Mandrills use olfaction to socially avoid parasitized conspecifics

Area of Science:

• Evolutionary biology
• Behavioral ecology
• Parasitology

Background:

• Social living increases parasite transmission risk, yet sociality is widespread.
• Hosts are expected to evolve behaviors to mitigate infection risk.
• Pathogen-mediated selection on antiparasitic behavior in vertebrates is understudied.

Purpose of the Study:

• Investigate the relationship between parasitism and social behavior in wild mandrills.
• Determine if mandrills can detect and avoid parasite-infected conspecifics.
• Assess the role of "behavioral immunity" in primate sociality.

Main Methods:

• Long-term field observations of mandrill social interactions.
• Controlled experiments involving parasite treatment and behavioral response.
• Chemical analysis of fecal odors to detect parasite indicators.
• Observational studies on avoidance of conspecifics and their fecal matter.

Main Results:

• Mandrills actively avoid grooming infected individuals.
• Parasite-treated mandrills receive increased grooming post-treatment.
• Parasitism alters host fecal odor profiles.
• Mandrills demonstrate selective avoidance of feces from parasitized conspecifics.

Conclusions:

• Mandrills exhibit adaptive antiparasitic behaviors, including partner selection based on parasite status.
• "Behavioral immunity" is a key mechanism for managing the costs of sociality in primates.
• These findings highlight the coevolutionary interplay between host behavior and parasite transmission.