• Guinea-Bissau
• chimpanzees
• conservation
• zoonoses
• parasites

All chimpanzee species are classified as endangered by IUCN Red List. Their survival is menaced by ongoing anthropogenic pressures, such as hunting, pet trade, climate change and habitat fragmentation. Moreover, infectious diseases can impact their health status, sometimes becoming life-threatening. Infections can be caused by many different microorganisms, including gastrointestinal parasites. The aim of this study is to evaluate the gastrointestinal symbionts of two communities of chimpanzees from Guinea-Bissau inhabiting different areas: one inside a protected area (Cufada Lagoons Natural Park) and one outside (Tite sector). We will test two hypotheses in this study: 1. statistically significant differences in terms of prevalence and richness of gastrointestinal symbionts would be found between the two communities, in particular for zoonotic parasites; 2. chimpanzees inhabiting outside the protected area should be more infected, because of their closer contact with human communities. Fresh faecal samples (N = 155) were collected opportunistically from unhabituated chimpanzees during the dry season (March-April 2017) and analyzed performing standard parasitological analyses of flotation and sedimentation. Descriptive statistics and multivariate inference was used to interpret the results. Results in terms of prevalence and richness of gastrointestinal microorganisms suggest that the community living inside the natural park could suffer of higher anthropogenic pressures. We suggest that the role of parks be revised to provide more successful strategies in chimpanzee conservation efforts.