DESCRIPTION: Howler Mantle of blond fur on the back that distinguishes this species from five other howler species found in Central America. 50 cm, 5 kg: (20 in., 11 lbs.) males larger than females. Fur of the baby Howler is silver at birth, but turns pale or golden with a few days. The fur gradually darkens from then on , reaching adult coloration by the three months old. Babies are carried by the mother until the baby is four or five months old. Other members often help carry the babies.

EATING HABITS: Howlers forage by day often starting before dawn. Feeding heavily on leaves their diet is extremely challenging for the Howler. The cellulose and toxins that are in the leaves are very difficult for the Howler to digest. They must ferment leaves in the hindgut and have trouble with digestion unlike other mammals. Howlers eat leaves of dozens of different tree species, but they select the leaves carefully. About two thirds of the foliage eaten are young, tender leaves with lesser toxins. Howlers are not exclusively folivorous (leaf eating). Flowers and fruit comprised about a third of the diet. Their diet varies depending on the season. They dry season will take the life of the weaker Howlers when they have to resort to eating more mature leaves that contain high levels of toxin. With the low energy diet, Howlers are more lethargic than other species of monkeys.

TROOPS - Mantled Howler troops contain anywhere from 2 to 45 individuals. All males are dominant over all females. Home ranges are 3 to 76 ha. Troops seldom move more than 2 km in a day and usually cover less than 1 km. Females depart their natal troop between two and three years of age, and integrate with a new troop within a year, by which time they are sexually mature. Like males, females prepare to work their way into a troop by hanging out nearby. They woo and then mate with a dominant male, thus securing his protection and other troop members’ respect. They give birth on average every one and a half to two years from then on. Howlers can live at least 25 years in the wild. SOUNDS Grunts and intimidatingly loud, pulsating roars lasting four to five seconds, often repeated several times, given mainly by adult males. Often times, calls are to neighboring troops. Generally troops avoid each other. The calls can be heard several kilometers away.