Black-horned Capuchin

This is a medium-sized Neotropical primate characterized by its dense, coarse fur, which exhibits coloration ranging from dark brown to sooty black. Adults possess distinctive tufts of hair on the crown of their head that resemble small horns, and their facial skin is typically dark with lighter gray or pale contours around the eyes. Sexual dimorphism is moderately pronounced; adult males weigh between 7.0 and 10.5 pounds (3.2 to 4.8 kg), while females are smaller and lighter, weighing between 4.8 and 7.7 pounds (2.2 to 3.5 kg). They feature a highly muscular prehensile tail that acts as a fifth limb, providing stability and support when foraging in the forest canopy. Their hands are highly dexterous, with semi-opposable thumbs that allow for precise manipulation of objects.

Geographical distribution: This species is endemic to the southern regions of South America, with its core distribution centered in the Atlantic Forest of southeastern Brazil. This includes populations in the states of Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul. Its geographic range extends southwestward into northeastern Argentina, specifically within the Misiones province, and historically into eastern portions of Paraguay.

Habitat: It primarily inhabits subtropical and tropical rainforests, as well as semi-deciduous seasonal forests and gallery forests. The taxon exhibits outstanding ecological resilience, frequently occupying disturbed secondary forests, isolated forest fragments within agricultural landscapes, and commercial timber plantations of pine and eucalyptus. They exploit all vertical strata of the forest, although they regularly descend to the forest floor to travel, play, or forage.

Feeding: They possess an omnivorous and opportunistic diet that is heavily based on seasonal fruits. They consume a vast array of ripe fruits, seeds, flowers, leaves, and nectar. To satisfy their protein requirements, they actively hunt invertebrates such as caterpillars, beetles, and spiders, and opportunistically capture small vertebrates, including frogs, lizards, and nesting birds, as well as raiding bird nests for eggs. Notably, they are highly skilled tool users, utilizing heavy stones as hammers and hard surfaces as anvils to crack open tough palm nuts and hard-shelled seeds.

Behavior: They live in highly cohesive, multi-male, multi-female social groups typically consisting of 6 to 30 individuals. These groups operate under a strict, linear dominance hierarchy led by an alpha male who dominates breeding access and coordinates group defense against predators and rival troops. Communication within the troop is complex, involving a diverse repertoire of high-pitched vocalizations, subtle facial expressions, and chemical scent-marking. Social bonds and group cohesion are maintained through extensive periods of mutual grooming.

Reproduction: The mating system is generally polygamous, with the dominant male securing the majority of matings during the females´ peak estrus. Following a gestation period of approximately 150 to 180 days, females give birth to a single offspring. Births are highly seasonal, coinciding with the onset of the rainy season when food resources are most abundant. Infant care is highly cooperative, as subadults and even adult males assist the mother by carrying the infant on their backs, a behavior known as alloparental care, which is crucial for infant survival and maternal energy conservation.

Conservation status: It is currently classified as Near Threatened (NT) by the International Union for Conservation of Nature (IUCN). The primary threats jeopardizing its survival are habitat fragmentation and deforestation of the Atlantic Forest for agriculture and urbanization. Additionally, populations face severe pressures from illegal poaching, the pet trade, and mortality from vehicular collisions along highways that cut through their native forest fragments.