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Chimpanzees (Pan troglodytes ) are a large-bodied, highly adaptable great ape species, characterized by remarkable across-and-within-population variation in habitat use, behavior, and feeding ecology. Chimpanzees are found across the forested mid-region of Africa, occupying a variety of habitat types, though they are frequently described as a rainforest-dwelling species (McGrew, 1979; Russak & McGrew, 2008). Research, however indicates that chimpanzees inhabit a wide range of ecotypes, such as primary and secondary moist lowland forests, swamp forests, submontane and montane forests, savanna woodlands, and occasionally farmland areas (Humle et al., 2016a; Russak & McGrew, 2008). A robust literature derives from chimpanzee field studies conducted in sites across Africa, documenting an array of site-specific strategies for everything from resource extraction to ranging patterns and even patterns of social interactions (Boesch, 2012; Goodall, 1986; Gruber et al., 2012; Herbinger et al., 2001; Matsuzawa et al., 2011; McGrew, 1983). It is thought that many of these behavioral and ecological differences reflect strategies specific to differences in resource availability on different landscapes (Chapman, Chapman, Ghai, et al., 2010; Chapman & Lambert, 2000; Koops, 2011; Krief et al., 2014; Potts, 2008; Potts et al., 2011; Watts et al., 2012). In this dissertation I investigate the interactions of behavior and ecology of a newly habituated chimpanzee community, the Buraiga community, in Kibale National Park in southwestern Uganda. The Buraiga community is estimated to number over 100 individuals, occupying the region with the largest remaining population of eastern chimpanzees, yet one experiencing unprecedented habitat loss due to human population expansion. I characterize habitats within the Buraiga community’s range and assess resource availability within these habitats. I document the degree of habituation across Buraiga individuals, examining habitat and diet preferences for habituated individuals, and creating activity budgets to better understand seasonal ecological and behavioral dynamics for this community. Results of this research deepen our understanding about chimpanzee behavioral variability and adaptations on a landscape shared with humans.

There have been reports that rainfall in East Africa is changing or becoming more variable. This can have significant implications for conservation initiatives and the food security of this populace region that is heavily reliant on the rain fed agricultural system. The perceptions of farmers regarding rainfall along with 30 years of satellite data and 16 years of ground level observations were analyzed in order to characterize rainfall in and around Kibale National Park, a protected area in the Ugandan portion of the Albertine Rift. Two homogenous rainfall regions exist in the area, and the onset, cessation, and amount of rainfall during seasons is highly variable. The perceptions of farmers align with the analysis of rainfall data, indicating that the season beginning in March shows the highest degree of variability. Decreases in the amount of rainfall are found for both rainy seasons.

Chimpanzees are well known for their territorial behavior. Males defend heavily-used core areas and routinely patrol the periphery of their territories, apparently seeking signs of or contact with individuals from neighboring communities. In this research, I add to our understanding of chimpanzee territoriality via a study of an unusually large community of chimpanzees at Ngogo, Kibale National Park, Uganda. Using 19 months of observations, I estimated the sizes of the Ngogo chimpanzee territory and core area, the most heavily used portion of the territory. Different methods produced similar estimates, although subsampling data to reduce autocorrelation substantially reduced estimates calculated using nonstatistical techniques. I found that a biologically meaningful estimate of the core area represented an area about 1/3 of total territory size. Food availability and intercommunity relations are frequently hypothesized to influence territory use and size. I assessed their effects, but found little evidence that either affected the ranging patterns of the Ngogo chimpanzees. Patrolling chimpanzees cover long distances, and patrols are likely to involve energetic costs for participants. To evaluate these costs, I compared observations of travel and feeding during patrols and matched control periods. Chimpanzees covered longer distances, spent more time traveling, and spent less time feeding during patrols than during control periods. These results suggest that ecological factors may constrain the ability of chimpanzees to patrol. I also investigated factors affecting where chimpanzees patrol. Nest counts of neighboring chimpanzees did not predict patrolling locations, suggesting that chimpanzees do not respond to power imbalances between themselves and neighbors when choosing areas to patrol. Over the long but not short term, Ngogo chimpanzees patrolled more frequently in peripheral areas where they experienced more intercommunity encounters. In the most heavily patrolled areas, intercommunity encounter and patrol frequency were also positively correlated over the short-term. I found evidence that Ngogo chimpanzees defended some boundary areas of their territory more keenly than others, apparently adjusting their territorial activities in response to different neighbors in various ways. These chapters present a picture of how chimpanzee communities use and defend their territories, and contribute to our arsenal of methods for assessing ranging and territoriality.