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
Neotropical pygmy squirrel through the trees, and are highly excitable, giving an alarm call described as similar to the sound of a cricket. They give birth to one or two young at a time, with pregnant females having been observed in June. Neotropical pygmy squirrel The Neotropical pygmy squirrel ("Sciurillus pusillus") is a South American species of tree squirrel, being the only living species in the genus Sciurillus and the subfamily Sciurillinae. Genetic analysis has shown it to be the sister group to all other squirrels. The Neotropical pygmy squirrel is the smallest species of tree squirrel native to the Americas, measuring on