| Guatemalan Black Howlers look and behave much like Mantled Howlers, but their long, thick fur is all black, and they live in smaller groups, usually of 2 to 6. Where they are hunted, they howl mainly at night, but where they are protected they vocalize at dawn and dusk. They also howl when they are disturbed or to comment on the weather: a rainstorm brings forth a chorus. Howlers are slower-moving than spider monkeys. They do not swing arm-over-arm. Instead, they walk or run along branches on all fours, communicating with woofs, grunts, and barks. They are locally common and can easily be seen by day where they are protected, but are shy where they are hunted. Hunting, deforestation, and disease - including yellow fever epidemics - are the main threats. Their reproduction rate is not high, either: females typically have one offspring.
Head and Body: 380-580 mm; Tail: 498-630 mm
Lawrence, 1933. Bulletin of the Museum Comparative Zoology, 75:333.
Mammal Species of the World (opens in a new window).