Staff at Smithsonian's National Zoo in Washington, D.C., are keeping a close eye on giant panda Mei Xiang's newborn twins. They say the cubs look strong and powerful.
"The cubs are doing pretty well. These early days everything's still touch and go, so we're watching them closely but we're very hopeful right now," zoo's lead veterinarian Brandie Smith told CNN Monday.
Dr. Smith said the new cubs are fragile and that problems with the mother panda's ability to care for the two new small babies could still arise.
Pandas usually don’t nurse twins. In the wild, they typically care for one and allow the other to die. To make sure both cubs get their chance to nurse, zookeepers are swapping the twins between the incubator and the mother's enclosure.
"It's very rare, obviously, for them to manage two cubs. If she were able to do it, we would certainly let her," giant panda biologist Laurie Thompson told the Associated Press on Sunday. "She couldn't figure out how to hold both of them. She couldn't get ahold of one and have the other one under her arm and pick it up at the same time. She just kept fumbling with them."
Panda keepers will continue performing the swaps as long as it's needed and as long as Mei Xiang lets them.
The swapping technique has been successfully used to rear twin pandas born two years ago at Zoo Atlanta.
Mei Xiang, who was artificially inseminated in April with sperm from Hui Hui, a panda in China, and from the National Zoo's Tian Tian, gave birth to the twins on Saturday. It is not clear which insemination was successful.
For more than three decades breeders have been trying to breed pandas at the National Zoo, but most of the cubs have died.
"A lot of things have to happen. This is a very critical period," Don Neiffer, the zoo's chief veterinarian, told AP. "Until the cubs are both out walking around, acting normal, being a panda, that's probably when we'll exhale."
Giant pandas, native to China, are endangered species. There are between 300-350 giant pandas in captivity and roughly 1,600-1,800 in the wild.
This report includes material from Reuters and the Associated Press.