Comprehensive Breeding Techniques for the Giant Panda.

The dramatic growth of the captive giant panda (Ailuropoda melanoleuca) population exemplifies how the application of scientific findings to animal care and reproductive management can improve conservation breeding outcomes. Detailed behavioral studies of giant panda estrus, pregnancy and cub rearing have demonstrated the importance of husbandry management that supports natural reproductive behavior to enhance breeding success. Natural breeding has been valuably augmented by the development of assisted reproductive techniques founded through detailed studies of the reproductive physiology of the giant panda and outlining fundamental information about reproductive seasonality, male fertility and characterization of the estrous cycle. The resultant holistic understanding of giant panda reproduction has improved reproductive success in the captive population to such an extent that it is now self-sustaining and provides surplus animals for reintroduction. Despite these significant advances, there are knowledge gaps and remaining challenges to be addressed. Pregnancy detection remains the single biggest challenge when determining if natural mating or assisted breeding have been successful. Because pregnancy can only be determined in the few weeks prior to parturition, there are gaps in understanding and detecting delayed implantation and early embryonic loss. Additionally, dynamic management practices and standard of care for reproductive assistance needs to be developed. Only large breeding centers in China have the ability to promote normal reproductive behaviors and allow mate choice for the giant panda. These challenges need to be addressed in the near future in order to maintain a self-sustaining, genetically diverse and behaviorally competent captive population. This chapter documents the development of successful giant panda managed breeding programs by focusing on three key areas, (1) the development of science-driven reproductive techniques to improve fecundity in a species where the mating system was poorly understood, (2) how targeted research and adaptive management of social settings surrounding estrus and breeding improved reproductive success, and (3) insights and solutions to challenges faced across the program's history with future directions for research.

Improving the sustainability of ex situ populations with mate choice.

Many breeding programs managed by the Association of Zoos and Aquariums' (AZA) Species Survival Plans® (SSPs) are not meeting goals for population size and genetic diversity due to failure of recommended pairs to breed successfully. According to AZA Population Management Center analyses, as many as 80% of recommended breeding pairs fail to produce young before the next breeding and transfer plan is issued. Determining reasons for failure and ensuring that a specific pairing produces offspring can be challenging. Mate incompatibility, one possible reason for failure, might be addressed by allowing mate choice. Although many SSP® coordinators and breeding managers, who implement breeding recommendations at their institutions, recognize the potential benefits of mate choice, examples and models for presenting and assessing choice are lacking. Here we review examples from birds, rodents, lagomorphs, marsupials, carnivores, fishes, and insects where mate choice has been incorporated. These examples provide strong evidence that free mate choice and mating with preferred partners increase a variety of reproductive success measurements when compared to assigned mate pairings. We suggest innovative housing and breeding arrangements for better incorporating mate choice into the management strategies for species held ex situ. Further, we discuss the fitness consequences and welfare implications of allowing choice. We advocate for a more systematic use of behavioral research in cooperative breeding programs. Behavioral management for mating can yield more successful programs, thus ensuring SSP® genetic and demographic goals are met, while simultaneously improving welfare.

Blood Lead Levels in Captive Giant Pandas.

Fifteen giant pandas (Ailuropoda melanoleuca) from the Chinese Conservation and Research Center for the Giant Panda (CCRCGP) in Bifengxia, Sichuan, China were analyzed for blood lead concentrations (Pb-B) during the 2017 breeding season. Thirteen of the 15 bears showed Pb-B below the method detection limit (MDL) of 3.3 µg/dL. The two remaining bears, although above the MDL, contained very low concentrations of lead of 3.9 and 4.5 µg/dL. All 15 giant pandas in this analysis had Pb-B concentrations that were within normal background concentrations for mammals in uncontaminated environments. For a threatened species, whose native country is plagued by reports of extremely high air pollution, our findings suggest that giant pandas at the CCRCGP are not absorbing lead at concentrations that would adversely affect their health.

Total Mercury in Six Antarctic Notothenioid Fishes.

We analyzed white muscle samples from six species of Antarctic fish (suborder Notothenioidei) collected in 2011 from McMurdo Sound, Ross Sea, Antarctica, to assess levels of total mercury (THg). Gymnodraco acuticeps and Trematomus bernacchii exhibited the highest concentrations of THg followed by Trematomus pennellii, Trematomus nicolai, Trematomus newnesi and Pagothenia borchgrevinki, (71.3, 53.9±32.1, 45.8±27.3, 37.2±18.6, 35.7±23.6, and 21.9±2.8 ng/g wet weight, respectively). The results from this study suggest that THg has the potential to bioaccumulate from various marine Antarctic ecosystems into biota.

Stereotypic behaviour predicts reproductive performance and litter sex ratio in giant pandas.

Breeding and welfare problems confront many conservation breeding programs. Stereotypies-repetitive, unvarying, functionless behaviours -are common abnormal behaviours that often arise in suboptimal conditions. While the role of stereotypies in welfare assessment is well studied, few investigations address the relationship between stereotypic behaviour and reproduction. We examined the correlation between stereotypic behaviour and reproductive performance in 101 giant pandas (Ailuropoda melanoleuca). High stereotyping males copulated more and produced more cubs, suggesting that highly sexually motivated males were prone to stereotypy but also had high reproductive competence. Female stereotypies were negatively associated with all reproductive measures closely tied to behavioural competence: high stereotyping females were less likely to copulate, less likely to mother-rear cubs, and-probably a result of poor maternal care-had lower cub survival. However, females that exhibited stereotypies were more likely to produce a cub, suggesting stereotypies are tied to behavioural but not physiological competence. High stereotyping female pandas also displayed strong and consistent bias toward production of female offspring while paternal relationship to sex allocation was the reverse. These results are consistent with stress-mediated sex allocation theory. Our findings raise concern about differential reproductive success among high and low stereotyping pandas, and possible genetic adaptation to captivity.