Pygmy hippopotamus population that freely breeds in zoos around the world. Between 1970 and 1991 the population of pygmy hippos born in captivity more than doubled. The survival of the species in zoos is more certain than the survival of the species in the wild. In captivity, the pygmy hippo lives from 42 to 55 years, longer than in the wild. Since 1919, only 41 percent of pygmy hippos born in zoos have been male. While the common hippopotamus was known to Europeans since classical antiquity, the pygmy hippopotamus was unknown outside its range in West Africa until the 19th century. Due
Kozlov's pygmy jerboa Kozlov's pygmy jerboa Kozlov's pygmy jerboa ("Salpingotus kozlovi") is a species of rodent in the family Dipodidae. It is found in northwestern China and southern and eastern Mongolia. Its natural habitat is temperate desert. Kozlov's pygmy jerboa is a very small rodent with a relatively large head and a very long tail; it has a head-and-body length of and a tail length of and its weight is between . The fur is silky, the upper parts are sandy-grey with the bases of the hairs yellowish-grey, the flanks are rather paler and the underparts white or yellowish. The hind feet have