Mating Season Begins for Zoo Atlanta’s Giant Pandas, Lun Lun and Yang Yang

panda breeding updates available online

ATLANTA – Mar. 22, 2006 - Zoo Atlanta, a leader in the study of giant panda behavior, today confirmed that breeding season has begun once again for its giant pandas, Lun Lun (female) and Yang Yang (male). The pair, who has known each other from a year old, began exhibiting behavior changes over the past couple of days. Hormone values this week were slightly elevated, agreeing with behavioral observations — that estrus for Atlanta’s female giant panda has begun.

Spring 2006 marks the third time that both giant pandas are mature enough to mate and results from annual physical examinations indicate that both animals are in great health. This year, the Center for Behavioral Neuroscience (CBN) a consortium of universities, that includes Georgia State University, will be measuring Lun Lun’s hormones for the third year. In addition, Smithsonian’s National Zoological Park in Washington, D.C, which had a cub last year through artificial insemination, will also be providing an endocrinologist for hormone assays to assist with Zoo Atlanta’s breeding season. These experts will work closely with Zoo Atlanta’s researchers and animal care staff to precisely target Lun Lun’s ovulation window, which is suspected to be less then three days.

If successful, a giant panda cub birth at Zoo Atlanta would be the fifth U.S. birth, since 1990. Only an estimated 1,600 giant pandas remain in the wild today, with approximately 185 additional giant pandas living in captivity. Although the global captive population has increased over the past year — a positive sign — Zoo Atlanta is hopeful for a cub to further increase genetic variation in the population and to collect data on giant panda maternal behavior for research being led by Zoo Atlanta scientist, Dr. Rebecca Snyder.

“Our optimism surrounding the birth of a cub from Lun Lun and Yang Yang has not wavered,” said Dennis Kelly, Zoo Atlanta president and CEO. “We are thrilled that the National Zoo has offered to support our efforts by loaning us one of their scientists and as they say, the third time is a charm.”

The Zoo Atlanta Giant Panda Mating Timeline:

Lun Lun’s Estrus and Synchronization:
Female giant pandas, which normally live alone in the wild, undergo an estrous period for seven to ten days only one time per year in the spring. During this period the female experiences behavioral and hormonal changes that inform males in the area she will soon be receptive to mating. In the wild, a female near ovulation spends much of her time in a tree, which permits her to fend off male advances until she is ready. Zoo Atlanta has created a similar environment for Lun Lun and Yang Yang, keeping the giant pandas separated much of the year. They see each other through a mesh barrier, and exchange enclosures frequently, permitting them to communicate using scent.

Ovulation and Attempted Natural Mating:
After hormone levels indicate ovulation is approaching, the pair will be put together to allow natural mating to take place. Natural mating provides the best probability of fertilization. If natural mating is unsuccessful this year, Zoo Atlanta will employ artificial insemination, referred to as AI.

Artificial Insemination:
Reproductive specialists from the University of Georgia College of Veterinary Medicine, San Diego Zoo and Zoo Atlanta believe that Lun Lun has been sexually mature for nearly five years. If staff determined that the giant pandas were unsuccessful in natural breeding attempts, Zoo Atlanta has the opportunity to employ AI. Artificial insemination has no effect on future natural efforts to reproduce .

Ovulation and Beyond:
Zoo Atlanta will continue hormonal and behavioral monitoring and begin using ultrasound to collect additional data as well as track a possible pregnancy.

Giant Panda Reproductive Factors:

With the support and encouragement of its Chinese partners, Zoo Atlanta is committed to doing everything possible to ensure successful breeding. Giant panda females are only fertile for approximately for less than three days a year. Giant pandas normally experience delayed implantation and often undergo pseudo-pregnancy in which typical hormonal and physical changes occur even without actual pregnancy. These characteristics make pregnancy difficult to confirm until the last two weeks of gestation.

In addition to collecting vital behavioral data, Zoo Atlanta should know if giant panda reproductive efforts were successful by August.

About Giant Pandas and Zoo Atlanta’s Research:

Because of the small population of giant pandas and their elusive nature, limited data exists on the species, particularly maternal and developmental behavior. Zoo Atlanta, a leader in giant panda behavioral research, is committed to increasing knowledge of the species through collecting data and publishing research findings.

"One goal of our giant panda research program is to document how mothers care for cubs and how this affects behavioral development in giant panda cubs. Our studies will provide information on maternal care and behavioral development, which would be difficult to obtain in the wild," said Dr. Rebecca Snyder, curator of giant panda research and management.

Zoo Atlanta’s pair of giant pandas, who have been playmates since they were very young, are two of eleven pandas in zoos in the United States. Other institutions studying the giant panda include the Zoological Society of San Diego Zoo, Memphis Zoo and Smithsonian’s National Zoological Park (Washington, DC). In addition to collaborative relationships with these zoos, Zoo Atlanta partners with local, national and international experts. Professionals who contributed their expertise to reproductive efforts at Zoo Atlanta included scientists from Chengdu Research Base and Chengdu Zoo (China); reproductive and behavioral specialists from Smithsonian’s National Zoo, The Zoological Society of San Diego; Georgia Tech; The Center for Behavioral Neuroscience; and the University of Georgia Veterinary School.

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