It is endemic to Brazil, found in the southeastern Amazon and disjunctly in the Atlantic Forest between Rio Grande do Norte and Sergipe.

[4] The red-handed howler remained variable in ecology, colour and pattern of the fur, shape of the cranium, and shape of the hyoid bone (of great importance in the voice of the howler monkeys; a likely isolating mechanism between the species),[5] but a geographical pattern was not clear, resulting in it being treated as a monotypic species.

Once born, if the mother is experienced, she will carry her young ventrally for three weeks and then switch to dorsally once the offspring is slightly more developed.

[8] When not foraging, red-handed howlers rest in the canopy of mature trees 20 m (66 ft) from the forest floor.

Increasing population pressures have forced farmers to clear more land for farming and these clear-cut methods are too much of a disturbance for the red-handed howler.

Some small disturbances are tolerated by species that focus more on leaves, but since A. belzebul is mostly frugivorous, it is harder for them to adapt to change.

If the forest does eventually regenerate, there will still be no way for new howlers to come back into the area and it also prohibits gene flow and the amount of genetic variation will decrease.

Since this species relies so heavily on fruit, certain habitats with a variety of fruit-producing tree stands should be focused on for protection.