Head to head
Bald Uakari vs Howler Monkey
The bald uakari and howler monkey are both New World monkeys of the Amazon basin, but one stands out for its face and the other for its voice.
| Bald Uakari | Howler Monkey | |
|---|---|---|
| Scientific name | Cacajao calvus | Alouatta |
| Signature feature | Bright red bald face | Extremely loud vocal calls |
| Tail type | Short, not prehensile | Long, fully prehensile |
| Vocal amplification | None notable | Enlarged hyoid bone |
| Habitat preference | Seasonally flooded forest | General rainforest canopy |
| Conservation status | Vulnerable | Least Concern |
| Population trend | Decreasing | Decreasing |
| Habitat | Rainforest, wetlands | Rainforest |
Bald Uakari vs Howler Monkey: common questions
Why does the bald uakari have a short tail while the howler monkey has a long one?
The bald uakari's short, non-prehensile tail is an unusual trait among New World monkeys, while the howler monkey retains a long, fully prehensile tail used almost like an extra limb for gripping branches, a more typical adaptation for moving through the rainforest canopy.
How does the howler monkey produce such loud calls?
This species has an enlarged hyoid bone in its throat that amplifies its vocalisations into some of the loudest calls of any land animal in the Americas, audible for kilometres through dense rainforest, a vocal adaptation the bald uakari does not share.
What does the bald uakari's red face tell other monkeys?
This species' bright red bald face functions as an honest signal of health, since illness or parasitic infection can cause the skin to fade to a paler, duller shade, giving potential mates a visible way to judge condition that the howler monkey's face does not provide in the same way.