Hear the booming cries that gave the howler its name. Learn just what these vocal monkeys may be trying to say.

Brown howler monkeys are endemic to the Atlantic Forest in Brazil and Argentina and became one of the 25 most threatened primate species following a yellow fever outbreak in late 2016. In response, ...

The daily movements of brown howler monkeys (Alouatta guariba) in the forest are determined by an interplay of environmental, behavioral and social factors. This is one of the conclusions of a study ...

Howler monkeys are relatively small primates known for their incredibly loud, low-frequency roars that sound as if they come from a much larger creature. This is useful in the animal kingdom because ...