Linne’s Two-Toed Sloth
aka Southern two-toed sloth or Unau
Choloepus didactylus

Sloths spend their lives hanging upside down in treetops by the sickle-shaped claws of their four limbs. Sometimes called the slowest animals on earth, bit by bit they move deliberately along branches, conserving energy and avoiding detection from predators.

What They Eat
Sloths feed primarily on vegetation-leaves, small twigs, berries, flowers, and fruit-and occasionally insects and small prey. Food is digested slowly and remains in the stomach for as long as one month.

Where They Live
Found in the coastal and mountainous tropical forests of Central America and northern South America, sloths live high in the forest canopy.

What They Do
Sloths sleep, eat, mate, and give birth hanging upside down in a tree. They descend from a tree every 4-8 days to urinate and defecate at the base. Excellent swimmers, sloths will take to the water during the wet season to change trees in search of food.

How They’re Doing
Some species of sloths are stable, while others are endangered. Threats to populations include habitat destruction and hunting for their meat, fur, and claws. Because of their slow nature, sloths are also frequently hit by cars in places where roads have been cut through the forest.

Linne’s Two-Toed Sloth

With weak hind legs and bodies designed for a life upside down in trees, sloths are basically unable to walk when on the ground. Instead, they crawl slowly along the ground, usually from one tree to another.

Because of their slow metabolism, sloths only need to defecate and urinate every 4-8 days and may lose up to 30% of their body weight when they do.

The hair their belly parts down the middle. This directs water away from their bodies while hanging upside down in the rain. 

Less muscle means sloths are lighter than most animals their size. This allows them to climb high in the forest canopy, closer to food and farther from large predators.

Sloths’ body temperature changes with the temperature of their surroundings, and can vary as much as 10º F in 24 hours. For most animals, including humans, this would be life-threatening.

Things you can do

One of most important things you can do to protect animals that live in the rainforest is to learn all you can about their unique environment and then share that information with others.

Many products we use everyday such as rubber, coffee, and wood, come from rainforests. When you shop, consider where these products were made, and support companies and programs that make a commitment to using safe environmental practices.

Your visit to the Zoo helps support our conservation programs. You can also sponsor an animal at the Zoo.

Become a Member of the Minnesota Zoo!

 

 

Linne’s Two-Toed Sloth

There are six species of sloth. The Brazilian three-toed sloth is endangered in its entire range. Exact population numbers are unknown for the Linne’s two-toed sloth. Threats to sloths include pesticides, deforestation, and power lines. Their continued survival depends on protecting their rainforest habitats.

Things the Zoo's done/doing

Aviarios del Caribe, the only sloth rescue, research, and rehabilitation center in Central America, has rehabilitated and released over 40 sloths. Adult sloths with permanent disabilities are kept at the center for scientific behavioral research, observation of their natural history, and environmental education.

When Aviarios needed to update and expand their educational curriculum in 2005, Melanie Sorensen, Minnesota Zoo Education Interpretive Naturalist, volunteered to spend a month in Costa Rica to help. While there she wrote curriculum, cared for sloths, led center tours, and assisted with the Costa Rican Environmental Education Program. The Minnesota Zoo provided Melanie with financial support to cover her travel costs and buy much needed supplies for the center.

After word got out about Melanie’s experiences in Costa Rica, keepers from around the country began to contact her with questions about their sloths. As a result, the Minnesota Zoo held the first ever “sloth symposium” in 2008. Keepers from around the country were invited to come together at the zoo to exchange information on sloths and put together a comprehensive manual on their care.

Conservation Notes

Large numbers of toe-toed sloths still exist in the wild, but their habitat continues to be destroyed. Sloths are hunted for their lean meat, which is similar to mutton in flavor. Their straw-like fur is popular for use as saddlecloths and native people use their claws for necklaces.

Linne’s Two-Toed Sloth

Sloths are unusual mammals. They are extremely slow moving and designed for a life hanging upside down in trees. Their limbs are modified so that the arms are longer than the legs and the narrow hands and feet terminate in long sickle-shaped claws. Fingers and toes are fused and reduced in number to two (Toe-toed sloths) or three (Three-toed sloths). Sloths are nocturnal and solitary by nature, although several females may group together in one tree. The animals space themselves throughout the forest but do not defend territories.

Range and Habitat
Two-toed sloths live in the forest canopies of northern South America down to the Amazon basin, occurring in Surinam, southern Venezuala, the Guyanas, southern Columbia east of the Andes, and along both banks of the Amazon basin in Brazil. They are arboreal and have a range of about 10 acres.

Diet
Sloths are omnivores. They move extremely slowly from one tree to another and eat leaves, buds, slender twigs, blossoms, fruits, insects, and small prey. They have no incisors or canines, and simply sever vegetation with their hard, horny lips.

Sloths have an unusually low metabolic rate allowing them to live on little food or poor quality food. They have a stomach that is divided into right and left halves, each of which is divided into several compartments. Because a sloth’s body temperature falls with the surrounding temperature, and proper digestion requires warmth, sloths take a long time to digest their food. Vegetation can be low in nutrition, and food may spend up to a month in the stomach so that the sloth can extract every bit of available nutrients. Sloths get needed moisture through juicy leaves and by licking dew drops or water collected inside bromeliads.

Adaptations and behavior
Sloths hang in the treetops by the curved claws of their four limbs. It is easier to for them to hang than to try to balance upright. Slowly they sway through the branches belly up. The sloth's main predators, birds of prey, look out for sudden movements, so a sloth in slow motion will not register as prey.

Only when the food supply is depleted will sloths move to a neighboring tree, preferably by way of branches. If that option is not available, they will abandon their tree. They are extremely helpless on the ground and must lay prone, dragging themselves forward to the next tree, which puts them at risk from predators. They are good swimmers, however, and take to water readily.

Their bladder is uncommonly large and possibly serves as a moisture reservoir. Sloths typically come down from their trees only every 4-8 days to urinate and defecate, which reduces their exposure to predators. When they do, they eliminate wastes in large volumes and may lose as up to 30% of their body weight.

Sloths have a variable temperature fluctuating between 75º F and 91º F degrees depending on the ambient temperature. On the average, sloths spend 15 hours a day sleeping; to conserve heat they hang with their limbs close together and their heads tucked into their chests. They have very little muscle and cannot shiver to keep themselves warm.

Reproduction
There is no fixed mating season for sloths. Births have been recorded in all months except April, September, and November. When mating, the animals hang from a branch by their arms and turn to face each other. After a gestation of 4-5 months, females give birth to a single young while hanging by upside down in a tree. The infant is fully furred, with eyes open and a complete set of teeth.  It is born head first and immediately begins to help itself until it is able to cling to the mother with its claws. The infant remains hidden in the fur of the mother’s belly for 4 weeks. Then it starts to show interest in its surroundings and will start to grab at nearby branches. At 10 weeks it starts to eat part of the mother’s meals, and at 9 months it starts hanging independently from the mother. Sloths reach maturity at approximately 2 ½ years.