HOWLER MONKEYS AND SPIDER MONKEYS FACTS
The atelids (members of the Atelidae family) are the largest New World primates. They range in color from yellowish beige to dark red to black. Males and females of some howler species differ in color. Many spider monkeys have light-colored masks around their eyes. Howler and woolly monkeys have stocky bodies and shorter limbs, while spider monkeys and muriquis have slimmer bodies and long tails. All tails are prehensile, capable of grasping tree branches, so that the monkeys usually feed while suspended.
Atelids are found in Mexico, all of Central America (Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama), and South America (including Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, and Venezuela).
HOWLER MONKEYS AND SPIDER MONKEYS HABITAT
Howler monkeys and muriquis inhabit secondary forests with open canopies. Spider and woolly monkeys prefer fullcanopied primary forests, although spider monkeys are also found in semideciduous and secondary forests.
HOWLER MONKEYS AND SPIDER MONKEYS DIET
Howler monkeys prefer leaves, while other atelids favor ripe fruits. All diets are supplemented with flowers, seeds, and insects.
BEHAVIOR AND REPRODUCTION
All atelids are arboreal (tree-dwelling) but occasionally descend to the ground. They are diurnal (active during the day). Some species have grooming sessions and play time. Atelids do not defend territories. They generally move through the forest on all fours with brachiation (brake-ee-AY-shun; swinging below branches using the arms), usually assisted by the tail.
Adults have several mating partners. Females have single births, which occur at different intervals depending on species. The mother alone tends to the infant. Except for howler monkeys, young males remain with the group, while females leave to join other males. Male howler monkeys form their own group and invade another group, killing the young.
ATELIDS AND PEOPLE
Atelids are valued for their meat. Spider monkeys and muriquis are collected as pets because they are typically good-natured.
The IUCN lists eleven species as threatened because of continued hunting and habitat loss and degradation from human activities. The variegated spider monkey, the northern muriqui, and the yellow-tailed woolly monkey are listed as Critically Endangered, facing an extremely high risk of extinction, dying out, in the wild. The Guatemalan black howler monkey, the white-whiskered spider monkey, and the southern muriqui are listed as Endangered, facing a very high risk of extinction. The Colombian woolly monkey is classified as Vulnerable, facing a high risk of extinction, and two other species are listed as Near Threatened, not currently threatened, but could become so.