Nature didn’t quite take its course, so scientists at the National Zoo used the last hours of the panda breeding season Friday to try a new method of artificial insemination. They put the chances of producing a panda cub at about 50-50.
The 6-year-old female Mei Xiang and 7-year-old male Tian Tian made several attempts to mate naturally, but weren’t successful, said zoo reproductive scientist Jo Gayle Howard.
Researchers decided to periodically separate the pair and reunite them to heighten their interest in each other. But in the end, experts say male pandas just don’t know much about reproduction — a problem that has plagued efforts to breed the animals around the world.
“I think males learn this over time, so there’s a good chance he will get it right next year,” Howard said of Tian Tian. “This year it seemed like he was helping her more.”
The pandas had one last encounter early Friday morning, but Mei Xiang had lost interest. By 6:30 a.m., zoo researchers sedated both pandas to try artificial insemination. Howard used a lighted fiber optic scope for the first time in the operation to place the male’s semen directly into Mei Xiang’s reproductive track.
With the light and camera “we know we got it in the right place,” Howard said.
Tian Tian woke up first, late in the morning, followed by Mei Xiang.
“He was walking around his cage, very happy and wondering where she is,” said zoo veterinarian Sharon Deem.
While they continued to recover, the panda exhibit was temporarily closed. There was a chance the pandas would return to public view on Saturday. The "panda cam" on the zoo's Web site remained active.
There are few towns as wild about pandas as Washington, and that’s one reason why Jim and Lauren Modzelewski of Wilmington, N.C., brought their daughters to the zoo Friday.
“I’m from here, and that’s the one thing I remember about the zoo,” said Lauren Modzelewski.
Her husband said they were disappointed to miss the pandas; 7-year-old Hailey said seeing the Cheetah cubs was the next best thing.
Giant pandas are found in only four zoos in the United States — Atlanta, Memphis, San Diego and Washington — and only San Diego has bred healthy panda cubs.
Attempts here have always failed, or the cubs lived only a few days.
The gestation period for a panda is three to six months, but it’s difficult to know when Mei Xiang is pregnant because the cub is about the size of a stick of butter. The good news is Mei Xiang is trained to roll over for ultrasound examinations, Howard said, “and she likes the attention.”