SAN DIEGO (AP) — The panda cub born at the San Diego Zoo nearly a month ago is a boy.

The zoo said the mother panda briefly left the den Thursday, allowing veterinarians to examine the 2.8-pound (1.27-kilogram) baby panda for the first time.

The cub has not yet been named.

Senior zoo veterinarian Geoff Pye says the cub is healthy and starting to show its black-and-white markings. He says the cub has reached its “initial cute stage’’ and is “very roly poly.’’

The tiny cub’s birth on Aug. 5 attracted so much traffic to the zoo’s Web site that the online Panda Cam camera feed crashed. The zoo’s blog also went down for a period.