"The red howler monkey's range encompasses much of South America: Bolivia, Brazil, Colombia, Ecuador, French Guyana, Peru, Suriname and Venezuela.

Males in a group perform long calls (amplified by a hyoid bone that acts as a resonator), which are answered by all other howler troops in area. Calls can travel up to eight miles and are used to communicate group location, distance and composition; they can be directed at solitary individuals or other group members. These howls are most often heard at sunrise and are referred to as the "dawn chorus."

Read more about the loudest land animal, the Red Howler Monkey