Habitat fragmentation, livelihood behaviors, and contact between people and nonhuman primates in Africa

Bloomfield, Laura S. P. [Stanford University School of Medicine, Stanford University, Stanford] McIntosh, Tyler L. [Earth Systems Program, Stanford University, Stanford] Lambin, Eric [UCL]

Context Deforestation and landscape fragmentation have been identified as processes enabling direct transmission of zoonotic infections. Certain human behaviors provide opportunities for direct contact between humans and wild nonhuman primates (NHPs), but are often missing from studies linking landscape level factors and observed infectious diseases. Objectives Our objective is to better understand landscape and livelihood factors influencing human-NHP contact in rural communities whose landscapes undergo deforestation. We investigate core loss and edge density within a buffered area around survey respondent households to identify which landscape changes and behaviors increase the risk of human-NHP contact. Methods Behavioral survey data were collected from small-scale agriculturists living near forest fragments around Kibale National Park in western Uganda. We combined spatially explicit behavioral data with high-resolution satellite imagery. Using land cover classification and change detection, we investigated the relationships between forest loss and fragmentation, behavioral data, and human-NHP contact using logistic regression. Results Between 2011 and 2015, there were differences in the landscape metrics around the households of individuals who had experienced human-NHP contact compared to those who had not had contact. Increased edge density around households, collection of small trees for construction, and foraging and hunting for food in forested habitat significantly increase the likelihood of human-NHP contact. Conclusion This study provides empirical evidence that forest landscape fragmentation and certain smallholders’ behaviors in forest patches jointly increase the likelihood of human-NHP contact events. Combining spatially explicit data on land use and human behaviors is crucial for understanding the social and ecological drivers of human-NHP contact.