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
Pygmy shrew tenrec parameters of the species and its populations were unknown until the mid 1990s, it was listed as "Endangered" in 1996 when scientists found sufficient data to back up the category. This was recently redacted and changed to "Least Concern" in 2006. The pygmy shrew tenrec is a nocturnal hunter, using its keen senses of sight and hearing to find and capture prey. While it may also use scent to find the delicious insects it feasts on, this tiny mammal prefers to utilize the night vision evolution has granted it. Shrew tenrecs in general tend to have very large auditory structures