Olfactory Inspection of Female Reproductive States in Chimpanzees

In mammalian species, olfactory cues are important for within and between species communication. These can be part of multimodal signals indicating, example, female fertility potentially perceived by male conspecifics. However, a large gap exists in our understanding signaling non-human catarrhines. Chimpanzees ( Pan troglodytes ) live fission-fusion societies, mate promiscuously express high levels male-male competition. Females show striking visual signal, an exaggerated sexual swelling, known to proxy ovulation, while the maximum swelling is not matching exact time ovulation. The question remains if males use additional when being able approach females closely. This would allow pinpoint timing ovulation could one reason why high-ranking sire offspring more successfully than other males. Here, we present first systematic test such investigating sniffing behavior directed relation their group 13 captive chimpanzees. Our results that significantly increased with size, age as well fewer competitors were present. Hence, odors might cue, supporting idea monitor both gain comprehensive information on fertility.