Species Fact Profile: Black Howler Monkey (Alouatta caraya)

Black Howler Monkey

Alouatta caraya (Humboldt, 1812)

Range: Central South America (eastern Bolivia, southern Brazil, Paraguay, northern Argentina)
Habitat: Tropical Semi-Deciduous Forest
Diet: Leaves, Fruits, Buds, Flowers
Social Grouping: Family Groups of 5-8 (sometimes more)
Reproduction:  Promiscuous within group.  Gestation 7-12 months (younger females have longer gestation than older ones).  One offspring per birth, care for infant for one year prior to mating again.  Males mature at 2.5 years old, females at 3.  Adult males may help with young (young males can be dangerous to infants). Females may care for each other’s young
Lifespan: 15-20 Years
Conservation Status: IUCN Least Concern, CITES Appendix II

• Body length 1.6 - 2.2 feet.  Tails of males are of similar length to the body.  Tails of the females are slightly longer.  Males weigh an average of 6.7 kilograms, females average 4.4 kilograms.  The muzzle is prominent (but less so than other howler monkeys), tail is prehensile with a hairless pad on the underside.  
• Sexually dimorphic.  Males have black hair; females are yellow-brown or olive.  Infants are born with golden coat, changing as the monkey ages.  Black face is hairless with bushy eyebrows.   Some males may have patches of red or buff fur
•  Enlarged hyoid and larynx houses vocal apparatus which allows howling.  Calls can be heard 1.8 miles away on land, 3 miles away over water.
• Groups are roughly equal sex ratio (somewhat more females).  Territorial, but only defend area where they are at a given moment, all members howl in the morning to maintain distance between groups.  Also defecate and rub selves on branches to mark scent
• Diet is poor in energy, monkeys spend up to 70% of the day resting while leaves ferment in enlarged cecum
• Active by day, rarely come to the ground.  Avoid leaping, but can leap 3-4 yards in necessary.  Can swim if necessary
• Obtain most of their water from their diet, but in dry times will come to the ground to drink or to feed on ground plants
• Threatened by clear-cutting.  Hunted for meat and fur