Przewalski's horse is a wild species reintroduced into the steppes and semi-desert areas of China and Mongolia. It is characterized by a short, erect mane and a stocky body, and is a grazer that primarily feeds on grasses of the Poaceae family. Its social structure is based on harems, and foals become independent at about two years of age. The gestation period is about 11–12 months and a single foal is born, which can walk shortly after birth. Once extinct in the wild, its numbers have been increasing following reintroduction, but severe winters and hybridization remain threats, and it is classified as Endangered (IUCN Category I B).