National Geographic : 2014 Oct
140 national geographic • OCTOBER 2014 Basic Instincts Consider the male giant panda, the ultimate long-suffering suitor. The object of his desire, the female Ailuropoda melanoleuca, goes into heat once a year—for just 24 to 72 hours. Small wonder that pan- das are endangered and their procreation in captivity is monitored as obsessively as the begetting of British royals. With such a fleeting chance to make that love connection, what’s a panda lad to do? Be anatomically equipped and on sexual standby. Female pandas’ fertility spell can occur at any time from Febru- ary through May. To be forearmed for that moment, males go into hormonal overdrive starting in autumn. During the females’ four “maybe” months, the males’ testes may balloon to two or three times their normal size. When scientists in Chengdu, China, studied anesthetized panda males, they found the animals’ sperm was more abundant and motile during females’ peak season than at other times of the year. In short, the would-be panda daddy gives it his all—making those months a prime time to collect sperm for use in captive-breeding programs. A swain can stay so ready for only so long, after all. Come June or July, the giant pandas’ gonads will go out of production until the next breeding season. — Patricia Edmonds A genteel disquisition on love and lust in the animal kingdom HABITAT China STATUS Endangered FASCINATING FACTS Ravenous for bamboo, the average panda eats more than 60 pounds of it a day. Given their breeding habits, small wonder that pandas are endangered. Ready When She Is PHOTO: JOEL SARTORE 140 This giant panda was photographed at Zoo Atlanta in Georgia.