We're on panda cub watch! A spine, leg and heartbeat have been detected. This is considered a high-risk pregnancy due to Bai Yun’s age. If a cub is born, Bai Yun will be one of the oldest giant pandas known to give birth. Keep your fingers crossed!

We're on panda cub watch! A spine, leg and heartbeat have been detected. Due to Bai Yun’s age, this is considered a high-risk pregnancy. If a cub is born, Bai Yun will be one of the oldest giant pandas known to give birth. Keep your fingers crossed! sandiegozoo.org/pandacam

Full release:
Based on hormone testing, behavioral observations and ultrasounds, the staff believes that Bai Yun, a 20-year-old female giant panda, is pregnant and they are beginning their birth watch for a cub. Ultrasound video taken Thursday clearly showed a panda fetus. The spine and a leg are visible and veterinarians were also able to detect the heart beat.

The giant panda team, composed of zookeepers, veterinarians, nutritionists, scientists and others, are keeping the area of Bai Yun’s den as quiet as possible, and only critical staff is being allowed in the area. While all testing shows that she is still reproductively viable, due to Bai Yun’s age, this is considered a high-risk pregnancy. If a cub is born, Bai Yun will be one of the oldest giant pandas known to give birth to a cub.

Keepers will be watching Bai Yun in her den around the clock. The nursery is prepared and ready to care for the cub if there are any signs of distress in the cub or Bai Yun.
Following signs of estrus in March 2012, Bai Yun was paired with Gao Gao, a 20-year-old, rescued, wild-born giant panda. This pair has produced four cubs while they have lived at the San Diego Zoo.

A panda’s fertilized egg remains suspended until a trigger in the environment indicates it is time to implant. The trigger is still unknown to scientists. Giant pandas routinely delay the implantation of the fetus as long as four months. The team estimates implantation occurred in Bai Yun six to seven weeks ago. After implantation the fertilized egg begins to develop. Impending birth is predicted on the basis of behavioral, hormonal and anatomical changes documented by scientists at the San Diego Zoo’s Institute for Conservation Research.

The mother and the cub will remain in the den for four to five months before returning to a public exhibit. The male, Gao Gao, has no role in raising the cub. During the denning period, the only way to see the panda cub and mother will be through the San Diego Zoo’s live Panda Cam, available at www.sandiegozoo.org/pandacam.

Newborn giant panda cubs are born pink and grey, without sight and weigh an average of 4 ounces, or 112 grams. Their trademark black-and-white markings develop within the first months. The sex of the cub will not be known until animal care staff examine the cub, which is expected to happen in approximately two months.