Lemurs are a critically endangered species, but this year in three Eastern zoos, some baby lemurs are thriving and getting lots of attention. Three red-ruffed lemurs were born April 5 at the National Zoo in Washington, D.C. The D.C. lemurs are healthy and strong, according to zookeepers. Last month, three baby lemurs made their debut at the Bronx Zoo. There are about 10 different species of lemur, and the Bronx Zoo has six kinds. Of the three Bronx babies, two are ring-tailed and one is a brown-collared lemur. The Philadelphia Zoo's four baby lemurs, born in February, had their big debut on Friday. The zoo described the babies as playful siblings who "bounced around the exhibit and hung upside-down by their feet to eat treats such as apples and bananas." Lemurs are native to the northeastern forested areas of Madagascar and are considered "critically endangered by the International Union for Conservation of Nature," but the species has thrived in captivity.