The National Zoo's celebrated giant pandas could have an early fling -- anytime in the next three days -- but the public will have to watch the annual mating ritual via the Internet.
Starting today, a zoo official announced, the Panda House will be closed to visitors and remain off-limits while the mating effort is underway. And, in their quest for a surviving panda cub, the staff is trying something a bit different this year: The panda pair will be kept apart until the female is thought to be at peak fertility.
The zoo is keeping Mei Xiang (left) and Tian Tian apart until her fertility peaks. A webcam provides public viewing.
(Robert A. Reeder -- The Washington Po St)
"The idea is to create a longer and sustained interest" in mating, Peper Long, the zoo's spokeswoman, said yesterday. "It's a different management strategy."
The pandas, male Tian Tian (pronounced t-YEN t-YEN) and female Mei Xiang (may-SHAWNG), were separated Friday after Mei Xiang began marking a scent and making chirping noises, both signs that she was going into estrus, or heat. Zoo officials had not expected to see this activity until April, based on past experience.
Officials decided yesterday to close the Panda House and keep the pandas indoors after tests on Mei Xiang showed "very high" hormone levels, Long said. In the past, news of the mating attempts has drawn large crowds to the panda exhibit.
Since arriving from China in 2000, Mei Xiang, now 6, and Tian Tian, 7, have been kept together during the day and have gotten along very well. They mated for the first time, very briefly, in April 2003, but no pregnancy resulted.
After the pair failed to mate last April, zoo scientists tried artificial insemination, without success. Mei Xiang was not anesthetized for that procedure. Long said that if mating does not occur this year, the panda will be anesthetized for a second attempt at artificial insemination.
The pandas are in the fifth year of a 10-year loan from China, at a cost of $1 million a year. There are only about 1,000 pandas left in the mountain forests of central China and about 140 in breeding facilities and zoos.
The zoo's previous panda pair, Ling Ling and Hsing Hsing, produced five cubs, but none lived more than a few days.
The National Zoo is one of four zoos in the country to exhibit giant pandas. The others are in San Diego, Atlanta and Memphis. The San Diego Zoo, which has had two successful panda births, is the only zoo among the four to keep its pandas apart except for a short mating period.
"We've done it very differently, but that's because our pandas are adults and were adults when they arrived," said Yadira Galindo of the San Diego Zoo. "The other zoos have housed them together, but they got them at a younger age."
Long said experts in China recommended separating the pandas until Mei Xiang is at peak fertility. Extensive tests conducted on Mei Xiang every spring indicate that there are probably only two good days a year for optimal mating.
The Panda House has been closed intermittently during construction of the zoo's Asia Trail, the first phase of which opens next year.
But Long said the current closure is because of mating concerns. The public, she said, can still view the pandas on a webcam by visiting the zoo's Web site at www.nationalzoo.si.edu/Animals/GiantPandas.