Yucatán black howler

The Yucatán black howler is the largest of the howler monkey species and one of the largest of the New World monkeys. Yucatán black howler males are larger than those of any other Central American monkey species. On average, males weigh and females weigh . The body is between in length, excluding the tail. The tail is between long. Adults of both sexes have long, black hair and a prehensile tail, while infants have brown fur. This hyoid bone amplifies the male howler's calls, allowing it to locate other males without expending much energy, which is important, since leaves are a low-energy food. Howling occurs primarily at dawn and at dusk. ==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). == Predation==

Yucatán black howlers are occasionally eaten by jaguars, cougars, and harpy eagles. Other cats, large birds of prey, and large arboreal snakes are also potential predators. == See also ==