Red Howler Monkey (Alouatta seniculus)


Class: Mammalia
Order: Primates
Family:    Cebidae
Size:    Length: 1.5 to 2.5 feet (46 to 76 cm)
Weight: 10 to 14 pounds (4.5 to 6 kg)
Diet: Leaves, flowers, seeds, fruit and nuts
Distribution: Northwestern South America
Young:  1 every other year
Animal Predators:  Jaguars
IUCN Status: No special status/Vulnerable (see Conservation) 
Terms: Group: Troop 
Lifespan: 20 years



       There are six species of howler monkeys in Central and South America.

       They have the loudest call of any animal in the New World.

       Red howlers sleep for more than 15 hours per day.

       Although they spend most of their time in trees, howlers are proficient swimmers. 



Red howler monkeys have a muscular, prehensile tail that enables them to grasp branches or even swing from them. As the name suggests, they have reddish, silky fur all over except for their face and the underside of their tail. Their arms and legs are long, and their hands are extremely strong and dexterous. Males are larger than females.



Red howler monkeys range throughout northwestern South America, including Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, and Venezuela, as well as the island of Trinidad. They inhabit the canopy of tropical rainforests and tropical deciduous forests, and they especially like teak and Cecropia trees. 


Feeding Habits

 Red howler monkeys feed mostly on leaves, although they also enjoy eating nuts, seeds, fruit and flowers.



The female usually initiates courtship by showing her tongue to a male. If he does not respond, she moves on to another male. Mating can occur throughout the year and females give birth to one (twins are extremely rare) young after a gestation period of six months. Females usually first give birth when they reach five years of age, which is two years before males begin to mate. Although newborns are helpless, they are born with fur and are soon capable of hanging onto their motherís belly. By the time they are one month, they can use their tail to hang on to their mother and eventually ride on her back wherever she goes, until one year of age. The young monkey nurses until it is 18 to 24 months old. The other females in the troop, especially those without infants, are very fond of other femalesí babies and will cuddle them and play with them. The males are also very affectionate with the youngsters, but only with their own, not with ones that are fathered by other males.



Red howlers are large monkeys that live in groups of one to three males and two to seven females with varying numbers of juveniles. Males living in bachelor groups attempt to gain control of a female group from time to time by fighting with the lead male. Male red howlers wake up the forest in the early morning with their loud howls that can be heard up to two miles (5 km) away. They howl again at night, before they go to sleep, and the calls are answered by males from other red howler groups, to let them know their location so that their territories do not overlap. Red howlers do not like rain and will howl in protest to rainstorms as they sit hunched over in trees. Howlers usually remain high up in trees where they can find the most leaves. They are mischievous animals who like to sit in trees and pester jaguars by throwing sticks and branches down at them. When invading males come in and take over a troop of females from the current male or males, the new males kill all the existing infants and then mate with the females, to produce their own offspring. The females try to protect their infants, but being smaller, they are rarely successful at saving them. 



Red howler monkeys are heavily hunted and their territories have been reduced by human encroachment. A subspecies, the Trinidad howling monkey (Alouatta seniculus insulanus) is listed as Vulnerable by the IUCN.



Red howler monkey Wildlife Fact File, IM Pub, US