Black-and-Gold Howler Monkey
Alouatta caraya
Quick Facts
- Scientific Name: Alouatta caraya
- Spanish Name: Mono carayá
- Family: Atelidae
- Known Nicknames: Black Howler, Caraya, Paraguayan Howler Monkey
- Average Length: 105–130 cm / 41–51 in (including tail)
- Average Weight: 4–10 kg / 9–22 lb
- Wingspan: N/A
- Key Feature: Extreme sexual dichromatism where adult males are entirely black and females are yellowish-gold
- Primary Diet: Folivore and Frugivore
- Range: South-central South America (Eastern Bolivia, Southern Brazil, Paraguay, and Northern Argentina)
- Habitat: Gallery forests, semi-deciduous forests, and wooded savannas
- Social Structure: Highly Social (living in groups of 3 to 19 individuals)
- Nesting/Breeding: Arboreal canopy
- Conservation Status: Near Threatened (NT)
- Population Trend: Decreasing
The Black-and-Gold Howler Monkey (*Alouatta caraya*) is a striking primate native to the forests of South America, best known for its extreme sexual dichromatism: while adult males boast a coat of solid jet-black fur, females and juveniles display a soft, honey-gold or buff coloration. These arboreal specialists are famous for their thunderous, guttural roars, produced by a specialized, enlarged hyoid bone in the throat that acts as a resonating chamber, allowing their calls to travel up to three miles through dense canopy. Equipped with a strong prehensile tail that functions as a fifth limb for grasping branches, they lead a relatively sedentary lifestyle, spending much of their time resting to conserve energy as they digest a fibrous diet primarily composed of leaves and fruit.
Faits amusants
The Black-and-Gold Howler Monkey exhibits extreme sexual dichromatism, where adult males are solid black while females and juveniles maintain a bright golden-buff color. Their namesake roar is amplified by a specialized, hollow hyoid bone in the throat that acts as a resonator, making their vocalizations audible up to three miles away. To manage a low-energy diet of leaves, these primates are incredibly sedentary, often spending up to 80% of their day sleeping or resting. They also possess a remarkably strong prehensile tail equipped with a sensitive, hairless tactile pad on the underside, which functions like a fifth limb for navigating the canopy.
Habitats et répartition
This species is native to central South America, with a geographical range that encompasses northeastern Argentina, eastern Bolivia, southern and central Brazil, and the majority of Paraguay. It maintains one of the southernmost distributions of any New World monkey, successfully inhabiting both tropical and more temperate climates within these regions. In terms of habitat, these primates are remarkably adaptable and occupy a diverse array of environments. They are most commonly found in gallery forests along riverbanks, semi-deciduous woodlands, and tropical or subtropical forests. Additionally, they are well-suited to savanna-like landscapes such as the Cerrado and Pantanal, and they demonstrate a high tolerance for fragmented forests and areas partially disturbed by human activity.
Comportements & Reproduction
Social groups typically consist of one or two dominant males, several females, and their offspring, maintaining a cohesive structure through grooming and vocal communication. These primates are highly territorial, using powerful roars enabled by an enlarged hyoid bone to announce their presence and avoid physical confrontations with rival troops. Both males and females usually emigrate from their natal groups upon reaching sexual maturity, a behavior that minimizes inbreeding and helps establish new social hierarchies within the population. Mating occurs year-round and is often initiated by the female through a distinct rhythmic tongue-flicking gesture. After a gestation period of approximately six months, a single infant is born with a golden coat, regardless of its sex, though males will eventually turn black as they mature. A notable reproductive strategy includes the potential for infanticide by incoming dominant males, which prompts females to enter estrus sooner to ensure the new leader's offspring are produced. Mothers provide the majority of care, carrying their young for several months until they become independent members of the troop.
Alimentation
The Black-and-Gold Howler Monkey is primarily a folivore-frugivore, maintaining a diet that consists largely of leaves and fruits, supplemented by flowers, buds, and occasionally bark. These primates possess a specialized digestive system featuring an enlarged cecum, where symbiotic bacteria ferment the tough cellulose found in foliage, allowing them to extract nutrients from high-fiber food sources that other monkeys might find indigestible. Interestingly, they are highly selective foragers, often prioritizing young leaves over mature ones because younger growth typically contains higher protein levels and fewer toxic secondary compounds like tannins. Because their leaf-heavy diet provides relatively low caloric energy, these monkeys have evolved a slow metabolism and spend up to eighty percent of their day resting to conserve energy. Additionally, they play a crucial role in their ecosystem as seed dispersers, as many of the fruit seeds they consume pass through their digestive tracts intact and are deposited across the forest floor in nutrient-rich waste.
Couleurs
The Black-and-Gold Howler Monkey exhibits extreme sexual dichromatism, where adult males are entirely jet-black and females are a pale golden-yellow or honey color. Infants of both sexes are born golden to blend with their mothers for protection, with males darkening only as they reach maturity. Their solid, monochromatic coats lack intricate patterns, instead using these distinct earthy hues to provide effective camouflage within the sun-dappled forest canopy.
