A vigil continues at the Smithsonian's National Zoo to see whether giant panda Mei Xiang is pregnant.
Nearly 40 cameras, and an online Pandacam, have been monitoring the panda since yesterday afternoon.
Zoo scientists say Mei Xiang's hormone levels are approaching baseline. That means she's either nearing the end of a pregnancy, or a pseudo-pregnancy.
Hormone levels and behavior can falsely indicate pregnancy in female pandas. So volunteers are watching for signs, such as nest-building and the cradling of small objects. Recently, watchers have observed the panda spending more time shredding bamboo to make a nest.
In anticipation of increased traffic to the Pandacam this weekend, the Zoo will limit each view to five minutes per session. Visitors must refresh their browser to view the webcam again.