As quiet falls upon the rain forest at dusk, a whooping sound rises above the trees. Black howler monkeys call to each other as they settle in the treetops for the evening. These calls can be heard over three miles away.
Male and female black howler monkeys are colored quite differently. Mature males are black, while the young and females are blonde. This difference between male and female is called sexual dimorphism. Males are also larger than females, weighing about 16.5 pounds as opposed to females at 12.5 pounds.
Howlers have greatly enlarged lower jaws which accommodate egg-shaped resonating chambers. These chambers enable howlers to make their unique reverberating calls. The calls warn nearby troops to keep away from feeding areas.
Howlers have prehensile tails which are used mostly for balance or a sense of security.
The Zoo is protecting wildlife and habitats in Latin America through the Scott Neotropical Fund.
The black howler monkey has a strong prehensile tail that has a hairless underside. This helps the monkey determine the texture of whatever it is holding onto.
Howler monkeys are slow moving, thus easily falling prey to humans, who hunt them for meat. Most of their time is spent in trees. They live in groups of 8 to 20, with females outnumbering males. There is one dominant male per group. They do not groom each other, and this could account for the high incidence of disease among them.
Breeding takes place throughout the year, yielding one offspring. The mother has complete control of the young.