Challenging night for caretakers of National Zoo panda cubs

WASHINGTON -- The National Zoo says two panda cubs born Saturday are doing well, but their caretakers had a challenging night.

Because pandas won't usually nurse twins if left to their own devices, officials are following a procedure developed by Chinese breeders. Panda mom Mei Xiang gets to nurse and bond with one cub at a time. The other cub is kept in an incubator. Every several hours, the cubs are swapped.

The zoo said Monday that when caretakers tried to swap the cubs late Sunday, Mei Xiang would not set down the cub she was holding. As a result, the team cared for the smaller cub, feeding it with a bottle and through a feeding tube, until about 7 a.m. Monday when a successful swap was made.

The surprise news that a giant panda gave birth to not one, but two cubs, came late Saturday from the National Zoo in Washington.

Mei Xiang gave birth to her first cub at 5:35 p.m. on Saturday. The zoo sent a tweet announcing the second arrival a few hours later, which came at 10:07 p.m.

Mei Xiang's first cub, Tai Shan, was born in 2005. Her second cub, Bao Bao, turned 2 years old on Sunday.

Keepers will be watching the newest cubs closely. Pink, hairless and blind, newborn cubs weigh three to five ounces and are about the size of a stick of butter.

The zoo has also had disappointments in the past. Mei Xiang gave birth to another stillborn cub in 2013. And in 2012, she gave birth to a cub that died after just six days. Its lungs hadn't fully developed.

Even if the new cubs are healthy, panda fans shouldn't expect to see them in person for a while. After Mei Xiang's second cub Bao Bao was born in 2013, it was about five months before she made her public debut. Fans who want to see the newest panda will have to try to catch a glimpse of them on the zoo's online panda cam.

The National Zoo is one of only four zoos nationwide to have pandas, which are on loan from China.