As solitary animals, giant pandas (Ailuropoda melanoleuca) rely on chemical communication in order to determine reproductive condition of conspecifics. Therefore, we hypothesize certain biogenic volatile compounds affect mating behavior in giant pandas. Giant pandas housed at Memphis Zoo, Zoo Atlanta, San Diego Zoo, Edinburgh Zoo, and Toronto Zoo (n=5 males and n=5 females) were the subjects of this study. Urine, anatomical site, and environmental samples were collected during the breeding period (Feb-June) and non-breeding period (Aug-Dec) from 2012-2016. Volatile compounds in urine and the environment were extracted using solid phase micro-extraction (SPME), while compounds collected from various body sites of giant pandas were extracted with hexane. Compounds were analyzed and identified using gas chromatography mass spectrometry (GC-MS). Male behavioral trials consisted of a simultaneous choice test between days of the estrous cycle (e.g. proestrus, estrus, and metestrus) and pooled diestrus urine of unknown female giant pandas. The experimental period included eight 15-minute behavior trials over the course of 12 days. In addition, male giant pandas were exposed to isolated compounds found naturally in female urine during four 15-minute behavior trials over the course of 7 days. We predict that urine from a specific day of the peri-estrual period motivates sexual behaviors and physiological responses in males. Male physiological responses to female urine and specific chemical compounds were examined by changes in urinary androgen metabolites and the urinary volatile profile. By coupling male behavior responses and the female urinary chemical profile during the peri-estrual period, relevant compounds may be identified as possible pheromones related to estrus and mating behavior. To increase genetic viability of small populations, giant pandas require continued conservation and management aimed at facilitating communication and breeding across isolated populations. With low population numbers of giant pandas in the wild spread across fragmented habitats, a better knowledge of chemical communication in this species may provide vital information to improve the conservation and management of giant pandas.

Many ecological and evolutionary processes have been described underlying natural selection but supporting evidence in wild settings is often lacking and our understanding remains incomplete. Using a multi-scale approach, I investigated expression of facultative den behavior (denning) among and within ursid species. Among species, lack of denning behavior was supported by relaxation of selection pressures of seasonal food availability due to realization of two sources of ecological opportunity; colonization of new habitat and adaptation of key innovations. Of denning species, I found evidence of adaptive ecological plasticity in den chronology among and within populations consistent with relaxed selective pressures influencing seasonal food availability and energetic budgets. I supported these finding using indices of fitness and established ecological theory. Further knowledge of organismal response to selection pressures has practical applications in predicting responses to novel and fluctuating pressures and aids in our understanding of the complexities of ecology and evolution.