reach sexual maturity between six and eight years old. Males leave their natal group upon reaching sexual maturity, but females generally remain with their natal group. They can live up to 20 years. Conservation status The Yucatán black howler belongs to the New World monkey family Atelidae, which contains howler monkeys, spider monkeys, woolly monkeys and muriquis. It is a member of the howler monkey genus Alouatta. No subspecies are recognized. The species is considered to be endangered by the International Union for Conservation of Nature because the species population is expected to decline by up to 60% over the next 30 years. Threats to the species include habitat loss, hunting, and capture as pets. In Belize, it is illegal to hunt this species. Sympatry The Yucatán black howler is sympatric with the mantled howler along the edges of its range in Mexico and Guatemala near the Yucatan Peninsula. A theory for how this sympatry occurred and why the Yucatán black howler has such a restricted range is the ancestors of the Yucatán black howler and the Central American squirrel monkey migrated to Central America from South America during the late Miocene or Pliocene. However, passage through the Isthmus of Panama then closed for a period due to rising sea levels, and later opened up to another wave of migration about two million years ago. These later migrants, ancestors to modern populations of white-headed capuchins, mantled howlers and Geoffroy's spider monkeys, out-competed the earlier migrants, leading to the restricted range of the Yucatán black howler (and the Central American squirrel monkey). References External links ARKive – images and movies of the Yucatán black howler (Alouatta pigra) Sound recordings of Yucatán black howlers at BioAcoustica Howler monkeys Primates of Central America Mammals of Mexico Fauna of Southern Mexico Fauna of the Yucatán Peninsula Endangered biota of Mexico Endangered fauna of North America Mammals described in 1933 Taxa named by Barbara Lawrence (zoologist)