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
Mountain pygmy possum offer some protection from predation. "Burramys parvus" is noted to be the only small mammal in Australia that hibernates seasonally for long periods of time. All other members of "Burramyidae" are capable of opportunistic hibernation. Adult mountain pygmy possums enter hibernation for a period of up to seven months, whereas juveniles generally hibernate for about five months. Both males and females rely heavily on Bogong moths as an energy rich food and for the fattening period which occurs prior to hibernation. Mountain pygmy possums are also noted to cache seeds and berries which they will feed on during periods when