Chemical communication in the giant panda (Ailuropoda melanoleuca): the role of age in the signaller and assessor

Abstract

As a solitary species, giant pandas Ailuropoda melanoleuca appear to use chemical signals to maintain a communication network with individuals in the community with whom they have little direct contact. Chemosensory discrimination abilities undoubtedly play a large role in determining the efficiency of this communication system. The hypothesis that pandas could discriminate the age of the signaller was tested by presenting subjects with a simultaneous choice test between odours collected from adult and subadult donors. Twenty-eight pandas were tested with three types of stimuli: male urine; male anogenital gland secretions; female urine. The results indicate that individuals from both age classes readily discriminate between adult and subadult odours emanating from all three odour types, showing a pronounced investigatory preference for adult odours in all cases. Female reproductive condition influenced general responsiveness to male odours, but did not significantly alter adult/subadult discrimination patterns. The prevalence of overt discrimination across odour types and age classes suggests an important and multifunctional role for this ability, and highlights the importance of studying chemical communication at all developmental stages. It is proposed that these results may be explained in part by: (1) assessment of competitive ability, which correlates with the age class of the signaller; (2) identification of potential mates that have attained reproductive maturity.