By: Susie Ellis and David Wildt
The endangered giant panda (Ailuropoda melanoleuca) is endemic to the mountains of Sichuan, Gansu and Shanxi Provinces in China. Historically, the species was widely distributed and may have numbered 100,000 animals, but has declined to no more than 1,200 animals as the result of numerous detrimental forces. In the wild, giant pandas are fragmented into perhaps 32 subpopulations with no opportunity for large-scale genetic exchange. The giant panda serves as a worldwide ambassador for the need to conserve endangered habitats and species.
Because of the precarious status of wild populations, giant pandas in captivity play a crucial role for educating the public about the plight of their wild counterparts. Captive giant pandas also function as a critical 'hedge' against extinction and serve as a potential resource for future reintroduction efforts. For now, however, captive-held giant pandas are especially important as a research and educational resource and as a means for attracting substantial public support for conservation of the giant pandas living in the wild as well as other endangered endemic species in China.
Currently, there are about 117 giant pandas living in 33 zoos and breeding centers in China. The Chinese Association of Zoological Gardens (CAZG), under the umbrella of the Ministry of Construction, manages a significant portion of these animals. The CAZG recognizes the need for a scientifically-based management plan for giant pandas held in its member zoos.
After a formal invitation from CAZG and the Ministry of Construction, the Conservation Breeding Specialist Group (CBSG) agreed to facilitate a Captive Management Planning Workshop for the giant panda that was held in Chengdu from the 10th to 13th of December, 1996. A neutral facilitator, catalyst and source of technical advice, CBSG is a small non-governmental organization (six staff, but with a volunteer network of more than 800 people) affiliated with the IUCN-World Conservation Unions Species Survival Commission. Supported by the AZA Giant Panda Conservation Action Plan Group and the Columbus Zoo, the workshop was led by CBSG Chairman, Dr. U.S. Seal, and a five-member team of specialists in reproduction, population biology, behavior and veterinary medicine. Approximately 50 other giant panda specialists representing various Chinese institutions and Chinese governmental organizations participated. The general outcome of this first workshop was a 'blueprint' for developing a practical and scientific management program that will result in a healthy, growing population of giant pandas in China. This blueprint was developed by workshop participants working together who identified high priority issues and elaborated strategies with specific actions and timelines. There were three working groups that addressed: 1) the giant panda studbook and records; 2) reproduction, behavior and management; and 3) mortality, veterinary issues and nutrition.
The workshop generated significant new information on the giant panda. One discovery was that only one captive born male and 6 captive-born females have ever reproduced. At the same time, computer simulation modeling revealed that, if the trigger to reproduction could be identified, then the captive population of giant pandas in China had the potential to double within the next 10 to 14 years.
There was consensus that developing a self-sustaining population would require a series of steps. Workshop participants made more than 25 explicit recommendations, one of the most important for a biomedical assessment of all available, adult giant pandas to: (1) evaluate health, reproduction and behavioral status; (2) collect and store biomaterials useful for future genetic evaluations; and (3) ensure the unambiguous identification of all individuals.
Final negotiations between CAZG, CBSG, and AZA member institutions to conduct the biomedical survey occurred in September 1997, with all parties agreeing to work together as integrated scientific teams. In March 1998, in a first-ever effort of its kind, a team of scientific specialists from three AZA accredited zoos worked with Chinese zoo experts to carry out the first health and reproductive survey of giant pandas in Chinese zoos, with the aim of trying determine why captive giant pandas are not reproducing as well as they might. Veterinarians, reproductive specialists, geneticists and animal behavior specialists combined their skills in the intensive collaboration, jointly organized by the CBSG and the CAZG.
The multi-disciplinary team of US specialists, from CBSG, the Smithsonian's National Zoological Park, the San Diego Zoo, the University of California at Davis, the Columbus Zoo and Zoo Atlanta worked side-by-side with Chinese colleagues over a three-week period at three of the most prominent giant panda breeding facilities in China: the Chengdu Zoo, the Chengdu Research Base of Giant Panda Breeding and the Beijing Zoo.
The teams worked together to assess which animals were prime breeders, which animals will have value as breeders in the future (when they become sexually mature) and which have problems that require further attention or make the animal unlikely to ever reproduce. Of the 18 giant pandas examined, all but five were found be good breeding prospects: seven animals were classed as prime breeders; six as potential breeders; and two as questionable breeders.
In addition to the health and reproductive assessments, animals were implanted with transponders and tattooed in the upper lip with a studbook number. These complementary marking systems allow easy identification of animals, and also will facilitate better record-keeping and management.
The teams examined six male and twelve female giant pandas. In addition to the physical and reproductive examinations, small skin samples were processed for future genetic analysis. Because many of the older pandas in Chinese zoos are wild born, these samples will be useful in determining the pedigree of animals living in the existing zoo populations. Blood samples were evaluated at a local human hospital to begin to develop a crucial database on blood values from both healthy and unhealthy animals. Additional targets of the studies were reproductive history, diets and behavior. Semen was collected from four males, evaluated, used to test various sperm freezing methods and was then stored for future artificial insemination (AI) studies. The Chinese have used AI for many years to help breed giant pandas in zoos.
Female giant pandas have extremely short periods of reproductive activity, usually coming into estrus once a year for only 3 days. The need to perfectly time breeding, with a compatible mate, is essential. An analysis of breeding records revealed that many females at the Beijing Zoo were skipping years between estrus, unlike giant pandas in the Chengdu facilities. Adding to this interesting finding is the fact that few males are available for breeding. Since the scientific teams found that all males examined were producing high numbers of motile sperm, the lack of reproduction may be related to behavioral incompatibility or perhaps to facility design that may hamper successful introductions or other combinations of factors.
Some institutions involved in the current giant panda breeding program often rely on a combination of natural and assisted breeding (artificial insemination). Therefore, some (or many) females receive sperm from different males, generating many questions about parentage. To have an effective, long-range genetic management program, unambiguous pedigree information is needed. Genetic evaluations were recommended to establish provenance and to estimate how much of the heterozygosity from the wild population remains in the captive population. Genetic assessments would provide independent evidence about the effectiveness of artificial insemination. Therefore, a high priority for the future will be to analyze all collected genetic samples, as well as to collect and process samples from other giant pandas in the captive breeding program.
Of special concern was one giant panda whose paternal grandfather and maternal great-grandfather possibly may be the same individual. Half the sperm of this male were abnormally shaped. It has been well-documented that inbred animals usually produce more abnormal sperm, which has the potential of reducing fertility (Wildt 1994). The teams also were able to exchange information on the latest techniques for semen freezing and thawing. Techniques that had been developed in China were found to be equal in effectiveness to those in use in the United States.
Even giant pandas classified as prime breeders were occasionally found to have medical questions that require further diagnosis. For example, a few animals showed blood values that may be indicative of poor liver or kidney function. This clearly illustrates how little we now know about this species and how much more needs to be done to ensure its future.
The US-based team that carried out the project was comprised of scientists from the National Zoological Park in Washington (Dr. David Wildt, team leader and reproductive physiologist and Dr. JoGayle Howard, reproductive physiologist), CBSG (Dr. Susie Ellis, behaviorist), the Zoological Society of San Diego (Dr. Don Janssen, veterinarian and Arlene Kumamoto, geneticist), University of California at Davis (Dr. Lyndsay Phillips, veterinarian), the Columbus Zoo (Dr. Ray Wack, veterinarian) and Zoo Atlanta (Rebecca Snyder, behaviorist).
Generous travel support for the project was provided by British Airways through the National Zoo's NOAHS Network at the Conservation & Research Center. Generous direct financial support was provided by the American Association of Zoos and Aquarium's (AZA) Giant Panda Group, the Zoological Society of San Diego, the Columbus Zoo, and Zoo Atlanta. Equipment was donated by Nellcor Puritan Bennett Incorporated (Pleasanton, CA), Air-Gas Incorporated (Linthicum, MD), the Zoological Society of San Diego and CBSG. Sensor Devices Incorporated (Waukesha, WI) loaned a portable blood analyzer for the project.
At the end of the project, a two-day workshop, including all project participants, was held in Beijing to discuss the results and to determine the next steps to help to make the captive giant panda population self-sustaining. One of the highest priorities is enhancing medical and nutrition programs for the giant panda. (These issues also were considered high priority at the December 1996 conference on giant panda master planning.) Participants in the two-day workshop recommended the development of a combined veterinary medicine/nutrition training course provided through CAZG and CBSG sometime in 1999. This workshop will be a "hands-on" type course focusing on diagnostics, anesthesia, and pathology. In parallel with this training course will be training in standard tools used for the enhancement and study of nutrition. A second workshop, focusing on behavioral methods, including enrichment, facility design and developing standardized studies of behavior, also was recommended.
The CBSG has been invited to formally present the results of the survey to the Technical Committee on Giant Panda Breeding in Chengdu, China in December 1998, and to meet to formulate the next steps in the CAZG/CBSG partnership. This meeting also may provide an opportunity to expand the survey to other, interested institutions holding giant pandas. Other discussions underway are focusing on expanding this type of captive management planning to other endangered species endemic to China, a major commitment that the CAZG is keen to undertake.
For additional information on the project, contact Susie Ellis, Senior Program Officer, CBSG, 138 Strasburg Reservoir Road, Strasburg VA 22657. Telephone and fax 540-465-9589. Email: SusieEllis@compuserve.com.
Wildt, D.E. 1994. Endangered species spermatazoa: diversity, research and conservation. Pages 1-24 in A. Bartke, editor. Function of Somatic Cells in the Testes. Springer Verlag: New York.
Archives | Bulletin Board | Comments | Contribute to the ESU | ESU Staff | Home | July/August 1998 Contents | Links | Next Issue | Subscriptions