Scientists observe reproductive seasonality in male giant pandas

Apr 04, 2012
The state-of-the-art Chengdu Research Base of Giant Panda Breeding has provided an unprecedented opportunity for researchers to study multiple pandas in a single location. Credit: Zhang Zhihe, Chengdu Research Center for Panda Breeding.

A three-year study of giant pandas published today in Biology of Reproduction's Papers-in-Press reveals that reproductive seasonality exists not only in female pandas, but in male pandas as well.

According to the authors of the study, this new understanding of the regulators of male reproductive function will allow continued improvement of the captive panda management program and will, one day, assist in reintroducing into the wild.

The is a specialized bear whose wild habitat now consists of only a few mountain ranges in central China. Attempts at preserving this endangered species have met with varying success, but over the last decade, substantial progress in giant panda breeding within China has resulted in a significant increase in the population of captive pandas.

Female panda reproduction has been thoroughly studied, and it is well known that a panda's estrus, the state of sexual excitement that immediately precedes ovulation, occurs only once a year, sometime between February and May, and lasts only 24 to 72 hours. Few studies have examined male reproductive capacity and physiology in similar detail, and none involved sample sizes larger than one or two individuals.

Now, an international research team led by Dr. Copper Aitken-Palmer of the Smithsonian Conservation Biology Institute and Dr. Rong Hou of the Chengdu Research Base of Giant Panda Breeding, along with senior researchers Drs. David Wildt, Mary Ann Ottinger, and the late JoGayle Howard, has published the results of their study of eight male giant pandas in a captive in China.

The team evaluated the interrelated seasonal changes in male panda androgen levels, sperm concentration, testes size, and , and found that unlike what is found for females, in the male giant panda varies throughout the year. Waves in male giant panda reproductive activity occurred 3 to 5 months before the interval when most females displayed their estrus, presumably in order to prepare for and then accommodate the brief and unpredictable female estrus.

These findings not only fill a knowledge gap, but the authors believe that they can be used to help researchers collect and preserve only the highest-quality panda spermatozoa for artificial insemination, an increasingly important tool in genetic diversity management within the captive panda population.

Explore further: Alternate mechanism of species formation picks up support, thanks to a South American ant

More information: "Reproductive Seasonality in the Male Giant Panda", Biology of Reproduction (in press).

Provided by Society for the Study of Reproduction

not rated yet

Related Stories

China announces first panda from frozen sperm

Jul 24, 2009

(AP) -- China announced the first successful birth of a panda cub from artificial insemination using frozen sperm, giving a new option for the famously unfertile endangered species, officials said Friday.

China panda baby boom aids against extinction

Oct 26, 2010

(AP) -- China's panda population is booming this year thanks to a record number of births in captivity, a rare accomplishment for the endangered species known for being poor breeders.

China to release six pandas into wild

Dec 21, 2011

Six captive-bred pandas will be freed into an enclosed forest in southwestern China next year in the first mass release of the highly endangered animals, the official Xinhua news agency said Wednesday.

US zoo receives $4.5 mn panda donation

Dec 19, 2011

The National Zoo in Washington announced Monday it had received a $4.5 million donation from a rich US benefactor which will fund a five-year study into preservation of the giant panda.

Plan to reintroduce giant pandas to the wild

Dec 07, 2010

(PhysOrg.com) -- Scientists in China have been so successful at breeding giant pandas in captivity that they are now planning for their reintroduction to the wild with 15 years.

Pandas mate with help at the National Zoo

Mar 24, 2008

U.S. veterinarians have artificially inseminated Mei Xiang, a female giant panda at the Smithsonian's National Zoo, after natural mating was unsuccessful.

Recommended for you

Orb-weaving spiders living in urban areas may be larger

Aug 20, 2014

A common orb-weaving spider may grow larger and have an increased ability to reproduce when living in urban areas, according to a study published August 20, 2014 in the open-access journal PLOS ONE by Eli ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

panorama
not rated yet Apr 04, 2012
Because sometimes the guys are tapped out too, but check your lease panda's...