Southern maned sloth

(Bradypus crinitus)

other common names

Southern maned three-toed sloth
Brazilian three-toed sloth

Taxonomy

Order: Pilosa
Family: Bradypodidae

description

This sloth has a head-body length of 59–75 cm and a short tail of 4–5 cm. It weighs around 4.5–10.1 kg. Male maned sloths are smaller than females. The fur is brown with long, coarse hair that is often colonized by algae. Both males and females have black manes around the dorsal region of the neck, which are longer and darker in males. 

diet

This is a strict folivore that feeds on a relatively small number of plants. One study found that leaves from 21 species formed 99% of the diet of three animals.

reproduction

The females give birth to a single young per year. Most births occur at the end of the wet season and beginning of the dry season (February-April). Sexual maturity is probably reached between the second and third year.

range

Bradypus crinitus is restricted to the Atlantic coastal forests of eastern Brazil, where its range is discontinuous.At present, the mountainous region of the state of Espírito Santo is the primary stronghold for the species. Its northern distribution is currently delimited by the Rio Doce River, in the coastal Atlantic forest of central Espírito Santo. The southernmost part of the distribution corresponds to the north-central portion of Rio de Janeiro.

curious facts

Unlike other Bradypus species, male maned sloths do not have a dorsal speculum, but they have long black manes.

Population trend

Decreasing.

HaBITAT and ECOLOGy

This largely arboreal species is found in wet tropical forest. Most records are from evergreen forests, and just a handful of sightings are from semi-deciduous forests. It can be found in regenerating secondary forests. Maned sloths are active at day and at night, although more regular activity occurs during the day. However, in some areas, such as Poço das Antas Biological Reserve in Rio de Janeiro State, maned sloths are mainly active at night. Maned sloths climb slowly and positioning themselves on undersides of branches. They move, on average, only 17 m during the day and 5 m at night. Home ranges have been estimated at 0.8–10.8 ha. Longevity in the wild is at least 12 years.

threats

The expansion of pasturelands, wood and pulp plantations, urban sprawl, and agricultural areas —with the consequent habitat loss—are the main threats to the species. Although the rate of deforestation in the Atlantic forest of eastern Brazil has decreased dramatically in the last three decades, it has not stopped and, in fact, has rebounded a bit in the last five years, so the pressure on habitat continues. This is particularly true in the state of Espírito Santo, where illegal or unregulated deforestation for several reasons, mainly for urban sprawl and agricultural expansion (especially for pasturelands), is still taking place. Additional threats include accidental mortality of B. crinitus on roads. In fact, vehicle accidents might be considered a growing impact due to road expansion or duplication. A number of other significant threats need to be addressed, including attacks of domestic dogs and deaths caused by electrocution. Bradypus crinitus is affected by the increased seasonality and prolonged droughts. These threats could become more intense due to climate change. Furthermore, such new conditions can affect resource availability, as prolonged droughts can increase the risk of fires and change local vegetation.

conservation status

The IUCN SSC Anteater, Sloth and Armadillo Specialist Group has recently assessed the conservation status of this species. The assessment is currently under review and is therefore not yet final.

Bradypus crinitus is considered to be Endangered because it has a restricted area of occupancy (i.e., area of suitable habitat) based on remaining forest within its highly fragmented range. Its area of occupancy and habitat are in continuing decline due to ongoing habitat loss and degradation in the Brazilian Atlantic Forest. Furthermore, this species, like all sloths, is susceptible to vehicle collisions, a growing impact considering current and future city sprawl and road development in the region of the Atlantic forest occupied by the species. Poaching or capture for the illegal animal trade, electrocution, and attacks by dogs might be minor threats whose impact, nevertheless, should not be ignored, particularly in smaller forest fragments where the population is down to a few individuals.