Discrimination of oestrous status in giant pandas (Ailuropoda melanoleuca) via chemical cues in urine

Abstract

Giant pandas Ailuropoda melanoleuca are a solitary, seasonally mono-oestrous species, and as such are likely to rely heavily on chemical signals to co-ordinate mating efforts. Perhaps the most crucial chemosensory task facing male pandas is the assessment of female reproductive condition on the basis of chemical cues. To test for this ability, eight male and 10 female giant pandas were presented with urine from oestrous and non-oestrous females. Males but not females displayed a significant investigatory preference for oestrous over non-oestrous female urine, as indicated by sniffing and flehmen. Males also investigated, displayed flehmen, and licked female urine more than did females. These findings indicate that female urine contains chemical cues permitting discrimination of oestrous status, and probably serves a reproductive advertisement function. The prevalence of flehmen and licking by males suggests that males may rely on the vomeronasal organ to assess female reproductive condition. Female odours may play an important role in the reproductive behaviour of male giant pandas and, therefore, may have implications for captive-breeding programmes.