Range:Central America and northern South America, including portions of Brazil and Peru.
The high canopy of tropical rain forests.
The coloration of this animal's fur varies from gray-brown to beige with a greenish cast. They possess a short, fine undercoat and an overcoat of longer, coarser hairs. A unique feature of this fur is that each strand has grooves that collect blue-green algae in moist conditions, giving the sloth a greenish tint and camouflaging it from predators. The algae in their fur are high in fat, and as the sloth grooms itself, it consumes some of the algae providing it with extra nutrients. Unlike other mammals, this sloth’s coat grows from its stomach to the back. Their fur also serves as a home for moths, ticks, and beetles.
On its hind legs, Linne’s sloth has three toes per foot, whereas each foreleg has only two webbed toes. Each of the sloth's digits is equipped with a long, three to four-inch curving claw that helps it hang and climb along branches high above the rainforest floor. Their hind-limbs are not built for walking, so they have to drag themselves along the ground using their front legs when defecating or moving to a new tree.
The teeth of two-toed sloths are small, simple molars that continuously grow but are constantly ground down by the chewing of their food. Due to a lack of sharp teeth, two-toed sloths have hardened lips which are used to shear and crop leaves. Despite their length, two-toed sloths are very light in weight compared to other mammals. This adaptation allows them to move out onto long, thin branches when collecting leaves.
Sloths need to be good at conserving energy because their diet of leaves, shoots, and bark isn't very nutritious. To compensate, sloths have large, multi-chambered stomachs that can hold huge quantities of food. Sloths chew their food for a very long time before swallowing in order to maximize digestibility. Still, it can take up to a month for a sloth to digest one meal, and the sloth gets very little energy from the meal, which is only enough for slowly moving around.
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. This is because they have reduced muscles, about half the relative weight of most terrestrial mammals. Shivering burns too much energy for the amount of food they consume, so they cannot afford to do it. Depending on the weather, a sloth's temperature can range from 74-92 degrees Fahrenheit, and they regulate their body temperatures by moving in and out of the sun. If a sloth's body temperature drops too low, the bacteria in its gut that helps it digest food might stop working, and the sloth can starve to death even with a full stomach.
Two-toed sloths have good spatial memory. This is important for sloths as they have poor eyesight and rely on their memory and sense of smell to navigate their home ranges.
Linne’s two-toed sloth, also known as Unau, is thought to be the slowest mammal in the world. These sloths spend most of their lives hanging upside-down from tree branches; sleeping, eating, mating, and giving birth all happen here. Sloths are primarily nocturnal, sleeping for 15 or more hours during the day and waking at night to feed. Sloths eat by grasping vegetation with one foot, pulling it to their mouths, and chewing it repeatedly.
In order to find enough food, each sloth has a home range of about 10 acres. Two-toed sloths have one of the slowest digestive rates of any mammal. It takes approximately 30 days for their food to travel from ingestion to excretion; in fact, they only have to make the trip to the ground once every five days to eliminate waste! Sloth poop is important to the tree it lives in; since decomposition happens so quickly in the rainforest, a tree can easily become nutrient depleted. Sloth poop provides the tree with some of the nutrients it needs to grow. Sloths get the water they need from their food and by lapping dew off leaves and fruits.
Linne’s sloths are usually solitary animals, although females can sometimes be seen feeding in the same tree at night. Sloths may move to a new tree each night but rarely move more than 40 yards per night. They use their long claws to cling onto the branches of trees.
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, resembling a termite nest or a knot in the wood. This behavior, combined with the green color of their fur, helps them hide from predators.
When on land, Linnaeus’s sloths are very clumsy. However, when in the water, they are accomplished swimmers, using their long arms to move through the water.
Two-toed sloths are generally silent animals. However, when threatened, they will emit hissing sounds, low cries, and moans. Their main tool of defense is camouflage, although claws and teeth are also used to protect themselves.
Sloth teeth and nails grow continuously throughout their life; therefore, it is impossible to determine the age of a wild sloth. In zoos, two-toed sloths have lived as long as 50 years. However, sloths were not bred in zoos until 50 years ago, and so there has been little chance for any individual to exceed this figure. To date, no one has followed a wild sloth from birth until death.
Linne’s sloths are generally solitary animals and are only together for reproduction. Mating lasts only for a few seconds, and the males leave shortly after mating and do not participate in rearing the young.
Females appear to initiate mating. To locate a mate, sloths leave secretions in their dung at the base of a tree, indicating that they are interested in mating. Females will also emit a high pitched call, signaling that they are in estrus. Mating may occur at any time of the year, with a peak mating season occurring from March to April. Females become sexually mature at age three and males at four to five years of age.
Females of this species produce young once a year. The gestation period is about six months, yielding a single baby, or pup, which lives clinging onto the belly of its mother for the first five weeks of its life. The pup starts eating solid foods within a couple of weeks after birth, and becomes independent at about one year of age. However, the young sloth will continue to stay near its mother until it is two years old. Young often inherit the home ranges of their parents.
• The scientific name of Linne’s sloth is ‘Choloepus,’ meaning "lame foot" in Greek and refers to the extreme slowness of this animal. As a matter of fact, Linne’s sloth is thought to be the slowest animal in the world.
• Their metabolisms are so slow that two-toed sloths typically only defecate once a week, lowering to the base of their tree to do so.
• Two-toed sloths are accomplished swimmers, using a breaststroke technique, like humans.
About Our Animals:
The Zoo is home to one Linne’s two-toed sloth.
The biggest threat to this species is habitat destruction. One and a half acres of rainforest are lost every second to logging and burning. Where rainforests once covered nearly 40 percent of the earth's surface, they now make up only six percent, 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, harpy eagles, and domestic dogs. In addition, when they have to cross roads built through the rainforest, sloths are struck by passing cars and trucks. Sloths are hunted for their coat, meat, and claws and now face the new threat of being collected as part of the illegal pet trade. Sloths require special care and do not make good pets!
You can help sloths by recycling aluminum cans or enjoying sustainably harvested tropical nuts, chocolate, and coffee.
||Did YOU Know?
Two-toed sloths really are slow: their maximum tree climbing speed is ten feet per minute, and when traveling on the ground, they reach a top speed of six and a half feet per minute.