Animal Diversity Web

Ge­o­graphic Range

Brown-throated three-toed sloths are na­tive to South Amer­ica and south­ern Cen­tral Amer­ica. Their ge­o­graphic range in­cludes Bo­livia, Brazil, Co­lum­bia, Ecuador, Hon­duras, Nicaragua, Panama, Paraguay, Peru, and Venezuela. Al­though once pre­sent in Ar­gentina, it is now thought to be ex­tinct. (Chiarello, 2008)

• Biogeographic Regions
• neotropical
  • native

Habi­tat

Brown-throated three-toed sloths can be found in many new-world trop­i­cal forests, though some have also been dis­cov­ered in semi-de­cid­u­ous forests and sub­trop­i­cal low­lands and swamps. They live in the canopy for the ma­jor­ity of their lives and are ca­pa­ble swim­mers. They sel­dom travel on the ground. They can be found at el­e­va­tions rang­ing from sea level to 2400 m. Al­though not se­lec­tive about the species of tree they choose to in­habit, they tend to seek out trees with crowns that are highly ex­posed to sun­light. This pref­er­ence has been at­trib­uted to the sloths using sun­light to ful­fill their ther­moreg­u­la­tory needs. ("Brown-throated three-toed sloth (Brady­pus var­ie­ga­tus)", 2008; Chiarello, 2008)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest

• Aquatic Biomes
• rivers and streams

• Wetlands
• swamp

• Other Habitat Features
• riparian

• Range elevation

  0 to 2400 m

  0.00 to 7874.02 ft

Phys­i­cal De­scrip­tion

As in­di­cated by their com­mon, brown-throated three-toed sloths have brown col­oration on their throat and head. Their coat con­sists of a layer of short, soft, and fine fur and a layer of thick, woolly fur. Algae often re­sides on outer layer, giv­ing some in­di­vid­u­als a green­ish ap­pear­ance. They have long fore­limbs with three clawed-toes on each limb. They also have ap­prox­i­mately 10 cer­vi­cal ver­te­brate that en­able them to ro­tate their necks up to 270 de­grees. Their teeth are cylin­dri­cal and lack enamel. Sim­i­lar to many un­gu­lates, their stom­achs are multi-com­part­men­tal­ized, with in­testi­nal mi­cro­fauna that help di­gest cel­lu­lose from their ex­clu­sively veg­e­tar­ian diets. Even as en­dotherms, brown-throated three-toed sloths have dif­fi­culty reg­u­lat­ing their body tem­per­a­ture in cold en­vi­ron­ments and in cooler am­bi­ent tem­per­a­tures. This is likely due to sparse mus­cle mass, their rel­a­tively small heart, and low-rang­ing heart rate. Adults range in mass from 3.49 to 5.19 kg, with an av­er­age of 4.34 kg. Av­er­age length is 60 cm, and they have a basal meta­bolic rate of 147 cm^3 oxy­gen/hour. Al­though size-di­mor­phism is not pre­sent in this species, males have a mid-dor­sal specu­lum that is not pre­sent in fe­males. (Feld­hamer, et al., 2007; Gilmore, et al., 2001; Gilmore, et al., 2000)

• Other Physical Features
• endothermic
• homoiothermic
• bilateral symmetry

• Sexual Dimorphism
• sexes colored or patterned differently

• Range mass

  3.49 to 5.19 kg

  7.69 to 11.43 lb

• Average length

  60 cm

  23.62 in

• Average basal metabolic rate

  147 cm3.O2/g/hr

Re­pro­duc­tion

Brown-throated three-toed sloths are thought to be monog­a­mous. Fe­males vo­cal­ize to at­tract males when they are ready to mate. Fe­males typ­i­cally mate with the first male they en­counter. Al­though it is un­clear if they have a de­fined breed­ing sea­son, ev­i­dence sug­gests mat­ing oc­curs just prior to the rainy sea­son. Cop­u­la­tion lasts 10 to 15 min­utes and takes place in the fe­male's tree, ap­prox­i­mately 15 m above the ground. Dur­ing cop­u­la­tion, the male po­si­tions him­self be­hind the fe­male. Once mat­ing is com­plete, the male leaves shortly there after. (Bez­erra, et al., 2007)

• Mating System
• monogamous

Once cop­u­la­tion is fin­ished, males im­me­di­ately leave and do not pro­vide any parental care to young. Brady­pus var­ie­ga­tus gives birth to a sin­gle off­spring once a year. Dur­ing ges­ta­tion, which lasts for 5 to 8 months, the mother does not make any prepa­ra­tions, such as nest-build­ing. After birth, neonates are held ven­trally, which is thought to help pro­vide pro­tec­tion for young, in­clud­ing at­tack from preda­tors. Neonates weigh less than 1 kg at birth. Most in­di­vid­u­als be­come in­de­pen­dent once wean­ing is com­plete, which takes ap­prox­i­mately 4 months. Fe­males be­come re­pro­duc­tively ma­ture by 3 years of age, and males be­come re­pro­duc­tively ma­ture be­tween 3 and 5 years of age, with an av­er­age of 4 years of age. (Bez­erra, et al., 2007; SOARES and CARNEIRO, 2002)

• Key Reproductive Features
• year-round breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
• viviparous

• Breeding interval

  Brown-throated three-toed sloths breed once yearly

• Average number of offspring

  1

• Range gestation period

  5 to 8 months

• Average weaning age

  4 months

• Range time to independence

  2 to 4 months

• Average age at sexual or reproductive maturity (female)

  3 years

• Range age at sexual or reproductive maturity (male)

  3 to 5 years

Brown-throated three-toed sloths give birth on the ground or in trees. Dur­ing birth, the mother pulls the in­fant be­tween her hindlegs, and other sloths aid in the birthing process by clean­ing the mother and in­fant and by en­sur­ing that the in­fant doesn't fall. Moth­ers help young es­tab­lish motor be­hav­ior, pos­ture, learn­ing de­vel­op­ment, and in­de­pen­dent ex­plo­ration in young. Pa­ter­nal care is thought to be non-ex­is­tent in this species. (Gilmore, et al., 2000)

• Parental Investment
• female parental care
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Lifes­pan/Longevity

In the wild, the lifes­pan of adult brown-throated three-toed sloths is typ­i­cally be­tween 30 and 40 years. There is no other in­for­ma­tion avail­able re­gard­ing the lifes­pan of this species. (MORAES-BAR­ROS, et al., 2011; MORAES-BAR­ROS, et al., 2011; MORAES-BAR­ROS, et al., 2011)

• Range lifespan
  Status: wild

  30 to 40 years

• Typical lifespan
  Status: wild

  30 to 40 years

Be­hav­ior

Brown-throated three-toed sloths sleep ap­prox­i­mately 14 to 16 hours a day and are both di­ur­nal and noc­tur­nal. They are ac­tive for ap­prox­i­mately 8 to 10 hours a day, which is typ­i­cally par­ti­tioned into dis­crete 2 to 3 hour pe­ri­ods. They are most ac­tive be­tween 1200 and 1800 hours, and most in­di­vid­u­als sleep be­tween 0600 and 1200. Brown-throated three-toed sloths ex­hibit two dif­fer­ent rest­ing modes. The first is that of an "awake-alert" state dur­ing which the an­i­mal's eyes are ac­tively open and blink­ing; the sec­ond is that of a "be­hav­ioral sleep", dur­ing which the an­i­mal's eyes are closed but still re­mains sus­pended from a tree. Adults have never been ob­served in the same tree with an­other adult. Ag­nos­tic be­hav­ior is rel­a­tively rare be­tween con­specifics; how­ever, they read­ily pro­tect ter­ri­tory, food, or other re­sources. (Duarte, et al., 2003; Gilmore, et al., 2001; Greene, 1989)

• Key Behaviors
• arboreal
• scansorial
• diurnal
• nocturnal
• motile
• sedentary
• solitary

• Average territory size

  20000 m^2

Home Range

The av­er­age home ranges of brown-throated three-toed sloths is less than 2 hectares. There is no fur­ther in­for­ma­tion on the home range of this species. (Gilmore, et al., 2001)

Com­mu­ni­ca­tion and Per­cep­tion

So­cial in­ter­ac­tions be­tween Brady­pus var­ie­ga­tus adults are rel­a­tively rare. How­ever, com­mu­ni­ca­tion be­tween moth­ers and their young is sig­nif­i­cant, par­tic­u­larly in the form of vo­cal­iza­tion. Vo­cal­iza­tions are also used to com­mu­ni­cate with other con­specifics dur­ing breed­ing sea­son, as fe­males call out to at­tract a po­ten­tial mate. Brady­pus var­ie­ga­tus lack a cil­iary mus­cle in their eyes and have very few gan­glion cells and nerve fibers, which re­sult in poor eye­sight and vi­sual acu­ity. Ev­i­dence sug­gests that vi­sion func­tions op­ti­mally at low light in­ten­si­ties. Defe­ca­tion and uri­na­tion occur on the ground, and both have been sug­gested to func­tion as a means of com­mu­ni­cat­ing with other con­specifics. (Bez­erra, et al., 2007; Gilmore, et al., 2000; SOARES and CARNEIRO, 2002)

• Communication Channels
• visual
• acoustic
• chemical

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

Brady­pus var­ie­ga­tus is a strict her­bi­vore that feeds pri­mar­ily on trees in the genus Cer­cropia (e.g., em­bauba). They con­sume var­i­ous parts of the tree, in­clud­ing leaves, flow­ers, and fruits. Brady­pus var­ie­ga­tus is a fac­ul­ta­tive drinker and re­ceives most of its water from in­gested plant ma­te­ri­als. (Bez­erra, et al., 2007; Duarte, et al., 2003; Gilmore, et al., 2000)

• Primary Diet
• herbivore
  • folivore
  • frugivore

• Plant Foods
• leaves
• fruit
• flowers

Pre­da­tion

Brown-throated three-toed sloths are highly cam­ou­flaged and slow-mov­ing, both of which help de­crease risk of pre­da­tion via de­creased vis­i­bil­ity. Major preda­tors of this species in­clude spec­ta­cled owls, harpy ea­gles and a va­ri­ety of felid species. Brown-throated three-toed sloths de­scend from the canopy to defe­cate and uri­nate on the ground. Al­though they only de­scend from teh canopy once every 3 to 8 days, this be­hav­ior greatly in­creases vul­ner­a­bil­ity to pre­da­tion. (Gilmore, et al., 2001; Touch­ton, et al., 2002; Voirin, et al., 2009)

• Anti-predator Adaptations
• cryptic

• Known Predators

  • spectacled owls, (Pulsatrix perspicillata)
  • harpy eagle, (Harpia harpyja)
  • felids, (Felidae)

Ecosys­tem Roles

Brown-throated three-toed sloths have are mu­tu­al­ists with algae, which re­side in the coats of sloths. The pres­ence of algae con­fers a green­ish tint to the out­er­most fur coat, which is hy­poth­e­sized to func­tion as cam­ou­flage. It has also been sug­gested that algae pro­vides es­sen­tial trace el­e­ments and nu­tri­ents. In ex­change, algae re­ceives shel­ter in the coats of their host and sun­light, as sloths pre­fer sec­tions of sun-ex­posed canopy. Brown-throated three-toed sloths are pri­mary prey for a num­ber of ver­te­brate preda­tors in­clud­ing harpy ea­gles and many species of felid; how­ever, they do not make up a large por­tion of any one species' diet. Known par­a­sites of this species in­clude Leish­ma­nia and Pneu­mo­cys­tis carinii. (Gilmore, et al., 2001)

• Ecosystem Impact
• creates habitat

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

There are no known pos­i­tive ef­fects of Brady­pus var­ie­ga­tus on hu­mans.

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

There are no known ad­verse ef­fects of Brady­pus var­ie­ga­tus on hu­mans.

Con­ser­va­tion Sta­tus

Brady­pus var­ie­ga­tus is clas­si­fied as a species of least con­cern on the IUCN's Red List of Threat­ened Species. Al­though pre­cise pop­u­la­tion trends are un­known, is has been es­ti­mated that den­si­ties rang­ing from 2.2 to 8.5 an­i­mals per hectare occur through­out their ge­o­graphic range. Al­though some pop­u­la­tions in the Brazil­ian Ama­zon are thought to be de­clin­ing due to de­for­esta­tion, there are no major threats to the long-term per­sis­tence of this species. (Chiarello, 2008)

• IUCN Red List

  Least Concern
  More information

• IUCN Red List

  Least Concern
  More information

• US Federal List

  No special status

• CITES

  No special status

• State of Michigan List

  No special status

Con­trib­u­tors

Hee-Jin Jung (au­thor), The Col­lege of New Jer­sey, Matthew Wund (ed­i­tor), The Col­lege of New Jer­sey, John Berini (ed­i­tor), An­i­mal Di­ver­sity Web Staff.

Ref­er­ences

2008. "Brown-throated three-toed sloth (Brady­pus var­ie­ga­tus)" (On-line). World As­so­ci­a­tion of Zoos and Aquar­i­ums - United For Con­ser­va­tion. Ac­cessed March 12, 2011 at http://​www.​waza.​org/​en/​zoo/​visit-the-zoo/​sloths-anteaters-armadillos-pangolins-and-aardvark/​bradypus-variegatus.

Bez­erra, B., A. Souto, L. Halsey, N. Schiel. 2007. Ob­ser­va­tion of brown-throated three-toed sloths: mat­ing be­hav­iour and the si­mul­ta­ne­ous nur­tur­ing of two young. Japan Etho­log­i­cal So­ciet, 26: 175–178.

Chantelois, M. 2009. "Brady­pus var­ie­ga­tus: Brown-throated sloth" (On-line). Ac­cessed Feb­ru­ary 22, 2011 at http://​www.​eol.​org/​pages/​328518.

Chiarello, A. 2008. "Brady­pus var­ie­ga­tus" (On-line). The IUCN Red List of En­dan­gered Species. Ac­cessed March 12, 2011 at http://​www.​iucnredlist.​org/​apps/​redlist/​details/​3038/​0.

Duarte, D., A. Jaguaribe, M. Pe­drosa, A. Clementino, A. Silva, A. Bar­bosa, D. Gilmore, C. Da Costa. 2004. Car­dio­vas­cu­lar re­sponses to lo­co­mo­tor ac­tiv­ity and feed­ing in un­re­strained three-toed sloths, Brady­pus var­ie­ga­tus. Brazil­ian Jour­nal of Med­ical and Bi­o­log­i­cal Re­search, 37: 1557-1561.

Duarte, D., V. Silva, A. Jaguaribe, D. Gilmore, C. Da Costa. 2003. Cir­ca­dian rhythms in blood pres­sure in free-rang­ing three-toed sloths (Brady­pus var­ie­ga­tus). Brazil­ian Jour­nal of Med­ical and Bi­o­log­i­cal Re­search, 36: 273-278.

Feld­hamer, G., L. Drick­amer, S. Vessey, J. Mer­ritt. 2007. Mam­mal­ogy: Adap­ta­tion, Di­ver­sity, Ecol­ogy. Mary­land: Johns Hop­kins Uni­ver­sity Press.

Gilmore, D., C. Da Costa, D. Duarte. 2001. Sloth bi­ol­ogy: an up­date on their phys­i­o­log­i­cal ecol­ogy, be­hav­ior and role as vec­tors of arthro­pods and ar­boviruses. Brazil­ian Jour­nal of Med­ical and Bi­o­log­i­cal Re­search, 34: 9-25.

Gilmore, D., C. Da-Costa, D. Duarte. 2000. An up­date on the phys­i­ol­ogy of two- and three-toed sloths. Brazil­ian Jour­nal of Med­ical and Bi­o­log­i­cal Re­search, 33: 129-146. Ac­cessed Feb­ru­ary 22, 2011 at http://​www.​scielo.​br/​pdf/​bjmbr/​v33n2/​3528c.​pdf.

Greene, H. 1989. Ag­nos­tic Be­hav­ior by Three-toed Sloths, Brady­pus var­ie­ga­tus. Biotrop­ica, Vol­ume 21, Issue 4: 369-372. Ac­cessed Feb­ru­ary 23, 2011 at http://​www.​jstor.​org/​stable/​2388289.

MORAES-BAR­ROS, ., J. SILVA, J. MOR­GANTE. 2011. Mor­phol­ogy, mol­e­c­u­lar phy­logeny, and tax­o­nomic in­con­sis­ten­cies in the study of Brady­pus sloths (Pi­losa: Brady­po­di­dae). Jour­nal of Mam­mal­ogy, 92: 86-100.

SOARES, C., R. CARNEIRO. 2002. SO­CIAL BE­HAV­IOR BE­TWEEN MOTH­ERS ´ YOUNG OF SLOTHS Brady­pus var­ie­ga­tus SCHINZ, 1825 (XE­NARTHRA: BRADY­PO­DI­DAE). Brazil­ian Jour­nal of Bi­ol­ogy, Vol­ume 62, Issue 2: 249-252.

Touch­ton, J., Y. Hsu, A. Palleroni. 2002. FOR­AG­ING ECOL­OGY OF REIN­TRO­DUCED CAP­TIVE-BRED SUBADULT HARPY EA­GLES (HARPIA HARPYJA) ON BARRO COL­ORADO IS­LAND, PANAMA. OR­NI­TOLO­GIA NEOTROP­I­CAL, 13: 365–379.

Ur­bani, B., C. Bosque. 2007. Feed­ing ecol­ogy and pos­tural be­hav­iour of the three-toed sloth (Brady­pus var­ie­ga­tus flac­cidus) in north­ern Venezuela. Mam­malian Bi­ol­ogy, Vol­ume 72, Issue 6: 321-329.

Voirin, J., R. Kays, M. Low­man, M. Wikel­ski. 2009. Ev­i­dence for Three-Toed Sloth (Brady­pus var­ie­ga­tus) Pre­da­tion by Spec­ta­cled Owl (Pul­satrix per­spic­il­lata). Eden­tata, 8-10: 15-20.