Sloths are slow-moving mammals that dwell in the rainforest canopies of South and Central America. There are two types of sloth: three-toed sloths and two-toed sloths. Across these types, there are six individual species:
- Pale-throated (Bradypus tridactylus)
- Pygmy three-toed (Bradypus pygmaeus)
- Maned (Bradypus torquatus)
- Brown-throated (Bradypus variegatus)
- Linnaeus’s two-toed (Choloepus didactylus)
- Hoffman’s two-toed (Choloepus hoffmanni)
The average sloth is around the size of a small dog and has grayish-brown hair. At times, however, they can look almost green because of the tiny algae that grow all over their coats. They are known for their inactive lifestyles and distinct faces that always appear to be smiling.
Want to know more about this sweet but slow animal? In this article, we take a look at this treetop-dwelling species in more detail, focusing on where sloths live, what the sloth diet is made up of, and why sloths move so slow.
Where Do Sloths Live?
Both the two-toed sloth and three-toed sloth are native to Central and South America and are commonly found in Peru, Brazil, Panama, and Costa Rica. They thrive in the canopies of tropical rain, mangrove, and cloud forests, and spend most of the day hanging or perching within the branches.
The typical sloth habitat is thus the treetops, and they spend nearly all of their time there. These animals are built for a life of hanging around and have long claws and a powerful grip that enables them to comfortably live like this.
A sloth can hang upside down for long periods of time — even up to 90% of its life! Recent studies show that this is all thanks to their impressive biology. As their organs are attached the inside of the rib cage, they don't press down on the lungs and sloths can therefore breathe easily upside down. This means that they can sleep, eat, and even give birth while upside down.
Sloths do come down from the trees occasionally, and this is mainly for the purposes of defecation and urination. For three-toed sloths, this is around just one time a week and can be as long as 12 days. Sloths tend to avoid the forest floor due to their difficulty walking and the threat of predators.
Sloths do not walk well on land and their long claws are a hindrance. However, they are known to be good swimmers. In particular, the pygmy three-toed sloth is commonly found swimming, and while other species of sloth also swim, the pygmy is the only sloth known to swim in seawater.
Sloth Diet: What Do Sloths Eat?
The typical sloth diet depends on its type and species. The three-toed sloth is herbivorous, eating only a limited diet of leaves from a small selection of trees and plants. They get nearly all of their hydration from the leave of juicy plants.
The two-toed sloth is omnivorous, meaning that it eats a far more diverse diet. This includes leaves like the two-toed sloth but occasionally ranges from carrion and insects to fruit and even small lizards. The main component of their diet remains leaves and plants, as this enables them to eat at leisure from the treetops.
Both types of sloth digest their food at an astonishingly slow rate. Their slow metabolism means that it can take up to a whole month for a single meal to be digested by a sloth. As their metabolic rate is just 40-45% of what would be expected of a mammal for their body weight, sloths are frugal with their energy expenditure and don't venture far from their home ranges for food. Unlike other animals with a similar leaf-base diet, their slow metabolism also means that sloths don't need to eat a lot of food, as their stomach is rarely empty.
The sloth diet of predominantly leaves and plant matter requires a unique digestive system. Sloths have a large stomach comprised of four chambers which is full of bacteria to help digest these substances.
All species of sloth find plenty of food readily available in their natural habitat, but their limited diet means that they struggle to thrive in captivity.
What Threats Do Sloths Face in the Wild?
While sloths are quiet and peaceful creatures, they face a number of threats when in their natural habitat. Here we list the main threats that sloths face in the wild, which includes both natural and manmade dangers.
One of the most threatening predators to sloths is the Harpy Eagle. This large bird has a grip strong enough to break a human arm and claws larger than those of a grizzly bear. While Harpy Eagles have been known to eat land-dwelling animals, their main hunting ground is the forest treetops, making them a particular threat to sloths.
Jaguars and snakes also prey on sloths, and this can be a particular threat when sloths find themselves on the forest floor. While this is relatively rare, deforestation has meant that sloths are increasingly found on the forest floor, and are more susceptible to both animal and manmade threats.
Unfortunately, sloths are poached from the wild, usually for the purposes of hunting or for illegal trade as pets. Recently it was shown that sloths were one of the most illegally poached animals in Colombia.
According to The Sloth Institute Costa Rica, one of the biggest threats to sloths in the wild is deforestation. When trees are removed, sloths may lose vital pathways to safety, food, or their home. Unfortunately, sloths have been known to try and find other ways to travel, and attempt to cross manmade roads or climb onto electrical wires. This often results in severe injury or death.
Sloths are an essential component of the ecosystem of the rainforests they inhabit. They have a symbiotic relationship with a particular species of algae that is only found on sloths. The algae benefit from the sloth as it gains water and shelter through living in the sloth's thick coat, while the sloth benefits from the algae through the camouflage it provides. But, it isn't only algae that can thrive in the hair of sloths. Recent studies show that there is a huge range of fungi present on sloths, and some offer disease-fighting properties.
Why Do Sloths Move So Slowly?
In just about every language, the word for ‘sloth’ translates as something to do with ‘laziness’. Why? The sloth is the world's slowest mammal, and they can sleep for up to 18 hours per day. Despite their slow movement and lack of activity, sloths have been on the plant for nearly 64 million years, showing that speed isn't necessarily key to survival. But why exactly do they move so slowly?
One of the key factors in sloths' slow movement is their poor eyesight. They are only able to see in dim light and hardly at all in bright daylight. Due to an uncommon genetic condition named ‘rod monochromacy’, sloths are also completely colorblind. With poor vision at high heights, a careful pace is the safest pace for a sloth and is just one of the reasons that they move so slowly.
Ultimately, though, the reason why sloths move so slow is all down to their metabolism. The metabolic rate of the typical sloth is extremely low, which means that they move at an incredibly languid pace through the treetops. Research suggests that sloths travel around a mere 41 yards per day. But this slow pace, as it turns out, is all key to the survival of the species.
Their slow metabolism means that sloths are actually incredibly efficient at conserving energy, and can go long stretches of time without eating. In turn, this means that they can stay up in the treetops and away from predators for days on end. Further, the slowness of sloths actually enables them to grow the algae on their fur which keeps them camouflaged in the trees.
As a result of their slow metabolism, energy-saving adaptations, and poor eyesight, sloths don't physically possess the ability to move at a quick pace. Unlike monkeys and other tree-dwelling mammals, they don't have the option to just run away from predators. Instead, they must rely on the camouflage of their natural brown coats and algae.
The sloth's main predators are the Harpy Eagle and big cats like the Jaguar. These animals all use their exceptional site to detect their prey. Luckily, the slow pace of sloths means that they can often go undetected and avoid being singled out as prey.
It turns out, then, that sloths aren't slow because of laziness, but that it's actually a stealthy survival mechanism that allows them to continue to exist in the wild.