WASHINGTON — The National Zoo is celebrating the birth of a pair of Sumatran tiger cubs, a critically endangered species.

The zoo said yesterday that the cubs born to 4-year-old Damai on Monday appear to be healthy, and the new mother has been seen nursing them.Damai is being remotely monitored to allow her to bond with her cubs. The cubs won’t be shown for several months, but fans can watch them via Web cam.