(Reuters) - A giant panda surprised its keepers by giving birth to a stillborn cub at the Smithsonian National Zoo in Washington on Saturday evening, a day after the animal delivered a live cub, an official said.
The stillborn cub was born with "many abnormalities" and when a staff member retrieved it from the floor of its mother's den it was "very apparent it had never been alive," said zoo spokeswoman Pamela Baker-Masson.
The mother panda, 15-year-old Mei Xiang, while holding onto the firstborn cub, groomed the stillborn cub for 17 minutes before letting it down, Baker-Masson said.
"The fact that Mei never set down the first cub shows us, it demonstrates that she's a terrific mom," she said.
Giant pandas, which are one of the world's most endangered species, have their natural home in a few mountain ranges in central China. There are about 1,600 known to be living in the wild and another 300 in captivity, mostly in China.
About 50 percent of panda births are twins, but when midnight came and passed after the first birth, which occurred at 5:36 p.m. local time on Friday, officials at the zoo and a visiting panda expert from China believed there would be no second birth, Baker-Masson said.
But to everyone's surprise, the stillborn panda cub arrived at 7:29 p.m. local time on Saturday, she said.
The first born panda cub appears to be healthy.
A necropsy was under way on the second cub and officials at the National Zoo planned to provide more details on Sunday.
Reporting by Alex Dobuzinskis in Los Angeles; Editing by Xavier Briand