The Qinling panda (Ailuropoda melanoleuca qinlingensis) is a subspecies of the giant panda, discovered in the 1960s but not recognized as a subspecies until 2005. Disregarding the nominate subspecies, it is the first giant panda subspecies to be recognized. It differs from the more familiar nominate subspecies by its smaller skull and dark brown and light brown (rather than black and white) fur, and its smaller overall size. There are an estimated 200–300 Qinling pandas living in the wild. On August 30, 1989, a female of this species was captured and brought to the Xi'an Zoo to be mated with a regular giant panda. Her offspring was black-and-white, but reportedly started becoming brownish as it aged. According to other reports she gave birth to three cubs who all died shortly after being born. The mother, named Dan-Dan, died in 2000. This subspecies is restricted to the Qinling Mountains, at elevations of 1,300–3,000 metres (4,300–9,800 ft). Its coloration is possibly a consequence of inbreeding: the population is closed off from genetic variation and this might have led to the preservation of the mutation responsible.