Howler Monkeys and Spider Monkeys: Atelidae

Physical characteristics: The Venezuelan red howler monkey has thick, dark red to purplish red fur, with bright orange or gold underparts. The prehensile tail is used as a third hand for picking food. The black face is naked, and the wide jaw is covered with a thick beard. An enlarged hyoid (HYE-oid) bone at the root of the tongue gives the throat a swollen appearance. This bone is responsible for producing the loud howls that gave the monkey its name. Together with the enormous jaw, the swollen throat gives the monkey a grim appearance. It weighs 8 to 25 pounds (3.6 to 11 kilograms) and measures At dawn and dusk, Venezuelan red howler monkeys perform deafening howls that can be heard for at least 2 miles (3 kilometers). (Norman Owen Tomalin/Bruce Coleman Inc. Reproduced by permission.) 17.5 to 27 inches (44 to 69 centimeters), with another 21 to 31 inches (54 to 79 centimeters) for the tail.

Geographic range: Venezuelan red howler monkeys are found in Venezuela and Brazil.

Habitat: Red howler monkeys prefer the forest canopy and understory. They inhabit secondary forests where the canopy is less developed but the ground vegetation is dense. They are also found in mountain forests, mangroves, and forests by rivers and streams.

Diet: Leaves make up more than 60 percent of a howler monkey's diet. It prefers the young leaves that are plentiful in the treetops. It also eats fruits, seeds, flowers, and insects.

Behavior and reproduction: Venezuelan red howler monkeys are arboreal and diurnal. Sluggish creatures, these monkeys spend plenty of time resting during the day. At dawn and dusk, they perform deafening howls that can be heard for at least 2 miles (3 kilometers). These calls advertise territory and group size to avoid confrontations with other groups. The monkeys also howl during heavy rainstorms.

Red howlers form groups of three to ten individuals, generally consisting of several unrelated adults. Adults have several mating partners, although the dominant male mates with all the receptive females. Females have single births every eighteen to twenty-four months. Mothers carry infants for about six months, first against the stomach and later on the back. Young howlers leave home by two years of age, although females may stay with the group. Young males leave to form their own all-male groups, which later take over another group, sometimes killing the young.

Venezuelan red howler monkeys and people: Red howler monkeys are hunted for food.

Conservation status: The IUCN does not consider the Venezuelan red howler monkey a threatened species. ∎