Rebecca Snyder, the zoo's curator of mammals, said in an update this week that the firstborn cub used to be smaller, but has now surpassed his brother in weight. He has more than tripled his weight in two weeks. He now weighs 361 grams, while his brother weighs 360 grams.
The twin males born July 15 to Lun Lun and her partner, Yang Yang, are the first giant panda twins to be born in the U.S. since 1987.
A new photo released by Zoo Atlanta shows the faces of the cubs beginning to take shape, with their eyes and noses now clearly visible as they rest on baby blankets.
Copyright 2013 The Associated Press.