The surviving panda cub at the National Zoo has more than doubled in size in the nearly two weeks since he was born.
Zoo vets were able to conduct a quick exam on the cub Wednesday after his mother, Mei Xiang, left her den. The cub weighed in at 10 ounces. He weighed about four ounces at birth.
The cub and his twin were born Aug. 22, but the other cub -- the smaller of the two -- died four days after birth. Zookeepers had been swapping them out to ensure that both got time and attention from Mei Xiang, as is protocol with twin panda births. Giant panda mothers are typically unable to care for twin cubs on their own.
The surviving cub appears to be healthy and is developing normally. He's still mostly hairless, but his black markings are becoming visible. He has not yet opened his eyes, which is normal.
Mei Xiang had been artificially inseminated in late April with semen from both the zoo's male giant panda, Tian Tian, and from a panda living in China, Hui Hui. The zoo announced last week that DNA results showed that both cubs were fathered by Tian Tian.
Panda cubs are traditionally named at 100 days of age.