The twin newborn giant panda cubs were born on July 15 to parent pandas Lun Lun and Yang Yang and are the first giant panda twins born in the United States in over 25 years.
Staff at the Zoo Atlanta on 24-hour shifts awaiting Lun Lun's delivery captured the birth on video, which can be viewed below. Above is a video of the twin cubs in an incubator shortly after their birth two weeks ago.
The panda twins are the first born in the U.S since 1987 and Zoo Atlanta are running a 24-hour panda cam on their website thanks to Earthcam.
New photos released by Zoo Atlanta show the clear development of the facial features in the baby bears, with their eyes and noses now clearly visible.
The cubs are being 'swapped' with Lun Lun, a technique developed in China and one that has proved successful in the past. This technique involves placing one cub in an incubator while the other feeds with their mother, and then swapping cubs.
According to the Zoo Atlanta blog, however, "Lun Lun is reluctant to give up whichever cub she has". To counteract the delay this causes, each cub's diet has been supplemented with formula.
The veterinary staff have come up with a stategy of combining vocal imitations of cub noises and sugarcane to encourage Lun Lun to give up her cub to the officials. Zoo Atlanta posted a video of this technique to their YouTube channel.
Losing weight after birth is normal for newborn panda cubs but the cubs are now gaining weight rapidly, an encouraging sign for their development. According to officials at Zoo Atlanta, the smaller firstborn cub has tripled his weight in two weeks, surpassing his twin brother. The cubs now weigh in at 394.7g and 405.5g respectively, a weigh gain of over four times their birth weight.
In advance of the birth, the team at Zoo Atlanta were on 24-hour shifts, updating protocol, disinfecting surfaces and setting up a nursery for the cubs.
You can follow the cubs development on the Zoo Atlanta website or on their Twitter here.