Get out the party hats, a giant panda has been born! Yesterday afternoon, Mei Xiang, one of the ursine residents of the Smithsonian's National Zoo, gave birth to another little cub. Time to turn on the panda cam!

The panda team saw Mei Xiang's water break around 3:36pm ET yesterday, and at 5:32pm, she gave birth to a squealing cub. It's an especially happy event since it has been unclear whether Mei Xiang was truly pregnant or experiencing a pseudopregnancy. During her last ultrasound on August 5, veterinarians were unable to detect a fetus.

You can watch Mei Xiang on the panda cams, although they will be briefly shut off while the staff performs health checks on the cub. The first check will be performed within 48 hours of the birth and every few days after that, although the fact that the cub is already making noises is an excellent sign. Mei Xiang gave birth to her first cub, Tai Shan (although he will always be known as "Butterstick" in our hearts), on July 9, 2005. She gave birth to a second cub on September 16, 2012, but sadly that cub passed away six days later due to liver damaged resulting from its underdeveloped lungs. Fingers crossed that this cub will grow into a healthy adult.

News from the David M. Rubenstein Family Giant Panda Habitat [Smithsonian via Boing Boing]