We never get tired of learning about sloths! This isn’t just because we find them adorable, but also because they are extremely interesting creatures, utterly unique in the animal kingdom.
PopSloth features many articles about sloths, so you can find out more about them, but here are 10 sloth facts that show how weird and interesting sloths are:
Sloths live almost their entire lives in trees
Surely this one doesn’t surprise you, but it is very rare for a sloth to ever leave their natural habitat, the rainforest trees. This is logical because they have evolved to be perfectly suited for moving around in trees (more about their evolution later). Although a sloth moves slowly in a tree, it is very agile and a strong upper body which allows it to move in ways very few other animals can. So, a sloth can make it from branch to branch or tree to tree with relative ease.
Meanwhile, if the sloth were to be on the ground, they are virtually helpless; even slower than they are in trees but without the advantage of their agility. Just take a look at this video:
Likewise, a sloth’s fur (especially the algae that grows in it, which we will talk about later) help it blend in with foliage and avoid predators. So, it’s very clear that staying in the tree is the safest thing to do for the sloth, and they do everything there, even give birth:
Sloths only poop once a week
One of the few things sloths go to the forest floor for is to poop. In contrast, we are sure you make it to the porcelain throne to sit down at least once every day or two, if not two or three times a day (human diets vary a lot, and so do these habits for us). For an even wilder comparison, moose do their business about 20 times a day! Meanwhile, geese do the number two about 5 times an hour.
Given that they are basically sitting ducks when they are out of the trees, pooping is a dangerous affair for our sloth buddies. (We think that instead of saying ‘sitting duck’, we should start saying ‘pooping sloth’.) Scientists have found that nearly half of all sloth deaths occur while they are defecating on the forest floor and some predator, likely a jaguar, decides to take advantage. This is a good reason for sloths to poop as least often as possible, but it isn’t the only reason.
As you probably know, when you eat, let’s say, fruit and oatmeal for breakfast or when you chow down at Pancho’s Mexican Buffet the behavior of your bowels might be a little different, right? So, think about the fact that a sloth eats almost exclusively leaves. Those leaves take almost a month to digest. That means there isn’t too much urgency to get down to the forest floor.
And the frequency isn’t the only strange thing about a sloth’s pooping habits. When it poops it expels the whole load at once, and that load can be about 30% of its body weight. I sure wish I could lose about 50 pounds in one trip to the john!
Their fur is an ecosystem
We bet you are ready to be finished with the poop theme, right? Well, the last thing that is interesting about their poop is that certain moths lay their eggs in the sloth’s poop and then nest in the sloth’s fur, making these moths totally dependent on the sloth for survival.
And it goes beyond that: The main source of food for these moths is the algae that grows in the sloths’ fur. So, the moth reproduction, shelter and diet are all dependent on the sloth. Likewise, the algae found in the sloth’s fur are fertilized by the moth’s poop. So, it’s just love and poop for everyone!
Don’t forget that the sloth is benefitted too! The algae in their fur give them a green color which helps them blend in with the trees and avoid predators. All of this is known as a symbiotic relationship, but the fact that 3 creatures are involved in such broad ways makes sloths very remarkable creatures
Sloths have changed a lot through evolution
The way sloths are so perfectly adapted to their environment probably fascinates evolutionary biologists. But even more than that perfect adaptation is probably the fact that sloths were not always the tree creatures we know today. Take a look at this Ground Sloth, which was the most common species of sloth millions of years ago:
This sloth didn’t live in trees, but instead roamed around on the ground like a bison. It was also about the size of a bison, so it was far too big to climb trees. Here is an image for comparison:
Another ancient non-tree-dwelling sloth was the sea sloth.
Thalassocnus was a ground sloth that evolved to become semiaquatic. Once this sloth’s habitat in modern day Peru and Chile became a desert, it no longer had enough grass to graze, so the thalassocnus took to the Pacific ocean to feed on seaweed.
You might also notice that the sea sloth doesn’t look much like our modern day buddies. Rather than being light and buoyant, this sea sloth had dense, heavy bones that let the sloth dive deep into the water. Also, the shape of its head and snout look much more like a hippopotamus’ than a modern sloth. This makes sense because they had the same need to be able to eat aquatic plants and breath while remaining submerged in the water.
The thalassocnus looks so different from modern day sloths that it’s hard to imagine that it is even a sloth, but that evolutionary diversity is part of the remarkable nature of sloths.
Sloths are great swimmers
While the sea sloth died out millions of years ago, their modern day cousins do have a remarkable ability to move around in the water. Sloths can actually move faster in the water than they can on land thanks to that upper-body strength.
Also, because of the fermentation caused by the digestion of the leaves a sloth eats, the sloth's body fills up with gas. (Always with the poo and gas these guys!). And what happens when things filled with gas get put in water? They float! So, sloths have a high level of buoyancy. This makes it easier for them to swim, especially with their strong front limbs, since their energy is used just to move them forward, not to keep them afloat.
Also related to air and a sloth’s ability to move in water is another superpower they have: sloths can hold their breath for 40 minutes. That means they can stay submerged in water for long periods of time. This ability is due to the fact that a sloth has an extremely slow metabolism—In fact no mammal has a slower metabolic rate. So sloths are basically catamarans with strong arms that work as propellers, that can also submerge themselves under water for almost an hour without needing a breath.
Sloths live in the wettest habits on earth, often near bodies of water. So, flooding is common. This makes the ability to swim essential for their survival. You can learn more about this fact in an article we wrote about it.
Sloths can turn their head all the way around
If anyone knows anything about sloths, it’s that they’re slow. Given that fact, they need a head start to get away from predators. One head they can get a head’s up about an approaching predator is having a head that will turn about 280 degrees, that’s basically all the way back.
So, if a sloth is just hanging out in a tree and hears a rustling behind them, before having to expend any of their precious energy to try to escape they can check the situation out by using their crazy neck-twisting ability.
They aren’t the best at this though, not even among mammals. The tarsier, another tropical tree-dwelling creature, can do a full 360 with their head, and owls can actually turn their heads 400 degrees.
Sloths' mating and reproductive habits
Sloths in general are solitary creatures, so when they get the urge (wink, wink, ;) ) they are going to have to work hard to find someone to mate with. There are no nightclubs to try their luck at or apps with algorithms designed to help them make a connection. So how does sloth dating work?
They make this sound:
Another odd thing about sloth reproduction: two-toed sloth females carry their offspring in the womb for an entire year!
Pregnant sloths are resilient and able to continue functioning as they normally would despite their condition. (Well, come on, lying around and eating leaves can’t be much harder pregnant than it normally is, right? We kid, we kid.) As far as birth goes, remember that sloth do everything in trees, even giving birth. Have a look:
Sloths have one of the lowest metabolisms of any mammal
Although some sloths have a varied diet, three-toed sloths are entirely vegetarians, or as scientists call them ‘herbivores’. And though human vegetarians usually eat plenty of high-energy food such as fruits and nuts, sloths subsist almost entirely on leaves, which are a plentiful food source in the rainforests where they live. I guess if you only ate lettuce you might be a bit lethargic too!
To keep their bodies functioning on such a diet, and the reason that they are so low, sloths have an incredibly low metabolic rate. In fact it is the slowest metabolic rate of all mammals. As you can see in the chart, while a sloth only uses 450 kilojoules a day, a cat uses twice as much, and humans and elephants use much, much more energy. This means that sloths can’t spend their energy darting around quickly, and instead are one of the slowest creatures around, moving on average at about 100 feet per day from branch to branch, or taking 1 entire minute to move just one foot when crawling on the forest floor.
Sloths are slow for a reason
Sloths metabolic rate means they don’t have a lot of energy to move around. This is one reason why they are so lethargic. However, there is also another: it’s for their survival!
The jungles of Central and South America where sloths live are also home to some of the most fearful predators such as jaguars, panthers, ocelots, boa constrictors, anacondas and hawks. Almost all of these animals depend on their vision to catch prey. When an animal like a monkey or a parrot scurries along a branch or takes off in flight, it catches the eye of one of the jungle predators and can wind up being dinner. Since a sloth basically never makes any sudden movement it can avoid getting spotted (and eaten) by the predators of the rainforest. The next time your parents, partner, or roommates say you should get up off the couch and do something, maybe you can use the same excuse.
Sloths have the same name in almost every language
We all know that the word sloth is associated with being slow and lazy, and that it is even considered a sin in some religions. If you didn’t know, that word, sloth, existed before it was given as a name for our favorite animals. Apparently, the Portuguese settlers in Brazil first saw these creatures and named them preguiça, the Portuguese word for laziness, or sloth, and that same word has been translated in virtually every other language to serve as the name of sloths:
To contrast that, what is known as a sea lion in English is called a lobo marino, or sea wolf in Spanish. Meanwhile what we call a dolphin is known as a sea pig in Mandarin, and a turkey is called a seven-faced bird in Japanese.
For more information on the origin of the word sloth and its relation to our favorite animal the sloth, read our article Is it a sin to be a sloth? The meaning of "sloth"