They can use this tail as an extra arm to grip or even hang from branches—no Old World monkeys have such a tail. A gripping tail is particularly helpful to howler monkeys because they rarely ...

My adventure of a lifetime began in 2015 when I was asked to follow the tree-top lives of Costa Rica’s gravity-defying howler monkeys (Alouatta palliata palliata). Image by Justine Allan.

MEXICO CITY--It’s so hot in Mexico that howler monkeys are falling dead from the trees. At least 83 of the midsize primates, who are known for their roaring vocal calls, were found dead in the ...

BROWNSVILLE, Texas (ValleyCentral) — One man was arrested Monday for attempting to smuggle two Howler Monkeys into the United States, federal officials announced. On Monday, U.S. Customs and ...