Choloepus didactylussouthern two-toed sloth

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Geographic Range

Found in the tropical forest canopies of Central America and northern South America, including portions of Brazil and Peru.

Habitat

Choloepus didactylus is strictly arboreal, staying high in the canopy of the tropical rain forests, and maintaining a range of about 10-acres.

Physical Description

Two-toed sloths have been called the slowest animals on earth. Ranging in length from 21 to 29 inches, Choloepus didactylus is roughly the size and shape of a small dog. The body is composed of a short neck (only 6-7 vertebrae) with four long limbs of equal length, ending in two curved claws. The head is short and flat, with a snub nose, rudimentary ears, and large eyes.

Choloepus didactylus are covered in long brownish-grey hair that curves from stomach to back, opposite that of most mammals. A unique feature of this fur is that each strand has grooves which collect algae, giving the sloth a greenish tint and camouflaging it from predators.

The teeth of the two-toed sloth are small, simple molars that are continously growing but constantly ground down by the mastication of food. To compensate for a lack of sharp teeth, Choloepus didactylus has hardened lips which act to shear and crop leaves.

  • Range mass
    4 to 8 kg
    8.81 to 17.62 lb

Reproduction

Females of this species of sloth reach sexual maturity at 3 years of age, males reach sexual maturity between 4 and 5. After a gestation period of six months, females give birth to one offspring each year. When the young are born they are 10 inches in length and weigh 12 ounces. They cling to their mother's belly for 5 weeks until they have the strength to move on their own.

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
    1
    AnAge
  • Average gestation period
    279 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    1279 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    1644 days
    AnAge

Lifespan/Longevity

Behavior

Sloths move slowly and deliberately. They spend most of their life hanging upside-down from tree branches, whether sleeping, eating, mating, or giving birth. They descend to the ground only to change trees (food source) or to defecate. They have a low metabolic rate and defecate only once each week. Food remains in their relatively short digestive tract for approximately one month. Choloepus didactylus can move around quite well in the trees (125 feet per day), but are significantly less mobile on the ground, dragging their body across the ground. Sloths are also good swimmers, having a streamlined body and fur that has evolved for wet, tropical weather.

These sloths are primarily nocturnal, sleeping for 15 hours during the day, and waking during the night only to feed. The sloths eat by grasping vegetation with one foot and pulling it to their mouths.

Two-toed sloths are well camouflaged in tree canopies. Their most common resting position is curled into a ball in the branches of a tree and resembles either a termite nest or a knot in the wood. This, combined with the green color of their fur, makes for great protection from predators. Sloths have been known to defend themselves with their claws and teeth, but they are usually quite docile, relying primarily on camouflage to protect them. Two-toed sloths are also mostly silent, but can let out hisses and low cries or moans if distressed.

Choloepus didactylus are relatively solitary mammals. Groups of females sometimes occupy the same tree, and young may inherit the home range of their parents.

Communication and Perception

Food Habits

Choloepus didactylus feed primarily on vegetation, including berries, leaves, small twigs, and fruits, cropping the leaves with their lips. On occasion sloths have been known to eat insects and other small prey. They obtain water from vegetation and by lapping dew.

Economic Importance for Humans: Positive

Two-toed sloths are a valuable food source and are often hunted for their meat.

Economic Importance for Humans: Negative

There is no direct negative effect of sloths on humans.

Conservation Status

Two-toed sloths are in serious danger of losing their habitat due to logging of rain forests. Aside from captive animals, this is the only area in the world in which this species lives. Several organizations are currently working to protect these areas.

Other Comments

Average life span of two-toed sloths is 20 years in the wild, ages of 30 to 40 years have been recorded in captivity.

Contributors

Ali Felton-Church (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

arboreal

Referring to an animal that lives in trees; tree-climbing.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

rainforest

rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

threatened

The term is used in the 1994 IUCN Red List of Threatened Animals to refer collectively to species categorized as Endangered (E), Vulnerable (V), Rare (R), Indeterminate (I), or Insufficiently Known (K) and in the 1996 IUCN Red List of Threatened Animals to refer collectively to species categorized as Critically Endangered (CR), Endangered (EN), or Vulnerable (VU).

References

"Sloth-The Mammal" (On-line). Accessed November 15, 1999 at http://www.geocities.com/EnchantedForest/Dell/5094/SlothMammal.html.

Henson Robinson Zoo Education Department, October, 1997. "Two-Toed Sloth (Choloepus didactylus)" (On-line). Accessed November 15, 1999 at http://www.hensonrobinsonzoo.org/a001.html.

Klein, L. ""Easy Does It" For the 2-Toed Sloth" (On-line). Accessed November 15, 1999 at http://www.calnative.com/n_sloth.htm.

Parker, S. 1990. Grzimek's Encyclopedia of Mammals, Volume 2. McGraw-Hill Publishing Company.