AT A GLANCE
- Common Name: Maned Sloth
- Scientific Name: Bradypus torquatus
- Category: Mammals
- Subcategory: Pilosa
- Range: Endemic to the Atlantic Coastal Forest of eastern Brazil, restricted to fragmented coastal forests in Bahia, Espírito Santo, and Rio de Janeiro states
- Habitat Type: Dense, humid primary and mature secondary lowland and submontane tropical rainforests, strictly arboreal in the high continuous canopy
- IUCN Red List Status: Vulnerable
- Lifespan: 12 to 20 years
- Diet: Folivorous (strictly leaves, tender shoots, and young buds of select forest trees, particularly mandacaru and Cecropia)
- Average Size/Weight: Head-and-body length 55 to 72 cm; weight 4 to 7.5 kg
- Key Defining Feature: Arboreal three-toed sloth possessing a magnificent, lion-like mane of coarse black hairs draped over its neck and shoulders, and three curved hook-like claws on each foot
Overview
The Maned Sloth (Bradypus torquatus), known locally in Brazil as the ‘Preguiça-de-coleira,’ is one of the rarest, most specialized, and most threatened xenarthrans on Earth. Endemic exclusively to the fragmented remnants of Brazil’s Atlantic Coastal Forest, this tree-dwelling herbivore is easily distinguished from all other sloths by the striking, lion-like mane of long, jet-black hairs that cascades over its neck and shoulders. Moving at an imperceptible, deliberate pace through the emerald canopy, it lives an almost completely sedentary existence suspended upside down from high branches.
Biology and Physical Characteristics
Bradypus torquatus has a rounded head with tiny, inconspicuous ears hidden beneath fur and small, dark, forward-facing eyes. Its limbs are long and curved, terminating in three syndactylous digits encased in skin, each armed with a formidable, curved, hook-like claw that acts as a perpetual hanger. Its coat consists of a dense, fine underfur overlaid with long, coarse guard hairs that harbor symbiotic green algae (Trichophilus welckeri), providing living camouflage that turns the sloth greenish during wet seasons. In adult males, and to a lesser extent females, the neck and upper back are adorned with an extravagant mane of coarse, black hairs up to 15 cm long that resembles a dark horse’s mane.
Behavior and Ecology
Strictly arboreal, the Maned Sloth spends nearly its entire life suspended upside down in the high forest canopy, descending to the ground only once every seven to ten days to defecate at the base of its favorite tree. It has an exceptionally low basal metabolic rate—less than half of what is expected for a mammal of its mass—and poikilothermic tendencies, basking in high sunlit branches in the morning to warm its body before retreating into deep shade. Its diet consists exclusively of tree leaves, which ferment for weeks inside an enormous, complex, multi-chambered stomach packed with symbiotic cellulose-digesting bacteria.
Conservation and Human Impact
The Maned Sloth is listed as Vulnerable on the IUCN Red List. Its historical Atlantic Forest habitat has been devastated, reduced to less than 10 percent of its original extent by sugarcane plantations, cattle ranching, charcoal production, and urban sprawl. Surviving populations are fragmented into isolated genetic islands within protected areas such as Poço das Antas Biological Reserve and Monte Pascoal National Park. Canopy rope bridges and reforestation corridors are critical to reconnecting breeding populations.
Interesting Factoid
The Maned Sloth has such an incredibly slow metabolism that it can take an entire month for a single mouthful of leaves to pass through its four-chambered digestive system.