Climatic changes in Holocene Horn of Africa and animals

Climatic changes in Holocene Horn of Africa
and animals exploitation by human societies
Joséphine LESUR-GEBREMARIAM
UMR 5197, Archéozoologie, histoire des sociétés
humaines et des peuplements animaux – MNHN
UMR 5197
ARCHÉOZOOLOGIE,
histoire des sociétés humaines
et des peuplements animaux
1
Environmental
Environmental diversity
diversity in
in the
the Horn
Horn of
of Africa
Africa
Afro-alpine
Afro-alpine steppe
steppe
desert
desert
Moun
Mountain
tainforest
forest
Savannah
Savannah
IE
IE
AALL
M
M
O
SSO
UMR5 19 7
UMR5 19 7
AR CHÉ OZO OLO GIE,
R
OZO
OLO
GIE,
hi A
st
oi C
reHÉ
des
soci
ét és
humai nes
stoipeupl
re desem
soci
ethi
des
entést és
anihumai
maux nes
et des peupl ement s animaux
Ethiopia and more generally the Horn of Africa shows a great diversity of landscape and environments. This
region is shared between mountainous areas, the Ethiopian and Somali highlands, and arid plains with the
coastal plains, the Danakil depression and the Rift Valley. Moreover the position of the Horn in tropical
latitudes and the great altitudes variations have favoured the development of a great diversity of landscape
going from the afro-alpine steppe to desert with also mountain forest and different types of savannah. The
region is isolated from other parts of the continent by natural barriers such as the highlands and from Arabic
peninsula by the Red Sea. All those elements have influenced the development and the mobility of past and
present human cultures.
2
Climatic evolution in the Horn of Africa during Holocene
More humid
Wet phase
Wet phase
Arid phase
Arid phase
Lacustrine
episod
More arid
7 000
6 000
5 000 4 000
3 000
2 000
1 000 0 1 000
2 000
(Dates BC/AD)
(from Gasse et al., 1975)
UMR5197
ARCHÉOZOOLOGIE,
histoire des sociétés humaines
et des peuplements animaux
Many recent studies on the lacustrine sediments, pollen sequence and geomorphologic data contributed to the
reconstruction of the paleo-climate of the Horn of Africa, especially of the lakes of the Rift Valley (Gasse
1975; Grove et al. 1975; Williams & Adamson 1980; Beraki et al. 1998; Mohammed & Bonnefille 1998;
Chalié & Gasse 2002; Lamb et al. 2002). These data show that, until around 7,000 BC, humid conditions
prevailed in the region. Then a dry phase began with an optimum around 5,500 BC. It is followed from 5,000
BC by a new wet phase which ended around 3,000 BC. From that period starts the aridification that
continues until today. Only a short lake episode is noticeable during the 1st millennium AD.
Those different paleoclimatic phases provoked recompositions of biodiversity and different ecological
pressure according to environmental conditions. The evolution of human societies during the Holocene
shows therefore many different patterns characterized by changing and restrictive environmental conditions.
References:
Gasse, F. 1975. L'évolution des lacs de l'Afar central du Plio-Pléistocène à l'actuel. Paris: Mémoire de doctorat,
Université de Paris VI.
Grove, A. T., Street, F.A. and Gouldie, A. S. 1975. Former Lake Levels and Climatic Changes in the Rift Valley of
Southern Ethiopia. Geographical Journal 141, 177-202.
Williams, M. A. J. and Adamson, D.A. 1980. Late Quaternary depositional history of the Blue and White Nile rivers in
Central Sudan, pp. 281-304 in Williams, M.A.J and Faure, H.(eds.) The Sahara and the Nile. Rotterdam: Balkema.
3
Beraki, O., Brancaccio, L., Calderoni, G., Coltorti, M., Dramis, F. and Mohammed, U. 1998. The Mai Mekden
Sedimentary Sequence: A Reference Point for the Environmental Evolution of the Highlands of Northern Ethiopia.
Geomorphology 23, 127-38.
Mohammed, M. U. and Bonnefille, R. 1998. A late Glacial/late Holocene pollen record from a highland peat a Tamsaa,
Bale Moutains, south Ethiopia. Global and Planetary Change 16-17, 121-9.
Chalié, F. and Gasse, F. 2002. Last Glacial-Holocene diatom record of water chemistry and lake level change from the
tropical East African Rift Lake Abiyata (Ethiopia). Palaeogeography, Palaeoclimatology, Palaeoecology 187, 259-83.
Lamb, A. L., Leng, M. J., Lamb, H. F., Telford, R. J. and Mohammed, M. U. 2002. Climatic and non-climatic effects on
the d18O and d13C compositions of Lake Awassa, Ethiopia, during the last 6.5 ka. Quaternary Science Reviews 21,
2199-211.
4
Ethiopian highlands: Moche Borago
MOCHE BORAGO
M
SO
E
LI
A
To illustrate these evolutions and human adaptations, we will present archaeozoological results from 3
archaeological sites occupied during the second half of Holocene.
Moche Borago is a large rock shelter, located in the Wolayta, on the south-west edge of the Ethiopian
highlands.
5
Ethiopian highlands: Moche Borago
View of the shelter
MOCHE BORAGO
View of the Mount Damota with
location of Moche Borago
It is 2 300 m a.s.l., on the western slope of Mount Damota, a volcanic complex that reaches its highest point
at 2 908 m. The site is located halfway up a 20 m high cliff, which is the abrupt starting point of a steepsided valley.
6
The
The rock
rock shelter
shelter of
of Moche
Moche Borago
Borago
Location
Location of
of excavated
excavated areas
areas
View
View of
of the
the shelter
shelter
Test
Testpit
pit11
Test
Test pit
pit 22
Test
Test pit
pit 33
The site is a 600 m² shelter with a high ceiling opening on the west side and naturally well lightened. Its floor
is relatively flat and allows a large human group. The site was discovered during a 1995 survey of the
Sidamo region. Four excavation seasons were undertaken between 1998 and 2001 (Gutherz et al. 1998,
2000a, 2000b and 2001). Three areas were chosen for excavating test pits of between 4 and 10 m². These pits
all contained archaeological remains and pits 1 and 3 were especially rich. These last two have been linked
by an intermediate trench during the 2001 season (Gutherz et al. 2002).
References:
Gutherz, X., Jallot, L., Joussaume, R. and Poisblaud, B. 1998. Abri-sous-roche de Moche Borago (Wolayta -Soddo).
Campagne de sondages, novembre 1998. Unpublished Report.
Gutherz X., Jallot, L., Poisblaud, B. and Sordoillet, D. 2000a. Abri-sous-roche de Moche Borago : Campagne de
fouilles, janvier-février 2000. Unpublished Report.
Gutherz, X., Jallot, L., Lesur, J., Pouzolles, G. and Sordoillet, D. 2000b. Abri-sous-roche de Moche Borago (WolaytaSoddo) : Mission de Novembre 2000. Unpublished Report.
Gutherz, X., Jallot, L., Lesur, J., Pouzolles, G. and Sordoillet, D. 2001. Abri-sous-roche de Moche Borago (WolaytaSoddo) : Mission de Décembre 2001. Unpublished Report.
Gutherz, X., Jallot, L., Lesur, J., Pouzolles, G. and Sordoillet, D. 2002. Les fouilles de l'abri-sous-roche de Moche
Borago (Soddo, Wolyata). Premier bilan. Annales d'Ethiopie XVIII, 181-190.
7
Stratigraphy of Moche Borago
Phase 3
1 480 ± 60 BP (447-662 AD)
Phase 2
2 180 ± 45 BP (485-55 BC)
4 370 ± 70 BP ( 3330-2787 BC)
Late Phase 1
5500 BP
Intermediate Phase 1
7500 BP
Early Phase 1
Pleistocene sequence
Holocene sequence:
6th mill. BC → 1st mill. AD
The stratigraphy shows Pleistocene and Holocene occupation levels. This last sequence, on which this
presentation will focus, shows an occupation going from the 6th millennium BC until 5th century AD. All
the archaeological levels alternate with tephra layers suggesting a periodic but strong volcanic activity until
the first millennium AD (Gutherz et al. 2002).
References:
Gutherz, X., Jallot, L., Lesur, J., Pouzolles, G. and Sordoillet, D. 2002. Les fouilles de l'abri-sous-roche de Moche
Borago (Soddo, Wolyata). Premier bilan. Annales d'Ethiopie XVIII, 181-190.
8
Faunal spectrum of Moche Borago
E.Phase 1 I. Phase 1 L. Phase 1 Phase 2 Phase 3
NISP=236 NISP=26956 NISP=4346 NISP=679 NISP=713
Buffalo
Other Bovidae
Suidae
Lagomorphe
Procavidae
Cercopithecidae
Carnivore
UMR5197
ARCHÉOZOOLOGIE,
histoire des sociétés humaines
et des peuplements animaux
In all phases, faunal spectra are clearly dominated by bovid and especially by the African buffalo which
represents 35 to 80% of the Number of Identified Specimens (Lesur 2007; Lesur et al. 2007). Other bovids
consist of one species of Neotragini, one of Gazelle, two of Tragelaphini (a bushbuck and probably a
mountain nyala) and waterbuck.
Aside from bovid, we find many remains of warthog, bush pig and hare. In a more sporadic way, we
determined remains of Procavidae like rock hyraxes, of Primates like galago, baboon, colobe and grivet, and
of Carnivores like spotted hyena, serval, leopard and Vivveridae. Faunal spectra are therefore highly
diversified but dominated by buffalo. One notice also the complete lack of domesticate even during the very
recent phases.
References:
Lesur J., 2007. Chasse et élevage dans la Corne de l’Afrique entre le Néolithique et les temps historiques. Cambridge :
BAR 1602, Cambridge Monographs in African Archaeology 68.
Lesur J., Vigne J.-D. & Gutherz X., 2007 – Exploitation of wild animals in Southwest Ethiopia during the Holocene
(4000 BC – 500 AD): the finds from Moche Borago shelter (Wolayta). Environmental Archaeology 12-2: 139-159.
9
Natural environments
Dense mountain forest
MOCHE BORAGO
Grassy savannah
with dense bush
Mountain savannah and open forest
The location of the shelter on the slopes of a volcano and at an altitude of 2,300 m provided a wide range of
exploitable biotopes. Even though most of the volcano is now under cultivation, remnants of former biotopes
are still visible today. Around the shelter and generally up to 2,200 m elevation, there are still patches of the
dense and evergreen mountain forest with many tropical species that characterize the Ethiopian Woina Dega
(Getahun 1978). The mountain savannah and the deciduous open forest spread on the lower slopes of the
volcano and on the plain between 2,200 and 1,000 m, i.e. the upper Kwolla (Getahun 1978). Below this level,
stretches the grassy savannah with trees and dense bush that extends down to Lake Abaya, 30 km away south
of the site.
References:
Getahun, A. 1978. Zonation of highlands of Tropical Africa: the Ethiopian highlands. Addis Ababa: ILCA.
10
Moche
Moche Borago
Borago :: exploitation
exploitation of
of environment
environment
Semi-arid
Semi-arid
savannah
savannah
Mountain
Mountain Rocky
Rocky
savannah
savannah env.
env.
O
Open
pen
forest
forest
Dense
Dense
forest
forest
Phase
Phase 33
Phase
Phase 22
Late
Late Phase
Phase 11
Intermediate
Intermediate Phase
Phase 11
Early
Early Phase
Phase 11
Mountain
Mountain savannah
savannah and
and open
open forest
forest are
are
the
main
exploited
environments
the main exploited environments
Exploitation
Exploitation of
of environments
environments around
around the
the shelter
shelter
UMR5 19 7
UMR5 19 7
AR CHÉ OZO OLO GIE,
R
OZO
OLO
GIE,
hi A
st
oi C
reHÉ
des
soci
ét és
humai nes
stoipeupl
re desem
soci
ethi
des
entést és
anihumai
maux nes
et des peupl ement s animaux
In order to reconstruct the diversity of the ecosystems exploited by the hunters of Moche Borago in the
course of time, we have allocated each species of the bone accumulation to one or several natural
environments in which they live today, based on the data of Yalden et al. (1996), Kingdon (1997) and Stuart
& Stuart (1997). Five main environments have been defined: semi-arid savannah, mountain savannah, rocky
environments, open forest and dense forest. The relative importance of the different environments for each
phase of occupation of the site has been estimated by the addition of the Number of Identified Specimens
(NISP) of their respective taxa; for two environments, NISP have been divided equally between them (Lesur
2007; Lesur et al. 2007).
We see that, in all the phases, the mountain savannah was the main environment exploited (54 to 70%
following the different phases), followed by the open forest (18 to 24%). The percentage of the semi-arid
savannah is very variable, from 2 to 27%. Dense forest and rocky environments are always very underrepresented.
It appears that the inhabitants of Moche Borago exploited mainly the environments around the shelter, i.e.
mountain savannah and open forests from which they obtained the major part of their animal resources.
References:
Yalden, D. W., Largen, M.J., Kock, D.and Hillman, C. 1996. Catalogue of the mammals of Ethiopia and Eritrea. 7.
Revised checklist, zoogeagraphy and conservation. Tropical Zoology 9, 73-164.
Kingdon, J. 1997. The Kingdon field guide to African Mammals. London: Academic Press.
Stuart, C. and Stuart, T. 1997. The larger mammals of Africa, Cape Town: Struik Publishers.
Lesur J., 2007. Chasse et élevage dans la Corne de l’Afrique entre le Néolithique et les temps historiques. Cambridge :
BAR 1602, Cambridge Monographs in African Archaeology 68.
Lesur J., Vigne J.-D. & Gutherz X., 2007 – Exploitation of wild animals in Southwest Ethiopia during the Holocene
(4000 BC – 500 AD): the finds from Moche Borago shelter (Wolayta). Environmental Archaeology 12-2: 139-159.
11
Moche Borago : exploitation of environment
Semi-arid Mountain Rocky
savannah Savannah Env.
Open
forest
Dense
forest
Phase 3
Phase 2
df = 6
Chi2 = 53.6
p = 8.8 10-9
Late Phase 1
Intermediate Phase 1
96.2 % of Chi2 value
Early Phase 1
Wet phase
Occupation
More humid
Wet phase
Arid phase
Arid phase
Lacustrine
episod
More arid
7 000
6 000
5 000 4 000
3 000
2 000
1 000 0 1 000
2 000 (Dates BC)
(from Gasse et al., 1975)
Few changes over 6 millenniums of occupation
Moreover we notice very few changes during the 6 millenniums of occupation. If we compare with the
different climatic phases presented previously, it seems that the strong fluctuations of the climate during the
Holocene didn’t affect much the natural conditions of this mountainous area. Only the fluctuation of the
semi-arid savannah is statistically significant (Chi²= 53.6; p= 8.8 10-9) and mainly during the early phase I,
that is to say, during the very dry phase at the first half of the Holocene.
Therefore, in this area, altitude and developed hydraulic systems limited draught effects. The occupants of
the site have kept a stable exploitation of animal and the general faunal spectrum remains the same for
millenniums. Buffalo is always the dominant species and some animals that need humid environment such as
the colobe or the bushpig are still represented during the dry phases. In a general way, the site is
characterized by a strong inertia even in cultural features since occupation patterns as well as the lithic
industry show a very strong consistency trough the all occupation (Lesur 2007; Lesur et al. 2007).
References:
Lesur J., 2007. Chasse et élevage dans la Corne de l’Afrique entre le Néolithique et les temps historiques. Cambridge :
BAR 1602, Cambridge Monographs in African Archaeology 68.
Lesur J., Vigne J.-D. & Gutherz X., 2007 – Exploitation of wild animals in Southwest Ethiopia during the Holocene
(4000 BC – 500 AD): the finds from Moche Borago shelter (Wolayta). Environmental Archaeology 12-2: 139-159.
12
Djibouti: Gobaad’s plain
Location of the sites in the Gobaad’s plain
General view of the Gobaad’s plain
UMR5197
ARCHÉOZOOLOGIE,
histoire des sociétés humaines
et des peuplements animaux
Let’s see now the situation in another part of the Horn of Africa, the Gobaad’s plain in west part of Djibouti.
We are this time in a plain environment nowadays arid located at around 30 km from the Lake Abhé. In that
plain, several archaeological sites dated from the Holocene have been excavated and we will present today
the results from two them: Ali Daba and Asa Koma that are located 5 km from one another.
13
55 000
000 ±± 40
40 BP
BP
(3820-3730
BC)
(3820-3730 BC)
Ali
Ali Daba
Daba
General
Generalview
view of
of Ali
AliDaba
Daba
Faunal
Faunal spectrum
spectrum
NISP
NISP == 11 607
607
Buffalo
Buffalo
Hartebeest
Hartebeest
Lesser
Lesser kudu
kudu
Kob
Kob
Hippopotamus
Hippopotamus
Grevy’s
Grevy’szebra
zebra
Black
Black rhinoceros
rhinoceros
Golden
jackal
Golden jackal
Lion
Lion
Leopard
Leopard
Hare
Hare
Greater
Greater flamingo
flamingo
Ali
Ali Daba
Daba22
Ali
Ali Daba
Daba10
10
Cr
Crocodile
ocodile
Tilapia
Tilapia
Catfish
Catfish
Pierced
Piercedtooth
tooth of
ofcrocodile
crocodile
Ali
Ali Daba
Daba 22
UMR5 19 7
UMR5 19 7
AR CHÉ OZO OLO GIE,
R
OZO
OLO
GIE,
hi A
st
oi C
reHÉ
des
soci
ét és
humai nes
stoipeupl
re desem
soci
ethi
des
entést és
anihumai
maux nes
et des peupl ement s animaux
The site of Ali Daba contains 3 loci separated by 30 m each. Each locus presents small pits or spreading that
contains humans and animal bones, fractured, burnt and sometimes worked like this pierced crocodile tooth.
We will not discuss today the meaning of those sites as analyses are not finished. We can only say that those
accumulations don’t seem to be consumption refuses but funerary structures (Duday et al. 2002, 2004, 2006).
In any case, one of these sites is dated from the beginning of the 4th millennium BC and present a faunal
spectrum very diversified with large representation of crocodile, hippopotamus and fishes such as cat-fish
and tilapia. If we see then clearly a preferential exploitation of aquatic environments, other terrestrial species
vouch for hunting in wooded and grassy savannah, like African buffalo, hartebeest, lesser kudu, kob or
Grevy’s zebra, black rhinoceros, lion and leopard (Lesur 2007).
References:
Duday, H., Cauliez, J., Demangeot, C., Gutherz, X., Herouin, S., Lesur, J., Pene, J.-M. & Omar Ismaël, M., 2004 Mission archéologique en République de Djibouti. Mission 2003, réalisée en Janvier-Février 2004. As Eyla - District
de Dikhil. Sites d'Hara Idé 2 et 3 et d'Ali Daba 2 à 12. Mission archéologique franco-djiboutienne, CNRS, Ministère
des Affaires Etrangères, CERD (Djibouti): Unpublished Report.
Duday, H., Cauliez, J., Demangeot, C., Gutherz, X., Herouin, S., Lesur, J., Pene, J.-M. & Omar Ismaël, M., 2006 Mission archéologique en République de Djibouti. Mission 2005, réalisée en Janvier-Février 2006. As Eyla - District
de Dikhil. Sites de Wakrita, Ali Daba 10 et Hara Idé 3. Mission archéologique franco-djiboutienne, CNRS, Ministère
des Affaires Etrangères, CERD (Djibouti): Unpublished Report.
Duday, H., Gutherz, X., Herouin, S., Lesur, J., Pene, J.-M. & Omar Ismaël, M., 2002 -Mission archéologique en
République de Djibouti. Mission 2001, réalisée en Janvier-Février 2002. As Eyla - District de Dikhil. Sites d'Hara Idé 2
et d'Ali Daba 2 à 9. Mission archéologique franco-djiboutienne, CNRS, Ministère des Affaires Etrangères, CERD
(Djibouti): Unpublished Report.
Lesur J., 2007. Chasse et élevage dans la Corne de l’Afrique entre le Néolithique et les temps historiques. Cambridge:
BAR 1602, Cambridge Monographs in African Archaeology 68.
14
Asa
Asa Koma
Koma
3510
3510 ±± 70
70 BP
BP
(( 2040-1680
2040-1680 BC)
BC)
Faunal
Faunal spectrum
spectrum
NISP
=
NISP = 23
23 857
857
Other
Other taxa:
taxa:4%
4%
Fish:
Fish:96%
96%
Cattle
Cattle
Bushbuck
Bushbuck
Dorcas
Dorcas ggazelle
azelle
Salt’s
Salt’s dikdik
dikdik
Donkey
Donkey
Rec onstitu tio n de la a
t ill e des Tila pinii
Rec onstitu tio n de la a
t ill e des Tila pinii
340- 349
340- 349
310- 319
310- 319
L on gueu r T ot al e( m m )
L on gueu r T ot al e( m m )
280- 289
280- 289
250- 259
250- 259
220- 229
220- 229
190- 199
190- 199
160- 169
160- 169
130- 139
130- 139
100- 109
100- 109
0
0
10
10
20
20
30
30
40
40
5 0
5 0
60
60
NR
NR
Re cons titution de a
l taille de s Cla ria s
Re cons titution de a
l taille de s Cla ria s
Lo ngu eur Tot al e ( m m )
Lo ngu eur Tot al e ( m m )
1200- 1299
1200- 1299
1000- 1099
1000- 1099
800- 899
800- 899
600- 699
600- 699
400- 499
400- 499
200- 299
200- 299
0 9
-9
0 9
-9
0
0
1
2
1
2
3
70
70
8 0
8 0
90
90
Side-striped
Side-striped
jackal
jackal
Wild
Wild cat
cat
Hare
Hare
Hippopotamus
Hippopotamus
Bird
Bird
Crocodile
Crocodile
3
NR
NR
UMR5 19 7
UMR5 19 7
AR CHÉ OZO OLO GIE,
R
OZO
OLO
GIE,
hi A
st
oi C
reHÉ
des
soci
ét és
humai nes
stoipeupl
re desem
soci
ethi
des
entést és
anihumai
maux nes
et des peupl ement s animaux
Asa Koma is an open air site located at the top of a small volcano. Excavations unearthed different
occupation structures that testify of seasonal occupation around the beginning of the second millennium BC
(Gutherz et al. 1996, Gutherz & Joussaume 2000). Faunal spectrum is dominated by fishes that represent 96
% of the remains and are represented by tilapia and cat-fish. Among other taxa, we see two domestic species:
cattle and probably donkey but also wild bovids such as dik-dik, dorcas gazelle and bushbuck, and sidestriped jackal and hare (Guérin & Faure 1996, Lesur 2007). The domination of fish remains testify of the
particular interest for fishing that must have taken place in the lake Abhé or in the wadi flowing at the foot of
the site. A detailed study for the reconstitution of fishes sizes highlighted the presence of large size
specimens that could suggest fishing during the rainy season when adults spawn on the lake or wadi shores
(Van Neer & Lesur 2004). Besides this strong exploitation of aquatic resources, the presence of other
animals testifies of hunting in the semi-arid savannah and, to a lesser extent, in a more humid environment
developing along wadis (Lesur 2007).
References:
Guérin, C. & Faure, M., 1996 - Chasse au chacal et domestication du boeuf dans le site Néoltihique d'Asa Koma
(République de Djibouti), Journal des Africanistes 66(1-2): 299-311.
Gutherz, X. & Joussaume, R., 2000 - Le Néolithique de la Corne de l'Afrique, in J. Guilaine (ed) Premiers paysans du
monde, Paris: Ed. Errance.
Gutherz, X., Joussaume, R., Amblard, S. & Mohammed, G. 1996 - Le site d'Asa Koma (République de Djibouti) et les
premiers producteurs dans la Corne de l'Afrique, Journal des Africanistes 66(1-2): 255-97.
Lesur J., 2007. Chasse et élevage dans la Corne de l’Afrique entre le Néolithique et les temps historiques. Cambridge :
BAR 1602, Cambridge Monographs in African Archaeology 68.
Van Neer, W. & Lesur, J. 2004 - The ancient fish fauna from Asa Koma (Djibouti) and modern osteometric data on 3
Tilapiini and 2 Clarias catfish species, Documenta Archaeobiologiae 2: 141-160.
15
Climatic
Climatic evolution
evolution in
in the
the Gobaad
Gobaad
and
and its
its impact
impact on
on fauna
fauna
M o re h u mid
M o re h u mid
M o re a rid
M o re a rid
(Dates BC)
7 0 00 6 000 5 000 4 000 3 000 2 000 1 0 00 0 1 00 0 20 00 (Dates BC)
7 0 00 6 000 5 000 4 000 3 000 2 000 1 0 00 0 1 00 0 20 00
( d’a pr ès Ga sse et a .l , 19 75)
( d’a pr ès Ga sse et a .l , 19 75)
33800
800BC
BC
M or e h um id
M or e h um id
M or e arid
M or e arid
(Dates BC)
)
7 00 0 6 0 00 5 000 4 00 0 30 00 2 000 1 000 0 1 000 2 00 0 (Dates BC
7 00 0 6 0 00 5 000 4 00 0 30 00 2 000 1 000 0 1 000 2 00 0
(d ’ap rè s Gas se et al . , 197 5)
(d ’ap rè s Gas se et al . , 197 5)
~~ 22000
000 BC
BC
UMR5 19 7
UMR5 19 7
AR CHÉ OZO OLO GIE,
R
OZO
OLO
GIE,
hi A
st
oi C
e
rHÉ
des
soci
ét és
humai nes
stoipeupl
e
r desem
soci
ethi
des
entést és
anihumai
maux nes
et des peupl ement s animaux
If we now compare data from those two sites, it seems that Ali Daba, dated around 3800 BC was occupied
during one of the humid climatic phase of Holocene. According to Gasse’s study on the evolution of the
Lake Abhé at that time, it seems that the lake was then nearby the site and wadis were flowing all year round.
Those data correspond absolutely to the fauna from the site that gives the image of a more humid
environment and of developed wooded vegetation. Unfortunately, on this site, no plant remains have been
found to inform us more precisely on the plant species present at that time.
1800 years later, during the occupation of Asa Koma, we are now at the beginning the arid phase from the
second half of the Holocene. Lake Abhé started to recede and wadis were flowing only seasonally. It is
precisely during the rainy season that humans came at the site for fishing but also probably for cattle pasture.
We see then a terrestrial fauna more adapted to drier environment than at Ali Daba with the presence of sidestriped jackal, dorcas gazelle and dik-dik (all those species are still present in this area nowadays). Those
results are confirmed by botanical data since arid steppes plant formations prevailed in the spectrum (Newton
et al. 2008).
Unlike the Ethiopian highlands, we notice this time a great change in the landscape and therefore in the
faunal diversity in a relatively short time, less than 2 000 years.
References:
Newton, C., Thiébault, S., Thiam el Hadji, I., Gutherz, X., Lesur, J. and Sordoillet, D. 2008 - Fuel and Vegetation at
Asa Koma (Republic of Djibouti) during the Second Millennium BC, Journal of African Archaeology 6(1): 87-102.
16
CONCLUSIONS
CONCLUSIONS
Dur
During
ing Holocene,
Holocene, in
in the
the Horn
Horn of
of A
Africa
frica
alternation
alternation of
of humid/arid
humid/arid phases
phases
Reconstruction
Reconstruction of
of animals
animals and
and plants
plants assemblages
assemblages
Variable
Variable impact
impact according
according to
to region:
region:
>> very
weak
in
ethiopian
very weak in ethiopian higlands
higlands
>> strong
strong in
in plains
plains
Evolution
Evolution of
of animals
animals uses
uses in
in areas
areas
where
biodiversity
deeply
changed
where biodiversity deeply changed
Beginning
Beginning of
of husbandry
husbandry in
in semi-desertic
semi-desertic
plains,
plains, probably
probably linked
linked with
with aridification
aridification
AAckn
cknowledgment
owledgment::XX. .Gutherz
Gutherz(P
(Prof.
rof.UU. .Paul
PaulVValery-M
alery-Montpellier
ontpellier III),
III),HH. .DDuday
uday (CN
(CNRS,
RS, UM
UMRR51
5199),
99), JJ.-D.
.-D.Vigne
Vigne (CNR
(CNRS,S,UUMR
MR 5197
5197))
With
Withparticipation
participation of
of CNR
CNRS,S,M
MNH
NHN,
N,M
Minis
inistère
tère des
desAAffair
ffairesesEtrang
Etrangères,
ères, Université
UniversitéPPaul
aul Valery-M
Valery-Montpellier
ontpellier III,
III, l'U
l'UMR
MR 5199
5199 PPACEA
ACEA-- Bordeau
Bordeaux,x,
M
Mais
aison
ondes
desSSciences
ciences de
del'Homme
l'Hommedd 'A
'Aquitaine,
quitaine, Centre
Centre d’Etud
d’Etudeeetet de
deRRecherche
echerchede
deDDjib
jibou
outi,ti,AAuth
uthority
ority for
for Res
Research
earch and
andCConservation
onservation
of
of Cultural
CulturalHHeritag
eritagee(Ethiopie)
(Ethiopie)
UMR5 19 7
UMR5 19 7
AR CHÉ OZO OLO GIE,
R
OZO
OLO
GIE,
hi A
st
oi C
reHÉ
des
soci
ét és
humai nes
stoipeupl
re desem
soci
ethi
des
entést és
anihumai
maux nes
et des peupl ement s animaux
In conclusion, in the Horn of Africa during the Holocene, there was alternation of dry and humid climatic
phases that provoked the reconstruction of animal and plant diversity. However, its impact varied according
to areas. Thus on the Ethiopian highlands, the site of Moche Borago show no noticeable change in the faunal
spectrum during the major part of the Holocene. Conversely, in the Gobaad’s plain in Djibouti we notice a
deep upheaval in biodiversity from 2 000 BC with the presence of fauna and flora typical of arid
environment. We notice therefore an evolution in the exploitation of the faunal diversity in this region with
seasonal occupation of the sites and an intensive exploitation of few species such as fishes at Asa Koma
(Van Neer & Lesur 2004). Finally, it is probable that those climatic changes have also provoked economic
and cultural evolution with especially the beginning of husbandry at Asa Koma since the beginning of the 2d
millennium BC, which is the oldest evidence of husbandry in the Horn of Africa (Lesur 2007).
On the opposite, some mountainous areas with abundant natural resources and where climatic changes had
little impact, such as Moche Borago, were natural refuges where people had a late interest to adopt an
economy of production (Lesur et al. 2007).
In conclusion, the Horn of Africa because of its geographical and environmental diversity has been affected
in many different ways by the climatic changes during the Holocene. Human communities living in these
regions had to adapt to those variations partly by a strong mobility to find necessary resources to their
survival but also by the adoption of new way to exploit animal such as husbandry.
References:
Lesur J., 2007. Chasse et élevage dans la Corne de l’Afrique entre le Néolithique et les temps historiques. Cambridge :
BAR 1602, Cambridge Monographs in African Archaeology 68.
Lesur J., Vigne J.-D. & Gutherz X., 2007 – Exploitation of wild animals in Southwest Ethiopia during the Holocene
(4000 BC – 500 AD): the finds from Moche Borago shelter (Wolayta). Environmental Archaeology 12-2: 139-159.
Van Neer, W. & Lesur, J. 2004 - The ancient fish fauna from Asa Koma (Djibouti) and modern osteometric data on 3
Tilapiini and 2 Clarias catfish species, Documenta Archaeobiologiae 2: 141-160.
17
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