Colombian red howler

The Colombian red howler, also called the Venezuelan red howler and known to science as Alouatta seniculus, is a South American howler monkey found in the western Amazon Basin across Venezuela, Colombia, Ecuador, Peru and Brazil. It belongs to the New World monkey family Atelidae. Adults are deep reddish brown, males measuring roughly 49 to 72 cm and weighing 5.4 to 9 kg, females somewhat smaller, and a long prehensile tail with a bare patch on the underside lets the animal grip branches while it moves on all fours through the canopy during the day. Groups of three to nine animals are led by one dominant male, whose dawn chorus of roars can carry up to 5 km through the forest and helps groups avoid costly fights. Leaves are the staple food, supplemented by fruit, seeds, flowers and small animals. Populations in Bolivia and in northeastern South America have been split off as the Bolivian and Guyanan red howlers, so the name now covers a narrower range than older sources give.