NOTE ON THE SEASONAL USE
OF LOWLAND AND HIGHLAND HABITATS BY THE WEST AFRICAN CHIMPANZEE PAN
TROGLODYTES VERUS (SCHWARZ, 1934) (PRIMATES: HOMINIDAE): IMPLICATIONS FOR
ITS CONSERVATION
Papa Ibnou Ndiaye1, Gérard Galat 2, Anh Galat-Luong 3& Georges Nizinski 4
1 UCAD, Université Cheikh Anta Diop, Département de Biologie animale, B.P 5005,
Dakar-Fann, Senegal
2,3 UCAD - IRD, Université CheikhAnta Diop - Institut de Recherche pour
le Développement, Département Ressources vivantes, and IUCN Species Survival Commission, Route des Pères Maristes, Dakar, Senegal
4 IRD, Institut de Recherche pour le
Développement, UMR 211 Bioemco, 5 rue du Carbone,
45072 Orléans cedex 2, France
1 ibnou.ndiaye@ucad.edu.sn (corresponding author), 2 gerard.galat@ird.fr,
3 anh.luong@ird.fr, 4 georges.nizinski@ird.fr
doi: http://dx.doi.org/10.11609/JoTT.o3229.3697-700 | ZooBank: urn:lsid:zoobank.org:pub:2CBC03FE-07F5-4E33-A7F7-5B52B8E1872E
Editor: Jill Pruetz,
Iowa State University, Ames, USA Date of publication: 26
February 2013 (online & print)
Manuscript details: Ms #
o3229 | Received 31 May 2012 | Final received 20 October 2012 | Finally
accepted 10 February 2013
Citation: Ndiaye,
P.I., G. Galat, A. Galat-Luong& G. Nizinski (2013). Note on the seasonal
use of lowland and highland habitats by the West African Chimpanzee Pan troglodytes verus (Schwarz,
1934) (Primates: Hominidae): Implications for its
conservation. Journal of Threatened Taxa 5(2): 3697–3700; doi:10.11609/JoTT.o3229.3697-700.
Copyright: © Ndiaye et al.
2013. Creative Commons Attribution 3.0 UnportedLicense. JoTT allows unrestricted use of this
article in any medium, reproduction and distribution by providing adequate
credit to the authors and the source of publication.
Funding: The study was carried out and
financially supported by the IRD (Institut de Recherche pour le Développement -
the French Institute of Researc for Development),
IPMO Research Program (Impact des Perturbations Naturelleset anthropiques sur les
populations de Mammifères et d’Oiseaux- Impact of Natural and Human Perturbations on Mammals and Birds populations)
and the University Cheikh Anta Diopde Dakar (Sénégal).
Competing Interest: None.
Acknowledgements:The authors thank IRD for logistical facilities, the Senegalese authorities for
kind permission to work in the field, local people for their warm
welcome and help, and Yeremakhan Keita for help as
IRD field assistant. Authors wish to thank also the anonymous reviewers and the
Online Access to Research in the Environment (OARE) for facilitating
literature.
For
figure, table -- click here
In recent years wild Chimpanzee
populations have declined by more than 66% (Butynski2001). This decrease is of
particular concern for the Western Chimpanzee, including the West African
subspecies Pan troglodytes verusSchwarz, 1934. The IUCN 2011 Red
Data Book lists P. t. verus as Endangered
(A4cd; Humle et al. 2008). It has already disappeared in the wild
from Togo, Benin and The Gambia (Campbell & Radley2006) and is very rare or close to extinction in Burkina Faso, Ghana,
Guinea-Bissau and Senegal (Kormos et al. 2003). The survival of the West African
Chimpanzee is, therefore, a very high conservation priority. Galat et al.
(2000) carried out a large-scale survey (more than 100 villages surveyed) of
its distribution area in Senegal, but according to Carter et al. (2003) a
systematic survey of the total area of Senegal inhabited by Chimpanzees has yet
to be conducted, which partially explains the difficulties encountered in their
conservation. At the time the
present study was undertaken, between March 1998 and March 1999, it was
generally acknowledged that Chimpanzees were only to be found in Niokolo Koba National Park (PNNK)
(Larivière & Dupuy1978). Available scientific
information thus dealt with the PNNK Chimpanzee population, for instance in the
studies conducted at Mount Assirik by McGrew et al. (1981), Baldwin et al. (1981, 1982), Tutin et al.
(1981); McGrew (1983), Tutinet al. (1983), Bermejo et al. (1989), Galatet al. (1994)
and Galat-Luong (1995). During our study we discovered a
relatively abundant Chimpanzee population outside of the protected area, living
within the transitional area between PNNK in Senegal and BadiarPark in Guinea and the southern part of the national hunting reserve, namely
Zone of Cynegetic Interest (Ndiaye1999; Galat et al. 2000; Galat-Luonget al. 1999–2000; Pruetz 2002; Pruetz et al. 2001, 2002). The most recent data on the population
of Chimpanzees living outside the protected area stem from studies focused on
diet (Pruetz & Kuntsen2003; Pruetz 2006; Bogart & Pruetz2011; Pruetz & Lindshield2012), use of tools (McGrew et al. 2005; Pruetz& Bertolani 2007; Bogart & Pruetz 2008), behavior in relation to the high temperatures
of the savannah habitat (Pruetz 2007), drinking water
filtering (Galat-Luong & Galat2000; Galat-Luong et al. 2009), nesting behavior (Stewart
et al. 2007; Pruetz et al. 2008), intestinal
parasites (Howells et al. 2011) and seed reingestion(Bertolani & Pruetz2011). For the present study we
assessed the influence of the season and topography on the distribution of Pan
troglodytes verus Chimpanzees within their
habitat outside of the PNNK, which is not previously reported.
Material and Methods: Study area: Our study was conducted in the southeastern region of Senegal, in
the Kedougou region (12033’N
& 12011’W) (Fig. 1), outside the protected areas. A Sudano-Guinean
type of climate prevails, as defined by Aubreville(1949), sometimes making way for forests with clear understory. Annual rainfall
within the 1995–1998 period ranged from 1000mm to 1600 mm, with a mean
annual temperature of around 28.60C (tmax = 35.20C, tmin = 21.90C) (Galat et al.2009). The dry season is from
November to April and the rainy season from June to October. During the rainy season, the gallery
forests are flooded. The month of May
is a transition point between the dry and the rainy season. Certain forest or gallery forest areas
located along the course of Gambia River or at the head of the rivers have
typical Guinean species such as Pterocarpus erinaceus, Anogeissus leiocarpus, Parkia biglobosa, and Syzygium guineense, among others. These could well be relics from a time
when there was greater forest cover, which in turn was reduced by the
contemporary climactic drying trend (Mühlenberg et
al. 1990). The gallery forest
recession may also be attributed to the high number of bushfires lit during the
dry season for clearing by farmers and livestock breeders and for visibility by
hunters (hardly any visibility when the grassy vegetation, often over 2m tall,
is intact). Throughout the dry
season, practically all of the species, except for forest gallery cells that
still retain their greenery, lose their leaves (vegetative dormancy). Most of them do not regrow their leaves
until right before the first rains.
Method: A
basic assumption is that a Chimpanzee builds a nest every evening before
spending the night in it (Fruth & Hoffmann
1996). Such nests are generally not
reused. The nest density within a
site is thus useful for indirect measurement of the population density (Fleury-Brugiere & Brugiere2010). The nest density, together
with other criteria such as their age, can also give other indications on the
presence or absence of these Chimpanzees.
In a previous study (Galat-Luong et al.1999–2000), in a 15,000km survey carried out in a
vehicle, we first identified Chimpanzee nesting sites in southeasternSenegal. Then in the present
study over 80 days between March 1998 and March 1999 we covered Chimpanzee
nesting sites on foot for 380km outside of protected areas and sampled data on
the season (dry
or rainy), location (highlands with 200–300 m
of altitude or valleys with less than 30m of altitude) and
age (old or recent, e.g., less than two weeks old, with green leaves that indicate
their freshness; Papa Ibnou Ndiayepers. obs.). Data were analyzed
statistically by applying chi squared test.
Results: From March 1998 to March 1999
we recorded a total of 1,397 nests, 436 of which were recent. The distribution of recent nests in the
valleys and highlands according to the season is given in Table 1. The statistical analysis of these
findings indicated a significant difference between seasons in the type of
habitat used (Chi-square=112.730, df=1, two-tailed
P<0.0001).
Discussion: The analysis of the results
in Table 1 show that the frequency of recent nests was higher in the valleys
during the dry season, while in the highlands this frequency was much
significantly higher during the rainy season. The proportions of recent nests observed
in the valleys and the highlands throughout the different seasons of the year
showed that, during the dry season, Chimpanzees were more frequently nesting in
the gallery forests, likely due to the availability of drinking water, food and
the vegetation density, which created a humid microclimate (Papa Ibnou Ndiaye 1999 unpub. obs.). Conversely, flooding of valleys during the rainy season and the
diminution of the availability of suitable nesting trees may have prompted the
Chimpanzees to move to higher grounds (hills and gallery forests on plateau
edges). According to Balcomb et al. (2000), the density of fruit trees
and food sources is a determining factor in the distribution of Chimpanzees
living in the wild. In Kibale National Park in Uganda, these authors observed an
abundance of Chimpanzee nests in areas in which there were concentrations of
trees whose fruits constituted a major component of these primates’ diet. For Schoeningeret al. (1999), Savanna Chimpanzees are highly dependent on food from
trees, and they feed both in the gallery forest closest to the river and in the
dry forest beyond. According to
Stanford & O’Malley (2008), 93% of the Chimpanzee nests recorded (N=3414)
in Bwindi National Park (Uganda) were in fruit trees,
which is also in line with the observations of Basabose& Yamagiwa (2002) in Kahuzi-BiegaNational Park (Congo) and of Brownlow et al. (2001) in Budongo forest (Uganda). Hernandez-Aguilar (2006, 2009) note that availability of foods and water are determining
factors for the distribution of the Chimpanzees in Issa,Ugalla. Our study showed that the elevation and liability to flooding can also have an impact on seasonal Chimpanzee
distributions.
Conclusion: The results of our study
showed that Pan troglodytes verus Chimpanzees
migrate within their habitat. These
migrations seem to be determined by the seasons. The habitats where they nested were
gallery forests in valleys in the dry season and highlands (hills and plateau
edge galleries) in the rainy season. It is therefore essential to preserve these habitats in order to ensure
the survival of these Chimpanzees in Senegal - this must be a biodiversity
conservation priority. When creating or managing a protected area (e.g. a
“Community Heritage Area” by local people) for the purpose of preserving
Chimpanzees on the basis of their presence in a gallery forest or on a
hillside, it would thus be necessary to preserve both habitats, i.e., lowland
forest galleries and the surrounding highlands, along with a migration area to
allow them transit between these two habitats. The
present results will provide conservation managers with information on how to
protect the species and help them to make appropriate management decisions.
References
Aubreville, A.
(1949). Climats, forêts et désertification de
l’Afrique Tropicale. Société d’Editions Géographiques, Maritimes et
Coloniales, Paris, 99pp.
Balcomb, S.R., C.A. Chapman & R.W. Wrangham(2000). Relationship between Chimpanzee (Pan troglodytes) Density
and Large, Fleshy-Fruit Tree Density: Conservation Implications. American Journal of Primatology 51: 197–203.
Baldensperger, J.
(1965). Etude pédologique d’un bassin versant de la
région de Kédougou (Sénégal Oriental). ORSTOM. Dakar,
68pp.
Baldwin, P.J., J. Sabater-Pi, W.C. McGrew & C.E.G. Tutin(1981). Comparisons of nests made by different populations of Chimpanzees (Pan
troglodytes). Primates 22: 474–486.
Baldwin, P.J., W.C.
McGrew & C.E.G. Tutin (1982). Wide ranging Chimpanzees at Mt. Assirik, Senegal. International
Journal of Primatology 3: 367–385.
Basabose, A.K. & J. Yamagiwa (2002). Factor
affecting nesting site choice in Chimpanzees at Tshibati,Kahuzi-Biega National Park: Influence of sympatric
Gorillas. International Journal of Primatology 23(2):
263–282.
Bermejo, M., G. Illera & J. Sabater-Pi
(1989). New observations on the tool-behavior of
Chimpanzees from Mt Assirik (Senegal, West Africa). Primates 30(1): 65–73.
Bertolani, P. & J.D. Pruetz(2011). Seed reingestionin Savannah Chimpanzees (Pan troglodytes verus)
at Fongoli, Senegal. International
Journal of Primatology 32: 1123–1132.
Bogart S.L.
& J.D. Pruetz (2008). Ecological context of Savanna
Chimpanzees (Pan troglodytes verus) termite
fishing at Fongoli, Senegal. American
Journal of Primatology 70:
605–612.
Bogart S.L. &
J.D. Pruetz (2011). Insectivory of Savannah Chimpanzees
(Pan troglodytes verus) at Fongoli,
Senegal. American Journal of Physical Anthropology,
145: 11–20.
Brownlow, A.R., A.J. Plumptre, V. Reynolds & R. Ward (2001). Sources of variation in the
nesting behavior of Chimpanzees (Pan troglodytes schweinfurthii)
in the Budongo forest, Uganda. American
Journal of Primatology 55: 49–55.
Butynski, T.M. (2001). Africa’s Great Apes, pp.
3–56. In: Beck, B., T.S. Stoinski, M. Hutchins,
T.L. Maple, B. Norton, A. Rowan, E.F. Stevens & A. Arluke(eds). Great Apes and Humans: The Ethics of
Coexistence. Smithsonian Institution Press, Washington, D.C., USA.
Campbell, G. & P.M. Radley (2006). Primate and bird diversity in the Fazao-Malfakassa National Park, Togo. Technical
report. Conservation International, Washington, D.C.
Carter, J., S. Ndiaye, J. Pruetz & W.C.
McGrew (2003). Senegal, pp. 5–12. In: Kormos,
R., C. Boesch, M.I. Bakarr& T.M. Butynski (eds). Status
Survey and Conservation Action Plan: West African Chimpanzees. IUCN, Gland, Switzerland and Cambridge, UK.
Fleury-Brugiere, M-C & D. Brugiere (2010). High
Population Density of Pan troglodytes verus in the Haut Niger National Park, Republic of
Guinea: Implication for local and regional conservation. International
Journal of Primatology 31: 383–392.
Fruth, B. & G. Hohmann (1996). Nest building behavior in the great apes : the great leap forward? pp.
225–240. In: McGrew, W.C., L.F. Marchant, T.
Nishida (eds.). Great Ape Societies. Cambridge University Press, Cambridge.
Galat, G., A. Galat-Luong, M. Benoit, H. Chevillotte, A. Diop, J.M. Duplantier & G. Pichon(1994). Primate density in the Niokolo Koba National Park, Senegal. FoliaPrimatologica 62: 197.
Galat, G.,
A. Galat-Luong, P.I. Ndiaye& Y. Keita (2000). Geographical
distribution of Chimpanzees and baboons in Senegal. Folia Primatologica 71: 249–267.
Galat, G., A. Galat-Luong & G. Nizinski (2009). L’impact du changement
climatique sur les variations des populations de grands vertébrés à leur extrême
limite de répartition est-il fonction de leurs régimes alimentaires? Geographia TechnicaNuméro spécial 205–210pp.
Galat-Luong (1995). Du statut et de l’avenir des primates au Sénégal.AfricanPrimates 1(1): 12–13.
Galat-Luong A. & G. Galat (2000). Chimpanzees and baboons drink filtrated water. Folia Primatologica 71: 258.
Galat-Luong, A., G. Galat,
I. Ndiaye & Y. Keita (2000). Fragmentation
de la distribution et statut actuel du Chimpanzé, Pan troglodytes verus, en limite d’aire de répartition au Sénégal. African Primates 4(1&2): 71–72.
Galat-Luong A., G. Galat & G. Nizinski (2009). Une conséquence du
réchauffement climatique: les chimpanzés filtrent leur eau de boisson. Geographia Technica Numéro spécial, 199–204pp.
Hernandez-Aguilar,
R.A. (2006). Ecology and nesting patterns of Chimpanzees (Pan
troglodytes) in Issa, Ugalla,
Western Tanzania. PhD Thesis. University of Southern California, Los
Angeles.
Hernandez-Aguilar,
R.A. (2009). Chimpanzee nest distribution and site reuse in a dry habitat:
implications for early hominin ranging. Journal of Human Evolution 57: 350–364.
Howells, M.E., J. Pruetz & T.R. Gillespie (2011). Patterns of
gastro-intestinal parasites and commensals as an index of population and
ecosystem health: the case of sympatric Western Chimpanzees (Pan troglodytesverus) and Guinea Baboons (Papio hamadryas papio) at Fongoli, Senegal. American Journal of
Primatology 73: 173–179.
Humle, T., C. Boesch,
C. Duvall, C.M. Ellis, K.H. Farmer, I. Herbinger, A. Blom & J.F. Oates (2008). Pan troglodytesssp. verus. In: IUCN 2012. IUCN
Red List of Threatened Species. Version 2012.2. <www.iucnredlist.org>.
Downloaded on 21 February 2013.
Kormos, R., C. Boesch,
M.I. Bakarr & T.M. Butynski(2003). West
African Chimpanzees: Status Survey and Conservation Action Plan. Gland, Switzerland, IUCN/SSC Primate Specialist Group, 219pp.
Larivière, J.
& A.R. Dupuy (1978). Sénégal, Ses parcs, Ses animaux. Fernand Nathan, 144pp.
McGrew, W.C. (1983). Animal food in the diets of
wild Chimpanzees: Why cross-cultural variation? Journal of
Ethology 1: 46–61.
McGrew, W.C.,
P.J. Baldwin & C.E.G. Tutin (1981). Chimpanzees in a hot, dry and open habitat: Mt. Assirik,
Senegal, West Africa. Journal of Human Evolution 10:
227–244.
McGrew, W.C., J.D. Pruetz & S.J. Fulton (2005). Chimpanzees use tools to
harvest social insects at Fongoli, Senegal. Folia Primatologica 76:
222–226.
Mühlenberg, M., A. Galat-Luong,
P. Poilecot, B. Steinhauer-Burkart& I. Kühn (1990). L’importance
des îlots forestiers de savane humide pour la conservation de la faune de forêt
dense. La Terre et la Vie 45: 40–57.
Ndiaye, P.I.
(1999). Biogéographie et Éléments d’écologie du
Chimpanzé (Pan troglodytes verus) au
Sénégal. Mémoire de DEA de Biologie Animale, Université Cheikh Anta Diop de Dakar.
Pruetz, J.D. (2002). Competition
between humans and Savanna Chimpanzees in southeastern Senegal. American
Journal of Physical Anthropology, Supplement 34: 128.
Pruetz, J.D. (2006). Feeding ecology of Savanna
Chimpanzees (Pan troglodytes verus) in Fongoli, Senegal, pp. 161–182. In: Boesch, C., G. Hohmann & M.
Robbins (eds). The Feeding
Ecology of Great Apes and other Primates. Cambridge
University Press, Cambridge.
Pruetz, J.D. (2007). Evidence of cave use by
Savanna Chimpanzees (Pan troglodytes verus) atFongoli, Senegal: Implication for behavioral
thermoregulation. Primates 48(4):
316–319.
Pruetz, J.D. & P. Bertolani(2007). Savanna Chimpanzees, Pan troglodytes verus, Hunt with tools. Current
Biology 17: 412–417.
Pruetz, J.D., S.J. Fulton, L.F. Marchant, W.C. McGrew, M. Schiel& M. Waller (2008). Arboreal nesting as anti-predator adaptation by
Savanna Chimpanzees (Pan troglodytes verus) in
southeastern Senegal. American Journal of
Primatology 70(4): 393–401.
Pruetz, J.D. & P. Knutsen (2003). Scrambling for a common resource: Chimpanzees,
humans, and Saba senegalensis, in southeastern
Senegal. American Journal of Physical Anthropology(supplement) 120–172.
Pruetz, J.D. & S. Lindshield (2012). Plant-food
and tool transfert among Savanna Chimpanzees at Fongoli, Senegal. Primates 53:
133–145.
Pruetz,
J.D., L.F. Marchant, J. Arno & W.C. McGrew
(2002). Survey of Savanna Chimpanzee (Pan troglodytes verus) in southeastern Sénégal. American Journal of Primatology 58: 35–43. doi: 10.1002/ajp.10035
Pruetz, J.D., W.C. McGrew, L.F. Marchant & J. Arno (2001). Status of
the Savanna Chimpanzees (Pan troglodytes verus)
at Mont Assirik in ParcNational du Niokolo Kobaand in adjacent areas in southeastern Sénégal[abstract]. American Journal of Physical Anthropology 32: 121.
Schoeninger, M.J., J. Moore & J.M. Sept (1999). Subsistence Strategies of
two Savanna Chimpanzees populations: the stable isotope evidence. American Journal of Primatology 49: 297–314.
Stanford, C.B. & R.C. O’Malley
(2008).Sleeping tree choise by BwindiChimpanzees. American Journal of Primatology 70:
642–649.
Stewart, F.A., J.D. Pruetz & M.H. Hansell (2007). Do Chimpanzees build confortables nests? American Journal
of Primatology 69: 930–939.
Tutin,
C.E.G., W.C. McGrew & P.J. Baldwin (1981). Responses
of wild Chimpanzees to potential predators, pp. 136–141. In. Chiarelli, A.B. & R.S. Corruccini(eds.). Primate behavior and sociobiology. Springer, Heidelberg, Germany.
Tutin, C.E.G., W.C. McGrew &
P.J. Baldwin (1983). Social organization of Savanna-dwelling Chimpanzees, Pan troglodytes verus, at Mt. Assirik, Senegal. Primates 24(2): 154–173.