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 signi®cant investigatory preference for oestrous over non-oestrous female urine, as indicated by snif®ng and¯ehmen. Males also investigated, displayed¯ehmen, and licked female urine more than did females. These ®ndings indicate that female urine contains chemical cues permitting discrimination of oestrous status, and probably serves a reproductive advertisement function. The prevalence of¯ehmen 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.

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.

This is the first study that demonstrated the phenotypic and genetic characterizations of antimicrobial and disinfectant resistance in E. coli isolates from more than 60 giant pandas. Frequent transfer of pandas to other cages may lead to the dissemination of antimicrobial resistance. The study highlights the need for regularly monitoring the antimicrobial and disinfectant resistance in bacteria from giant pandas.

As a solitary species, giant pandas Ailuropoda melanoleuca have a chemical communication system that allows for avoidance with conspecifics throughout most of the year and facilitates breeding during their brief reproductive period. To date, most studies have focused on adults during the breeding season, but much remains to be learned about developmental and seasonal effects on chemical communication. Here, using odour discrimination methodology, we examine these contextual influences on chemosignalling in giant pandas for the first time. During the breeding season both adult and subadult giant pandas overtly discriminated conspecific sex using chemical cues in urine. Male urine was consistently investigated more than female urine by pandas across all age-sex categories. This preference for male urine was observed for both adult and subadult urine donors, indicating that adult levels of reproductive hormones are not necessary for the production of sex-specific urinary odour cues. By contrast, giant pandas did not overtly discriminate sex during the non-breeding season. This finding underscores that negative results for discrimination studies need to be interpreted with caution, as many contextual factors may influence overt expression of this ability. Evidence points to seasonal changes in motivation, rather than in the availability of sex-specific chemical cues in urine, as the causal factor for changing odour discrimination patterns. These and other findings are discussed in the light of the potential role that discrimination of odour plays in the regulation of competitive and reproductive interactions in nature.

Although several mammals impregnate their fur with environmental odors, a phenomenon termed scent anointing or rubbing, the functional relevance of this behavior often is unclear. One theory is that scent anointing could be a form of scent matching with environmental odors to signal competitiveness and home range occupation. In this study we presented giant pandas with a range of odors to determine whether scent matching could provide a functional explanation for scent anointing in this species. We found that only a musk-based perfume elicited significantly more scent-anointing and scent-marking behavior than control. Males were also significantly more likely to scent-anoint and scent-mark than females. A preference for anointing, but not scent marking, when presented with peppermint (an insecticide) also was revealed. Our results suggest that giant pandas differentially scent-anoint with foreign odors to signal home range occupation, and possibly to repel ectoparasites. We also highlight how chemical signaling of resource-holding potential is likely to play an important role in determining competitive interactions between adult male giant pandas.