The Colombian red howler[1] or Venezuelan red howler is a South American species of howler monkey, a New World species of monkey found in the western Amazon basin.
- Alouatta seniculus have a slight sexual dimorphism.
- The females have a body length of 46 to 57 centimeters; the males, which are larger, have a body length of 49 to 72 cm.
- Both sexes have a long prehensile tail of about 49 to 75 centimeters.
- The coat color of this primate is dark reddish brown, although the hue slightly varies with age.
- Colombian red howlers have large necks with massive jaws and hyoid bones, giving them a menacing expression.