Colombian Red Howler

Identification

The Colombian red howler is a medium-sized New World monkey with a distinctive deep reddish-brown coat that darkens with age. Males are noticeably larger than females, ranging from 49 to 72 cm in body length and weighing 5.4 to 9 kg, while females measure 46 to 57 cm and weigh 4.2 to 7 kg. Their most striking feature is a long prehensile tail measuring 49 to 75 cm, covered in fur except for the last third of the underside, which is bare and allows the animal to grip branches with extraordinary precision. The face is framed by fur with a characteristically stubby nose. Perhaps most remarkable are the anatomical adaptations for their famous vocalizations: an enlarged hyoid bone, expanded jaw, and inflated middle-ear bulla that give them exceptional acoustic capabilities.

Range & Habitat

The Colombian red howler inhabits the western Amazon Basin, with populations distributed across Venezuela, Colombia, Ecuador, Peru, and Brazil. Related populations in Bolivia and northeastern South America have been recognized as separate species. These arboreal primates spend most of their time high in the forest canopy, moving deliberately through the trees with minimal leaping. Their preferred mode of locomotion is quadrupedal walking, and their prehensile tails provide both support and active grasping ability as they navigate the three-dimensional world of the canopy.

Behaviour & Diet

Colombian red howlers live in social groups of three to nine individuals, usually five to seven, structured polygynously with one dominant alpha male who leads the group to feeding sites and defends the group's territory. Females care for the offspring. These diurnal monkeys are most active in the morning as they forage and move between feeding areas. They are folivores, subsisting primarily on leaves supplemented with nuts, seeds, fruits, flowers, and small animals. Leaves are essential—the monkeys cannot survive without them for more than a week. Specialized dentition including narrow incisors and sharp-crested molars, combined with a complex digestive system featuring a large hindgut containing specialized bacteria, enables them to process fibrous plant material efficiently.

Best Time & Places to See It

Early morning is the optimal time to locate Colombian red howlers, as groups are most active during the dawn hours when they move to new feeding spots. Listen for the famous "dawn chorus"—loud roaring and howling calls that can be heard up to 5 kilometers away and are performed primarily by males. These calls serve to establish territory and prevent confrontations between groups. Throughout the western Amazon Basin in Venezuela, Colombia, Ecuador, Peru, and Brazil, patient observers positioned in suitable forest habitat can experience these remarkable vocalizations that announce the monkeys' presence across the landscape.

Photography Tips

Photograph Colombian red howlers early in the morning when they are most active and moving through the canopy. Position yourself with clear sightlines into the canopy, ideally at or above the monkeys' level if possible. The deep reddish-brown coloration photographs well in dappled forest light, though avoid harsh midday sun which can obscure detail. Use binoculars to locate groups first, then slowly approach. Remember that males' vocalizations often precede visual sightings, so listen carefully. A telephoto lens is essential for canopy work, and fast film or higher ISO settings help compensate for the dappled light of the forest interior.