# Howler Monkey (*Alouatta spp.*)

> The howler monkey is a large, leaf-eating New World primate famous for having one of the loudest calls of any land animal in the Americas. Living in the tropical forests of Central and South America, it weighs around 5 to 10 kg and spends almost its whole life high in the canopy. Its booming dawn chorus, produced with the help of a specialised throat bone, can carry for several kilometres. Howlers live 15 to 20 years in the wild and are listed as Least Concern.

- **Category:** Mammal
- **Conservation status (IUCN):** Least Concern
- **Range:** Tropical forests from southern Mexico through Central America to Brazil, Bolivia, and Paraguay.
- **Canonical page:** https://globalanimalguide.org/animals/howler-monkey/
- **Last reviewed:** 2026-07-16

## Scientific classification

- **Kingdom:** Animalia
- **Phylum:** Chordata
- **Class:** Mammalia
- **Order:** Primates
- **Family:** Atelidae
- **Genus:** Alouatta

## Facts at a glance

| Attribute | Value |
| --- | --- |
| Scientific name | Alouatta spp. |
| Diet | Folivore — leaves, fruit, flowers, and buds |
| Habitat | Tropical forests of Central and South America |
| Lifespan | 15–20 years in the wild |
| Weight | 5–10 kg (11–22 lb); males larger |
| Top speed | Up to 16 km/h (10 mph); mostly slow arboreal movement |
| Conservation status | Least Concern (IUCN) |

## The famous howl

Howler monkeys are named for the deep, roaring calls that make them one of the loudest land animals in the Americas. Males produce these booming howls using an enlarged hyoid bone in the throat that acts as a resonating chamber. The calls carry for several kilometres through dense forest and are used to space out rival troops without the need to fight. Choruses are most striking at dawn and dusk, when neighbouring groups answer one another across the canopy.

## Range and habitat

Howler monkeys, of the genus Alouatta, live throughout the tropical forests of Central and South America, from southern Mexico to northern Argentina. They inhabit a range of woodland, including rainforest, dry forest, and mangrove, wherever there are enough tall trees. Almost their entire life is spent in the canopy, where they find food, sleep, and travel. They are among the most widespread of the New World monkeys.

## Diet and slow metabolism

Howlers are folivores, feeding mainly on leaves along with fruit, flowers, and buds. Leaves are low in energy and slow to digest, so the monkeys have an enlarged gut where bacteria ferment the tough plant material. To cope with this low-energy diet they rest for much of the day, sometimes for 15 hours or more. When fruit and young leaves are plentiful they take advantage of the richer food.

## Movement through the canopy

Howler monkeys move slowly and deliberately through the trees, rarely leaping and instead climbing carefully from branch to branch. Their strong, fully prehensile tail acts as a fifth limb, gripping branches and even supporting the animal's full weight while it reaches for food. Top speeds of around 16 km/h are reached only in short bursts, as their leaf-based diet leaves little energy to spare. They almost never come down to the ground, staying safe among the high branches.

## Social structure

Howlers live in troops of around 6 to 15 individuals, usually including several adults of both sexes along with juveniles and infants. Rather than fighting over territory, neighbouring groups rely on their loud calls to keep their distance. Within the troop, grooming and vocal exchanges help maintain social bonds. Males are larger than females and take the lead in the roaring contests that define howler society.

## Reproduction and lifespan

Females give birth to a single infant after a gestation of around six months, and the newborn clings to its mother as she moves through the trees. Young howlers are weaned gradually and learn which leaves and fruit are safe to eat by watching the adults. In the wild, howler monkeys live around 15 to 20 years. Their slow, energy-conserving lifestyle is reflected in their unhurried pace of breeding and growth.

## Frequently asked questions

### Why are howler monkeys so loud?

Male howler monkeys have an enlarged hyoid bone in the throat that acts as a resonating chamber, letting them produce deep, booming calls. These howls can carry for several kilometres and are used to advertise a troop's presence so that rival groups keep their distance without fighting.

### What do howler monkeys eat?

Howler monkeys are folivores, feeding mainly on leaves along with fruit, flowers, and buds. Leaves provide little energy and are slow to digest, so howlers have an enlarged gut to ferment them and spend much of the day resting to conserve energy.

### Where do howler monkeys live?

Howler monkeys live in the tropical forests of Central and South America, ranging from southern Mexico to northern Argentina. They occupy rainforest, dry forest, and mangroves, spending almost their entire lives high in the canopy.

### How loud is a howler monkey's call?

A howler monkey's call is among the loudest of any land animal in the Americas and can be heard several kilometres away through dense forest. The calls are loudest at dawn and dusk, when neighbouring troops answer one another across the canopy.

### How long do howler monkeys live?

Howler monkeys live around 15 to 20 years in the wild. Their slow, energy-conserving lifestyle, driven by a low-energy diet of leaves, is reflected in their unhurried pace of growth and breeding.

### Are howler monkeys endangered?

Howler monkeys are listed as Least Concern by the IUCN, meaning they are not currently at high risk of extinction. They remain widespread across the Americas, though habitat loss and hunting affect some populations more than others.

## Sources

- [IUCN Red List — Alouatta spp..](https://www.iucnredlist.org/search?query=Alouatta%20spp.&searchType=species)
- [Animal Diversity Web — Alouatta spp.. University of Michigan Museum of Zoology.](https://animaldiversity.org/accounts/Alouatta_spp./)

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Source: Global Animal Guide (https://globalanimalguide.org/animals/howler-monkey/). Licensed CC BY-NC 4.0 — free for non-commercial reuse with attribution.