The distribution and abundance of food resources are among the most important factors that influence animal behavioral strategies. Yet, spatial variation in feeding habitat quality is often difficult to assess with traditional methods that rely on extrapolation from plot survey data or remote sensing. In a manuscript currently in press in Behavioral Ecology, I show that maximum entropy species distribution modeling can be used to successfully predict small-scale variation in the distribution of 24 important plant food species for chimpanzees at Gombe National Park, Tanzania. The level of resolution is 10 meters, and the predictive accuracy of species distributions ranges between 70-95%, with most species lying above 80%. Combined with behavioral observations on what food is being selected in any given time period, the predicted species distributions allow the assessment of feeding habitat quality as the cumulative dietary proportion of the species predicted to occur in a given location. This measure exhibits considerable spatial heterogeneity with elevation and latitude at Gombe, both within and across main habitat types. This illustrates that reliance on broad habitat types can mask important determinants of behavior.

I have begun to use this new measure of habitat quality to gain insights into the ecological correlates of chimpanzee behavior. In a first analysis, I assessed individual variation in habitat selection among adult chimpanzees during a ten-year period, testing predictions about tradeoffs between foraging and reproductive effort. I found that non-swollen females selected the highest quality habitats compared to swollen females or males, in line with predictions based on their energetic needs. Swollen females appeared to compromise feeding in favor of mating opportunities, suggesting that females rather than males change their ranging patterns in search of mates. Males generally occupied feeding habitats of lower quality, which may exacerbate energetic challenges of aggression and territory defense. Finally, I documented an increase in feeding habitat quality with community residence time in both sexes, suggesting an influence of familiarity on foraging decisions in a highly heterogeneous landscape.