|Scientific Name:||Bradypus torquatus|
|Species Authority:||Illiger, 1811|
Three genetically distinct populations of this species occur in the states of Bahia, Espírito Santo and Rio de Janeiro (Moraes-Barros et al. 2002, 2006; Lara-Ruiz et al. 2008). The northern population (in southern Bahia) might be considered a separate subspecies (Lara-Ruiz et al. 2008), although indistinguishable from the others in external morphology (A. Chiarello pers. comm. 2010).
|Red List Category & Criteria:||Vulnerable B2ab(ii,iii) ver 3.1|
|Assessor(s):||Chiarello, A. & Moraes-Barros, N.|
|Reviewer(s):||Superina, M. & Abba, A.M.|
In 2008, Bradypus torquatus was listed as Endangered based on its very restricted extent of occurrence. However, since then new data and a detailed range analysis based on all confirmed locations and habitat preferences revealed that the extent of occurrence is larger than previously thought, resulting in the species being downlisted to Vulnerable (in 2009). This reassessment of the species confirms its Vulnerable status, with a minor adjustment: in the 2009 assessment it was suspected that extent of occurrence (EOO) was shrinking for this species, however a re-examination of the available information concludes that although area of occupancy (AOO) is declining, there is no evidence at present to support declining EOO. Therefore the subcriterion B2b(i) is now removed from the assessment.
Recent analyses of the available habitat left for B. torquatus suggest that this species might have an area of occupancy of less than 1,000 km² (based on remaining forest within its highly fragmented range). Nevertheless, its area of occupancy and habitat are in continuing decline due to ongoing habitat loss and degradation in the Brazilian Atlantic Forest. Furthermore, poaching might be a real threat, particularly in smaller forest fragments where the population is down to a few individuals. Bradypus torquatus is therefore listed as Vulnerable, with the caveat that a re-assessment should be performed as soon as more data on the wild populations become available.
Bradypus torquatus is restricted to the Atlantic coastal forests of eastern Brazil. Historically, it possibly occurred throughout the coastal forest of Bahia through to the state of Pernambuco (footnote by O. Pinto in Wied's 19th century account, Wied-Neuwied 1958). At present, the southern part of the state of Bahia is the primary stronghold for the species. A recent record of the species is in the state of Sergipe (Chagas et al. 2009) but thus far no records have been collected in the adjacent state of Alagoas. The extensive deforestation of suitable habitat in this state suggests that it is unlikely to survive there. A natural biogeographic gap occurs in northern Espírito Santo, perhaps due to a higher degree of deciduity in the forests of this region (Hirsch and Chiarello 2012). Recent sightings suggest that the species might have a broader distribution in Rio de Janeiro than is indicated by the available data (Boffy et al. 2010).
The species does not occur from the left bank of Doce River to the vicinity of Mucuri River. It has been reported, but not confirmed, from extreme northern Minas Gerais on the left bank of Jequitinhonha River. Bradypus torquatus has been introduced to some National Parks in Espírito Santo (Caparaó National Park) and Rio de Janeiro (Tijuca National Park), among other areas, although it is not known if the species is still present at these sites. A recent record increased the extent of occurrence in the state of Rio de Janeiro. It ranges from sea level to 1,290 m asl.
Native:Brazil (Bahia, Espírito Santo, Rio de Janeiro, Sergipe)
|Range Map:||Click here to open the map viewer and explore range.|
In some parts of Bahia and Espírito Santo, the animals are locally abundant in forest fragments (Chiarello pers. comm. 2010) although the population density is not well known. Studies of population genetics indicate no gene flow between the populations of southern Bahia (Ilhéus) and Espiríto Santo (Santa Teresa), and those of Poço das Antas (Rio de Janeiro). It appears that these populations have been isolated before the anthropogenic fragmentation of habitat, possibly beginning in the Pleistocene (Moraes-Barros et al. 2006, Lara-Ruiz et al. 2008). In general, little genetic diversity is exhibited within individual populations, but the northernmost population (Bahia) is the genetically more diverse (Moraes-Barros et al. 2006, Lara-Ruiz et al. 2008). Overall, the global population of B. torquatus is assumed to be decreasing in response to the continuing loss and fragmentation of suitable habitat, the Atlantic Forest (Ribeiro et al. 2009).
|Habitat and Ecology:||This largely arboreal species is found in wet tropical forest, most typically in areas with an annual precipitation of 1,200 mm or higher and lacking a dry season. Most records are from evergreen forests, and just a handful of sightings are from semi-deciduous forests (Hirsch and Chiarello 2012). It can be found in secondary forest habitats, including cabrucas (cocoa plantation under native forest in southern Bahia; Cassano et al. 2011). Some animals have been sighted in forest fragments as small as 20 ha, although the long-term persistence of populations at these sites is unknown. It is a strict folivore that feeds on a relatively small number of food plants; Chiarello (1998) found that leaves from 21 species formed 99% of the diet of three animals. Like other congeneric sloths, animals descend from trees periodically to urinate and defecate. The females give birth to one young annually, predominantly at the end of the wet season and beginning of the dry season (February-April), and copulation concentrates in the late dry and early wet seasons (August-October; Dias et al. 2009). Sexual maturity is probably reached between the second and third year and longevity in the wild is over 12 years (Lara-Ruiz and Chiarello 2005).|
|Use and Trade:||Although the species is not actively pursued, individuals might sometimes fall victims of subsistence hunting when spotted by local people. Hunting is legally forbidden in Brazil, but enforcement is ineffective. Very few specimens exist in museums so the pressure from scientific collections is practically inexistent. The maned sloth is rarely used for other purposes apart from food.|
The rate of deforestation in the Atlantic forest of eastern Brazil has decreased dramatically in the last three decades but has not stopped (Ribeiro et al. 2009), so the pressure on habitat continues. In southern Bahia the economic crisis of the cocoa plantation (Theobroma cacao) puts a pressure on farmers of this product to clear their forest to make room for other economic alternatives, mainly pastures. In other areas, native forests are cleared for other reasons, including coal production, agriculture and city sprawl. The genetic integrity of distinct populations is threatened by the release of confiscated animals at different sites without knowledge or understanding of their origins. Additional threats include subsistence hunting and accidental mortality of B. torquatus on roads.
Bradypus torquatus is present in a number of protected areas, such as the Biological Reserves of Una (Bahia), Augusto Ruschi (Espírito Santo) and Poço das Antas (Rio de Janeiro), among others. There is an Action Recovery Plan for mammals of the Central Atlantic Forest, which includes the maned three-toed sloth (ICMBio 2010).
The low genetic diversity within fragmented populations indicates a need to develop corridors of suitable habitat between these populations. Confiscated animals should be genetically characterized to determine the most appropriate release site. Data on dispersal ability, sex ratio, mating system, and population density are virtually unknown but important for conservation planning and monitoring.
|Citation:||Chiarello, A. & Moraes-Barros, N. 2014. Bradypus torquatus. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 03 July 2015.|