Chimpanzees sniff out strangers and family members

October 23, 2018, Max Planck Society

Chemical communication is widely used in the animal kingdom to convey social information. For example, animals use olfactory cues to recognize group or family members, or to choose genetically suitable mates. In contrast to most other mammals, however, primates have traditionally been regarded as "microsmatic—having a poor sense of smell. Although research on olfaction in some primate species has increased in recent years, non-human great apes have been greatly neglected in these studies. Researchers from the University of Leipzig and the Max Planck Institute for Evolutionary Anthropology as well as Durham University have now conducted one of the first studies investigating the signaling function of social odors in non-human great apes. 

The scientists presented two groups of chimpanzees with urine from group members, strangers and an unscented control in aerated plexiglass boxes and videotaped their behavior. Chimpanzees sniffed longer at urine than at the control, suggesting they perceive the odor of other chimpanzees. More importantly, they discriminated between the smell of group members and strangers, sniffing outgroup odors longer than ingroup odors. "Chimpanzees are highly territorial, and encounters between groups are mostly hostile—in fact, they sometimes kill individuals from other communities—so olfactory cues might help them to locate other animals and determine whether they are group members or strangers, enhancing their survival and leading to fitness benefits", says lead author Stefanie Henkel of the University of Leipzig and the Max Planck Institute for Evolutionary Anthropology. "Odor might be especially important because most chimpanzees live in dense forests where visibility is low, and because in chimpanzee societies, group members split up into subgroups that may not see each other for days", Henkel adds. 

Read more at: