Endangered Sumatran tigers got two new additions this week: A female named Damai at the National Zoo in DC gave birth to a pair of healthy cubs on Monday. Only about 500 of the tigers exist in the wild, with 65 in zoos in North America, notes the Washington Post. (That includes Damai's mate, Kavi.) The cubs won't be on exhibit for a few months, but you can check them out via a webcam at the zoo's website. "All I can do is smile because the team has realized our goal of producing critically endangered tiger cubs," says a zoo biologist. "Damai came to us as a young tiger herself, so it's really special to see her become a great mom."