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
Mara (mammal) nocturnal, simply to avoid social interaction. Mara (mammal) The maras ("Dolichotis") are a genus of the cavy family of rodents. They are the sole extant representatives of the subfamily Dolichotinae. These large relatives of guinea pigs are common in the Patagonian steppes of Argentina, but also live in Paraguay and elsewhere in South America. Maras are the fourth-largest rodent in the world, after capybaras, beavers, and porcupines, reaching about in height. Two species of maras are recognised, the Patagonian mara ("Dolichotis patagonum"), and the Chacoan mara ("Dolichotis salinicola"). "Dolichotis" means ‘long-earred’ (from ‘long’ + ‘ear’) in Ancient Greek. Maras have