the workers that cared for the brood had no impact on gyne size. These results
strongly suggest that a genetic polymorphism or maternal effect transmitted to the eggs influences an
important phenotypic trait that is associated with variation in social structure. (265 words)
15
Genetic diversity for disease resistance: an experimental test in an
ant with variable queen number
Reber, Anabelle; Castella, Grégoire; Christe, Philippe; Chapuisat, Michel
Department of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland
Increased colony genetic diversity resulting from polyandry or polygyny may improve colony resistance
to pathogens (Hamilton W.D. 1987. Animal Societies: theories and facts pp. 81–102). This “genetic
diversity for disease resistance” hypothesis has received strong empirical support with respect to
polyandry (Baer B. and Schmid-Hempel P. 1999. Nature 397:151–154; Hughes W.O.H. and Boomsma
J.J. 2004. Evolution 58:1251–1260), but has not been assessed in the context of polygyny. In this study,
we used ants from a population of Formica selysi containing both monogynous and polygynous colonies
(Chapuisat M. et al. 2004. Evolution 58:1064–1072) and performed experimental infections in the lab
with Metarhizium anisopliae, a virulent fungal parasite isolated from the study site. First, we found that
workers from distinct monogynous colonies differed significantly in their resistance to infection,
suggesting the presence of genetic variation among matrilines in disease resistance. Second, we
experimentally manipulated group genetic diversity by mixing workers from different monogynous
colonies. Importantly, we found that increased group genetic diversity improved the survival of workers
challenged with Metarhizium. Finally, we compared the susceptibility of groups of workers collected
from monogynous or polygynous field colonies. Surprisingly, workers originating from polygynous
colonies had a lower resistance to the parasite, which might be associated with their lower body size
(Schwander T. et al. 2005. Behav. Ecol. Sociobiol. 59:215–221). The higher resistance of workers in
groups with experimentally increased genetic diversity supports the hypothesis that the presence of
multiple matrilines increases colony resistance to disease. However, monogynous and polygynous
colonies in the field differ in multiple ways, including allocation strategy and life-history, and this
“polygyny syndrome” apparently masked the advantage of genetic diversity.
16
The influence of population isolation on reproductive success and
sexual selection in the alpine newt (Triturus alpestris)
Hangartner, Sandra B.; Garner, T.W.J.
Institute of Zoology, University of Zürich, 8057 Zürich, Switzerland
Institute of Zoology, Zoological Society of London, London, NW1 4RY, UK
Restricted gene flow into a population may lead to loss of heterozygosity and increased inbreeding. In
many amphibian species, reduced genetic variability results in lower fitness. In the polyandrous alpine
newt (Triturus alpestris), less genetically related males have previously been shown to father more
offspring than more related males within a population. The goal of this study was to find out if population
isolation affects reproduction of T. alpestris populations. In a first experiment we investigated the
influence of population isolation on female reproductive success by providing females with either two
conpopulation or two heteropopulation males. Paternity was determined in a second experiment by
providing females from isolated and non-isolated populations with one conpopulation and one
heteropopulation male. The first experiment showed that females from all populations exhibited higher
fecundity when mated with males from isolated populations and hatching success was higher in withinpopulation rather than among-population crosses. Results from the second experiment showed that
heteropopulation males fathered significantly more offspring than conpopulation males. We did not detect
any evidence of inbreeding depression. The patterns of fecundity and paternity might indicate multiple
female mate preferences, shifting between direct and indirect benefits.
Seed size and relative growth rate: do small-seeded species really
grow faster?
Turnbull, Lindsay A.1; Paul-Victor, Cloé1; Schmid, Bernhard1; Purves, Drew W.2
1
Institute of Environmental Sciences, University of Zurich, CH-8057 Zurich, Switzerland
Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08542, USA
2
Many experiments find a strong negative correlation between seed size and relative growth rates (RGR),
where RGR is an average over the whole growth period. However, because of the size-dependency of
RGR we show that such a relationship can emerge without any differences in species’ physiology other
than the differences in initial size. We develop a method of modelling daily growth increments which
separates the size-dependency of growth from intrinsic growth physiology and explicitly models the
effects of both temperature and nutrient supply on the growth of each species. The size-dependency is
included by assuming that plants grow exponentially until they reach some reference mass and then
switch to linear growth. The intrinsic growth physiology is encapsulated by a single parameter, the
fundamental growth rate, which is independent of plant size and aboveground allocation. In a multipleharvest experiment involving almost 1800 plants of nine species we found a strong negative relationship
between seed size and average RGR. However, this relationship was entirely due to the common sizedependency of growth across all species, so that small-seeded species spent longer in exponential growth.
In complete contrast, large-seeded species had higher fundamental growth rates, higher aboveground
allocation and suffered greater frost damage.
17
How do so many Pentaschistis species fit into the Cape Region,
South Africa?
Galley, Chloé1; Zimmermann, Niklaus2; Linder, H. Peter1
1
Institute of Systematic Botany, University of Zürich, Zürich, Switzerland
Swiss Federal Institute for Forest, Snow and Landscape Research, Birmensdorf Switzerland
2
We investigate the role of habitat heterogeneity in allowing species co-existence in the Pentaschistis
clade (Poaceae) in the Cape Floristic Region (CFR, South Africa). We contrast the CFR, with 65
subspecies and species, to the adjacent Drakensberg region, which has only 10 species. This contrast
allows us to factor out age and lineage-specific effects. A combination of environmental variables are
categorised to construct “Units of Habitat”, used to quantify spatial and taxonomic habitat diversity. The
amount of habitat available in the Cape and Drakensberg is not significantly different, but the amount of
habitat occupied by Pentaschistis in the Cape is significantly greater than in the Drakensberg. The
estimated niche size of the species in each region is similar, but more species can fit in one habitat unit in
the Cape, and we suggest that microhabitat niches (which we did not use the construction of the Units of
Habitat) play an important role in allowing coexistence in a landscape. There is also greater species
turnover in the Cape compared to the Drakensberg, which is not explained by a greater turnover in
habitats. Both extreme and partially range restricted species need to be explained to understand species
turnover. We show that some species are range restricted because they occupy range restricted niches,
whereas others have widespread niches but do not occupy the full geographical range of these.
The Daraina region: a key for understanding the phytogeography of
North Madagascar
Nusbaumer, Louis1; Ranirison, Patrick2; Gautier, Laurent 1; Spichiger, Rodolphe
1 : Conservatory and Botanical garden of Geneva, Case postale 60, 1292 Chambésy/Genève; Switzerland
2 : Departement of Biology and Vegetal Ecology; University of Antananarivo; 101 Antananarivo; Madagascar
Our understanding the biogeography of northern part of Madagascar is still incomplete due to a complex
environment. The Daraina region (NE) is at the meeting point of three phytogeographical units and displays as
mosaic of mountain and lowland forests, deciduous or evergreen. Despite its relatively small area (ca. 50 x 50 km)
there is a strong microendemic component. A new species of primate (Propithecus tattersalli) was discovered in
1988 followed by new species of scorpions, frogs and micromammals.
We hypothesis that a) the Daraina is a fragment of a northern corridor forest connecting northwestern and eastern
lowlands evergreen forest otherwise separated by the main N-S mountain system b) Mountain forest of the two
highest peaks of Daraina are the only connection for species between the mountain forest of isolated Montagne
d’Ambre 80 Km to the North and the main N-S mountain system 50 Km to the South .
In parallel with a total of 50 Km of linear transect, we realized a plant checklist of the area. Among collected
material, 4 new plant genera and 47 new species were spotted, cluing to the important microendemism component
of the area for plants also. We analyzed the distribution of a selection of the other 1000 inventoried species. We
found that a) species distributed in both evergreen lowlands forests which are separated by mountain are present in
Daraina and b) some of the previously endemic species of Montagne d’Ambre are present in Daraina mountain
forest confirming its rule as bridge between Montagne d’Ambre and Central Montain Chain.
18
Disentangling reticulation patterns: an example from the Aleuritiapolyploid complex (Primula L.)
Guggisberg, Alessia1, 2; Mansion, Guilhem1; Conti, Elena1
1
Institut für Systematische Botanik, Universität Zürich, Switzerland
Present address: Institut für Systematische Botanik, Universität Zürich, Zollikerstrasse 107,CH- 8008 Zürich,
Switzerland
2
Given the challenges of detecting and interpreting reticulate patterns of speciation by using the phylogenetic approach, a deeper knowledge of the effects of hybrids on phylogeny reconstruction is necessary.
In this regard, Primula sect. Aleuritia subsect. Aleuritia (Aleuritia) represents an ideal case study to
investigate reticulation, because speciation in Aleuritia has been proposed to occur via hybridisation.
Indeed, Aleuritia displays variation of ploidy levels from diploidy to 14-ploidy, while morphological,
caryological and distributional data indicate a hybrid origin for most polyploids. Sequences from six
chloroplast DNA (cpDNA) and one nuclear ribosomal DNA (nrDNA) loci were analysed with maximum
parsimony and Bayesian inference to reconstruct uni- vs. biparental phylogenies, which were used to
derive combined consensus networks. Additionally, extensive cloning of the nrDNA marker was performed to identify the putative parents of hypothesised allopolyploids via principal coordinate analyses.
Lastly, the tracing of diagnostic nucleotide positions in the nrDNA permitted the detection of recombinant sequences recovered from cloning experiments. The results support many cases of reticulation both
at the diploid and polyploid level, for the cpDNA and nrDNA phylogenies were largely incongruent with
each other. At least three polyploid series were inferred: a North-American, a South-American and a
European series, and many clones obtained for the European polyploids were shown to be recombinant.
Overall, this study highlights the need for diverse experimental and analytical approaches in the study of
reticulate evolution, for direct sequencing and commonly used phylogenetic analyses may not be
sufficient to disentangle complex patterns of hybridisation.
19
Do AMF harbour meiosis-specific genes in their genome?
Colard, Alexandre; Corradi, Nicolas; Sanders, Ian R.
Department of Ecology and Evolution, University of Lausanne, Biophore, 1015 Lausanne, Switzerland
The mutualistic arbuscular mycorrhizal fungi (AMF) are the biggest fungal phylum thought to be asexual.
The genes involved in meiosis, mitosis and recombination are well known in other fungal organisms but
no sequence information has been provided so far for AMF. By surveying EST and gene databases of the
AMF Glomus intraradices we identified short sequences of several genes that could play a role in these
processes. We increased the sampling in Glomus intraradices by designing several sets of degenerate
primers for new genes playing role in meiosis, mitosis and recombination. Consequently, we successfully
isolated several genes of putative high importance in meiosis, mitosis and recombination from Glomus
intraradices. By RT-PCR, we proved that these genes are expressed. We also show that these genes are
under purifying selection. This approach allowed us to identify the presence of gene families and events
of gene duplications, as well as to identify the nature of selective forces that act on these genes in this
putatively ancient asexual organism.
20
The paradox of ecosystem services: Ecology, economics and the
pollination crisis
Ghazoul, Jaboury
Ecosystem Management, ETH Zürich, Universitätsstrasse 16, CH- 8092 Zürich 8092, Switzerland
Ecosystem management emphasises the integration of ecosystem service concepts to achieve sustainable
land and resource management, and to use such concepts to justify conservation within this context. The
approach rests on the assumption that by conserving natural or semi-natural elements we will be able to
maintain the ecosystem services that deliver net benefits for human welfare, which at its most basic is
measured in terms of economic development. To be credible, these arguments must recognise the
constraints that may limit the reliability of this assumption, including the trade-offs with other land-use
benefits. The fact that ecosystem service concepts have not yet been well integrated into management
implies that land managers, agriculturalists and policy makers have not been sufficiently persuaded by
such initiatives. I argue that this is due to the failure of scientists, conservationists and other advocates of
ecosystem management approaches, to account for the trade-offs and opportunity costs inherent in land
management, and the limited recognition that managing for ecosystem services may place constraints on
future management options. Even so, ecosystem service concepts may make substantial contributions to
more effective management by, gradually, influencing thinking among policy makers, land managers and
the wider public, as it is equally na to assume that decisions made by these actors are based purely on
economic criteria.
21
Occurrence of AM fungi in agricultural habitats and landscapes of
Central Europe
Oehl, Fritz1; Sieverding, Ewald2; Bogenrieder, Arno3; Stahr, Karl4 ; Laczko, Endre5; Mäder, Paul6; Kuss, Patrick1;
Ineichen, Kurt1; Wiemken, Andres1
1
Zurich-Basel Plant Science Center, Institute of Botany, University of Basel, Hebelstrasse 1, 4056 Basel,
Switzerland
2
Institute of Plant Production and Agroecology in the Tropics and Subtropics, University of Stuttgart Hohenheim,
Garbenstr. 13, 70593 Stuttgart-Hohenheim, Germany
3
Institute of Biologie II, Research Area Geobotany, Albert-Ludwigs-University of Freiburg, Schänzlestr. 1, 79104
Freiburg, Germany
4
Institute for Soil Science and Land Evaluation, University of Stuttgart Hohenheim, Emil-Wolff-Str. 27, 70593
Stuttgart-Hohenheim, Germany
5
Functional Genomics Center, UNI ETH Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
6
Research Institute of Organic Agriculture, Ackerstrasse 1, 5070 Frick, Switzerland
We studied the occurrence of arbuscular mycorrhizal fungi (AMF) in selected grasslands and arable lands
in Central European lowland, mountainous and alpine areas. We asked which impacts type of land use,
farming practices, geology, chemical and physical soil parameters and elevation have on different AMF
species and on the AMF community structure. Morphological methods were used to analyze AMF spore
populations from field soils and trap cultures. Uni- and multivariate analyses were applied to model
spore, land use and environmental data. About 70 species were detected. Parameters of all mentioned
categories influenced the spore populations. Intensified land use and farming practices, but also soil pH >
7.0 affected in particular spore and species numbers of Acaulospora and Scutellospora spp. negatively.
Spore and species numbers of Gigaspora and Scutellospora declined with increasing altitude, while
Pacispora numbers were highest at the highest alpine elevations investigated (2700–3000 m asl). A few
species occurred in all habitats (e.g. Glomus intraradices and G. versiforme). We called those ‘ecological
generalists’. We identified also ‘ecological specialists’, found only under particular conditions (e.g. A.
alpina and P. robigina). The studies contribute to the understanding of the ecological conditions which
control occurrence of AMF species. They improve the scientific base for species selection for inoculation
technology, or for revegetation/rehabilitation practices.
22
Island invaders: the role of introduced mutualists in pollination in
Mauritius
Kaiser, Christopher N. 1, 2; Müller, Christine B.1
1
Institute of Environmental Sciences, University of Zürich, Switzerland
Present address: Institute of Terrestrial Ecosystems, Ecosystem Management, ETH Zürich, Switzerland
2
Little is known about the effects of introduced species, or the removal of invasive plant species for habitat
restoration, on native mutualistic plant-pollinator interactions. We used fully quantified flower visitation
webs to investigate plant-pollinator communities of a restored and an unrestored site in Mauritius.
Interactions between all flowering plant species and their pollinator species were recorded for both sites
for an eight month period. The restored site showed higher plant and pollinator species richness and
abundance than the unrestored site. Plant species in the restored site produced larger and heavier fruits,
which contained more seeds per fruit than those in the unrestored site. Visitation webs in both sites were
dominated by a few super-abundant, disproportionately well-connected plant and pollinator species, and
many rare and specialised species. Most key animal species were introduced to Mauritius. Introduced
plant species produced a high fruit set, despite being visited by relatively few pollinators. Our findings
indicate that the effect of introduced species on plant-pollinator interactions may differ according to
whether they are plants or pollinators. The low visitation rate to introduced plant species suggested a low
level of indirect competition for pollinators with native plant species. However, the infiltration of the
local pollinator community by introduced flower visitors suggested strong competition between native
and introduced pollinators for floral resources, which may have resulted in the displacement of native
pollinators and consequently the disruption of co-evolved plant-pollinator interactions.
Epichloë fungi and Botanophila “pollinating” flies: unspecific
attraction through fungitoxic volatile
Steinebrunner, Fabrizio1; Schiestl, Florian1; Twel, Robert2 ; Francke, Wittko2; Leuchtmann, Adrian1
1
ETH, Plant Ecological Genetics, Institute of Integrative Biology (IBZ), CH-8092 Zurich, Switzerland
University of Hamburg, Organic Chemistry, D-20146 Hamburg, Germany
2
Epichloë fungi (Ascomycota) are widespread endophytes found in temperate grasses. It appears that
Epichloë fungi live in a balanced mutualism with dipteran flies (Botanophila) in which the fungus
benefits from the fly as a reliable vector of spermatia for cross-fertilization, and the fly larvae depend on
the stroma as a food source. We investigated odour communication in the Epichloë-Botanophila system
by sampling odour bouquets of Epichloë stroma in the spermatial stage, and testing them using GC-EAD
(gas chromatography with electroantennographic detection) for detection. Two compounds, identified as
Chokol K and (Z2)-methyl 3-methyldodec-2-enoate, triggered electroantennographic responses in the fly.
We applied synthetics of these substances in ratios as found in different Epichloë species. We
successfully caught Botanophila flies under field conditions. Interestingly, flies of the same species
preferred two contrasting odour profiles. Chokol K application clearly reduced the growth of an Epichloë
parasitic fungus. Our results demonstrate that Chokol K is a key substance produced by Epichloë to
attract Botanophila “pollinators”. Moreover, it has fungitoxic properties and may help to protect Epichloë
from secondary infections. On the other hand, the interaction of Epichloë and Botanophila may be of
generalised nature. We hypothesize that the primary function of Chokol K was antimicrobial and that it
secondarily became involved in “pollinator” attraction.
23
Differences in light interception in productive grass monocultures
predict short-term competitive outcomes in pairwise mixtures
Vojtech, Eva; Turnbull, Lindsay A.; Hector, Andy
Institute of Environmental Sciences, University of Zurich, 8057 Zurich, Switzerland
Due to its inherent asymmetry, increased competition for light is thought to cause loss of diversity from
eutrophied systems. Increased resource availability belowground allows the development of taller
canopies by some species which intercept incident light and deny shorter species access to this directional
resource. We present the results of an experiment designed to investigate the outcome of short-term
competition for light among five perennial grass species under fertilized and irrigated conditions using a
combination of trait-based and resource-based approaches. Differences in species traits associated with
competition for light (seedling relative growth rate, maximum canopy height and specific leaf area) were
good trait-based predictors of the relative competitive effect of different neighbour species on a selected
target plant in pairwise mixtures. However, the best predictor of relative competitive ability was the level
of incident light intercepted by each species in monoculture, a direct mechanistic measure of the resourcereduction abilities of species. Quantitative analysis of the relationship between the relative competitive
effect and differences in traits associated with competition for light confirmed that competition for light
under fertilized and watered conditions is asymmetric. A slightly greater seedling relative growth rate or
maximum canopy height led to asymmetric interception of light and a thus to a disproportionate
competitive advantage. Our results are consistent with the idea that when light is a limiting resource,
competition between species can be strongly asymmetric, leading to strong dominance and low diversity.
Under such conditions, the ability of species to intercept incident light is a better predictor of short-term
competitive interactions in pairwise mixtures than are differences in species traits.
Identification of parasitoid species using PCR amplification and
restriction enzyme digestion
Jourdie, Violaine; Alvarez, Nadir; Turlings, Ted C.J.
Université de Neuchâtel, Institut de Biologie, Emile-Argand 11, Case Postale 158, 2009 Neuchâtel, Switzerland
Spodoptera frugiperda is a pest of great economic importance in the Americas. It is attacked by several
species of parasitoids, which act as biological control agents. Parasitoids are morphologically identifiable
as adults, but not as larvae. Laboratory rearing conditions are not always optimal to rear out parasitic
wasps from S. frugiperda larvae collected from wild populations, and it frequently happens that
parasitoids do not complete their life cycle and stop developing at the larval stage. Therefore, we explored
ways to identify parasitoids larvae using molecular techniques. Sequencing is one possible technique, yet
it is expensive. Here we present an alternate, cheaper way of identifying seven species of parasitoids
(Cotesia marginiventris, Chelonus insularis, Chelonus cautus, Meteorus laphygmae, Campoletis
sonorensis, Pritomerus spinator and Eiphosoma vitticolle) using PCR amplification of COI gene
followed by a digestion with a combination of four restriction endonucleases. Each species was found to
exhibit a specific pattern when the digested amplification product was run on an agarose gel. Identifying
larvae revealed that conclusions on species composition of a population of parasitic wasps can be biased
if only the emerging adults are taken into account.
24
Are shy individuals more cooperative? using the animal personality
approach to study cooperation in a cleaning mutualism
Bergmüller, R.1; Pinto, A. 1; Bshary, R. 1
1
Institute of Biology, University of Neuchâtel, 2009 Neuchâtel , Switzerland
The theory of cooperation among animals often assumes consistent differences between individuals in a
population such as co-operators and defectors. However, up to now the attempts to detect such individual
differences among animals have been rare. We used the animal personality approach to determine
whether shy individuals are more likely to engage in cooperative behaviour. We tested cleaner fish
(Labroides dimidiatus) repeatedly for neophobia, i.e. their tendency to approach a novel object with food
attached. Shy individuals who frequently retreated to a safe area in the experimental tank were also less
likely to approach a novel food plate. These individual differences in shyness were consistent over time.
We calculated an index for shyness for each individual (combining the frequency of retreats and the
probability to approach the novel object) and analyzed whether shyness predicts the likelihood to engage
in cooperation. In order to get access to a large plate with several food items (separated by a clear
partition) the fish had to cooperate by (a) refraining from feeding on a small plate with only one food item
and (b) by providing tactile stimulation to the small plate. We found that shy individuals were more likely
to cooperate. Our results suggest there are different types of individuals in cleaners with regards to
shyness and the propensity to engage in cooperation and that these traits are not independent from each
other. We conclude individual differences in animal personalities need to be taken into account when
studying the evolution of cooperation among animals.
25
Differential food allocation of male and female parents in the great
tit (Parus major): is it under parent or offspring control?
Tanner, Marion1; Kölliker, Mathias2; Richner, Heinz 1
1
Institute of Zoology, University of Bern, 3012 Bern, Switzerland
Institute of Zoology, University of Basel, 4051 Basel, Switzerland
2
Food distribution among young of altricial birds is the result of an interaction between parental feeding
decisions and scramble competition between nest-mates, raising questions on behavioural control in the
interaction. There is good evidence that the intensity of scramble competition is affected by the hunger
state of the young. Differential investment by the two parents in relation to offspring phenotype could
occur as a consequence of relatedness asymmetries or different trade-offs between parental care and other
activities. In great tits, each parent feeds from a distinct and temporally stable location on the nest rim,
forcing nestlings to choose between the father’s or mother’s feeding location. It was previously found that
hungry nestlings approached the female preferentially, and were more likely to be fed by their mother
than by their father. However as nestlings were free to move, the effects of nestling positioning towards
the parent could not be disentangled from those of parental food allocation decisions. For this purpose, we
experimentally forced nestlings to be fed by a single parent. Broods were divided in halves and each half
randomly assigned to one parent. In addition one nestling in each half-brood was food-deprived to
manipulate short-term hunger. When nestling position towards mother and father was controlled, hungry
nestlings were equally fed by the father and by the mother, suggesting that the previously observed
difference was a consequence of offspring positioning rather than parental choice. The study shows that
food allocation is at least partially under nestling control, and suggests that nestlings can adjust feeding
behaviour to the profitability of a given position in the nest cup. It remains to be elucidated why nestlings
show a preference for the mother’s feeding position in the natural unmanipulated situation given that both
provisioning sites are in principal equally profitable as shown here.
Genetic variances and co-variances of sperm and female tract
characters
Thüler, Karin1; Paul Ward1
1
Zoological Museum, University of Zurich, 8006 Zürich, Switzerland
The outcome of sperm competition is often largely determined by the relative numbers of spermatozoa
from competing males. However recent work, stimulated by the significant inter- and intra-specific
variation found in reproductive traits, has suggested that morphology of sperm and the female
reproductive tract can also influence paternity. To clarify the interactions important for the evolution of
reproductive morphology, we estimated the inheritance and genetic architecture of sperm and female tract
characters in a half sib/full sib experiment using the yellow dung fly, Scathophaga stercoraria.
Preliminary results to date are restricted to daughters. We found significant heritabilities and dam effects
for the size of the three spermathecae, the size of the accessory gland and its associated duct length. For
spermathecal duct width we found only a significant sire effect, and for the spermathecal duct length
neither sire nor dam effects were significant. We found significant positive phenotypic correlations
between the sizes of the three spermathecae, as well as between the widths of the different spermathecal
ducts. We also found a significant positive correlation between the size of the accessory gland and the
length of the accessory gland duct. We will interpret these findings in the context of data from sons and
from genetic correlations within and between the sexes (currently being compiled).
26
Preen wax deposition mediates the immuno-dependent rapid change
in bill coloration
Piault, Romain1; Gasparini, Julien1; Paulet, Mariane1; Bize, Pierre2 ; McGraw, Kevin3; Roulin, Alexandre1
1
Department of Ecology and Evolution, Biophore, University of Lausanne, 1015 Lausanne, Switzerland
Division of Environmental and Evolutionary Biology, IBLS, Graham Kerr Building, Glasgow University, Glasgow
G12 8QQ, UK
3
Department of Neurobiology and Behavior, Cornell University, Ithaca, NY 14853, USA
2
Variation in body condition can cause rapid changes in coloration in traits used in sexual selection and
parent-offspring communication. The underlying mechanisms usually involve molecular pigments,
biological nanostructures, or blood flux. Behaviourally-mediated deposition of substances on the external
body surface has been proposed as an alternative mechanism that can generate covariation between
condition and coloration. In birds, preen wax spread on feathers using the bill might affect bill and
plumage coloration. We therefore evaluated the hypothesis that variation in condition due to diseases
results in preening-mediated changes in bill coloration. Using tawny owls (Strix aluco) whose bill is
carotenoid-free, a pigment known to mediate infection-induced changes in bill coloration, we induced
immune challenges of different intensities to determine whether they differentially cause a change in bill
coloration. We injected in nestlings either lipopolysaccharides (LPS) or phytohaematogglutin (PHA).
LPS is known to reduce individual condition to a larger extent than PHA by inducing a more costly
immune response. Individuals immunized with LPS showed higher bill brightness than nestlings injected
with PHA. Since we found that preen wax causally reduces bill brightness, this difference in coloration
between treatments is probably due to a lower quantity of preen wax deposited on bill in LPS-injected
nestlings. This may result from a decreased investment in preening activities and/or decreased wax
production since LPS impaired the development of the uropygial gland. Our findings provide a
behavioural mechanism to explain short-term variation in the intensity of colourful condition-dependent
signals.
27
Plant-herbivore interactions and biodiversity
Olff, Han
Community and Conservation Ecology group, University of Groningen, PO Box 14, 9750 AA Haren, the
Netherlands
Correspondance: [email protected]
For decades, the concentration of diverse mammalian herbivores found on African savannas and their
joint reliance on the same food resource (grass), has interested ecologists. Two ideas explaining this
diversity have been suggested. On the one hand competition leads to the evolution of niche differentiation
(e.g. through radiation of body sizes) allowing more species to coexist. On the other hand, some niche
overlap may promote diversity especially when larger species enhance food quality from which smaller
species benefit (facilitation). I will show results of recent work in an African savanna in which we tested
whether niche overlap between herbivores is predictable from their body size difference. Not only did we
test ‘classic’ niche differences (different habitat, plant height, plant species selected), I also present results
of an experiment where we manipulated the spatial arrangement of resources, to test for body size-related
‘spatial niches’ in savannas. Finally, I will show results that indicate that herbivores themselves create the
heterogeneity that they require for coexistence, causing ‘diversity to beget diversity’.
28
Combining plant and animal traits to assess functional responses to
disturbance
Moretti, Marco1; Legg, Colin2
1
2
WSL Swiss Federal Research Institute, Ecosystem Boundaries Research Unit, Bellinzona, Switzerland,
The University of Edinburgh, Centre for the Study of Environmental Change and Sustainability, Edinburgh, UK
The changes in ecosystem functions following disturbance are a central issue in disturbance ecology.
There is general consent that ecological traits are reliable indicators of adaptation to particular
environmental characteristics across higher taxonomic levels and biomes. This study combines plant and
animal traits to assess the emergent response to disturbance.
In a region of southern Switzerland affected by regular winter fires, we assessed the functional response
of fire and clear-cutting by analysing the ecological traits of 1,087 invertebrate species (117,000
individuals) and 120 plant species. Here we explore the relationships between ecological traits and
disturbance by fire, as well as between the responses of plants and animals to disturbance. Weighted
averaging was used to combine the "species by site" with the "species by traits" matrices to obtain a mean
trait score for each site in new "traits by sites" matrices for each of the plant and animal datasets.
Co-inertia analysis clearly showed the association between the traits and fire (Monte-Carlo test, P =
0.0045). Warmth demanding insects, herbivores, flying carnivores and pollinators were associated with
recent fires, along with annual, ruderal and light-demanding plant species with long flowering duration.
On the other hand, small arthropods feeding on dead wood and those with narrow habitat requirements, as
well as competitive plants with large seeds favouring moist sites were associated with unburnt sites and
sites with single fires.
We present a clear example of a way to monitor community and ecosystem responses and assess the
impact of management practices on ecosystem function. Nevertheless, we believe there is an immediate
and serious need for sensitive, reliable, and rapid indicators of ecological processes combining plant and
animal traits that will inform the future management of forest ecosystems. Such indicators would provide
powerful and promising tools for validating management procedures and manipulating ecosystem
function.
29
Synchronous flowering increases seed predation in small Silene
latifolia patches: a field experiment
Elzinga, Jelmer A.1; Bernasconi, Giorgina1
1
Pre-dispersal seed predation imposes strong fitness costs on plants, and is therefore expected to contribute
to selection on flowering phenology. Plants may evade pre-dispersal seed predation a) by flowering early
or late in the season, or b) by flowering synchronously with conspecific neighbours to satiate the seed
predators. Whereas the first strategy leads to prolonged flowering, the second strategy results in distinct
flowering peaks. In addition, the number of neighbours, i.e. population size, may influence the optimal
strategy and selection on phenological characteristics. We tested the seed predator-satiation hypothesis in
different patch sizes in a field experiment with the white campion, Silene latifolia (Caryophyllaceae). In
its native, European range, the white campion is heavily attacked by the seed predating and pollinating
moth Hadena bicruris (Noctuidae). In a fully-crossed, two-factor design (synchronous vs. asynchronous
and large vs. small), we created 24 patches by transplanting arrays of plants of different age classes to 24
field sites. We monitored the plants during thirteen weeks and measured realized synchrony, fruit
predation, flower/fruit abortion and seed set per fruit. Plants experienced more intense fruit predation in
synchronous small patches, compared to the three other patch types. As a result, in combination with
higher abortion in small patches, plants in synchronous small patches produced fewer undamaged fruits.
Within all patches, individual plants that flowered more synchronously with their neighbours, in general
suffered increased fruit predation but aborted fewer flowers or fruits. These results refute the idea that
synchronous flowering evades seed predation in this species, and suggest instead that synchronous
flowering increases patch attractiveness to seed predators and possibly pollinators. However, no
advantage of either synchronous or asynchrounous flowering was apparent in large patches, indicating
that selection pressures on flowering phenology through biotic interactions strongly depend on patch, and
thus population, size.
30
The impact of logging on distance- and density-dependent seed
predation in a Southeast Asian rain forest
Bagchi, Robert 1, 2; Philipson, Christopher P.2; Slade, Eleanor 3; Phillips, Sam 2; Villeneuva, Jerôme 4; Hector,
Andrew 2; Lewis, Owen T.3; Scholes, Julie D.1; Press, Malcolm C.1
1
Department of Animal and Plant Sciences, Univeristy of Sheffield, Western Bank, Sheffield S10 2TN, UK
Institute for Environmental Sciences, Winterthurerstrasse 190, 8057 Zurich, Switzerland
3
Department of Zoology, University of Oxford, OX1 3PS, Oxford, UK
4
Danum Valley Field Centre, PO Box 60282, 91112 Lahad Datu, Sabah, Malaysia
2
Few areas of unlogged forest remain in Southeast Asia, but large regions of selectively logged forest remain within
logging concessions. An important question is whether forest biodiversity can recover after selective logging. While
there has been extensive work comparing the species diversity of unlogged forest and forests recovering after
logging, there has been much less work on the long-term impacts of logging on processes involved in controlling
diversity. If logged forests are to regenerate and eventually resemble primary forest these processes must not be
disrupted by logging.
The Janzen-Connell hypothesis proposes that seeds and seedlings growing close to conspecific adults or in areas of
high conspecific density suffer high mortality through the activity of specialist natural enemies. Consequently,
locally rare species have an advantage, and this promotes species coexistence. We studied the effect of distance
from parent trees (distance-dependence) on seed survival in a common tree species, Parashorea malaanonan in
Sabah, Malaysia in previously logged and unlogged forest. Seed survival increased with distance from parent trees,
and the relationship between distance and survival was not affected by logging history. This suggests that timber
extraction does not disrupt distance dependence in the species studied.
A field test of chemical defence in an alpine leaf beetle
Naisbit, Russell E.; Aerni, Gilles; Margraf, Nicolas; Rahier, Martine
Institute of Biology, University of Neuchâtel, 2009 Neuchâtel, Switzerland
Many of our favoured crops are grown not for their direct nutritional value, but for the secondary plant
compounds that they contain. Insects often also take advantage of these chemicals by sequestering them
for use as defence against predators. The alpine leaf beetle Oreina elongata (Coleoptera: Chrysomelidae)
is able to sequester the pyrrolizidine alkaloids (PAs) found in host plants of the genus Adenostyles. We
have already shown that sequestration of PAs bears a cost for larvae, so presumably must also show a
benefit. Here we describe a field test of the survival value of chemical defence for this species using a
combination of high and low tech methods. O. elongata is one of the few species in its genus able to both
sequester PAs and to synthesise cardenolides, while the closely related O. cacaliae lacks the ability to
produce cardenolides. By manipulating their diet, we were therefore able to produce larvae with both
types of defence, with either one alone, or with no defence. Monitoring the short-term survival of a total
of 634 larvae (with an overall predation rate of around 33%) we were unable to detect an advantage in
having chemical defence. It seems that these beetles may be caught between a host plant with costly
defence and predators that are undeterred.
31
Winter tourism evokes behavioural and physiological stress in the
endangered capercaillie Tetrao urogallus
Thiel, Dominik1, 2; Jenni-Eiermann, Susi1; Jenni, Lukas1
1
Swiss Ornithological Institute, 6204 Sempach, Switzerland
Institute of Environmental Sciences, University of Zurich, 8057 Zurich, Switzerland
2
Human disturbances are a significant factor to be considered in nature conservation efforts. Recreational
activities are discussed as a possible reason for the significant population decline of the endangered
capercaillie, although this has never been investigated. Stress hormone level in capercaillie droppings and
the spacing behaviour of radio-tracked capercaillie were measured to investigate physiological and
behavioral stress responses to winter tourism. Capercaillie in areas with high winter recreation intensities
exhibited longer flusing distances and higher stress hormone levels than birds in undisturbed sites. During
the ski season, capercaillie preferred undisturbed forest patches, which was not the case before the start of
the ski season. These behavioural and physiological responses to winter recreation have high potential to
negatively affect capercaillie fitness. By establishing officially declared wildlife refuges with prohibited
human access and by implementing restrictions for recreationists to stay on-trail in capercaillie core areas,
the situation for the capercaillie may be improved upon as human-caused stress is decreased.
Coping with stress as an altricial nestling: short- and long-term
effects of moderately elevated corticosterone on development,
immunocompetence and survival
Müller, Claudia1, 2; Jenni-Eiermann, Susi1; Jenni, Lukas1
1
Swiss Ornithological Institute, Luzernerstrasse 6, 6204 Sempach, Switzerland
Zoological Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zürich, Switzerland;
2
While elevated stress hormones in adults help to survive stressful situations, it is unclear what the costs
and benefits of elevated glucocorticoids are in altricial nestlings. Benefits may result from changing
energy allocation under restricted food supply and from leading parents to bring more food through more
intense begging. Costs may arise from reduced growth and immunocompetence, delayed development
and reduced cognitive abilities, resulting in reduced survival. We investigated short and long term effects
of a moderate elevation of corticosterone for some days in the middle of the nestling stage in European
kestrels. To separate the effect of corticosterone from food deficiency, we used corticosterone implants to
manipulate corticosterone levels. We looked at short-term effects of elevated corticosterone on various
growth parameters, immunocompetence and behaviour in the nest. We also examined long-term effects
after fledging, such as full-grown body size, learning to hunt, time until independence and survival.
32
New insights into Gentiana Sect. Calatianae Froehl. (Gentianaceae)
based on chloroplast PCR-RFLP in combination with chloroplast
matK and nuclear ncpGS-sequences
Haemmerli, Marc
Institut de botanique, Université de Neuchâtel, 2007 Neuchâtel, Switzerland
Gentiana Sect. Calatianae Froehl. is a small section defined by strong morphological similarities and growing
mainly in European and Asian mountain ranges with each one taxon in Northern Africa and North America. Based
on a chloroplast PCR-RFLP from 8 different non-coding regions, each digested by 4 enzymes, and chloroplast matK
as well as nuclear ncpGS-sequences, a detailed new order of that section is developed, composed by an annual and a
perennial group of taxa, the perennial one itself divided into basically three components: one hosting most non-G.verna-taxa, one comprising of western European G. verna and related taxa and the last built by eastern-G.-vernataxa. The classification is supported both by morphological and geographical criteria.
biology07 – poster presentations
33
1- Eagle owl (Bubo bubo) mortality assessed by radio tracking and
by satellite telemetry – towards targeted conservation measures
Aebischer, Adrian; Koch, Silvia; Nyffeler, Peter; Arlettaz, Raphael
Institute of Zoology, Conservation Biology, University of Bern, Baltzerstr. 6, 3012 Bern, Switzerland
The Eagle owl is an endangered bird species in Switzerland. Many breeding sites have been abandoned in
recent years despite a high breeding success. This suggests that Eagle owls have a low survival in the
modern Swiss landscape. The analysis of 116 dead individuals that were found incidentally and that could
be aged showed a surprisingly high mortality after fledging (86% in the first 3 years of life) for this longliving species. In order to propose targeted conservation measures, the main factors threatening the
population have to be identified. In a sample of 228 dead birds, electrocution, car traffic and collisions
with cables were the most important mortality factors. Altogether 82% of all individuals died due to
direct anthropogenic factors. However, birds that die far away from human habitations are less likely to
be found. To get results from an unbiased sample, 45 young have so far been followed by means of radiotracking and satellite telemetry. While the high mortality rate has been confirmed by this method, the
respective importance of the various mortality factors in tagged individuals were different compared to
individuals found incidentally. Still, among the anthropogenic mortality factors, electrocution was the
most important factor in both samples. In collaboration with energy power companies, a catalogue of
dangerous electric pylons has been elaborated and many of the pylons already mitigated.
2- Contrasting observed and simulated genetic structure of
bottlenecked alpine ibex populations reveals evidence for gene flow
Aeschbacher, Simon1; Biebach, Iris1
1
Zoological Museum, University of Zurich, 8057 Zurich, Switzerland
Genetic differentiation between small or fragmented populations and inbreeding within these populations
have been of growing interest to the conservation of species. The relative importance of genetic drift and
gene flow should be accounted for in species management. Genetic differentiation and inbreeding are
generally quantified by estimates of FST or related measures. However, these measures depend on the
history of populations and it is difficult to obtain a neutral expectation for them. Often, FST and the like
are used to infer gene flow based on Wright’s island model, but this is associated with many unrealistic
assumptions. The successful reintroduction of Alpine ibex (Capra ibex ibex) into the Swiss Alps provides
a well suited framework for an alternative approach to address the question of expected vs. observed
structure and the relative importance of genetic drift and gene flow. We used detailed information on
founder events and demography to simulate most of the major Swiss ibex populations, starting from
1906. The individual-based simulation provided pedigrees and expectations for pairwise FST for different
scenarios of drift and gene flow. Contrasting them with observed results based on 42 neutral
microsatellite loci, we found that genetic drift, mainly caused by founder events, might not be sufficient
to explain the observed structure. Instead, a scenario with additional gene flow among connected
populations showed a better congruence: It provided evidence for an annual emigrant proportion of about
5% relative to the population size for both sexes. We relate our findings to inbreeding coefficients based
on simulated pedigrees and discuss their relevance for management of Alpine ibex populations. The
assumptions of our approach to estimate gene flow are compared to the assumptions of a Wright’s island
model approach.
34
3- Seed bank and vegetation of a soil with gilgai microrelief in
temperate chile
Alvarez, Miguel1;, Deil, Ulrich1; Ramírez, Carlos2
1
Institute of Biology, Dept. of Geobotany, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany;
Institute of Botany, Austral University, Casilla 567, Valdivia, Chile
2
Pastures in the temperate climatic zone of Chile are dominated by non-native species, except in vernal
micro-pools, where endemics occur. Such habitats are observed on vertisols near Cholchol (9th Region of
Chile) in a gilgai microrelief. The ephemere vegetation in the small depressions (about 1.50 m2 surface)
clearly differs from the surrounding matrix. Our interest was to study the role of the seedbank for these
native plant species and for the vegetation cover. We expected that the small scale horizontal pattern in
above-ground vegetation is reflected in the the seed banks and that soil dynamics result in a weak vertical
pattern of the seed bank. Soil samples form both habitats (pools and matrix) and from 2 soil layers (0–5
and 5–10 cm) were submitted to a germination experiment.
The seed bank is larger in the pools (96.057 seeds m-2) than in the matrix (30.742 seeds m-2). The seeds
are concentrated in the upper soil layer, however, the relation 0–5 cm vs. 5–10 cm is bigger in the pools
(82.7 %) than in the matrix (68.2 %). Most seeds belong to therophyte species (e.g. Cicendia
quadrangularis, Micropsis nana and Juncus bufonius). Pool and matrix species exhibit a different
germination pattern, thus pointing out to different dormancy strategies.
The spatial pattern of the above-ground vegetation is not reflected in a identical pattern in the seed bank.
The patter in the plant cover seems to be the result of an environmental filter (factors like flooding and
soil moisture duration), triggering germination, establishment and survival rates.
35
4- Dispersal success of the European treefrog in habitat connectivity
projects in the Reuss valley
Angelone, Sonia; Holderegger, Rolf
Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland
Species and habitats of great conservation value are supported by means of the Swiss Cantonal
Governments within the scope of habitat connectivity projects, aiming to enhance dispersal behavior of
individuals among remnant populations within fragmented landscapes. Dispersal and gene flow are
essential for the long-term survival of endangered species as they counteract the negative effects of
genetic erosion. Within the Reuss Valley, specific connectivity measures have been taken since 1992 to
stop the drastically decline of European Treefrog populations. Our goal here is to verify the effectiveness
of those measures by investigating the genetic structure of the remnant populations of this endangered
species. In total, 582 Treefrogs from 34 populations have been genotyped with eight microsatellite loci.
Only two individuals shared the same genotype. We found substantial heterozygosity (Ho = 0.69) and
significant isolation by distance over all populations. Frequency based analysis with STRUCTURE revealed
six geographically defined population clusters. Assignment tests in GeneClass based on a Bayesian
method allocated 51% of the Treefrogs to the population in which they were sampled, but 92 % to the
correct cluster of populations identified with STRUCTURE. Our findings show that the management
measurements for the Treefrog in the Reuss Valley have been successful. Individuals disperse and
exchange genes among populations when they are located within the same cluster and we recaptured two
frogs that had moved 1 km from one pond to the other. In contrast, individual exchange among clusters
happens less frequently. This is due to landscape barriers like the Reuss River, woods and villages, which
are difficult to overcome for Treefrogs. As a next step, landscape elements within the Reuss valley will
thus be evaluated with respect to their impact on Treefrog dispersal by using a geographic information
system (GIS).
36
5- Presence of a third Plecotus bat species in the Swiss Alps
confirmed by morphology and DNA
Ashrafi, Sohrab1; Bontadina, Fabio1, 2; Kiefer, Andreas3; Pavlinic, Igor4; Arlettaz, Raphaël1
1
Institute of Zoology, Division of Conservation Biology, University of Bern, 3012 Bern, Switzerland
SWILD – Urban Ecology & Wildlife Research, 8003 Zürich, Switzerland
3
Institut of Zoology, Division of Ecology, Johannes Gutenberg-University, D-55099 Mainz, Germany
4
Croatian Natural History Museum, Dept. of Zoology, HR-10000 Zagreb, Croatia
2
The identification of cryptic species may significantly change the perspective on distribution, abundance,
ecology and, hence, conservation status. In central Europe two sympatric sibling long-eared bat species,
Plecotus auritus (Linnaeus, 1758) and P. austriacus (Fischer, 1829), were recognized since the 1960s.
Recent molecular and morphological studies revealed the existence of another, cryptic species in the
alpine arch. In the frame of a conservation research project we aim to unravel the ecological requirements
and the conservation status of the newly discovered species P.macrobullaris in Switzerland. In 2006 we
sampled 220 individuals from 28 roosts in the Cantons Valais, Argovia and Vaud. Morphometric
characters were measured in the field and biopsy punches collected for the lab. In a preliminary step we
analysed a fragment of the mitochondrial 16s rRNA gene of 74 specimens. All sequences were aligned to
published sequences of European long-eared bats. Results of molecular analysis confirm the sympatric
occurrence of the three cryptic species in the Swiss Alps: the specimens are found to belong to 4
haplotypes of P.auritus, 1 haplotype of P.austriacus and 1 haplotype of P.macrobullaris. The three
species are characterized by slight morphological differences. Segregation in their altitudinal distribution
might contribute to resource partitioning. Running analysis on morphometric characters can help to
determine those external characters which reliably allow the discrimination of the three Plecotus species
in the field.
37
6- Towards eusociality in Ambrosia beetles
Biedermann, Peter H.W.1; Taborsky, Michael1
1
Department of Behavioural Ecology, Institute of Zoology, University of Berne, Wohlenstrasse 50a, CH-3032
Hinterkappelen, Switzerland
Advanced sociality should be expected in the haplodipoloid Xyleborini, a tribe of ambrosia beetles (bark
beetles, Scolytidae) cultivating fungi. All other known fungus cultivating insects (the attine ants and
macrotermitine termites) are eusocial, while eusociality has only been described in one species of
ambrosia beetles. Xyleborinus saxeseni (“der Kleine Holzbohrer”) which lives in large colonies and
shows delayed dispersal of adult daughters is particularly likely to advanced levels of sociality. We
established a breeding population of this species in the lab and conducted the first extensive behavioural
study performed on ambrosia beetles. Our results show that all developmental stages help in cooperative
fungus garden maintenance and mutual grooming. Additionally, larvae and females take part in altruistic
cleaning and protection of their home galleries. The retention period of females in the natal gallery after
reaching adulthood depends upon the number of offspring present, showing that cooperative breeding
occurs in X. saxeseni and possibly other Xyleborine species.
Apart from cooperative care of the maternal brood, some of the adult daughters do reproduce in their
natal gallery. Conflict over reproduction is probably low or completely absent because of regular sibling
mating, in combination with haplodiploidy. Ambrosia beetles comprise species with different mating
systems (exhibiting both inbreeding and outbreeding) as well as variation in diploidy/haplodiploidy and
environmental conditions. It would be worth testing whether this variation within the tribe is reflected by
different stages of sociality, which may yield important insights into the factors responsible for the
evolution of cooperative breeding and eusociality in general.
7- Early parasite exposure affects song rate of male great tits
Bischoff, Linda L.1, 3; Tschirren, Barbara2; Saladin, Verena1; Richner, Heinz1
1
Institute of Zoology, University of Bern, 3012 Bern, Switzerland
School of Biological, Earth and Environmental Sciences, NSW 2052 Sydney, Australia
3
Present address: Evolutionary Ecology Group, c/o Baltzerstrasse 6, 3012 Bern, Switzerland
2
Bird song is a sexually selected trait known to contain honest information on current condition and health
status of potential mates. It may, however, also contain information on past condition if the environment
experienced early in life has long-lasting consequences on male vocalization (develomental stress
hypothesis). Here we tested if a parasite infestation early in life affects the song rate or song repertoire
(different song types) of adult great tits (Parus major). We exposed nestlings during growth to
ectoparasitic hen fleas (Ceratophyllus gallinae) and, upon recruitment into the local breeding population
the following year, measured their response to a playback of a challenging male in their breeding
territory. Our results show that early parasite infestation affects adult song rate but not repertoire size. By
assessing song rates during mate choice, females may thus gain information on early developmental
conditions of potential partners.
38
8- Evidence of climatic niche shift during biological invasion
Broennimann, Olivier 1; Treier, U.A.2 ; Müller-Schärer, H. 2; Thuiller, W. 3; Peterson, A.T. 4; Guisan, A. 1
1
University of Lausanne, Department of Ecology and Evolution, The Biophore, CH-1015 Lausanne, Switzerland
University of Fribourg, Department of Biology, Unit of Ecology & Evolution, Fribourg, Switzerland
3
Laboratoire d'Ecologie Alpine, UMR-CNRS 5553, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9,
France
4
The University of Kansas, Lawrence, KA, USA
Correspondance: Olivier.broennimann@unil.
2
Niche-based models calibrated in the native range by relating species observations to climatic variables
are commonly used to predict the potential spatial extent of species’ invasion. This climate matching
approach relies on the assumption that invasive species conserve their climatic niche in the invaded
ranges. We test this assumption by analyzing the climatic niche spaces of Spotted Knapweed in western
North America and Europe. We show with robust cross-continental data that a shift of the observed
climatic niche occurred between native and non-native ranges, providing the first empirical evidence that
an invasive species can occupy climatically distinct niche spaces following its introduction into a new
area. The models fail to predict the current invaded distribution, but correctly predict areas of
introduction. Climate matching is thus a useful approach to identify areas at risk of introduction and
establishment of newly or not-yet-introduced neophytes, but may not predict the full extent of invasions.
9- In a cooperative breeder helpers pay a high price to stay
Bruintjes, Rick; Taborsky, Michael
Behavioural Ecology, Institute of Zoology, University of Berne, Wohlenstrasse 50a, 3032 Hinterkappelen,
Switzerland
Pay-to-stay is an important mechanism generating cooperation in highly social vertebrates. It is unknown,
however, which behaviours are preferentially used by subordinate helpers to pay for the commodities
provided by resource owners. Helpers could either provide “cheap” service to save costs, or trade
expensive actions against the benefit of being tolerated. In the cichlid Neolamprologus pulcher, helpers
pay to stay in a safe territory of dominant breeders by a range of behaviours including direct brood care,
territory maintenance and defence. Kin selection is only of minor importance for the behaviour of large
brood care helpers because of low relatedness levels. Here we tested by experimental variation of
perceived intruder pressure whether (1) helpers change their level of payment with the intensity of
competition, (2) cheap or expensive behaviours are chosen for payment, and (3) large and small helpers
differ in reaction to treatment. Our data show that in the high density situation all helpers increased
defence levels and large helpers spent significantly more effort than small ones in both treatments. No
effect of perceived density was found on the amount of digging behaviour and submissiveness. Received
aggression from dominant group members did not increase with external competition levels, which confirms previous results showing that helping serves as “pre-emptive appeasement”, i.e. it does not have to
be enforced by breeders’ demands. These results suggest that subdominant group members are prepared
to pay a high price for staying by increasing defence behaviour, which bears high risk and energetic costs.
39
10- The origin and colonization history of the barley scald pathogen
Rhynchosporium secalis
Brunner, Patrick C.1; Schürch, Stephanie1, 2
1
Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland;
Present address: ACW Research Station, 1260 Nyon 1, Switzerland;
2
The origins of pathogens and their past and present migration patterns are often unknown. We used
phylogenetic haplotype clustering in conjunction with model-based coalescent approaches to reconstruct
the genetic history of the barley leaf pathogen Rhynchosporium secalis using the avirulence gene NIP1
and its flanking regions. Our results falsify the hypothesis that R. secalis emerged in association with its
host during the domestication of barley 10,000 to 15,000 years ago in the Fertile Crescent and was
introduced into Europe through the migration of Neolithic farmers. Estimates of time since most recent
common ancestor (2,500–5,000 BP) placed the emergence of R. secalis clearly after the domestication of
barley. We propose that modern populations of R. secalis originated in northern Europe following a host
switch, most probably from a wild grass onto cultivated barley shortly after barley was introduced into
northern Europe. R. secalis subsequently spread southwards into already established European barleygrowing areas.
40
11- Antioxidant defenses and lifespan variation in bat and terrestrial
micromammal species
Bruyndonckx, Nadia; Devevey, Godefroy; Keller, Laurent; Christe, Philippe
The free radical theory of aging proposes that aging is the result of deleterious attacks of free radicals on
cellular structure (e.g., nuclear DNA, membranes, proteins, lipids…). This theory predicts that species
with greater longevity should decrease the deleterious effects of free radicals by producing fewer free
radicals and/or by eliminating them more efficiently. Here we tested whether there is an association
between total antioxidant defences (AOS) and lifespan among mammal species. We selected 17 species
of bats and terrestrial micromammal species of similar body mass but with important differences in
lifespan (maximum lifespan 2–30 years). Using phylogenetically independent contrasts, we found no
significant relationship between maximum longevity and AOS. When the bats and terrestrial
micromammal species are analyzed separately we found a significant relationship between maximum
longevity and the AOS in bats but not in terrestrial micromammals. Overall, these results suggest that
AOS does not account for the large difference in lifespan between the species studied but could play a
role in bats that are longer-lived than the terrestrial micromammals.
12- Do cleaner wrasses (Labroides dimidiatus) learn to feed against
their preference in a reverse reward contingency task?
Danisman, Evin
University of Neuchâtel, Eco-Ethologie, Rue Emile-Argand 11, Case Postale 2CH-2009 Neuchâtel, Switzerland
The ability to control impulsive behaviour, for instance by feeding against a preference, should be
advantageous when animals can thereby gain an overall benefit. However, previous studies in several
species suggest animals have difficulties to maximise a reward by choosing a small reward in order to
obtain a large one (reverse reward contingency). Evidence suggests cleaner wrasses (Labroides
dimidiatus) feed against their preference in nature when engaging in cleaning interactions with client fish.
Hence, we tested their ability to choose a non-preferred item in order to obtain a preferred one. None of
the 8 individuals learned to choose a non-preferred item after 200 trials. In a second procedure only the
small (non-preferred) item was rewarded. One subject learned to respond correctly to this large or none
contingency. After re-experiencing the large and small reward plate simultaneously, the individual was
again subjected to the reverse reward task. After 30 trials of initial random choice it subsequently chose
the small reward to obtain a large one. The results suggest cleaner fish have the potential to feed against a
preference in a reverse reward contingency. Furthermore, it supports the ecological approach to cognition
that proposes the cognitive abilities of animals are closely linked to the challenges they face in nature.
41
13- High variability and non-neutral evolution of the mammalian
avpr1a gene
Fink, Sabine1; Excoffier, Laurent1; Heckel, Gerald1
1
Computational and Molecular Population Genetics (CMPG) Laboratory, Zoological Institute, University of Bern,
Regulatory important structures like hormone receptors evolve under functional constraints and are thus
expected to be subjects to purifying selection. Some regions of a gene coding for functional units can
nevertheless be targets of positive selection and may thus result in phenotypic adaptations. The argininevasopressin 1a receptor in the brain has been identified as a key determinant for phenotypic variation in
social behavior in Microtus voles and other mammals. In this study, we examine genetic variation in the
arginine-vasopressin receptor 1a (avpr1a) gene across a range of mammal taxa in order to determine the
influence of non-neutral processes for the evolution of this receptor. We address potential functional
consequences by contrasting non-synonymous variation at this locus with life history traits (e.g. mating
system) and geographic variation. In comparison to other mammalian taxa, the substitution rates of the
Microtine avpr1a gene are high and comparable to those of immunologically relevant genes. Analysis of
the first exon of the gene revealed regions with a comparatively high rate of change which showed also
evidence for positive selection on particular sites. Genetic variation within the Microtus genus involves
deletions or insertions of amino acids in the protein coding region of the gene, the replacement of amino
acids with radically different physicochemical properties, and the presence of distinct protein variants
within individuals. These results are discussed in regards to functional constraints and the occurrence of
adapted receptor phenotypes.
42
14- Genetic basis of adaptation in the common vole (Microtus
arvalis)
Fischer, Martin C.1 ; Excoffier, Laurent1; Heckel, Gerald1
1
Computational and Molecular Population Genetics lab, Zoological Institute, University of Bern, Baltzerstrasse 6,
3012 Bern, Switzerland;
Selection, genetic drift and the demographic history of a population can deeply influence its current
genetic diversity. It is a challenging task to determine the relative importance of each of these factors in
natural populations; and e.g. balancing selection may be impossible to detect in species with low levels of
genetic differentiation among population like Drosophila or humans. The well-studied evolutionary
history and high divergence between populations of the European common vole (Microtus arvalis)
provides a favourable framework to determine the roles of directional and balancing selection vs. genetic
drift in shaping current genetic diversity. The focus of the study is on the colonization of the Orkney
Islands off Scotland by M. arvalis from the European continent. The colonization about 5,000 years ago
is relatively well characterized, and has resulted in morphological changes which led to the description as
a separate subspecies (M. a. orcadensis). We will compare populations of the Orkney voles with
populations from the source area in Western Europe and from other evolutionary lineages in Europe as
well as different elevations to determine the extent of genetic changes. We use a large array of AFLP
markers to scan a representative part of the vole genome for outlier loci potentially associated with recent
adaptations. Loci linked to potential targets of selection will be identified by comparing observed and
expected patterns of divergence simulated under neutrality. Our preliminary results demonstrate that a
very high reproducibility of AFLP results can be obtained under highly standardized analysis conditions.
Further validation of the marker system is derived from the comparison of the relative levels of
differentiation between Orkney and Belgian population as estimated from AFLP and microsatellite data.
43
15- Population biology of three species of the Campanula
rotundifolia aggregate (Campanulaceae): variation along altitudinal
gradients in the Swiss Alps
Frei, Eva S.1; Nyffeler, Reto1
1
Institute of Systematic Botany, University of Zurich, Zollikerstrasse 107, CH-8008 Zurich, Switzerland
The systematic and taxonomic status of the threecommonly in Switzerland occuring species of the
Campanula rotundifolia aggregate is not so clearly established as it might seem from the current
literature. There are many inconsistencies to be found in the described morphological characters. In
addition, many authors indicate that the species of this complex are not straigtforward to be identified.
The associated species are mainly distributed in the northern hemisphere, and the aggregate is known for
its huge variation, partly as a consequence of hybridization and polyploidization. In the present investigation the focus lies on three species, namely Campanula cochleariifolia, Campanula rotundifolia, and
Campanula scheuchzeri. To clarify the phenetic and genetic variation paterns, I examined populations in
five different regions of Switzerland along altitudinal transects from the base of the values (c. 800 m
a.s.l.) to the alpine zone (generally about 2300 m a.s.l.). An additional aim of this study was to investigate
the influence of different ecological parameters onto the variation patterns. In the first part of this study I
measured selected morphological characters from herbarium specimens. In addition to herbarium studies,
which put the focus on individuals, the present field study also investigated populations samples in their
ecological context. Every 100 meters in altitude a new sample of five individuals was collected, measured
and prepared for further lab work. Selected leaf samples were examined in the lab with Flow Cytometry
and ISSR fingerprinting investigations. The findings derived from statistical analyses, including
hierarchical clustering and principal component analyses, are presented.
44
16- Urgency-dependent alarm calls in cape ground squirrels (Xerus
inauris)
Furrer, Roman D.1; Manser, Marta B.1
1
Institute of Zoology, University of Zürich, 8049 Zurich, Switzerland
Alarm calls often differ in their informational content, depending on the situation in which they are
emitted. The acoustic structure may denote the approaching predator type (functionally referential alarm
calls), the degree of threat the caller faces (urgency-dependent alarm calls) or both. The major selective
force driving the evolution of functionally referential alarm calls has been proposed to be the need for
different strategies to escape different predators in three-dimensionally structured habitats. In contrast, in
open, two-dimensionally structured habitats where a single escape strategy appears to be sufficient,
urgency-dependent alarm calls are favoured. Contradictory to these hypotheses, the open semi-desert
dwelling meerkat (Suricata suricatta), which only use boltholes as retreat, evolved functionally
referential alarm calls. To shed light on the evolution of specific information in alarm calls, we
investigated the alarm calls of the similarly sized sympatric Cape ground squirrel (Xerus inauris) facing
the same predation pressure. We tested whether Cape ground squirrels evolved functionally referential
alarm calls like meerkats, or urgency-based alarm calls like many North American ground squirrels living
in similar structured environments by recording their alarm calls and performing playbacks.
The acoustic analysis of recorded alarm calls showed that Cape ground squirrels emit urgency-dependent
alarm calls. Responses to alarm call playbacks varied with the degree of the risk the caller faced at the
moment of predator encounter. Subjects were more likely to retreat to boltholes in response to playback
of alarm calls conveying higher urgency. Cape ground squirrels showed a single escape strategy by
retreating to boltholes, as observed in the sympatric meerkats. We therefore conclude that not only the
need for different strategies to escape different predators in three-dimensionally structured habitats, but
also other ecological or social factors can influence the evolution of particular alarm call systems.
45
17- A flea induced maternal effect modulates tick feeding behaviour
in great tit nestlings
Gallizzi, Katharina1; Gern, Lise2; Richner, Heinz1
1
Evolutionary ecology group, Zoological institute, University of Bern, Baltzerstr. 6, 3012 Bern, Switzerland
Eco-epidemilolgy group, Zoological institute, University of Neuchâtel, Rue Emile-Argand 11, 2009 Neuchâtel,
Switzerland
2
Parasites feeding on the same host are indirectly associated with each other via the host they share as
common habitat. Specifically, the host’s defence reaction against one parasite can modulate the habitat
for the other parasites either in a negative or in a positive way. On one hand resistance to one parasite
species can be accompanied with cross-resistance against an unfamiliar closely related species because
they share similar antigens. On the other hand, the resistance to one parasite species might also reduce
resistance to other species that are simultaneously present on the host, because the mounting of multiple
defence reactions is costly to the host. Here we test whether a flea induced maternal effect that is known
to protect great tit (Parus major) nestlings against flea (Ceratophyllus gallinae) infestations, can also alter
tick (Ixodes ricinus) feeding behaviour. In a field study we experimentally infested half of the tit nests
with fleas to induce the maternal effect, and subsequently cross-fostered nestlings to produce broods that
contained at the same time nestlings with and nestlings without maternal effect. At the age of five days
we put 5 tick larvae on each nestling of these broods. We then counted the number of ticks attached to
each nestling and measured the duration of the attachment. We found that ticks feeding on nestlings with
a maternal effect detached significantly earlier than ticks feeding on nestlings without maternal effect. It
suggests that the flea induced maternal effect changes nestling physiology in a way that alters tick feeding
behaviour and that maternal effect may protect nestlings against ticks, by reducing tick attachment times.
In addition more ticks attached to male than to female nestlings, confirming a pattern known from many
vertebrate species where parasites preferentially aggregate on males.
46
18- Temporal and spatial distribution of perch larvae (Perca
fluviatilis l.) in relation to prey availability in lake Zurich
Gegenschatz, Silvan E.1 ; Ribi, Georg1
1
Zoological Museum, University of Zurich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland
The European perch (Perca fluviatilis L.) makes up c. 30% of the annual catch in Swiss lakes. Perch
populations often exhibit high fluctuations in year-class strength leading to catch rates between 30 and
110 tons per year in Lake Zurich. Due to its economic importance, a lot of research has been done on the
survival of perch larvae, the life history stage that suffers the highest mortality rates. Possible factors
affecting larval mortality are food availability, predation and cannibalism. Previous work in Lake Zurich
detected a massive decrease of perch larvae in June. Predation and cannibalism are considered to be
unlikely primary causes because this decrease happened in a short period. Thus, it is hypothesized that
insufficient food availability leads to perch starvation as a decline in zooplankton density occurs a few
days prior to the larval mortality. Such predator-prey interactions are crucial processes in ecology.
To test this hypothesis, I collected data on perch larvae and zooplankton prey abundance using a larva net
and zooplankton net simultaneously from May to July 2006. Samples down to seven meters depth were
taken along 300m transects by boat during the day and night in Lake Zurich. Based on this data set, I
could further describe the vertical and horizontal distribution pattern of perch larvae. Data were analysed
in an ANOVA framework.
Interestingly, no period of low zooplankton abundance took place in 2006 such that sufficient food for
perch larvae was probably always available. Although I detected a decrease of perch larvae at the end of
May, a surprisingly high number was found at the beginning of July. Further results showed that larvae
were randomly distributed in the top seven meters of the water column and more larvae were caught
during night. Reasons for all these facts will be discussed.
47
19- Impact of invasive exotic knotweeds (Fallopia spp.) on
invertebrate communities
1
Gerber, Esther1; Schaffner, U. 1; Krebs, C. 1; Murrell, C. 1; Moretti, M.2
Biological Weed Control & Ecosystem Research, CABI Europe - Switzerland
Rue des Grillons 1, CH-2800 Delémont
2
WSL Swiss Federal Research Insitute, Switzerland
Correspendence: [email protected]
Exotic knotweeds (Fallopia spp) are considered to be among the most serious invasive exotic weeds in
Europe, causing significant damage to native ecosystems. However, with the exception of competitive
exclusion of native vegetation, their suggested ecological impact is poorly supported by experimental
studies.
In 2004, we started to investigate the ecological impact of exotic knotweed species in selected areas of
France, Germany and Switzerland. Specifically, we aim to assess their effects on invertebrate community
in natural and semi-natural habitats. Ten locations were selected along river courses with different levels
of knotweed infestations, and pitfall traps and combi traps (to catch flying insects) randomly established
in vegetation invaded by exotic knotweed, as well as in vegetation which can potentially be invaded by
knotweed: open vegetation dominated by grasses and forbs, and bush-dominated vegetation.
Results indicate that invasion by exotic knotweeds does not only have strong effects on native vegetation,
but also negatively affects invertebrate communities. The overall abundance, biomass and diversity of
invertebrates in plots invaded by exotic knotweed were strongly reduced compared to control plots.
Exotic plant species are in general introduced without their specific natural enemies and are also often
less palatable to generalist herbivores. In accordance with this, we found reduced diversity for herbivore
invertebrates in knotweed patches. In addition, a negative effect of exotic knotweeds could also be
detected in other trophic groups (predators, detritivores). However, not all invertebrate groups responded
in the same way, and species number for ground beetles was in fact highest in knotweed stands. Ground
beetles might nevertheless be negatively affected by these exotic plants as indicated by reduced size of
Abax parallelepipedus (Carabidae) individuals captured in knotweed, presumably resulting in a reduced
fitness of individuals.
48
20- Of mountains, goats and MHC
Grossen, Christine1; Biebach, Iris1 ; Keller, Lukas1
1
Zoological Museum, University of Zurich, 8057 Zürich, Switzerland
The major histocompatibility complex (MHC) plays an important role in the immune system of
vertebrates. This gene region is generally characterized by an extraordinary degree of polymorphism,
which is thought to be maintained, among others, by pathogen-driven selection. Alpine ibex present a
particularly interesting system to test this hypothesis because genetic variation in Alpine ibex (Capra ibex
ibex) is generally low and a previous study found one of the most variable MHC loci, the exon II DRB, to
be monomorphic in ibex. Using exon II DRB sequences and MHC-linked microsatellites, we show that
there is low genetic variability at three MHC loci.
At the exon II DRB we found only two alleles in 108 individuals, one of which is specific to domestic
goats. The allele frequency of this goat allele varies between populations, from 0.0 (populations in Valais)
to 0.27 (Grison). This variation can be explained by the founding history of Alpine ibex and by genetic
drift. We furthermore found the goat allele in the Gran Paradiso National Park, the founder population for
the reintroductions.
We discuss three possible hypotheses that can explain the prevalence of a goat allele in ibex populations:
1) recent and ongoing hybridization, 2) hybridization in the evolutionary recent past, when ibex numbers
were very low or 3) an ancient polymorphism shared between goats and Alpine ibex without
hybridization due to the long evolutionary life of genes under strong balancing selection.
With or without the goat allele, the levels of heterozygosity and the number of alleles found are low and
are comparable to the ones reported for endangered species. Future negative effects on fitness,
particularly if populations become exposed to disease epidemics, can therefore not be excluded.
21- Relationship between plant community traits and pollinator
species richness in urban and sub-urban areas
Hennig, Ernest; Ghazoul, J.
Institute of Terrestrial Ecosystems, Ecosystem Management, ETH, Universitätsstrasse 16,
8092 Zürich, Switzerland
Pollinators respond to floral traits in different ways and therefore species richness and the variety of floral
colours and structures in a plant patch may attract several distinct pollinator taxa.
Urbanization may affect the richness and variety of floral patches which, in turn, may have implications
for the pollinator community that services these flowers.
To reveal patterns driving pollinator diversity in urban and sub-urban areas, we investigated meadows
along the city margin of Zürich and gardens and swards within the city for pollinator species richness. We
also evaluated pollinator richness and visitation in the context of local plant patch richness.
49
22- Potential of AFLP technique and regression models to identify
genes under selection in response to environmental variation:
hundreds of AFLP markers in 198 populations of the alpine plant
Arabis alpina
Herrmann, Doris1; Poncet, Bénédicte2; Manel, Stéphanie2; Holderegger, Rolf1; Taberlet, Pierre2; Thuiller, Wilfried2;
Gielly, Ludovic2; Rioux, Delphine2; Aubert, Serge2; Gugerli, Felix1; IntraBioDiv Consortium3
1
Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
Laboratoire d'Ecologie Alpine, Université J. Fourier, Grenoble, France
3
http://lotus5.vitamib.com/hnb/intrabiodiv/intrabiodiv.nsf/Web/Frame?openform
2
The genetic variation studied with neutral markers is usually selectively neutral, i.e. it does not allow any
inference on how the studied populations are adapted to their environment or how adaptively favorable
traits are distributed across the landscape. This knowledge would be of high value in conservation
biology, since it would let us infer on the evolutionary potential of populations. However, this is a
formidable task due to the technical (adaptive markers are difficult to find) and logistic problems (work
load).
In this work, we aim to study the potential of AFLP markers and various regression models to identify
loci that are linked to environmental variables (elevation, habitat-type, etc). We chose the alpine plant
Arabis alpina as model, since we expect strong selection signals given the species' broad ecological
niche. The genetic relatedness of A. alpina to Arabidopsis thaliana should enable us to identify possible
candidate genes.
We first apply regression models to an existing data set of A. alpina consisting of 151 AFLP markers
genotyped for 400 individuals sampled on a regular grid in 131 populations from the Alps. This
preliminary work will be extended. Our objective is to genotype 1000 AFLP markers in 198 populations
of A. alpina from the French and the Swiss Alps. To favour the detection of loci under selection, we
optimized the altitudinal range (440 to 3133m) and habitat conditions (scree, moist, nutrient-rich) of the
sampled sites.
This study will broaden the knowledge of environmental interactions and is an important step towards our
comprehension of evolutionary relevant biodiversity.
50
23- Corolla colour similarity and spatial mingling between a
rewarding and a deceptive species affect pollinator visitation rate to
the deceptive species
Internicola, Antonina I.1; Gigord, Luc D.B.1; Bernasconi, Giorgina1
1
Department of Ecology and Evolution, University of Lausanne, 1015 Lausanne, Switzerland
While many plant species offer rewards (e.g. nectar) to pollinators, some entomophilous species,
particularly in Orchids, do not provide any reward. Ecological factors such as interactions with rewarding
co-flowering species may affect pollinator visitation rates to such deceptive species by influencing
pollinator ability to learn to avoid deceptive plants (avoidance learning).
We tested the effect of flower colour similarity (similar vs dissimilar) and fine-scale spatial mingling
(monospecific vs heterospecific patches) of rewarding and deceptive artificial plants on pollinator
visitation in a fully-crossed design. We also examined the effect of these factors over time on pollinator
learning by using initially naïve bumblebees.
Over time, bumblebees increasingly avoided the deceptive plants, but at a significantly faster rate when
deceptive and rewarding plants had dissimilar flower colours than when they were similar.Also, deceptive
plants received more visits when mingled in heterospecific patches with rewarding plants of similar
flower colour than when mingled with dissimilar ones. This difference was not significant when
rewarding and deceptive plants were spatially separated in monospecific patches.
In conclusion, both spatial mingling and flower colour similarity affected pollinator visitation to and
avoidance learning of deceptive plants. This proves the validity of artificial experimental systems to study
the isolated and joint effect of plant traits and ecological factors that are crucial for the maintenance of
deceptive species in natural populations.
51
24- An extensive network of gene flow by pollen at the landscape
scale
Kamm, Urs1, 2; Gugerli, Felix1; Holderegger, Rolf1; Rotach, Peter3; Ewards, Peter2
1
Division of Ecological Genetics and Evolution, Swiss Federal Research Institute WSL, Zürcherstr. 111, 8903
Birmensdorf, Switzerland
2
Geobotanisches Institut, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland
3
Institut für Terrestrische Ökosysteme, ETH Zürich, Universitätstrasse 16, 8092 Zürich, Switzerland
Human land use causes landscape fragmentation, which is considered as a major threat to biodiversity by
disrupting gene flow. In plants, long-distance gene flow counteracts the negative effects of landscape
fragmentation by providing functional connectivity. Research on long-distance gene flow is severely
limited as the direct evaluation of this rare and highly stochastic process is restricted by the spatial extent
of empirical data. Long-distance gene flow is therefore often shown in the form of model-based
“dispersal kernels”, a function characterizing the probability of dispersal to a certain distance. However, it
remains difficult to reliably quantify the tail of dispersal kernels (i.e. long-distance gene flow). Here we
show empirical data on gene flow by pollen in a rare, temperate forest tree (Sorbus domestica) at the scale
of a real landscape (>100 km2). All individuals occurring were precisely mapped allowing to precisely
describe current gene flow patterns in a genetic paternity analysis. The latter was performed on about
1200 seeds collected from 49 different mother trees distributed over the whole study area. Using 9
microsatellites we detected an extensive network of current gene flow by pollen over the fragmented
landscape including distinct pollen flow events over distances of 12–16 km. Although our results support
the usually shown predominance of short distance pollen flow, a remarkably high amount of assigned
pollen donors were further away at distances of more than 2 km (>10%) or even surpassed 5 km (>2%).
In summary, our empirical results underline that dispersal kernels in insect-pollinated trees are
characterized by a leptokurtic shape and long fat tails.
25- Are predator-prey body-size relationships driven by phylogeny?
Kehrli, Patrik; Bersier, Louis-Félix
Unit of Ecology and Evolution, Department of Biology, University of Fribourg, Switzerland
Body size is one of the most fundamental characteristics of organisms. It affects growth, reproduction,
space use as well as abundance and trophic position of organisms. Moreover, the ratio of body sizes
between consumers and their resource plays an important role in explaining who eats whom. Using a
unique global database on consumer and resource body sizes, Brose et al. (Ecology 2006) showed that the
relative size difference between predators and prey increases with increasing size of the species when
data are pooled. However, we believe that this result is confounded by the disregard of phylogenetic
constraints. Considering the taxonomy of predators and prey, we reanalysed the database. Taking the
phylogeny of species into account results change dramatically. First of all, relative size difference
between predators and prey decrease, instead of increase, with increasing body size of organisms. Second,
average predator-prey body-size ratios differ among and within taxa of predators and preys. Our results
shed light on the importance of evolutionary processes in the organisation of species communities.
52
26- Stress impacts telomere dynamics
Kotrschal, A.1; Ilmonen, P.2; Penn D.J.2
1
Departement of Behavioral Ecology, Zoology Institute,University of Berne, Wohlenstrasse 50a, 3032
Hinterkappelen, Switzerland
2
Konrad Lorenz Institute for Ethology, Austrian Academy of Sciences, Savoyenstraße 1a, 1160 Vienna, Austria
Telomeres are DNA-protein complexes at the ends of chromosomes that control genomic integrity, but
appear to become shorter with age and stress. To test whether stress causes telomere attrition, we exposed
the offspring of wild-caught house mice (Mus musculus) to stressful conditions, and examined changes in
telomere length over six months. We found that females exposed to males and reproductive stress (either
with or without crowding) had significantly shorter telomeres than controls, and males exposed to
crowding stress had shorter telomeres than males that were not crowded. Our results indicate that stress
alters telomere dynamics, causing attrition and hindering restoration, and these effects are sex-dependent.
Telomeres may thus provide a biomarker for assessing an individual’s cumulative exposure or ability to
cope with stressful conditions.
27- Molecular systematics of the tribe Trichocereeae (Cactaceae)
with special reference to biogeography and growth-form evolution
Lendel, Anita1, 3; Eggli, U.2; Nyffeler, R.1
1
Institut für Systematische Botanik, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
Sukkulenten-Sammlung Zürich, Mythenquai 88, CH-8002 Zürich, Switzerland
2
The tribe Trichocereeae (Cactaceae), comprising about 25 genera and up to 300 species, is remarkable for
its large diversity of the growth-forms, ranging from trees and shrubs to small caespitose or single
globular stems. Cacti from this tribe are found in various different habitats: from extremely arid areas in
the Atacaman desert of Peru to the dry deciduous forests of Northern Argentina and Bolivia; and from the
Patagonican plateau up to 4000 m in the Andes. The combination of diverse geological, climatical, and
ecological factors, as well as the remarkable diversity of cactus morphology resulted in a wide spectrum
of pollinators, ranging from bees and hawkmoths to the hummingbirds and bats.
Previous molecular phylogenetic investigations strongly support the position of the tribe Trichocereeae
within a one of the larger clades of Cactoideae, including members of Cereeae and Browningieae, but
raise questions about the monophyly of the tribe itself. The present study is based on a phylogenetic
analysis of combined cpDNA markers (aligned matrix includes close to 6000 bp) for 95 exemplars using
parsimony and Bayesian methods. This analysis, considers all relevant representatives of traditional
Trichocereeae, and confirms the previous doubts on the non-monophyly of the investigated tribe. Instead,
it provides evidence for a smaller and geographically more coherent subclade, comprising
Acanthocalycium, Cleistocactus, Echinopsis and an additional 17 smaller genera, but not Gymnocalycium
and Rebutia. In addition, Discocactus, Espostoopsis, Facheiroa, and Leocereus show close relationships
with the mainly Brazilian Cereeae. Brachycereus and Jasminocereus from the Galapagos Islands form the
sister-group to the investigated Armatocereus species from the Ecuadorian mainland. The present detailed
phylogeny of the tribe Trichocereeae and relatives clearly indicates a strong biogeographical pattern, but
does not indicate a clear trend in the evolution of the growth-form as previously hypothesized by various
authors.
53
28- The importance of sparse soil vegetation for the common
redstart Phoenicurus phoenicurus
Martinez, Nicolas
The Common Redstart Phoenicurus phoenicurus, a passerine bird species, suffers a strong and ongoing
population decline in Switzerland. Main negative factors are habitat decline in its breeding range due to
destruction of traditionally managed orchards and changes in grassland management. Intensified
management of the soil vegetation could lead to a reduction of the food availability, but also to lowered
prey detectability and accessability. In my master thesis I examined the importance of sparse vegetation
surfaces for the location of redstart territories and the degree of preference of such structures for feeding.
I further made experiments with captive birds to validate the results of the field study.
Occupied territories in orchards of north-western Switzerland contained significantly more sparse
vegetation surface than did unoccupied control areas. Potential food abundance tended to be lower in
experimentally established ruderal vegetation strips than in the surrounding meadows. Nevertheless
redstarts made significantly more hunting flights into the ruderal vegetation than into unmown meadows.
No difference was observed, when the meadow was newly-mown. Binary logistic regression showed that
a model including only vegetation height and proportion of open soil surface made correct predictions
about the direction of hunting flights in about 80%. Standardized experiments in aviaries supported the
results of the field experiments. Even a four-time increase of the potential food abundance in the meadow
did not lead to any change in preference for the available sparse vegetation types.
Redstarts seem to choose territories which have better foraging opportunities than other available places.
Redstarts strongly prefer sparse vegetation for feeding although the absolute prey mass tended to be lower
there. This is due to enhanced detectability and accessability of prey items in sparse vegetations. Beside
the conservation of traditionally managed orchards with tall trees, sparse vegetation areas should be
supported to preserve and possibly enhance redstart populations.
54
29- Urgency levels in heterospecific alarms
Müller, Corsin A.; Manser, Marta B.
Institute of Zoology, University of Zürich, 8057 Zürich, Switzerland
Predation is a powerful selective force shaping the behaviour of prey animals and, as a consequence, a
variety of birds and mammals have developed referential and/or urgency-based alarming systems. Since
anti-predator behaviour is likely to be costly, it should pay to attend to warning signals given by other
species. Evidence that animals respond to heterospecific alarm calls is abundant. However, studies
showing whether animals extract information on predator types or urgency level from heterospecific
alarms are rare. We investigated whether free-ranging banded mongooses (Mungos mungo) in Queen
Elizabeth National Park (Uganda) respond to alarm calls of sympatric plovers (Vanellus sp.) and how
mongooses respond to plover alarms that differ in their urgency level. Using playback experiments, we
show that banded mongooses respond to alarm calls of all three plover species tested. Plover alarms
varied consistently with urgency level both in call rate and call duration. However, even though response
intensity varied over a large scale, the mongooses’ responses to plover alarms did not differ between
playbacks of high and low urgency alarms. Our results indicate that banded mongooses use heterospecific
alarms for predator avoidance but do not use additional information provided in these signals. This might
be related to low costs of responding to these alarms and to the mechanism by which recognition of
heterospecific alarms is acquired.
55
30- QuantiNemo: an inidividual-based program for the analysis of
traits with explicit genetic architecture potentially under selection
Neuenschwander, Samuel
Dept. of Ecology and Evolution, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland
quantiNemo is an individual-based, genetically explicit and stochastic simulation program. It was
developed to investigate the explicit genetic architecture of the traits under selection, and the mating
system of the species. Individuals are distributed among populations connected among each other by
migration. These populations are located in a heterogeneous habitat, where for each population and trait
an individual selection pressure may be defined. The genotype is translated to the phenotype by
additivity, dominance or epistatic interactions between the different genes and may also interact with the
environment. Selection may act at different life phases; during breeding, migration, or mating. The
architecture of the traits can explicitly be defined. Several different mating systems are implemented
allowing one to investigate their effect on varying aspects. quantiNemo is coded in C++ using an object
oriented approach, runs on any computer platform, and is distributed under an open source license.
31- A spatially-explicit model of conflict zones between alpine black
grouse wintering habitats and snow sport activities to delineate
winter refuge areas
Patthey, Patrick1; Wirthner, Sven1; Signorell, Natalina1; Arlettaz, Raphaël1, 2
1
Zoological Institute, Division of Conservation Biology, University of Bern, Baltzerstrasse 6, 3012 Bern,
Switzerland
2
Swiss Ornithological Institute, Valais Field Station, Nature Centre, 3970, Salgesch, Switzerland
Human disturbance upon wildlife through continuously developing outdoor recreational activities is of
growing conservation concern. We previously showed that free-riding snow sports disturbance lead to
stress and represent a new threat for Black grouse (Tetrao tetrix), a declining emblematic species of
Alpine ecosystems. Our goals are 1) To test the effect of ski resorts on Black grouse abundance and 2) To
develop an occupancy suitability map to highlight the regions where major potential conflict may occur
between human-use of the Alpine ecosystems and grouse favorite wintering habitats. We used Poisson
regression to 1) determine relations between winter grouse abundance and habitat features on 1.5 km
length transects in ski resorts and in natural sites of South-western Swiss Alps 2) construct a spatiallyexplicit predictive abundance model. Black grouse abundance was estimated by winter censuses. GIS
variables expressing habitat characteristics (from habitat type to human pressure including snow sports
and hunting) were extracted from satellite imagery, geographic databases and aerial photographs. The
abundance model has an excellent predictive power and shows clearly that ski-lift density have a strong
negative impact on Black grouse abundance, with habitat types also playing a role. Ski resort may
decrease by 33% the abundance of grouses. Hunting pressure, however, has no influence on local density.
A final «pre-interactive» occupancy suitability map, i.e. an optimal distribution map in the absence of
human disturbance was generated and shows that ski resort may decrease the abundance of Black grouse
on large surfaces. Conservation action plans for Black grouse should aim at reducing the multiple
negative effects generated by ski resorts (habitat alteration, disturbance by snow sports, etc.). Wintering
preserves where human penetration is banned should be promoted. Our optimal occupancy suitability
map offers the possibility to delineate these winter refuge areas.
56
32- Exploring genetic challenges facing rapidly spreading Larix
decidua in the Aletsch region
Pluess, Andrea R.
ETH, Dept. Environmental Sciences, Inst. Terrestrial Ecosystems, Group Ecosystem Management, 8092 Zuerich,
Switzerland
Genetic diversity, gene flow and the evolution of spatial genetic patterns in Larix decidua along a
successional gradient on a lateral moraine of the Aletsch glacier in the Swiss Alps is investigated. The
study is motivated by the need to understand the ability of plant species to move within and among
landscapes subject to environmental change. Pioneer plants occurring along successional gradients on
land newly exposed by glacier retreat, provide a natural experiment to study movement of propagules, the
establishment of sub-populations and associated genetic challenges. The rapid spread of pioneer species
into these newly exposed habitats may result in genetic bottlenecks, for which future management
strategies for maintaining genetic diversity and supporting long-term species persistence may be needed.
33- How does biodiversity affect soil stability in alpine ecosystems?
Pohl, Mandy1; Rixen, Ch.1; Körner, Ch.2
1
Swiss Federal Institute for Snow and Avalanche Research SLF, Unit Ecosystem Boundaries, Team Alpine
Ecosystems, Flüelastrasse 11, CH-7260 Davos, Switzerland
2
Institute of Botany, University of Basel, Schönbeinstrasse 6, CH-4056 Basel, Switzerland
Effects of plant species diversity on ecosystem functions like productivity have been reported in
numerous studies. It has been hypothesised that a high number of plants with diverse growth forms are
more effective at stabilizing soil than vegetation with few species. However, this hypothesis is still poorly
supported by data.
Erosion control is particularly important for graded ski slopes, as the protective vegetation cover has been
damaged or removed to improve skiing conditions. The natural colonization takes decades, and
revegetation above the timberline remains difficult.
This study aims (i) at determining the below-ground growth of plant species on a machine-graded ski
slope at 2625 m a.s.l. Plant species are collected by in situ excavation, in order to obtain the whole root
systems and to assess root morphology. Single roots for each species are tested for tensile strength. We
further aim (ii) at quantifying the contribution of vegetation to soil stability and at testing differences
between functional groups. Therefore, we carry out measurements of soil aggregate stability. We finally
aim (iii) at evaluating the run-off and infiltration rates of different ski slopes with simulated rainfall.
The results of this study will both improve the scientific knowledge about the effects of biodiversity on
soil stability and help optimizing revegetation practices and slope stabilisation.
57
34- Comparative analysis of survival rates of five endangered
European bat species with contrasting ecology
Ragettli, Gian Andraia 1; Bontadina, Fabio1, 2; Schaub, Michael1, 3; Zoephel, Ulrich4; Arlettaz, Raphaël1
1
Institute of Zoology, Division of Conservation Biology, University of Bern, CH-3012 Bern, Switzerland
SWILD, – Urban Ecology & Wildlife Research, CH-8003 Zürich, Switzerland
3
Swiss Ornithological Institute, CH-6204 Sempach, Switzerland
4
Fledermausmarkierungszentrale, Sächsisches Landesamt für Umwelt und Geologie,D-01109 Dresden
2
The estimation of demographic parameters is important for conservation and management of endangered
populations. Most European bat species have experienced severe declines in the last decades, but some
populations seem to recover in recent years. In order to receive information on variation of local survival
rates in space and time we analyzed 42 populations of five endangered bat species (Myotis daubentonii,
Nyctalus leisleri, N. noctula, Plecotus auritus, Pipistrellus pipistrellus). These species include large
variation in body size (from 5 to 30g), ecology (foraging and roosting) and spatial use (residential vs.
migrating). Mark-recapture data of wing-banded bats was collected by many volunteers between 1963
and 2000 in Eastern Germany. .We analyzed local survival rates based on more than 100’000 marked
individuals (58% females) with 29’000 recapture events using Cormack-Jolly-Seber models in the
program MARK. Generally, females had higher local survival rates compared to males and adults had
higher survival rates compared to juveniles. We found a strong effect of site and migratory behavior. Site
differences were particularly large in the brown long-eared bat (e.g. local survival in adult females ranges
from 0.54 to 0.93) and in the common pipistrelle bat (range in adult females from 0.46 to 0.76). Contrary
to predictions derived from other mammals, we found no positive relation between body size and local
survival rate in bats. As a consequence of the observed strong variation in site effects we conclude that
management recommendations extracted from single populations should be handled with care.
Comparative studies can help to extend the knowledge about variation in survival and the role of key
factors influencing the population dynamics in threatened animals.
58
35- Patterns of vegetation changes along environmental gradient at
the meeting point of main phytogeographical units of Madagascar
Ranirison, Patrick1; Nusbaumer, Louis2; Gautier, Laurent2
1
Departement of Biology and Vegetal Ecology, University of Antananarivo, 101 Antananarivo, Madagascar
Conservatory and Botanical garden of Geneva, Case postale 60, 1292 Chambésy/Genève, Switzerland
2
Patterns of vegetation changes along environmental gradients is an as interesting as complex recurrent
question in vegetation study. Daraina region (NE Madagascar) is at the meeting point of three
phytogeographical units and displays a mosaic of mountain and lowland forests, deciduous or evergreen,
with all kind of transitions along sharp environmental gradients. We hypothesis that the presence of
theses sharps gradients in a small area (ca. 50 x 50 km) allow to understand the role of the predominant
environmental factors. To test this, we realized two types of linear vegetation samples on sites selected on
a Geographic Information System (GIS): 102 short linear releves (SLR) (100 m, 50 measure points) in
homogenous vegetation and 23 long linear releves (LLR) of 1–3.5 Km (100–350 measure points) along
gradients. In total this represents 9000 measure points along 50 kilometers of sample. For each point we
recorded the species encountered and their height of contact along a vertical line. Also recorded are
geographic coordinates, altitude, slope, exposition, soil morphology. From the GIS we can extract
topographic position, steep-sidedness, distance to the forest limit and soil type. We analyzed the species
frequencies in the SLR, the coocurence of species along environmental gradients on the LLR and tried to
determine the influence of environmental factors on plant species distribution. We found that altitude and
slope are predominantly correlated with and antipodial influence of orientation which is the first
determinant under 850 m high. Steep-sidedness presents an important rule in the driest forest and
longitude influence for the most eastern forest because of proximity to Indian ocean.
36- Parasite impact on Columbian ground squirrels
Raveh S.1 ; Tonetti N.1; Betschart B.1; Dobson S.F.2 ; Neuhaus P.1
1
Institute of Zoology, University of Neuchâtel, Emile-Argand 11, 2009 Neuchâtel, Switzerland
Department of Biological Science, Auburn University, AL 36849, USA
2
The role of parasitism and its evolutionary driving force on sexual selection and mate choice are at the
focus of behavioural ecology. Many studies investigated the effect of parasites on mate choice,
reproductive success, life history and the immune system. Hamilton and Zuk proposed in their famous
1982 paper that animals should choose parasite-free or parasite-resistant partners to obtain good genes for
parasite resistance in their offspring. Most research has been carried out on birds and insects, whereas
only few studies were conducted on free living mammals, mainly because of difficulties in manipulation
and observation.
Like all other mammals, Columbian ground squirrels are more or less infested with parasites. The parasite
load of female Columbian ground squirrels seems to play a role in reproductive success; though whether
benefits are direct or indirect is still unclear.
To clarify whether different parasitic loads have a direct influence on mate choice; the parasite load of
males was manipulated to measure the effect on female mate choice.
Stronghold, an anti ecto- and endoparasite solution, was applied to create parasite-free individuals. This
manipulation successfully reduced the ectoparasite load of the animals, which lays the foundation for
further investigation to verify the relationship of parasites and mate choice in this species.
59
37- Unraveling wintering sites of an endangered migratory bird
(Upupa epops) using stable isotopes and the potential for population
dynamics
Reichlin, Thomas S.1; Hobson, Keith A.2; Schaub, Michael1, 3; Jenni Lukas3; Arlettaz, Raphaël1, 3
1
Conservation Biology, Zoological Institute, University of Berne, Baltzerstrasse 6, 3012 Bern, Switzerland
Canadian Wildlife Service, 115 Perimeter Road, Saskatoon, SK S7N OX4, Canada
3
2
Populations of migratory animals may be regulated by environmental or density-dependent factors
operating in any of the areas that they visit during their annual migrations. Efficient conservation is only
possible, if the relative importance of the different environments on the population growth rate is known.
However, for many migratory species the required basic information, the spatio-temporal course of their
migration is not known detailed enough. The recently developed analyses of stable isotopes in feathers
has proven to be a valuable tool to identify wintering grounds.
We used the heavy isotopes of hydrogen, carbon, and nitrogen (D, 13C, 15N) in feathers of hoopoes
(Upupa epops) from central Valais (Switzerland) to unravel their wintering grounds. During winter,
hoopoes are observed in the Mediterranean area as well as in sub-Saharan Africa, but it is not clear
whether individuals from the Valais population only winter in one region or whether they use both. We
found high values of D in hoopoe feathers (n=137), suggesting that they winter in African savannahs
north of the equator. Results from the three isotopic analysis combined suggest a wintering quarter of the
hoopoes in the area of Eastern Africa.
Using this basic information, we can now study whether the environmental variation during winter is an
important factor for the population dynamics of the hoopoes in Valais.
38- Natural disturbance shapes habitat and plant diversity in the
subalpine forest belt
Rixen, Christian1; Haag, Susanne1; Kulakowski, Dominik1, 2; Bebi, Peter1
1
Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Switzerland
Swiss Institute of Geography, University of Boulder, Colorado, USA
2
Disturbances by avalanches have created unique habitat for animals and plants in subalpine ecosystems
world-wide, but at the same time avalanches can pose a major threat to humans. Thus, avalanches are
suppressed by means of snow barriers to protect settlements and infrastructures, which results in a
fundamentally changed disturbance regime in avalanche tracks.
We address ecological consequences of avalanche suppression on habitat and plant diversity.
Species richness was higher in avalanche tracks compared with undisturbed subalpine forest. The species
composition indicated a wider range of ecological niches in active than in inactive avalanche tracks.
Suppression of avalanches reduced the proportion of alpine species in formerly active tracks.
The results suggest that avalanche disturbance can exert an important influence on the habitat and species
diversity of subalpine forests. Anthropogenic changes in the natural regime of avalanche disturbance are
likely to contribute significantly to future landscape changes in subalpine forests.
60
39- Social dynamics in a fluctuating vole population
Rytz, Raphael1; Heckel, Gerald1
Computational and Molecular Population Genetics lab (CMPG), Zoological Institute, University of Bern,
1
Small mammals are key elements in many ecosystems due to their high abundance and the extreme
demographic fluctuations observed in many species. Baseline parameters of population dynamics and
social organization are very difficult to determine due to cryptic and often subterraneous life styles.
Consequently, such data are extremely scarce even for the probably most abundant European mammal,
the common vole (Microtus arvalis). In this study, the social dynamics and reproductive patterns in a free
living population of common voles (Microtus arvalis) were investigated using a combination of
individual-based field observations and genetic analyses. Capture-mark-recapture data on the population
over a period of one year allowed the identification of demographic fluctuations, changes in space use
patterns, and the detection of probable immigrants. The analysis of ten microsatellite loci provided
evidence for kin-based spatial associations of females and their offspring, which partially dissolved in the
early breeding season. Parentage data allowed the identification of complex pedigree structures, which
even included reproduction among close relatives. Overall, the mating system was polygamous with
several cases of polygyny and polyandry in the population. Reproductive skew was relatively high,
particularly among males, which led to a high proportion of voles that did not reproduce successfully. A
strong decline in population size in fall led to a decrease in genetic diversity in the population which was
partially restored by successful reproduction of immigrants in the next reproductive season. Our results
provide first indications for potential mechanisms behind the strong genetic structure among populations
of M. arvalis, which are surprisingly able to maintain very high levels of genetic diversity within
populations. Analyses of an extended data set will test the generality of the detected patterns particularly
in regard to the impact of temporal demographic fluctuations.
61
40- Increased human management negatively affects beetle
(Coleoptera) richness in Swiss cities
Sattler, T.1, 3; Duelli, P.2; Wirz, P.2; Siegwart, R. 1; Schulz, A.1, 4; Obrist, M.K.2; Milani, L.1; Kindermann, M.1;
Bontadina, F.3; Albin, V.1, 4; Arlettaz, R.3; Moretti, M.1
1
Swiss Federal Research Institute WSL, Ecosystem Boundaries Research Unit, Via Belsoggiorno 22, 6500
Bellinzona, Switzerland
2
Swiss Federal Research Institute WSL, Biodiversity and Conservation Biology Research Unit, Zürcherstrasse 111,
8903 Birmensdorf, Switzerland
3
Switzerland
4
University of Applied Sciences Waedenswil, Natural Resources Sciences, Gruental, Postfach 335, 8820
Waedenswil, Switzerland
Urban landscapes represent a heterogeneous environment that is constantly changing and expanding due
to developing human needs. The biodiversity of such mosaic habitats is influenced by many
environmental and man-made characteristics. In a strong ongoing debate scientists argue which of these
variables are essential for urban species diversity. We contribute to this discussion by analysing the
relationship between invertebrate diversity and urban environmental factors in three Swiss cities (Lugano,
Luzern, Zurich). In particular, we tested the influence of (i) sealed area, (ii) human management by lawnand meadow-mowing (short time scale) and (iii) age of settlement (long time-scale) on beetle diversity at
106 study sites. The recently developed Rapid Biodiversity Assessment (RBA) was applied. In the weeks
most favourable to invertebrates with a maximum number of active species (June/ July), invertebrates
were collected with standard pitfall and flight traps. We split invertebrates into 14 taxa groups (order and
family-level) and subsequently identified beetle specimens to morphospecies level within 14 different
families. The various families correspond to different trophic guilds (i.e. herbivores, carnivores,
pollinators). The number of morphospecies highly correlates with total species number. Thus, this socalled RBA-index is an indicator for local – diversity.
Analyses of the beetle morphospecies numbers reveal that human management exhibits the greatest
influence onto morphospecies richness. Increasing numbers of lawn cuts negatively affects the numbers
of beetle biodiversity. Age of settlement and sealed area show only minor influence on beetle
morphospecies richness. Analyses of the trophic guilds showed that human management negatively
affects particularly carnivores, but also herbivores and pollinators within beetles. In order to maintain and
enhance beetle richness in urban areas we recommend reducing the number of lawn and meadow cuts.
62
41- Ecological factors affecting the distribution of the bat sibling
species Pipistrellus pygmaeus and Pipistrellus pipistrellus in
Switzerland
Sattler, T.; Bontadina, F.; Arlettaz, R.
Zoological Institute, Division of Conservation Biology, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland
Only in 1997 the Common Pipistrelle, a widely distributed bat, has been recognised as two cryptic
species. Since then, the new Soprano Pipistrelle was detected in many European countries, among them
Switzerland. In order to clarify its distribution and the ecological differences between the two species
twenty road transects all over Switzerland were run once in June/July and once in August/September. Bat
calls were recorded and species determined based on their spectrograms. Ecological parameters are
compared at the habitat level by GIS-distribution models. It could be shown that the Soprano Pipistrelle is
rare compared to its frequent sibling species and its distribution in Switzerland is patchy and limited to
areas near water bodies below 800m altitude.
42- Do hybrids exclude chromosomes of one parental species during
gametogenesis?
Sbilordo, Sonja H.; Ribi, Georg
Zoological Museum, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
The two dioecious freshwater prosobranch snails Viviparus ater and V. contectus frequently mate with
each other where they live sympatrically and first generation hybrids are found in the wild. Experimental
crosses showed that first generation hybrids are fertile in spite of the different chromosome numbers of
the two parental species (V. ater 2n=18, V. contecus 2n=14). When hybrids are fertile in backcrosses with
their parental species, the outcome of a particular hybridization event depends largely on the gametogenesis of the hybrids. In hybridogenetic species, first generation hybrids exclude the chromosomes of
one parental species during gametogenesis (e.g. waterfrogs: Rana complex). Hybridogenetic reproduction
can effectively prevent gene introgression, but it may lead to a new hybrid species. If first generation
hybrids pass at least some of the chromosomes of both parental species to their offspring gene
introgression may occur. Here, we determined the reproductive mode of hybrids between V. ater and V.
contectus by examining the karyotypes of first generation and of backcross hybrid males.
We found that first generation hybrids had the expected intermediate chromosome number (2n=16).
Chromosome number of backcross hybrids was variable (2n=1518) and even if they were full-sibs,
backcross hybrids had different numbers of chromosomes. The pure parent influenced the number of
chromosomes with hybrid origin in the backcross offspring, but nonetheless, about half of the first
generation hybrids transmitted an intermediate chromosome number (n=8) to the next generation.
Because of these results we rule out that Viviparus hybrids reproduce hybridogenetically, thus gene
introgression by hybridization between the two species seems to be possible. This result agrees with
previous studies on allozyme markers.
63
43- Facilitation among alpine plants: do they help each other to
attract pollinators?
Sieber, Yasemin1, 2, 4; Wirth, L.1; Erhardt, A.3; Reyer, U.2; Holderegger, R.1
1
Eidgenössische Forschungsanstalt für Wald, Schnee und Landschaft WSL, 8903 Birmensdorf, Switzerland
Zoologisches Institut, Universität Zürich, 8057 Zürich, Switzerland
3
Institut für Natur-, Landschaft- und Umweltschutz, Abteilung Biologie, 4056 Basel, Switzerland
4
Present address: WSL, Evolutionsökologie, Züricherstrasse 111, 8903 Birmensdorf, Switzerland
2
Reduced pollinator activity in alpine environments has long been supposed to cause low reproductive
success in alpine plants. However, recent studies found similar reproductive success in lowland and in
alpine plants. Substantial reproductive success in alpine plants might be explained by pollination
facilitation among plants. To ascertain whether coexistence of alpine plants facilitates pollinator
attraction, direct pollinator observations were carried out using the cushion plant Eritrichium nanum and
its most frequent neighbouring plants (mainly Saxifraga-species) as a model system. The number of
pollinators, visiting time on flowers and the number of visited flowers were compared in the following
four situations: (1) Isolated E. nanum individuals, (2) a group of E. nanum individuals, (3) a group of
neighbour species and (4) a group of E. nanum and neighbour species. No direct effect of facilitation
(neither competition) was found, but the different species as well as the number of flowers exhibited
different attractiveness to pollinators. These results demonstrate that facilitation cannot account for
pollinator attraction at high elevation.
64
44- Maternal food provisioning to larvae through Trophallaxis in
the european earwig Forficula auricularia (Dermaptera:
Forficulidae)
Staerkle, Michael; Kölliker, Mathias
Zoological Institute, University of Basel, 4051 Basel, Switzerland
Parents of many animal species perform various forms of care that enhance their offspring’s survival
prospects. There are relatively few experimental studies on insect parental care and the nature of care is
often poorly understood. For instance, trophallaxis (i.e., mouth-to-mouth transfer of food) is known to be
an important part of social interactions in eusocial insects, but there is limited information on how
important trophallaxis is as a form of parental care in sub-social insects. Here we investigate
experimentally if trophallaxis occurs as form of maternal care behaviour in the subsocial earwig Forficula
auricularia. We used two food dyes to colour the food (pollen) provided to the earwigs. We setup
experimental family groups containing mother and larvae. During the experiment, the mothers were
temporarily separated from their larvae and had access to food which had either a different or the same
colour as the larval food. After returning the mother to the larvae and leaving them overnight, we
collected one larva from every family and froze it. Experiments were done over the first ten days after
larval hatching. For the quantification of larval gut content, we took pictures of the gastro-intestinal tract
content of the larvae and analysed its colour by using Adobe Photoshop® software.
Our experiments showed significant food transfer (trophallaxis) between mother and larvae. We further
found that the quantitative importance of trophallaxis, relative to larval self-feeding, declined with larval
age. Our results show, for the first time unambiguously, that trophallaxis plays an important role in
common earwig parental care.
65
45- The role of traditionally managed chestnut orchards as foraging
and roosting areas for the migratory bat Nyctalus leisleri
Szentkuti, Susanne1 ; Bontadina, Fabio1; Moretti, Marco2; Spada, Martina3; Zambelli, Nicola4; Martinoli, Adriano3;
Arlettaz, Raphaël1
1
Conservation Biology, Zoological Institute, University of Bern, Bern, Switzerland
WSL Swiss Federal Research Institute, Ecosystem Boundaries Research Unit, Bellinzona, Switzerland
3
Dipartimento Ambiente-Salute-Sicurezza, Università degli Studi dell'Insubria, Varese, Italy
4
Centro protezione chirotteri Ticino, Semione, Switzerland
1
Woodland habitats have undergone major changes during the last century by abandonment of traditional
management practices and increase in intensively cultivated plantations. In Southern Europe traditionally
managed chestnut orchards form a particular park-like landscape structure with mature trees providing
roosts for many species. We found the migratory bat species Nyctalus leisleri during pre- and postlactation periods remarkably abundant (97% of 990 bats) in 200 bat boxes in managed chestnut orchards
compared to their occurrence in unmanaged orchards. In order to explain this pattern we investigated a)
habitat selection in foraging areas, b) roost microclimate and c) roost availability by means of radiotracking and roost temperature loggers. The 12 radio-marked Leisler’s bat selected deciduous woodlands
over coniferous woodlands, pastures and settlements. But within woodlands there was no significant
selection of managed orchards as foraging area although chestnut woodlands were frequently used
habitats. There were no temperature differences between bat boxes in differently managed orchards and
the observed roost use revealed no differences in the availability of natural shelters in differently
managed woods. Thus we suggest that for the lek-mating system of Leisler’s bat an optimal arena is
presented by the accumulation of roosts with the semi-open vegetation structure in managed chestnut
orchards.
66
46- Testing for belowground resource partitioning in experimental
grassland communities
von Felten, Stefanie1, 2; Buchmann, N.1; Hector, A.2; Niklaus, P.1 ; Scherer-Lorenzen, M.1; Schmid, B.2
1
Institute of Plant Sciences, ETH Zürich, 8092 Zürich, Switzerland
Institute of Environmental Sciences, University of Zürich, 8057 Zürich, Switzerland
2
Resource partitioning due to niche separation is a possible explanation for positive diversity-productivity
relationships in terrestrial plant communities. However, experimental evidence for resource partitioning
among different plant species is scarce. In addition, it is far less known whether niche separation can
change along gradients of increasing species diversity. In a temperate grassland field with experimental
communities of different plant species richness we tested for resource partitioning of soil nitrogen
between plant species in monocultures, 3-species and 6-species mixtures. Nitrogen uptake by plants was
tracked using 15N-tracer solutions and determination of the 15N/14N ratio in aboveground plant material
48h after tracer application. Six different treatment combinations consisting of three different chemical
forms of 15N-labelled nitrogen (nitrate, ammonium and glycine) injected at 2 depths (3 and 12cm) were
applied to each community in a split plot design.
We hypothesized that (1) temperate grassland species show belowground fundamental niche separation
with respect to nitrogen uptake, (2) species in mixtures partition nitrogen due to niche separation, and that
(3) niche separation increases with species diversity.
Although we found niche separation between species in monoculture, it did not increase with species
diversity. Rather, our species behaved more similar in the 6-species mixtures than in monocultures or in
the 3-species mixtures. Furthermore, there was no significant uptake of intact glycine (organic N) by any
of the species.
Our results suggest that partitioning of nitrogen with respect to depth and chemical form is of minor
importance in mixtures of temperate grassland species.
67
47- Translocation of bats – a useful conservation tool to augment
relict colonies of endangered bat species?
Weinberger, Irene1; Bontadina, Fabio1, 2; Arlettaz, Raphaël1
1
Institute of Zoology, Division of Conservation Biology, University of Bern, 3012 Bern, Switzerland
SWILD – Urban Ecology & Wildlife Research, 8003 Zürich, Switzerland
2
Translocation has become an important tool in conservation biology in recent years. Yet, there is only
little information about the possibility and success of translocations in highly mobile mammals like bats.
In this study, we tried to assess the parameters for successful translocations of two highly endangered bat
species in Switzerland: the greater horseshoe bat (Rhinolophus ferrumequinum) and the lesser horseshoe
bat (Rhinolophus hipposideros). In the second half of the 20th century, both species underwent a dramatic
decline in Western and Central Europe, including Switzerland. During the past 15 years, intensive
monitoring in Switzerland revealed positive population trends for both species. As these bats are very
sedentary, recolonization of their formerly vast native ranges advances extremely slowly. In 2006, we
conducted translocation experiments with greater horseshoe bats (n=12) and lesser horseshoe bats (n=7)
within Switzerland in order to augment relict colonies. Bats were captured from large colonies and
released individually into nursery roosts of small colonies of the same species at distances of <20 km and
>40 km from their native roost. Subsequently animals were radiotracked for up to ten days. Of the 14
animals released at distances <20 km, eleven animals expressed directed travel movements towards their
native home range, though only ten homed successfully. Of the five animals released at distances >40 km,
none expressed homing tendencies. Within the first three days, one greater and one lesser horseshoe bat
were found predated, and two lesser horseshoe bats died due to shock. Although sample size in lesser
horseshoe bats is too small to draw final conclusions, this species seems very susceptible to stress,
therefore changes in procedure and other conservation approaches should be evaluated. For greater
horseshoe bats, the short-term monitoring revealed that translocation might be a promising conservation
tool but survival of the release generation has to be confirmed by long-term monitoring.
48- Winter climate change: how do alpine tundra plants respond to
reduced snow depth and advanced snowmelt?
Wipf, Sonja1, 2
1
WSL Swiss Federal Institute for Forest, Snow and Landscape Research – Research Unit Ecosystem Boundaries –
Team Alpine Ecosystems, Fluelastr. 11, 7260 Davos Dorf, Switzerland
2
Institute of Environmental Sciences, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland
Snow covers alpine ecosystems for more than half of the year. Its disappearance marks the start of the
growing season, which is gradually becoming earlier due to warming and changed precipitation patterns.
How do these snow cover changes affect alpine ecosystems in the short and long-term? In alpine tundra
in Davos, Switzerland, I test how natural communities react to changes in snow cover by experimentally
decreasing snow depths and advancing snowmelt. I recorded the response of key plant species
(phenology, fitness, reproduction, abundance) and ecosystem processes (herbivory, litter decomposition,
nutrient and carbon cycling). Advanced snowmelt generally extended the potential growing season.
However, plant fitness and fecundity responded negatively in most species. Increased sensitivity to spring
frosts seemed to play a key role. Our results suggest that a lower snow:rain ratio and warmer spring might
lead to harsher growing conditions following snowmelt, which may reduce plant fitness and nutrient
availability.
68
49- Indirect effects of tourist resort settlement on reproductive
success of alpine wildlife: a case study of the black grouse (Tetrao
tetrix)
Wittwer, Gregor1; Patthey, Patrick1; Arlettaz, Raphaël1, 2; Marin, Stéphane3; Magnani, Yann3
1
Zoological Institute, Division of Conservation Biology, University of Berne, Erlacherstrasse 9a,
3012 Bern, Switzerland
2
Swiss Ornithological Institute, Valais Field Station, Nature Centre, CH-3970 Salgesch, Switzerland
3
Office National de la Chasse et de la Faune, 90 impasse des Daudes - BP 41, 74320 Sévrier, France
Alpine ecosystems face an increase of tourism and related recreational activities over the last decades.
Human-induced modifications of landscape may influence wildlife population dynamics directly through
habitat quality changes or indirectly through stress-induced physiological and behavioural modifications
or through altered interspecific interactions. Tourist activities and infrastructure may influence the
distribution and abundance of mobile generalist predators and may negatively affect survival and fitness
of wildlife populations due to frequent disturbance. We investigated possible human-induced impacts on
wildlife in Alpine ecosystems with the Black grouse (Tetrao tetrix) as emblematic model species.
The aim of this study is to test whether a) nesting success and b) reproductive success of Black grouse is
lower in study sites with than without tourist resort settlement (“anthropized habitats” vs. “natural
habitats”). We estimated nesting success with an experimental approach based on the predation rate of
artificial nests and reproductive success based on Black grouse chick counts with the help of trained dogs
in 50 study sites in Valais and Vaud, Switzerland and the French Alps. Explanatory variables were avian
and mammalian predator indices (counts of corvids and faeces of mammals) and human disturbance
indices (counts of tourists, road and skilift density, hunting pressure). We assessed the relative influence
of avian and mammalian predator indices as well as human disturbance indices to a) artificial nest fate
and b) the number of chicks, while controlling for the effect of habitat type.
Predator abundance did not differ significantly between “anthropized” and “natural habitats”. However, it
had a negative effect on artificial nest fate in combination with human disturbance estimations. In contrast
human disturbance estimations had a major effect on Black grouse reproductive success. This study
shows that indirect effects of tourist resort settlement are critical factors for Black grouse reproductive
success and hence may affect the population dynamics of this species. It is a first step to suggest
conservation measures for wildlife populations in Alpine ecosystems.
69
50- Fire ant genomics
Wurm, Yannick; Wang, John; Jemielity, Stephanie; Keller, Laurent
Department of Ecology and Evolution, Université de Lausanne, Biophore, 1015 Lausanne, Switzerland
In many social insect species including ants, individuals show dramatic morphological, physiological, and
behavioral specialization to their roles. To help understand the molecular mechanisms behind these
characteristics, we developed a normalized EST library of 22,560 clones for the fire ant Solenopsis
invicta. They were partially sequenced and assembled into 11,934 putatively different transcripts. Here,
we describe an ongoing effort to characterize these sequences using bioinformatic annotation and
comparative genomic tools.
We found that 3950 of our ant transcripts showed significant homology to the nr database of known
genes. Among our ant transcripts, 652 were homologous to functionally annotated genes, encompassing a
broad range of molecular functions and biological processes. However, 54% of our putative transcripts
did not show homology to known genes. Through stringent comparison of these sequences with the
genome of another social Hymenoptera, the honeybee, we identified 17 potentially Hymenoptera-specific
sequences. Additionally, preliminary analysis indicates that several gene families have undergone
lineage-specific expansion in ants.
51- High frequency of multiple paternity in the largest rookery of
Mediterranean loggerhead sea turtles
Zbinden, Judith A. 1; Largiadèr, Carlo R. 2; Leippert, Fabio1; Margaritoulis, Dimitris 3; Arlettaz, Raphaël 1
1
Switzerland
2
Institute of Clinical Chemistry, Inselspital, University Hospital, University of Bern, 3010 Bern, Switzerland
3
ARCHELON, the Sea Turtle Protection Society of Greece, Solomou 57, 10432 Athens, Greece
Mating systems are a central component in the evolution of animal life histories. Sea turtles mate at sea,
where they are difficult to observe. For such species, genetic paternity analysis is of particular use to gain
insights into aspects of their reproductive behaviour. We investigated patterns of multiple paternity in
clutches of loggerhead sea turtle (Caretta caretta) females in the largest Mediterranean rookery using
four highly variable microsatellite loci. We tested for a relationship between the number of fathers
detected in clutches and female body size. We also investigated whether clutch hatching success was
related to the number of fathers discovered in clutches. More than one father was detected in the clutches
of 14 out of 15 females, with four females having mated with at least five males. Paternal skews within
clutches were relatively low. The number of detected fathers was positively correlated with female size.
Hatching success was significantly higher in clutches sired by three or more males compared to clutches
sired by one or two males. This indicates that males may prefer to mate with large, productive females,
which, in turn, may select better nest sites leading to higher hatching success. The high rate of multiple
paternity indicates that the population currently is not male-limited and hence a somewhat increased
female-bias of the sex ratio due to global warming (sea turtles have temperature-dependent sex
determination) may not become a problem in this rookery. Finally, the observed polyandry pattern may
considerably reduce founder effects when new nesting habitat is colonised by few females.
70
52- Phylogeography and population structure of Trypanosoma
brucei
Balmer, Oliver1,3; Caccone, Adalgisa1,2
1
Yale University, Department of Ecology and Evolutionary Biology, New Haven, CT 06511, USA
Yale University, YIBS-Molecular Systematics and Conservation Genetics Lab, New Haven, CT 06520, USA
3
Present address: University of Basel, Zoological Institute, 4051 Basel, Switzerland
2
Human African trypanosomosis (sleeping sickness) has seen a dramatic resurgence over the past decades
due to limited resources and civil unrest in disease-endemic countries. Poor understanding of the natural
dynamics of the parasite – despite over a century of sleeping sickness research – impedes effective
control. Because the parasite cannot be directly observed, indirect genetic approaches are necessary to
infer parasite dynamics. We combined microsatellite with mitochondrial sequence data to investigate the
population structure and phylogenetic relationships of Trypanosoma brucei and two closely related
species to gain insights into the patterns of spread and relatedness in these parasites. There was strong
differentiation of parasites from different taxonomic units or geographical locations and significant
deviations from Hardy-Weinberg and linkage equilibrium in virtually all T. brucei taxa and all locations.
However, no clear-cut overall correlation between parasite genotype and either geography or taxonomy
was found. These findings suggest that T. brucei consists of many isolated clonal lineages that have been
spread extensively over Africa by animal host migration or vector dispersal, repeatedly recombining
across the boundaries of the claimed subspecies and leading to a very complex population structure. This
may in part explain why it has been difficult to assign parasites to specific taxonomic units. The data
indicate that T. b. gambiense group 1, the parasite responsible for the typical chronic disease in West and
Central Africa, is a young lineage derived from T. b. brucei and has recently expanded throughout West
and Central Africa, further suggesting that T. brucei can spread over much larger distances than
commonly assumed. The concept of localized discrete disease foci that is commonly aserted for T. brucei
may therefore be inappropriate and may misguide control efforts. The results also imply that sexual
recombination between strains occurs rarely in the field despite ample contact in multiple infections.
71
53- Community and functional response of invertebrates to
knotweed (Fallopia japonica) invasion and management
Moretti, Marco1; Patocchi, Nicola2; Schaffner, Urs3; Gerber, Esther3
1
WSL Swiss Federal Research Institute, Ecosystem Boundaries, Research Unit, Bellinzona, Switzerland
Fondazione Bolle di Magadino, Magadino, Switzerland
3
CABI Switzerland Centre, Delémont, Switzerland
2
Little is known about the impact of exotic invasive plant species on invertebrate communities in the
invaded range. In 2005 we started an experiment to assess the effect of exotic knotweed (Fallopia
japonica) on arthropods, e.g. isopods, centipedes, spiders, beetles and ants, in vegetation along a seminatural water course in Southern Switzerland. We assessed species richness, community assemblage and
functional trait composition for 5 sites each in (i) areas invaded by Fallopia; (ii) open wetland habitat
dominated by grasses and forbs and (iii) dense scrubland. In addition, 5 areas dominated by Fallopia were
regularly cleared from April onwards and included in the study. Between April and September
invertebrates were sampled in pitfall traps and a total of 21.150 individuals captured. Here we present
preliminary results for spiders, and carabid beetles. Overall species richness was not affected by Fallopia,
while community and functional traits composition differed significantly among the 4 habitat types. After
one year of mechanical control, managed sites showed a species composition more similar to the openand scrubland than to sites invaded by Fallopia. We assume that change in the dominance hierarchy as a
consequence of both Fallopia invasion and mechanical control might be responsible for the observed
difference in epigaeic species composition. Nevertheless, both species and functional compositions at the
Fallopia-free sites revealed overall suboptimal ecological conditions for wetland species, due probably to
a lack of natural dynamic. Invasion by Fallopia sp. is likely to further accentuate the degradation of this
formal wetland habitat. We suggest that regular mechanical control and mosaic management are
important to mimic natural dynamic and to prevent further invasion of high-value habitats.
72
biology07 – Darwin's Birthday Party/replacement keynote
Having dinner with Darwin: biodiversity on the menu
Tack, Jürgen
Institute of Nature Conservation, Brussels, Belgium
Biodiversity loss is a serious threat to our planet but at the same time it is much more difficult to
communicate the research behind this conclusion than explaining climate change.
Three years ago Dr. Jurgen Tack took up the challenge to develop a product to communicate biodiversity
loss and the research involved to a wide audience. Looking around in bookshops he came to the
conclusion that people were very interested in cookery books. Because cooking is a true biodiversity
related activity he decided to write a cookery book. It became the first cookery book using environmental
indicators for each of the recipes described. But the book also informs on all kinds of biodiversity related
threats: GMOs, invasive species, habitat fragmentation, biodiversity use.
The cookery book became a bestseller in Belgium and the Netherlands getting several awards for science
communication. Translations in different languages are foreseen in the near future. But specially for
Darwin's birthday party he will inform us on what the environmental impact is of the food we eat and
why the conservation of biodiversity is so important for the food we will eat in the future.
What do hard-working women have to do with healthy forests? or
Of trees, fungi, nematodes, beetles, mistletoes, birds, goats, farmers,
foresters and …. global warming
Dobbertin, Matthias*; Rigling, Andreas; Wohlgemuth, Thomas
Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland
*Correspondence: [email protected]
Scots pine (Pinus sylvestris L.) forests cover the slopes of dry inner-alpine valleys of the European Alps.
Unusually high tree mortality of Scots pine has recently been observed in several of these inner-alpine
valleys. In the Swiss Canton Valais, locally, up to half of the Scots pine died between 1996 and 2006.
The extent and the exact causes of the present decline have been investigated by the Swiss Federal
Research Institute WSL using an inter-disciplinary approach.
We utilized permanent plots, long-term monitoring sites, several new experimental sites and historic
analysis to examine the possible causes. Pine percentage in the forest of Valais has decreased over the last
20 years by 13 percent due to high mortality and insufficient regeneration, while downy oak (Quercus
pubescens Willd.) is increasing in abundance. Pine mortality is usually triggered by drought years and hot
summers and is highest at altitudes below 1100 m and on sites prone to water shortage.
Increasing shrub cover, competition by hardwoods and mistletoe parasites, partially due to a change in
land use, i.e. grazing, litter raking and forest management, contribute to increasing drought stress and
higher mortality of the pines. Bark beetles and other phloeophagous beetles, nematodes, black stain fungi
have been identified on dying and moribund trees. But no insect species or pathogens have been shown
to be a primary cause of pine mortality. Increasing temperature and low annual precipitation since the mid
1980s have however increased the transpiration demands of the pines, making them more susceptible to
pathogens, mistletoe and beetle infestations, while certain competing hardwoods, such as downy oak,
seemed to me more tolerant. If temperature continues to increase pines at low altitudes will be replaced
by other species, such as downy oak.
This keynote replaced the one by Tord Snäll who was unable to attend the conference.

biology07

Transcription

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