“Mild” diseases and social interactions in wild primates: acquiring baseline data about causes and effects of Plasmodium spp. infection in Pan troglodytes

Dr. Fabian Leendertz, Berlin
Dr. Tobias Deschner, Leipzig

Phd Student: Doris Wu


As humans, wild primates are infected with a number of microorganisms, which may have non-lethal, yet negative effects on their health. Such pathogens might influence an individual’s behavior, either on a short-term (e.g., when not feeling well for a few days) or on a long-term basis (e.g., if an animal becomes frequently “ill”). Such non-lethal diseases could therefore have severe fitness effects, either via changes in dominance status, opportunities to sire offspring in males or in the context of feeding competition in females. Despite their biological relevance, researchers have neglected causes and effects of “mild” infectious diseases in wild primates thus far. In this study we propose to investigate Plasmodia (Plasmodium spp.), a group of blood parasites causing malaria in humans which have recently been described for wild great apes, and which cause malaria-like symptoms in experimentally infected chimpanzees. We will investigate parameters determining the susceptibility to Plasmodium spp. infection in wild African great apes. Specifically, we will focus on the genetic make-up of individuals and stress but also social factors, such as sleeping habits (height of nests or nesting group size). Furthermore, we will investigate the influence on great apes health based on a variety of parameters, such as activity patterns but also clinical symptoms (fever, inflammation, haemolyses). Thus, we will, for first time, provide baseline data about the “susceptibility > infection > health > susceptibility” loop of a non-lethal infection in wild primate communities. Furthermore, we will investigate how times of being “ill” may affect an individual’s social relationships and competitive abilities.

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