Observation of Sooty and Eleonora`s Falcons in Madagascar

Transcription

Observation of Sooty and Eleonora`s Falcons in Madagascar
151
Observation of Sooty and Eleonora’s Falcons
in Madagascar
Sama Zefania
Project ZICOMA BP 1074, Antananarivo (101), Madagascar
Abstract
Of the 281 bird species found in Madagascar, 26 are non-breeding visitors. Two of
these are migratory birds: Eleonora’s falcon and the sooty falcon. They can be found
in almost all habitats, according to food availability. Flying insects (particularly
dragonflies) constitute their main food. They hunt in groups and are particularly
active during the evening. They can be observed foraging on the large numbers of
insects that emerge after the rains. They are extremely silent and agile while hunting,
catching prey in their talons in mid-air and eating it in flight, for periods of up to
20 minutes. Feeding habitats comprise both natural areas and the man-modified
coastal plain, incorporating large agricultural areas, rice fields, and forest clearings
or secondary forest as well as the lake and city of Tananarive. The two species winter
mainly in Madagascar and breed mainly in the Mediterranean region. Eleonora’s
falcon is most common in the eastern part of the high plateau and less so in the
west. It is found from sea level to 2,000m. Most of the 37 sites where its presence
has been recorded are in the eastern humid forest. The sooty falcon is most common
in the south and west and may migrate in large groups over the high plateau in
April (33 sites recorded). Both species occur in Madagascar from late October to
late April or early May.
These species are not globally threatened in Madagascar, but Eleonora’s falcon is
classified as rare in Europe and loss of forest habitat and persecution pose a minor
threat to it, although it is still able to use the artificial urban and rural landscape
for feeding. Total population size remains to be estimated, but one to three individuals
have been seen flying over each site where the species has been recorded. The world
population of Eleonora’s falcon is 6250 pairs. The sooty falcon is particularly
abundant north of Morondava and near Andranomena, where hundreds may be
seen together.
Despite the interest to study in the migration route and wintering quarters of these
two migratory species in Madagascar, the subject has been neglected in research.
Lack of information about the species constitutes an obstacle in formulating a plan
of action for their conservation.
Résumé
Sur les 281 espèces d’oiseaux à Madagascar,26 sont des visiteurs non nicheurs. Deux
de ceux-ci sont des espèces migratrices: Faucon d’Eléonore et Faucon concolore. Ils
peuvent être trouvés presque partout habitat, suivant la disponibilité de la nourriture.
Les Insectes volant (particulièrement Libellules) constituent leur principale
nourriture. Ils chassent en groupe et particulièrement actifs le soir. Ils peuvent être
observés en fourrageant sur un grand nombre d’insectes émergeant après la pluie.
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Ils sont extrêmement silencieux, agile pendant la chasse en attrapant les proies à
l’air par leurs pattes et en les mangeant pendant le vol, pour une période plus de 20
minutes. Les lieux de nourrissage comprennent de plaine côtière à la fois naturelle
et modifiée par l’homme incluant les champs, les rizières, et les forêts claires ou
secondaires), ainsi que des Lacs et le cité d’Antananarivo. Les deux espèces hivernent
principalement à Madagascar et se reproduisent dans la région de méditerranéen.
Le Faucon d’Eléonore est commun dans la partie Est du haut plateau et rare à
l’Ouest. Il se trouve à partir du niveau de la mer jusqu’à 2,000m. Les 37 sites où
l’espèce a été recensée sont de forêt dense humide. Le Faucon concolore est commun
dans le Sud et Ouest et migre en large groupe sur le haut plateau malagasy en avril
(33 sites inventoriés pour l’espèce). Les 2 espèces occupent Madagascar à partir du
mois d’Octobre à la fin avril ou début Mai. Ces espèces ne sont pas globalement
menacées à Madagascar mais le Faucon d’Eléonore est classifié comme rare en Europe.
La perte de l’habitat forestier et la persécution lui constituent une menace faible le
fait qu’il peut utiliser la ville et le paysage rural pour se nourrir. La taille de population
total reste à estimer, mais un à trois individus peut être vus en vol sur chaque site où
les espèces ont été recensées. La population mondiale de Faucon d’Eléonore est de
6250 paires. Le Faucon concolore est particulièrement abondant au nord de
Morondava et proche d’Andranomena, où nous avions observé ensemble une
centaine d’individus.
Malgré l’intérêt d’étudier le trajet de migration et les quartiers d’hivernage de ces
deux espèces migratrices à Madagascar, le sujet a été négligé dans la recherche. Le
manque d’information sur les espèces constitue un obstacle pour formuler un plan
d’action pour leur conservation.
Introduction
Madagascar is located between latitudes 11°57' and 25°37' south (Langrand 1995) in
the Indian Ocean region of south-east Africa. Of the 281bird species of Madagascar,
there are 26 non-breeding visitors (Project ZICOMA, 1999). Two of these are migratory
birds wintering mainly in Madagascar: Eleonora’s falcon and the sooty falcon (Morris
1998). The two species inhabit most areas, according to food availability (mainly flying
insects). Habitats include wetlands (lakes, rivers, rice paddies), baobab trees, forest, woodland,
grassland and rural and urban areas, including the airport. (Walter, 1979 Safford 1990,
Morris 1998, Sinclair 1998). Flying insects constitute their main food and according
to some observations, they occasionally prey on small birds over the lake as well. (Walter
1979, Langrand 1995, Morris 1998, Ristow 1999). They hunt in groups and are particularly
active during the early evening. They can be observed foraging on the large numbers
of insects that emerge after the rains. Their local distribution varies according to food
availability. Their hunting movement is extremely silent and agile, catching the prey in
their talons in mid-air and eating it while in flight. However, they are unable to pursue
small birds in the vegetation. The species winter mainly in Madagascar and breed mainly
in the Mediterranean region. Eleonora’s falcon is most common in the eastern part of
the high plateau and less so in the west. The sooty falcon is most common in the south
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and west; it migrates in large loose groups over the high plateau in April. The two species
occur in Madagascar from late October to late April or early May (Morris 1998).
These species are not threatened in Madagascar but Eleonora’s falcon is classified as rare
in Europe (Morris 1998, Ristow 1999) and loss of forest habitat poses a minor threat
in Madagascar (Walter 1979, Ristow 1999). They are found from sea level to 2,000m.
Overall population size has not yet been estimated, but groups of 3-21 Eleonora’s falcon
have been spotted in areas of the east biome. The world population of Eleonora’s falcon
is 6250 pairs (Ristow 1992-94).
Methods
Following the bird inventory method of Mc Kinnon, we employ direct observations to
take census of the species in order to study their distribution. Counts have been made
at preferred feeding locations, such as the rice fields of Antananarivo, night light projectors
at Mahamasina stadium (Antananarivo), Antananarivo’s airport, and around the baobab
trees in the Morondava region.
Results
Habitat: The species can be found whenever there is a presence of large numbers of
flying insects, such as over rice fields, around lighting projectors at night, at the airport,
above the forest, in woodland, grassland, wetlands, and even in the city.
Feeding and behaviour: Flying insects (particularly dragonflies) constitute their main
prey. The species hunt in groups and are particularly active during the early evening
but the sooty falcon is also a nocturnal predator, observed hunting insects around a lighting
projector. The species can be found in different regions at different stages of its migration
according to the availability of food, as shown below.
Rice fields at Antananarivo: In February and March 2001, one Eleonora’s falcon and
two sooty falcons regularly hunted at around 18:00 to 18:24 over rice fields north of
the high plateau. During the twenty minute average period, these three birds flew continuously
over the two hectare area, between one and two metres above the ground. They displayed
swift and acrobatic motion, silent, never coming into contact with one another, and
catching their dragonfly prey in their talons. They ingested the prey on the wing, slowing
their movements. Neither species was observed active in these fields in the morning.
Mahamasina stadium (lighting projector), by night at Antananarivo: In April 2001,
two to 15 sooty falcon were observed flying around one lighting projector at Mahamasina
stadium from 22:40 to 23:10, catching many flying insects there. We determined the
species of these insects from the specimens collected at the base of the pole after their
death following contact with the lit projector; species included moth, green grasshopper,
flying ant, etc. The sooty falcon can therefore also be considered a nocturnal feeder (Tananarive).
Antananarivo airport: On the morning of April 28, 2001, at around 06:00, we registered
14 sooty falcons at Ivato airport (Antananarivo). They flew over the aircraft parking
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areas to catch flying insects, and sometimes remained near the aircraft. This species is
therefore also active in the early morning at this location. Because there are lighting projectors
here at night, which attract many flying insects, it is possible that the sooty falcon may
be found then too.
Baobab tree in Morondava region On 9 April 2001, we observed 19 specimens of sooty
falcon on a baobab tree and on eucalyptus along the road to Belo Tsiribihina, approximately
5 km from National Road 35. The birds were observed between 13:30 to 14:30. The
species is known to roost on both baobab and eucalyptus, sometimes flying over the
adjacent savannah area. The species is thus active there in the early afternoons. The Morondava
region appears to constitute an interesting area for future study of the sooty falcon in
its natural habit.
Table 1: The sites where the two species have been recorded in Madagascar
Endemic bird
areas
Sites recorded
Eleonora’s falcon
Biome
Presence
East West
Eastern humid
forest
X
FC Ankazomivady
PN Andringitra
X
PN and RS Montagne
d’ambre
PN Mantadia and
X
RS Analamazaotra
PN Marojejy
X
PN Masoala
X
PN Midongy-south
X
PN Ranomafana
X
PN Zahamena
X
RS Ambatovaky
X
RS Ambohitantely
X
RS Anjanaharibe-south X
RS Mangerivola
X
RS Manongarivo
X
SIB Manjakatompo
X
RS Daraina
RS Nosy Mangabe
X
PN Mananara-North
RS Ankarana
Sub-total
15
Sooty falcon
Biome
East
Presence
West
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
2
17
11
X
X
X
2
13
Endemic bird
areas
Sites recorded
Eleonora’s falcon
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Biome
Presence
East West
Western
deciduous
forest
South spiny
forest
Western
wetland
Eastern wetland
TOTAL
East
Presence
West
Complex Forest
Menabe
FC Tongay
PN Isalo
RNI Ankarafantsika
and SF Ampijoroa
RS Ankarana
Complex Forest
Kirindy South
PN Isalo
PN Zombitse-Vohibasia
RS Bemarivo
Sub-total
0
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
5
5
7
7
PN Andohahela
RS Cap Ste-Marie
Complex Forest
Mahafaly Plateau
Menarandra Forest
PN Andohahela II
RS Beza-Mahafaly
Sub-total
X
X
X
X
X
X
X
X
X
X
X
X
X
X
5
5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
0
2
2
ZH Complex
Manambolomaty and
FC Tsimembo
ZH Delta Tsiribihina
Complex RC lake
Ihotry, Delta Mangoky,
Lakes Anony-Erombo
PN Bay of Baly
RC Lake Sahaka
ZH South-west coast
RNI Tsimanampetsotse
Sub-total
0
Lake Alaotra
X
Lake Itasy
Sub-total
1
X
X
X
X
16
2
0
0
2
0
X
X
X
0
1
2
0
2
11
27
13
21
34
10 other sites (towns): Ambanja, Vohemar, Majunga,
Morondava, Tamatave, Ihosy, Tulear, Antananarivo,
Fort-Dauphin, Port-Berger
TOTAL
Sooty falcon
Biome
37 sites
7
7
X
X
1 other site
(town):
Antananarivo
35 sites
Distribution: Table 1 shows the sites where the two species have been recorded in Madagascar:
FC = Classified Forest
PN = National Park
RS = Special Reserve
SF = Station Forest
ZH = Wetlands
SIB = Biological Interest Sites
RC = Hunting Reserve
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Eleonora’s falcon was recorded at 37 sites including 27 sites of Endemic Bird Areas (EBA)
and 10 others sites in the town. The 27 (EBA) sites included 17 in eastern humid forest,
5 in western deciduous forest, 2 in the south spiny forest, 1 in eastern wetland, and 2
in western wetlands. The species occurs mainly in the eastern part of Madagascar (16
sites on the east biome against 11 sites on the west) and is scarce in the west and south
(Fig. 1).
The sooty falcon was recorded at 35 sites including 34 in EBA and 1 in the town. The
34 EBA sites included 13 in the eastern humid forest, 7 in the western deciduous forest,
5 in the southern spiny forest, 7 in western wetlands and, 2 in eastern wetland. The
species is common mainly in the south and the west wetland regions (21 sites on the
west biome against 13 sites on the east). Many individuals can be seen at several sites
in south-west Madagascar (Morondava region). Although also found in the eastern region,
it is generally less numerous there (Fig. 2).
Current population density and Status: Not yet evaluated. The two species do not seem
to be threatened, having recourse to rural and urban areas for their food. Their wild
habitat is threatened, however, as a result of shifting agriculture, burning of vegetation
and deforestation. Gathering firewood, forest grazing, and selective logging and harvesting
of local flora for food and medicaments, constitute additional threats, as do natural disasters
(ZICOMA 1999).
Conclusions
There remain many aspects of these two migratory species in Madagascar that are still
unknown. Further study should include identifications of migratory routes and strategies,
in order to discover how the birds reach their winter quarters.
• Determination of wintering areas in Madagascar, including distribution and population
size.
Table 2: Comparison of the two species
Characteristics
Eleonora’s falcon
Sooty falcon
Field identification
Adult pale phase
• Moustache, throat pale
• Underpart rufous with
dots and stripes
Adult dark phase :
• Dark
• Bars beneath tail
Juvenile
• Bars beneath wing and
under tail
• Underpart pale with
stripes.
Adult
• Grey
• Two middle feathers of
tail longer in flight
Juvenile
• Tip of tail fairly
conspicuous, pale
• Underpart more heavily
streaked
• No bars beneath
tail or under wing
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Characteristics
Eleonora’s falcon
Sooty falcon
Habitat
Everywhere according to availability of food (flying insects)
such as wetland, forest, woodland, grassland, rural and
urban areas.
Feeding behavior
• Flying insects
• Flying insects (dragonflies)
(particularly dragonfies),
• Birds according to a
previous report, but never
observed catching birds in
Madagascar. It catches
birds in its breeding sites
Behaviour: the species hunt in groups. They are active in the
evening and even by night according to the availability of
food. They catch the prey in their talons and eat it during
continuous flight, in up to twenty minute periods, never
stopping. Their movement is silent and agile.
Distribution
Mainly in the eastern part
of Madagascar
Common in the south and
west of Madagascar
(numerous individuals in
the Morondava region)
Range
Wintering sites
Mainly Madagascar
Breeding sites
Mediterranean region
Altitude
0 m to 2000 m
Threats
Loss of forest habitat, but this may not be major threat
because the species can find their food elsewhere.
Population size
• National total population • National total population
is not yet evaluated
is not yet evaluated
• 3 to 21 individuals in the • Tens to hundreds of
east biome
individuals may be seen in
• Assuming a minimum of
some sites (Morondava
one individual per site
region).
recorded, we can estimate • Assuming a minimum of one
a minimum population of individual per site recorded
37 individuals
we can estimate a minimum
• The world population is
population of 34
6250 pairs
Status
• Not known globally.
• Rare in Europe.
Not known globally.
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Figure 1: Distribution by
biome of Eleonora’s Falcon
in Madagascar (Project
ZICOMA 2000)
Figure 2: Distribution by
biome of Sooty Falcon in
Madagascar (Project
ZICOMA 2000)
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• Definitions of ecological requirements in the areas of winter diet, the relationship
between main insect prey species and vegetation, evaluation of present and future
status of habitat types, and assessing potential effects of environmental changes on
insects and other food sources for the falcons.
• Ecological research should include the study of roosting sites, pellet collection, study
of daily habits, timing weather conditions and biotope observations.
• Feeding habits should be studied in relation to habitat type, time, types, number,
behaviours, interactions, and the presence of other species. DNA analyses should be
made of fresh moult, feathers, blood, or tissue samples.
Finally, it is also of importance to evaluate the significance of habitat loss, persecution,
and other threats. While the ongoing loss of forest in Madagascar has been widely documented,
the effect of this environment change on insect life, and consequently on a food source
for the falcons, has yet to be studied.
Acknowledgements
I am grateful to Dr. Yossi Leshem and all his staff for their great efforts in organising
this meeting. I also acknowledge all the staff of the ZICOMA project for the realisation
and results of this work. Special thanks to Dr. Frank Hawkins for his help and support
in the preparation of this publication.
References
Langrand, O. 1995. Guide des Oiseaux de Madagascar. Delachaux et Niestlé. LausanneParis.
Morris, P.A.J. & Hawkins, A.F.A. 1998. A photographic field guides to the Birds of
Madagascar. Pica Press, East Sussex, U.K.
Projet ZICOMA. 1999. Les Zones d’Importance pour la Conservation des Oiseaux à
Madagascar.
Projet ZICOMA, Antananarivo, Madagascar.
Projet ZICOMA. 2000. Consultation des bases de données. Projet ZICOMA Antananarivo
Madagascar.
Ristow, D. & Wink, M. 1992-94. Distribution of non-breeding Eleonora’s falcon Falco
eleonorae. II-Merill No. 28. Neubiberg Germany
Ristow, D. & Bourdakis, S. 1999. International Species Action Plan Eleonora’s falcon
Falco eleonorae. Final Draft. BirdLife Greece, Germany.
Safford, R.J. & Duckworth, J. W., eds 1990. A Wildlife Survey of Marojejy Nature Reserve,
Madagascar: Report of the Cambridge Madagascar Rainforest Expedition. ICBP Study
reports no. 40, International Council for Bird Preservation, Cambridge, and U.K.
Sinclair, I. & Langrand, O. 1998. Birds of the Indian Ocean Islands. Struck publisher,
Cape Town, South Africa.
Walter, H. 1979. Eleonora’s falcon. Adaptation to prey and habitat in social raptor. University
of Chicago Press.

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