The black howler monkey is the largest of the New World primates reaching 14 pounds in the female and 25 pounds in the male. These arboreal animals are sexually dimorphic, which means that the female is brown and the male, which is born brown, will turn black as he matures.
Howlers are unique in their appearance.
They have an enlarged hyoid bone and a greatly enlarged lower jaw, which enables them to make vocalizations that can be heard up to three kilometers through the jungle. They also have a prehensile tail, which is strong enough to hold their entire body weight. The black howler monkey has a varied diet, but they mainly eat leaves, fruits and other vegetable matter. Howlers live in troops of one male with many females. The black howler monkey is listed as vulnerable.