Two baby animals are better than one—especially when they’re panda cubs. On Monday, June 20, a female panda at the Chengdu giant panda breeding research base in China's Sichuan province gave birth to twins, Reuters UK reports. Giving China extra reason to celebrate their arrival, this is the first set of giant panda cub twins to arrive in 2016.

The panda mother, Yali, is now the proud parent of two healthy female cubs. One of the bears weighs about 5 ounces, the other nearly 4. (At birth, baby pandas are around the size of a stick of butter.) Right now, the babies are tiny and pink, and covered in fine white fur. At about a week old, they’ll likely start developing their signature black patches on the skin around their eyes, ears, shoulders, and legs.

The cubs are currently being kept in an incubator, and taken out for routine feedings. However, animal keepers are likely keeping a close eye on them, as the first few months of life are precarious ones for baby giant pandas. Giant pandas give birth to twins around 50 percent of the time, but often only one survives. Scientists think this is at least partly because giant panda mothers are best at only caring for one cub at a time.

The outlook is a little more optimistic for giant panda cubs born in zoos or research centers than ones in the wild. About nine out of every 10 twin giant panda cubs born alive in captivity survive. That’s because zoo keepers can switch the cubs out so the mother can give them equal attention.

The Chengdu giant panda breeding research base remains optimistic that Yali's new babies will pull through. “The twins are quite healthy, their voices are quite clear, relatively speaking their fur and physical traits are all quite healthy,” a panda feeder, Tang Juwen, told Reuters UK.

[h/t Reuters UK]