By Michael E. Ruane
Washington Post Staff Writer
Wednesday, December 22, 2010; 8:22 PM
The National Zoo said Wednesday that China has granted an extension of its lease of Washington's two giant pandas, Mei Xiang and Tian Tian, while details of a new agreement are worked out.
Zoo Director Dennis W. Kelly was in China last week seeking to negotiate a new panda arrangement to replace the 10-year, $10 million lease that expired Dec. 6. China owns and leases all giant pandas in U.S. zoos.
The zoo said no new agreement has yet been signed, but details are being worked on and a new arrangement could be unveiled next month. The zoo's two adult giant pandas have been in Washington since Dec. 6, 2000. The extension was granted Dec. 6.
Although the zoo has had the two pandas for a decade - and has tried almost annually to achieve a pregnancy - experts have been disappointed that the only offspring produced was Tai Shan, the beloved male born in 2005.
He was sent to China, according to prior agreement, Feb. 4 to join a breeding program.
The zoo badly wants cubs for research purposes. And recent science suggests that if a female panda has not become pregnant for several years, it is increasingly unlikely that she will be able to get pregnant in the future.
"We've not had a cub here in the last five years," Kelly said in an interview in July.
"There's some data that suggests that after four [breeding] tries, there's something [negative] going on," he said in July. Pandas generally mate once a year.
"Our male seems to be performing fine," Kelly said. "Seems to be that we're focused on Mei Xiang."
But zoo scientists already are planning for Mei Xiang's upcoming breeding season. She went into heat last Jan. 9, and Jan. 15 the year before. And the zoo said it would not move her during her annual pregnancy watch, which usuually lasts until spring.
A total of nine cubs have been produced in recent years at the four U.S. zoos that have giant pandas. In addition to Tai Shan in D.C., three cubs have been born at Zoo Atlanta - including one last month - and five have been born at the San Diego Zoo.
The Memphis Zoo's panda pair - residents there since 2003 - have not produced any offspring.