Home › Mammalia › Atelidae › Black Howler Monkey (Alouatta pigra)
SPECIES PROFILE
Black Howler Monkey (Alouatta pigra)
Alouatta
IUCN STATUS
Endangered
CONSERVATION STATUS
Endangered
CLASS
Mammalia
GEOGRAPHICAL RANGE
Endemic to the Yucatan Peninsula and adjacent lowlands of Mexico, Guatemala, and Belize; one of the most restricted howler monkey species
DIET
Herbivore
HABITAT
Tall tropical forest and gallery forest in lowland and foothill areas; prefers large trees with abundant leaf cover
🔬 Classification
PHYLUM
Chordata
CLASS
Mammalia
ORDER
Primates
FAMILY
Atelidae
GENUS
Alouatta
📋 Description
SIZE
52–63 cm body; 6–11 kg — the largest Central American primate; males have an enlarged hyoid bone forming a resonating chamber
COLORATION
Males entirely black; females and juveniles dark brown to golden-brown; enlarged throat forming a resonating chamber; prehensile tail
ADAPTATIONS
Enlarged hyoid bone creates a hollow resonating chamber producing howls that carry 5 km through forest; highly folivorous gut with specialised bacteria for fermenting tough leaves
🌿 Ecology
HABITAT
Tall tropical forest and gallery forest in lowland and foothill areas; prefers large trees with abundant leaf cover
DIET
Herbivore
GEOGRAPHIC RANGE
Endemic to the Yucatan Peninsula and adjacent lowlands of Mexico, Guatemala, and Belize; one of the most restricted howler monkey species
REPRODUCTION
Single infant born after 6-month gestation; infant clings to mother for 6–12 months; social group of 4–10 with one dominant male
DIET DETAILS
Leaves make up 50–70% of the diet (more than any other American primate); also fruit, flowers, and buds
⚠️ Threats & Conservation
PRIMARY THREATS
Forest clearance for cattle ranching and agriculture; hunting; yellow fever epidemics killing entire groups; fragmentation creating isolated populations
💡 Interesting Facts
1
The Black Howler Monkey produces the loudest call of any land animal on Earth — a deep resonating roar that can be heard up to 5 km away, used to space out troops and prevent confrontation.
2
Howler monkeys are the most folivorous of the American primates; their specialised digestive system can extract nutrition from mature leaves that would be toxic to most animals.
🔭 Sighting Guide
📍 BEST PLACES TO SIGHT
Palenque ruins, Chiapas, have habituated Black Howler Monkey troops that roar from the treetops above the temples each dawn
Yaxchilán ruins on the Usumacinta River, Chiapas, have Black Howler Monkeys in the surrounding undisturbed rainforest
Montes Azules Biosphere Reserve in the Lacandon forest, Chiapas, has Black Howler Monkeys in primary forest
🗓️ BEST TIME TO SIGHT
Year-round. The loudest land animal in the Americas; roars audible from 5 km; Palenque and Yaxchilán ruins have habituated troops.
🎯 SIGHTING TIPS
Year-round near Palenque ruins, Chiapas, and along the Usumacinta River; howling choruses at dawn are unmissable from any forest camp.
