Mantled Howler Monkey

The mantled howler is native to Colombia, Costa Rica, Ecuador, Guatemala, Honduras, Mexico, Nicaragua, Panama and Peru. Within Honduras, Nicaragua, Costa Rica and Panama, the mantled howler is found in locations throughout the countries. In Colombia and Ecuador, it is found in a narrow corridor bordered by the Pacific Ocean to the west and the Andes Mountains to the east and also in Colombia in a small area near the Caribbean Sea close to the Panama border. In Guatemala, the mantled howler is found through the central part of the country, and into southeastern Mexico south of the Yucatán Peninsula. The mantled howler is among the most commonly seen and heard primates in many Central American national parks, including Manuel Antonio, Corcovado, Monteverde and Soberania. The mantled howler lives in several different types of forest, including secondary forest and semi-deciduous forest but is found in higher densities in older areas of forest and in areas containing evergreen forest. The mantled howler is sympatric with another howler monkey species, the Guatemalan black howler, A. pigra, over a small part of its range, in Guatemala and Mexico near the Yucatan Peninsula.

The mantled howler is the most folivorous species of Central American monkey. Leaves make up between almost 50% and 75% of the mantled howler's diet. The mantled howler is selective about the trees it eats from, and it prefers young leaves to mature leaves. This selectivity is likely to reduce the levels of toxins ingested, since certain leaves of various species contain toxins. Young leaves generally have fewer toxins, as well as more nutrients, than more mature leaves, and are also usually easier to digest. Mantled howler monkeys possess large salivary glands that help break down the leaf tannins by binding the polymers before the food bolus reaches the gut. Although leaves are abundant, they are a low energy food source. The fact that the mantled howler relies so heavily on a low energy food source drives much of its behaviour – for example, howling to locate other groups and spending a large portion of the day resting. Although leaves tend to make up the majority of the mantled howler's diet, fruit can also make up a large portion of the diet. When available, the proportion of fruit in the diet can be as much as 50%, and can sometimes exceed the proportion of leaves. The leaves and fruit from Ficus trees tend to be the preferred source of the mantled howler. …