Linnaeus's Two-toed Sloth

(Choloepus didactylus)

FUN FACT

Does everything hanging upside down — eating, sleeping, mating and even giving birth. May sleep as much as 15-18 hours per day! And, yes, sloths really are slow: their maximum speed climbing in trees is 0.2 miles per hour (on the ground it travels at only 0.01 miles per hour!)

If you notice a big furry lump tucked into the trees in our Tropical Rainforest, don't worry.  It's not a monkey or some weird kind of hairy fruit, it's just Wookiee, our Linnaeus's Two-toed Sloth.

Technically, two-toed sloths really should be called two-fingered sloths; they have three toes on their feet, but just two fingers on their hands, while three-toed sloths have three toes and three fingers. 

Each of the sloth's digits is equipped with a long, 3-4 inch curving claw that helps it hang and climb along branches high above the rainforest floor.  In fact everything about a sloth is built for hanging around!  Sloths spend almost their entire lives upside down -- eating, mating, and even giving birth upside down.  When a sloth does end up on the ground (they climb down every week or so to defecate), they are essentially defenseless.  Their hindlimbs aren't built for walking, so they have to drag themselves along the ground using their front legs. If caught on the ground by a predator, sloths will defend themselves with the powerful claws on their forelimbs.  Sloths can be surprisingly fast when necessary, and they can swim very well!

A sloth's life consists mostly of eating and sleeping.  Lots of sleeping.  Up to fifteen hours a day of sleeping.  But don't make the mistake of thinking a sloth is lazy.  It's just very good at conserving energy, which is a good thing, because a sloth's diet of leaves, shoots, and bark isn't very nutritious.  To compensate, sloths have large, multi-chambered stomach that can hold huge quantities of food.  Sloths chew their food for a very long time before swallowing in order to maximize digestibility.  Even so, it can take up to a month for a sloth to digest one meal.  With so much effort required just to get nutrition from his diet, is it any wonder the sloth doesn't move around any more than absolutely necessary?

The two-toed sloth has the lowest and most variable body temperature of any mammal, due in part to the fact that sloths can't shiver to keep warm.  Depending on the weather, a sloth's temperature can range from 74 - 92 degrees F.  If a sloth's body temperature drops too low, the bacteria in its gut that helps it digest food can stop working, and the sloth can starve to death even with a full stomach.

As with many rainforest animals, both two-toed and three-toed sloths are threatened by destruction of their habitat.  One and a half acres of rainforest is lost every second to logging and burning.  Where rainforests once covered nearly 40% of the earth's surface, they now make up only 6%, with experts fearing even that could be gone in the next 40 years.  The fragmentation of rainforest habitat means sloths must come down to the ground in order to drag themselves from tree to tree in order to get enough to eat.  This leaves them vulnerable to predation by jaguars, ocelots, and domestic dogs.  In addition, when they have to cross roads built through the rainforest, sloths often are struck by passing cars and trucks.

The next time you recycle an aluminum can, or enjoy sustainably harvested tropical nuts, chocolate, and coffee, you can be happy knowing that you're helping sloths like Wookiee.  That little smile on his face while he's napping is just his slothy way of saying, "Thank you for caring!"

Distribution

Ranges through Venezuela, French Guiana, Guyana, and Suriname south into Brazil and west into the upper Amazon Basin of Ecuador and Peru.

Habitat

Tropical moist lowland and mountain rainforests trees with interlacing crowns and many vines that allow for extensive lateral movement without descending to ground.

Diet

Leaves, twigs, buds, fruit, flowers, and occasionally insects.

Breeding

Two-toed Sloths are pregnant for about ten months. While hanging upside down, they give birth to a single offspring, which spends the first five weeks of its life hanging onto its mother as she moves through the rainforest in search of food. Young stay with their mother for up to two years.

Status

Not Under Threat (Least Concern)

At the Aviary

See "Wookiee" the Two-toed Sloth in our Tropical Rainforest