Sloths are well-known as docile, very slow-moving animals. They eat mostly leaves and rarely leave the treetops where they hang upside down.
It’s difficult to imagine a sloth harming another animal, even in defense. But they do have natural predators, so how exactly do they defend themselves?
Sloths protect themselves from predators by hiding themselves. They stay away from big cats by staying in trees, only coming down about once a week to relieve themselves. They also have algae in their fur that camouflages them against the foliage. If they do have to fight, sloths have long, sharp claws and very strong forearms with which to protect themselves.
Sloths Have Camouflaging Fur
Sloths have a unique type of hair that is part of a symbiotic relationship they share with fungi and algae.
Three-toed sloths have two layers to their fur. The interior layer is very soft and lies right next to the skin. On top of that is an outer layer of coarse oval hairs with cracks running through it.
Two-toed sloths only have one layer of fur, which appears fluted rather than cracked. In both species, though, the cracks and grooves of the fluted ribs collect moisture. Then, various fungi and algae can grow in the damp crevices.
This is what gives some sloths the distinctive green tinge to their fur. Many experts believe that this tinge provides camouflage for the sloths.
Sloths live in tropical rainforests of Central and South America. They spend almost their entire lives in the trees among dense foliage.
Sloth fur is gray and shaggy, to begin with, and could be mistaken for moss or creepers.
With the addition of the green tinge from the algae, sloths can blend in even more against the tropical backdrop. This kind of camouflage keeps sloths safe from predators.
This camouflage also benefits from the sloth’s pace of life. Because they don’t move much, the illusion of being part of the background is even more convincing.
They Move Very Slowly
Camouflage is even more important for sloths than other animals because of how slowly they move. Sloths are the slowest mammals on the planet. If a fast-moving predator such as a big cat attacks them, they have little chance of getting away.
In fact, their camouflage comes from the fact that they move so slowly. The fungi and algae in their fur wouldn’t grow if they weren’t such sedentary animals.
Part of the reason sloths are so slow is that they have very weak hind legs. Most of their strength lies in their strong grip instead.
They need to have strong forearms to hold their bodies as they hang upside down from branches. The average adult sloth weighs 9-17 pounds (4-8 kg), around the size of a small dog.
There’s also a sort of chain-reaction explanation for the slow movement of sloths. It stems from their natural habitat and tree-dwelling nature.
Sloths are native to rainforests, which are hot and humid. So, sloths don’t have as much need to thermo-regulate as other mammals. The warmth and energy they need for movement come from their environment, almost like a reptile.
Sloths evolved into tree-dwelling animals in this environment. High up in the trees, they are at less risk from predators. So, they don’t need to burn energy to protect themselves.
They also developed an almost entirely leaf-based diet. By eating mostly leaves, which are not very nutritious or high in calories, the sloth’s metabolism became slower and slower.
In short, sloths are slow due to a combination of climate, food sources, and lack of predators. These factors all came together to make for one very slow metabolic system and one very slow animal.
Sloths Can Fight With Their Claws
In order to spend so much time in the trees, sloths need some impressive upper-body strength.
Sloths have less overall muscle mass than other mammals. Their muscle only makes up only 20-25% of their overall body mass. Other mammals in general have about 30-45% of their body mass in their muscles.
Despite this, sloths have a surprising amount of muscle mass in their forelimbs, which they use to grip. These muscles make up 5% of a sloth’s total body mass – not just skeletal muscle mass.
Sloths can also use their strong front arms to swim. They may be slow-moving on land and in the trees, but sloths are excellent swimmers.
It’s sometimes easier for them to simply fall into rivers than climb down their trees. Once in the water, it takes them little effort to stroke towards the shore.
In addition to their strong arms, sloths also have special claws on their front limbs. These claws are between three and four inches and have a large curve. They help the sloth grip onto trip branches and grab food.
They’re also very sharp. If a sloth can’t run away from a predator on the ground, it can fight back with its claws. Their slow movements are still a hindrance, but their claws can give them at least a little defense.
Staying In Trees Is A Sloth’s Best Defense
Sloths spend almost their entire lives hanging from the treetops. They can sleep for over fifteen hours each day in the trees, then wake up at night to eat leaves.
They even mate and give birth in trees. The young cling to their mothers for nine months before moving to branches of their own.
Some sloths don’t even leave the trees after they die. Sloths can retain their strong grips on tree branches and hang there for a period of time after death.
Staying in the trees keeps sloths out of reach of predators such as ocelots and jaguars. They do face danger from large birds such as harpy eagles, of course. But their camouflage and thick foliage help protect the sloths.
The only time they ever come down is to defecate. And they only relieve themselves about once a week. It’s a very tasking job, taking up much of their energy. And it can be very dangerous for them, since it puts them closer to the big cats on the ground.
In fact, over half of all sloth deaths occur when they’re traveling to or from the ground to relieve themselves. So, it’s clear that staying up in the treetops is the safest place for a sloth to be.
If sloths are safest in the trees, then why do they leave at all? They do everything in the treetops from mating to eating to giving birth. It’s only for “bathroom” purposes that they leave.
Climbing up and down trees is very taxing for the slow-moving sloth, and it’s dangerous. And they’re likely able to relieve themselves easily while hanging from branches.
So, why do they spend the energy and take the risk to relieve themselves on the ground?
Sloths Provide Habitats For Others
Experts believe that sloths go to the ground due to an evolutionary symbiotic relationship between the sloths, algae, and insects.
Sloths have an entire ecosystem in their fur. In addition to the camouflaging algae, their fur also holds fungi and various insects.
In some cases, sloth fur is the only place these organisms exist. Crypotses moths, for example, only live in moth fur. Sloths can have as many as 120 of these moths living in their fur.
The moths depend on the sloths to venture down to the ground to defecate.
While there, female moths lay their eggs in the droppings, which is the only thing their larvae eat. Then, the larvae grow into adults, and fly back up to the sloths to reproduce more.
But what does this do for the sloths? The moths actually fertilize the algae that grows in the sloth’s fur.
It’s unclear whether this is due to decomposition or if the moths bring nutrients from the ground. But it is clear that the moths and algae do have a connection.
This is important for the sloths for more than just camouflage. Sloths actually eat the algae in their fur.
It’s easy for them to digest and provides as much protein and carbohydrate as their usual leaf diet. Plus, the algae has three to five times more fat than leaves.
So, the sloths go to the ground to leave their droppings, which the moths eat. The moths then return to the sloth and fertilize their algae growths.
The sloths eat the algae and get the energy to return to the ground. It’s a beneficial, natural cycle.
Sloth Teeth Are Dull But Grow All The Time
With a diet of mostly leaves, sloths don’t need much jaw power to eat their food. This also means that biting is not as good a defense as their claws if they’re in danger.
In fact, sloths lack deciduous teeth or baby teeth. They only have one set of teeth throughout their entire life, and, like sharks, their teeth grow continuously.
They have to continually chew plant matter to keep their teeth worn down. Sloths also lack incisors, but they do have hardened lips that can rip through leaves instead.
While sloths can bite, it doesn’t do much to deter predators. They’re better off using their claws or staying in the trees away from danger altogether.
They Can Turn Their Heads 270 Degrees
For sloths, defense is more effective than offense. Staying hidden from predators is much more effective for them than trying to escape from or claw at any attackers.
In addition to staying camouflaged in the trees, sloths need to keep a watchful eye out for any dangers. This is where their necks come in.
Almost all mammals have exactly seven vertebrae in their neck. One of the exceptions to this is three-toed sloths. They can have up to ten vertebrae in their necks.
With these extra bones, sloths don’t just have longer necks, but also have more flexibility. A sloth can turn its head about 270 degrees.
That’s about as far as an owl can twist its head. This is not only helpful to keep an eye out for predators, but also for sloths’ movements among tree branches.
Sloths tend to hang from branches by their front and back legs. This position would leave a human with an awkward head angle and limited field of vision.
Because the sloths have more flexibility in their necks, they can hold their heads in more comfortable positions. They can also move their heads to see at angles that other animals wouldn’t be able to.
Sloths may seem defenseless at first glance, but they do have ways of protecting themselves from danger. To begin with, they spend almost their entire lives in treetops away from ground predators like jaguars.
If the big cats can’t reach them, the sloths don’t have to worry about them. As for flying predators, sloths have ropy gray fur that grows green algae. Their appearance helps them blend into the foliage of the trees, hiding them from predatory birds.
Finally, on the rare occasions that they venture to the ground, sloths can defend themselves with their long front claws. They’re not the most protective attribute, but since sloths move too slowly for quick getaways, they do help a little.