Will the District soon have a brand-new Butterstick to croon over? Maybe... or maybe not. National Zoo scientists detected a secondary rise in Mei Xiang's hormone levels yesterday -- urinary progestagen, for the morbidly curious.
The hormone rise indicates that either the female giant panda is 40 to 50 days from delivering an adorable baby cub... or from reaching the end of a false pregnancy, dashing our hopes of enjoying cute photos on Flickr for years to come.
Unforunately, these fake-out pseudopregnancies are common in giant pandas.
"We study the hormone levels, work from past data and monitor her behavior closely, but all signs can indicate she is pregnant when she is not," said Janine Brown, a reproductive biologist at the zoo. "So we remain hopeful, but cautious."
Mei Xiang, 11, went heat in early January, and was artificially inseminated with sperm from Tian Tian, 12, on Jan. 9 and 10. Since then, scientists have been analyzing her hormone levels weekly -- nothing like a little privacy when trying to reproduce, right?
Zoo vets have also been conducting weekly ultrasounds. However, panda fetuses do not start developing until the last weeks of pregnancy, so it's still to early to spot a fetus if there is one.
The birth of Tai Shan -- Mei Xiang and Tian Tian's only cub so far -- managed to be a surprise in 2005; during the last weeks of Mei Xiang's pregnancy, she wouldn't cooperate for ultrasounds. Tai Shan made his butterstick-sized appearance on July 9, 2005, and left for his new home in China Feb. 4.
