Good Breeding: A University Lab is Helping Atlanta Panda Bear Cubs
Yang Yang is a real animal. But in the bedroom, he’s no Don Juan. Most days, sex is the furthest thing from his mind — he would rather climb trees, eat bamboo and goof off with his best pal, Lun Lun. But because the friends are giant pandas — and their species is endangered — scientists at Zoo Atlanta were hoping they’d drop the horseplay and start fooling around in earnest.
When attempts to make a love connection proved unsuccessful, zoo scientists enlisted the help of Georgia State researcher Mary Karom. Karom oversees the lab of Elliot Albers, a Regents’ Professor of Biology and director of the Center for Behavioral Neuroscience. It was in the university lab late last winter that Karom meticulously measured the daily estrone sulfate levels in Lun’s Lun’s urine, working to identify the onset of a two- to three-day period each spring when the female panda would be fertile. A panda’s level of estrone sulfate, a byproduct of estrogen, gradually rises and then briefly peaks just before ovulation, Karom says.
And that, says Rebecca Snyder, giant panda curator at Zoo Atlanta, is the perfect time to bring the pair together to mate — or, in this case, to artificially inseminate. Snyder also notes that shortly before ovulation, Lun Lun’s behavior changes: She becomes increasingly active and walks, scent-marks and vocalizes more than usual.
Zoo scientists artificially inseminated Lun Lun in March, and Karom continued to measure the daily progesterone levels in the panda’s urine to help determine whether she was pregnant. After months of anticipation, the zoo definitively called off its birth watch earlier this month — but Karom plans to carry on her work to help Lun Lun bear cubs.
It’s often difficult to tell if a panda has actually conceived because pandas commonly exhibit hormonal, behavioral and physical changes that mimic a pregnancy — even though one hasn’t actually occurred. Panda embryos also often undergo delayed implantation, meaning they may float unattached in the uterus for several weeks, delaying embryonic development. And a panda’s gestation period can vary from less than three months to more than six, Snyder says.