David C. Kersey, PhD – Assistant Professor, Physiology


Dr David KerseyI became involved in giant panda conservation a little more than 10 years ago.  I had experience in wildlife reproductive endocrinology and was looking for a project.  Surprisingly, our knowledge of giant panda reproduction was less than comprehensive, so I embarked on a six year study to characterize the reproductive cycle of the male and female giant panda via fecal hormone steroids.  This approach had never been tried on this scale in the species and offered us the best means to routinely sample a large number of individuals over multiple years.  In addition to reproductive hormones, we also investigated adrenal steroids, sometimes referred to as ‘stress hormones’. 

At the conclusion of the study we confirmed a number of suspicions about the reproductive cycle of both sexes, and we also found something interesting; upwards of 30% of females were not cycling normally.  It also turned out that these acyclic females did not have high levels of adrenal steroids, a common cause of acyclicity in other species, and therefore we could not conclude stress as a major factor in acyclicity. However, these findings led us down the path we are on today with one of my new studies; thyroid hormones.  Thyroid hormones are interesting in that they help control metabolism and therefore energy use, which is very important to maintain reproduction.  Because the giant panda walks a fine line in terms of energy balance due to its diet of almost exclusively bamboo, understanding metabolic changes associated with different reproductive stages will gives us valuable information about what contributes to successful breeding.

During the course of my research I developed a close and reciprocally beneficial relationship with some of the giant panda breeding facilities in China.  Specifically, I have trained some of their researchers and veterinarians, and in turn I have been educated by them about giant panda biology.  This relationship and collaboration leads me to China to work at these facilities on a number of occasions, most recently this past spring.  During this recent trip I was having a conversation with some of their researchers during a breeding encounter (a time when a male is introduced to a female in heat), and we acknowledged the biggest challenge in giant panda reproduction is a lack of a pregnancy test.  This issue has dogged researchers since the first panda was studied, but due to complications in studying the species has never been resolved.  So, we decided to tackle this issue head on and do a large-scale study of pregnancy in the giant panda.  With this study currently underway, we hope to identify a physiological marker of pregnancy and develop a test that can be employed by all institutions that house the species.  In addition to the pregnancy study, we are investigating the effect of light cycles on reproductive activity and how management affects their biology.  These projects will shed new light on the giant pandas and hopefully lead to improvements in efforts to conserve the species.

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