Causes of death in neotropical primates in Rio Grande do Sul State, Southern Brazil

Background Anthropogenic disturbances are the main threats to nonhuman primates conservation, and infectious diseases may also play a key role in primate population decline. This study aimed to determine the main causes of death in neotropical primates. Methods A retrospective study of post-mortem examinations was conducted on 146 neotropical primates between January 2000 and December 2018. Results Conclusive diagnoses were obtained in 68.5% of the cases, of which 59 corresponded to non-infectious causes and 41 to infectious diseases. Trauma was the main cause of death (54/100), with anthropogenic stressors caused by blunt force trauma injuries (collision with vehicles) and puncture wound injuries associated with interspecific aggression (dog predation) were the most common factors. Other causes of death included bacterial diseases (27%), followed by parasitic diseases (12%), neoplasms (2%), and viral diseases (2%). Conclusions Free-ranging primates were mostly affected by non-infectious causes, while captive primates were by infectious conditions.