Quadruplet red panda cubs have been born in the Denver Zoo. The three boys and one girl are only the fifth group of quadruplets born in the United States.
Their parents, Sophia and He-Ping, were matched up from different zoos in an effort to maintain healthy and genetically diverse populations. They gave birth to a set of twins last year.
Red pandas are listed as endangered species, with only 2500 in the wild. They are found in the Himalayas and feed mainly on bamboo. They are at risk because of hunting and habitat destruction.