SAN DIEGO — A giant panda at the San Diego Zoo was artificially inseminated this week following two unsuccessful natural breeding sessions, but it remained unclear Saturday if Bai Yun was pregnant.
San Diego Zoo Institute for Conservation Research scientists were testing the 23-year-old female panda’s urine daily and expect to know in about a month if she is expectant. But zoo officials said a panda’s fertilized egg remains suspended until a trigger in the environment indicates it is time to implant, so it could take up to three months to for thermal imaging to show whether a fertilized egg has implanted.
Bai Yun was artificially inseminated Wednesday morning after two half-hour mating session with male panda Gao Gao apparently failed. Hormone testing showed that Bai Yun had already ovulated, and staffers attempted to take advantage of the short cycle since female giant pandas only experience estrus once a year for 48 to 72 hours.
Zoo scientists and researchers will predict if and when she will give birth based on behavioral, hormonal and anatomical changes.
Zoo staffers used frozen sperm from Bai Yun’s first breeding partner, Shi Shi, who died in 2008. The pair conceived a female cub named Hua Mei through artificial insemination in 1999. She was the first giant panda cub born at the San Diego Zoo, park officials said.
A half-dozen giant panda cubs have been born at the zoo since 1999. In the wild, giant pandas are considered to be critically endangered.