61.
Maned Three-toed Sloth
(Bradypus torquatus)
EN
Overview
This species is named after its long mane of black hair, which runs down the back of the neck and over the shoulders. It is one of the two species of sloth found in the Brazilian Atlantic coastal rainforest, and is the only one endemic to this highly disturbed area. Like other species of sloth, the maned sloth spends most of its life hanging upside down from the branches of trees. It is so well adapted to its upside-down lifestyle that even its fur grows in the opposite direction to that of most mammals. The species is threatened primarily by the destruction of its rainforest habitat.
Urgent Conservation Actions
Further research into distribution, ecology and behaviour. The establishment of additional reserves. Creation of habitat corridors to link protected areas.
Distribution
Atlantic coastal rainforest in eastern Brazil.
Associated Blog Posts
29th May 12
It was the pygmy three-toed sloth last week, now we’re continuing with the sloth theme this week with the maned three-toed sloth (although it has been spec...  Read

22nd May 10
The maned three-toed sloth (Bradypus torquatus) is EDGE mammal conservation priority number 63, and is also today's IUCN Species of the Day. Named after i...  Read

Media from ARKive
ARKive video - Maned three-toed sloth - overview
ARKive image - Maned three-toed sloth infant sitting in palm of hand
ARKive image - Maned three-toed sloth infant being held and fed with milk
ARKive image - Maned three-toed sloth
ARKive image - Maned three-toed sloth
ARKive image - Maned three-toed sloth climbing
ARKive image - Maned three-toed sloth climbing
ARKive image - Maned three-toed sloth, head detail
ARKive image - Maned three-toed sloth climbing
ARKive image - Maned three-toed sloth feet around tree trunk
ARKive image - Maned three-toed sloth climbing tree
ARKive image - Maned three-toed sloth
Evolutionary Distinctiveness
Order: Pilosa
Family: Bradypodidae

Sloths belong to the ancient mammalian order Xenarthra, along with armadillos and the South American anteaters. Within this order, sloths are thought to be more closely related to anteaters than either group is to the armadillos. Recent molecular studies indicate that sloths and anteaters diverged around 37 million years ago. Sloths are the most diverse group of xenarthrans, with up to 100 known fossil genera, one of which was even aquatic (the Pliocene Peruvian genus Thalassocnus). Ground sloths were very diverse in the Americas during the Pleistocene, but all of these became extinct around 10,000 years during a major extinction of megafaunal mammal species following prehistoric human arrival in the Americas. Only five species of arboreal sloth survive today, in two families: Bradypodidae (three-toed sloths) and Megalonychidae (two-toed sloths). These families are thought to have diverged around 18 million years ago. There are four species of three-toed sloth, in the single genus Bradypus: B. torquatus (maned three-toed sloth) B. variegatus (brown-throated three-toed sloth) B.pygmaeus (pygmy three-toed sloth) and B. tridactylus (pale-throated three-toed sloth). B. torquatus is estimated to have split from the other two species about 7.7 million years ago.

Description
Size: 
Head and body length: approx. 413-700 mm
Tail length: approx. 20-90 mm
Weight: approx. 2.25-6.20 kg

The largest of the four species of sloth, the maned three-toed sloth is named after its long mane of black hair, which runs down the back of the neck and over the shoulders. The rest of the coat is a greyish-brown colour, although it frequently has a greenish tinge because of the algae that live in the hair. This algal growth provides the species with excellent camouflage, enabling it to blend in perfectly with the trees in which it lives. The fur is long and coarse, and grows in the opposite direction to that of most mammals, so that the hairs point downwards when the animal is hanging upside-down from a branch. The head is small and round, with a flat face and small ears hidden in the fur. Sloths have short bodies, long limbs and stumpy tails. Three-toed sloths are so-called because they have three digits on each limb (two-toed sloths have three digits on their hind limbs, but only two on their forelimbs). Each digit ends in a long curved claw, which the sloth uses to hook around branches. Whereas most mammals have seven neck vertebrae, three-toed sloths have eight or nine. This allows greater flexibility in the head movements, enabling the animals to turn the neck through an arc of 270 degrees.

Ecology
Sloths spend practically their entire lives in the trees, either hanging beneath branches or sitting in a fork. They descend to the ground about once or twice a week to urinate and defecate, and on occasion to move from one tree to another. The sloth is well camouflaged in the trees, but extremely vulnerable on the ground as it moves by crawling slowly on the soles and forearms. However, sloths are not completely defenceless – when faced with a predator, they are capable of inflicting serious wounds with their long, sharp claws. Since sloths tend to stay in one tree for long periods of time, feeding is restricted to that tree and to other plants supported by the tree. The diet consists almost exclusively of young leaves, tender twigs and buds. These items are pulled to the mouth with slow movements of the forelimbs. Since this species does not have any incisors it crops the leaves with its hard lips instead. Like other sloths, this species has a long, multi-chambered stomach filled with cellulose-digesting bacteria. This allows them to extract energy from nutritient-poor mature leaves. Sloths have an extremely low metabolic rate, about half that of most mammals their size. They sleep for around 15 hours each day and maintain a relatively low body temperature (30-34°C) to conserve energy. Body temperature is regulated by moving in and out of the shade in trees. The species generally moves slowly and methodically, although it can progress rapidly when necessary. Individuals are active both night and day, and are primarily solitary, although their large home ranges (3-6 ha) frequently overlap. Maned sloths appear to reach maturity at about three years of age, which is a relatively short time for animals of their size and low metabolic rate. Breeding appears to take place at the end of the dry season (September–November), with females giving birth to a single young each year after a gestation period of around six months. Infants are weaned at around 2-4 months and are independent by 11 months.
Habitat
Inhabits lowland tropical evergreen forests, particularly those with a continuous canopy.
Distribution
Restricted to remaining fragments of Atlantic coastal rainforest in eastern Brazil. Separate populations survive in the states of Bahia, Espirito Santo and Rio de Janiero. These are thought to be isolated and genetically distinct, with the Bahia population potentially a distinct subspecies.
Population Estimate
Unknown.
Population Trend
Decreasing.
Status

Classified as Vulnerable B2ab(i,ii,iii) on the 2011 IUCN Red List of Threatened Species.

Threats

The maned sloth is one of the most threatened of the South American sloth species, owing to its restricted geographical range and the disturbed and fragmented nature of its forest habitat. The Atlantic coastal rainforest of Brazil is diminishing rapidly as a result of logging, charcoal production, and clearance for plantations and cattle pasture. Today, the Atlantic forest is reduced to less than ten percent of its original area, and the Mata Atlântica region in which the species lives has the highest human population in Brazil. Maned sloths have a highly fragmented distribution, with large gaps between the major populations. This means that many existing populations may be too small to be viable. The species has traditionally been hunted for its meat, and this may continue to threaten its survival in some areas, despite now being protected by law.

Conservation Underway

Although maned sloths occur in at least eight protected areas, it is unlikely that any of these support viable populations, because of the highly fragmented distribution of this species. Extensive conservation efforts are currently underway to protect additional areas of the Atlantic coastal rainforest, since it is home to a great number of species found nowhere else on the planet. The WWF is currently involved in community projects which seek to educate local people about the importance of protecting this forest. The US Agency for International Development (USAID) is working on reduced-impact forest management and on providing alternatives to slash-and-burn agroforestry. Conservation International (CI) is focussing on ecotourism as a possible alternative income for local communities which might otherwise have cleared areas of forest for agriculture. In 1998 a canopy walkway was built near the Una Biological Reserve, saving 320 acres of valuable rain forest habitat from logging. Efforts to translocate individuals from urban or agricultural areas to protected forest reserves appear to have been relatively successful so far. Extensive post-translocation monitoring has been carried out, which is providing important data about the species’ ecology and habitat requirements, as well as an indication of the success of the translocations themselves. Attempts to breed the species in captivity have not proved as successful. This is primarily due to the fact that these sloths do not survive for more than a few months outside of their natural environment. Research projects are focusing on the close relationship between females and offspring, so that breeding and re-introduction programmes in the future are better informed and more successful.

 

As of 2010 this species has been included in the Brazilian government's ‘National Action Plan (NAP) for the conservation of central Atlantic forest mammals'. Costing an estimated US$32 million, this scheme aims to conserve geographic regions over specific species. Nonetheless, 27 named species, including the maned three-toed sloth are specifically targeted in the plan. The early stages of this NAP focused on compiling all known biological and threat data relative to these target species. With this information, 60 individuals, representing a range of national and international bodies, were able to construct 6 main goals and 100 specific actions to guide future conservation efforts. Compiled in 2010, the goals of this project include: maintaining, enlarging and connecting protected habitats, managing sloth populations (genetically and demograpically) to ensure their viability, reducing hunting pressures, ensuring scientific knowledge on taxa and threats remains up to date and pressuring for guidelines documented in this project to be reflected in national policy.

Projects
Conservation Proposed
Further studies into the distribution, ecology and behaviour of this species in the wild are recommended. Additional reserves are required in areas of primary forest and secondary forest in which the species occurs. Protected areas need to be connected to minimise the genetic isolation of populations. Although maned sloths do not survive for more than a few months in captivity, they have been maintained in semi-captivity, so it may be possible to establish temporary populations in this manner (UNEP). Further genetic research is needed to determine whether the isolated populations represent distinct subspecies. In the meantime, the Edentate Specialist group recommends that any efforts for population management should recognize and preserve the unique genetic character of the three separate populations. In particular, individuals should not be translocated to novel, distinct populations.
Associated EDGE Community members

Adriano is a sloth expert working to conserve sloths in Brazil

Adriano is an expert on maned three-toed sloths

Rebeca works on the conservation of maned sloths in Brazil

Links
References
Chiarello, A., Lara-Ruiz, P. & Members of the IUCN SSC Edentate Specialist Group 2008. Bradypus torquatus. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.4. <www.iucnredlist.org>. Downloaded on 12 November 2010.

Barros, M. C., Sampaio, I. and Schneider, H. 2003. Phylogenetic analysis of 16S mitochondrial DNA data in sloths and anteaters. Genetics and Molecular Biology 26(1): 5-11.

Chiarello, A., Lara-Ruiz, P. and Members of the Edentate Specialist Group. 2006. Bradypus torquatus. In: IUCN 2006. 2006 IUCN Red List of Threatened Species. Downloaded on 09 August 2006.

Edentata: The Newsletter of the IUCN Edentate Specialist Group 6. (Dec 2004).

Edentate Specialist Group. 1996. Bradypus torquatus. In: IUCN 2004. 2006 IUCN Red List of Threatened Species. Downloaded on 07 March 2006.

Lara-Ruiz, P. and Garcia Chiarello, A. 2005. Life-history traits and sexual dimorphism of the Atlantic forest maned sloth Bradypus torquatus (Xenarthra: Bradypodidae). Journal of Zoology 267(1): 63-73.

Nowak, R.M. 1999. Walker's Mammals of the World. Sixth edition. The Johns Hopkins University Press, Baltimore and London.

UNEP World Conservation Monitoring Centre

Villa-Lobos, J. 1998. Tree Top Walkway in Brazil . Biological Conservation Newsletter 176.

Distribution map based on data provided by the IUCN Global Mammal Assessment

if you can provide new information to update this species account or to correct any errors, please email us at info@edgeofexistence.org


Forum comments
  1. saudiya
    Member

    Hi Sally,

    I would like to see some ecological info on activity patterns and their life expectancy. I would also like to see the myth exploded that sloths are lazy. They are not. They sleep on average just 9+ hours (as opposed to the common perception of 15+ or even 20 odd hours).

    They occupy this peculiar ecological niche and have this intricate biological capacity for exhibiting activity patterns comparative to reptiles (in that they require direct sunglight to heat up their body temp and become active)

    I have been a zoo volunteer in my local zoo for some time and someone the other day asked my what the longevity for sloths (we are breeding the commonly maintained three toed sloth) and - allthough usually not on biological matters as hugely interested and with direct actual field experience of long-term ecological/biological field research - I was literally lost for words (and I hate to just speculate, so I said I just did not know ...).

    I would expect that given their slow metabolism - reflecting the common notion that taxa with high metabolism have extremely high activity patterns and short life spans - that sloths are long living species (again that is speculation). So, what is the truth behind all this?

    Regards,

    saudiya

    Posted 5 years ago #
  2. Anonymous
    Unregistered

    yo yo yo it p.J and i love this place

    Posted 5 years ago #
  3. Sally Wren
    EDGE Team

    Hello, if you have any extra information on this species then please email it to us and we'll gladly update the information.
    Thanks!

    Posted 5 years ago #
  4. Anonymous
    Unregistered

    get updated info

    Posted 5 years ago #
  5. Anonymous
    Unregistered

    not accurate

    Posted 5 years ago #

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