Chimpanzee Non-avoidance of Hyper-proximity with Humans
Résumé
A species, especially when it is endangered and surrounded by anthropogenic elements, can be
threatened by habitat fragmentation. Food resource availability in the species’ usual or surrogate habitats may
reinforce or decrease its use of certain areas. Our objective was to to determine the influence of natural and
anthropogenic variables on spatial distribution of eastern chimpanzees (Pan troglodytes schweinfurthii). We
first determined the home range of a wild chimpanzee community (hereafter Sebitoli Chimpanzee
Community [SCC]) based on global positioning system (GPS) point locations (n¼2,586 direct observations
and feces locations) collected between 2009 and 2013 in Sebitoli, Kibale National Park, Uganda. We
described SCC home range using grid cells (2,959 cells of 100m100m) referencing environmental, spatial,
and topographical variables (n¼15). We then determined diet and food species abundance within their
territory (n¼63 vegetation plots and 18 months phenological survey) and predicted distribution of the
10 most foraged fruit species within SCC home range, using environmental, spatial, and topographical
variables (n¼10) by applying a maximum entropy model (maxent). We then predicted chimpanzee presence
as a function of environmental, spatial, and topographical variables (n¼15) using the maxent model and
assessed its truthfulness with the kernel model, based only on GPS point locations. Chimpanzees in Sebitoli
were mostly observed in a core area of 5.42 km2 within the 25-km2 home range. They did not avoid forest
edges in contact with human populations, especially males who used larger core areas than females. Factors
with the greatest positive impact on the chimpanzee distribution model (maxent area under the curve
[AUC]¼0.907) were related to 3 different food resources: 1) proximity to forest edges considered as
attractive because of presence of crops cultivated by local farmers; 2) proximity to a tarmac road that crosses
the SCC home range with shoulders covered by attractive terrestrial herbaceous vegetation; and 3) presence
of wild forest fruiting resources. The results obtained with the maxent predictive model, applied on a fine
scale, were consistent with the kernel model, based on real observations. Therefore, such an approach may be
recommended for surveys or action plans interested in sustainable management of wildlife in an
anthropogenic environment and may be a useful tool to better understand parameters of a prefered zone for
an endangered species.