Welcome

A three-​year study of giant pan­das pub­lished 4 April 2012 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 pan­das into the wild.

The giant panda 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. In Jan­u­ary this year, six young ani­mals which were born and raised in the Chengdu Research Base of Giant Panda Breed­ing have been trans­fered to ‘Panda Val­ley’, a 134 hectares of enclosed for­est in south­west China Sichuan Province, where they are trained and reha­bil­i­tated to be released into the wild.

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.

Giant Pan­das eat­ing, mov­ing, and play­ing at the “Chengdu Research Base of Giant Panda Breed­ing” (成都大熊猫繁育研究基地), north­east of Chengdu, China:

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, has pub­lished the results of their study of eight male giant pan­das in a cap­tive breed­ing cen­ter in China. The team eval­u­ated the inter­re­lated sea­sonal changes in male panda andro­gen lev­els, sperm con­cen­tra­tion, testes size, and repro­duc­tive behav­ior, and found that unlike what is found for females, repro­duc­tive fit­ness 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.

The above news item is reprinted from mate­ri­als avail­able at Soci­ety for the Study of Repro­duc­tion and Wikipedia. Orig­i­nal text may be edited for con­tent and length.

(Sources: Soci­ety for the Study of Repro­duc­tion, 04.04.2012; Wikipedia)