The Javan rhinoceros is a member of the family Rhinocerotidae and one of five extant rhinoceroses. Its horn is usually less than 25 cm (10 inches), smaller than those of the other rhino species. Once the most widespread of Asian rhinoceroses, the Javan rhinoceros ranged from the islands of Java and Sumatra, throughout Southeast Asia, and into India and China. The species is critically endangered, with only one known population in the wild, and no individuals in captivity. It is possibly the rarest large mammal on earth, with a population of as few as 40 in Ujung Kulon National Park on Java in Indonesia. The decline of the Javan rhinoceros is attributed to poaching, primarily for their horns, which are highly valued in traditional Chinese medicine. The Javan rhino can live approximately 30–