The National Zoo has done all it can to try to ensure a baby giant panda this summer. Now it's up to Mei Xiang. Her brief window for breeding is over for the year.
How long until we know whether a cub is on the way? We don't know!
First of all, a giant panda Mom often has a false pregnancy - and her behavior and even her hormone levels are the same as if she's really expecting. And, then, an embryo can float around inside Mama for days, weeks...or even months. After that, from implantation to birth, it's only 40 or 50 days. But a cub is so tiny that it doesn't show up on ultrasound until the last few weeks before birth - and that's when Mei is not so cooperative about getting tested.
So we wait, in a routine that's become familiar across the DC area...but still frustrating!
Here's a link to the story about this weekend's efforts to get Mei pregnant.