It’s no wonder that sloths have been dubbed the world’s laziest creatures for decades, having been named after one of the Seven Deadly Sins. Sloths were dubbed “the lowest form of existence” when they were first documented in the scientific literature in 1749. Since then, we’ve discovered that sloths are far from being simple, lethargic creatures who spend their days sleeping. They’re complicated, fascinating creatures with a strange evolutionary history that you may think we made up. Dr. Rebecca Cliffe (SloCo Founder and Executive Director) has offered us her 10 favorite odd and beautiful sloth facts to give you an insight into the sloth’s misunderstood world (originally published for the BBC).
- There would be no avocados if sloths didn’t exist.
The extinct gigantic ground sloths were among the only animals with big enough digestive tracts to absorb entire avocado seeds. They ate the fruit and then disseminated the seeds over the world. All modern tree sloths descended from gigantic ground sloths. Over 80 distinct species were supposed to exist, with the biggest (Megatherium) reaching over six meters in height. There is also evidence that many different species of marine sloth existed, eating in shallow water on sea grass and seaweed.
2. They defecate a third of their body weight in a single bowel movement.
The strange toilet habits of sloths are well-known. They just have to go to the bathroom once a week and can shed up to a third of their body weight in a single sitting! Furthermore, they will only do it on the ground after digging a little hole around the base of a tree. One of the major mysteries surrounding sloth behavior is this strange weekly pattern. While numerous ideas exist, the most plausible explanation is that it is all about communication and reproduction.
3. In the water, they are faster than on land.
Sloths are remarkably adept swimmers, despite spending much of their time in the trees. They can go three times quicker through water than they can on land! Three-fingered sloths have the most vertebrae in their necks of any animal. This allows them to swivel their heads 270 degrees while swimming and keep their nose above water with ease.
4. They have the potential to heal cancer.
Sloths have an interesting camouflage technique. Many different types of algae and fungus can develop in the cracks in their hair, giving them a green appearance. Some kinds of fungus identified in sloth fur have been discovered to have antibacterial, anticancer, and antiparasitic properties! Sloth hair also supports a complete ecology of invertebrates, including some species that are found nowhere else on the planet (such as the’sloth moth’). A single sloth’s fur may hold up to 950 moths and beetles at any given time.
5. They can die of starvation even if they have a full stomach.
Sloths, unlike most mammals, have given up the capacity to regulate their body temperature in order to conserve energy. Instead, they are totally dependent on their surroundings, and their core temperature may change by more than 10°C in a single day! The unique bacteria that dwell in their stomachs can die if they become too cold, and the sloth will be unable to digest the leaves it consumes.
6. No one knows how long they will live.
Because sloths are so difficult to observe in the wild, no one has ever tracked a sloth from birth to death, and determining the age of an adult sloth is nearly impossible. We only have the sloth’s lifetime in captivity to rely on, but sloths do not thrive outside of their native habitat. The world’s oldest sloth, who lives in a zoo in Germany, just celebrated her 50th birthday. Wild sloths, on the other hand, are thought to live considerably longer.
7. Sloths can fall 100 feet without harming themselves.
The anatomical design of sloths is for them to fall out of trees. A sloth will fall out of a tree once a week on average for the rest of its life. But don’t worry, sloths are built to fall and survive. They may fall from a height of nearly 100 feet (equivalent to twelve double-decker buses) without being hurt. When two sloths fight, it’s usually over the right to mate with a female, and the goal of a sloth battle is to knock your opponent out of the tree.
8. A leaf takes a sloth 30 days to digest.
Because sloths have the slowest metabolic rate of any mammal, they require a long time to digest food. They have a massive, permanently full four-chambered stomach that can account for up to 30% of their total body weight. This over-sized stomach is supported by 46 ribs (23 pairs) in two-fingered sloths, which is more than any other animal!
9. In bright sunshine, sloths are blind.
They have a disease known as rod monochromacy, which means their eyes are totally devoid of cone cells. As a result, all sloths are colorblind, have poor vision in low light, and are entirely blind in strong sunlight. Thankfully, sloths make up for their low vision with a fantastic sense of smell and excellent spatial memory! Their poor eyesight contributes to their sluggishness as well – you can’t rush about in the woods if you can’t see where you’re going!
10. Sloths are three times as strong as humans.
The world champions in pull-ups are the Sloths. Sloths can raise their entire body weight upwards with just one arm from the moment they are born. Not only that, but sloths have 30% less muscular mass than animals of similar size and are three times stronger than the typical human. They have a unique muscular arrangement that allows them to create enough strength to resist the force of a jaguar attempting to tear them from the tree. The sloth’s hands and feet have specialized tendons that allow them to hang upside down for lengthy periods of time without spending any energy. Sloths may even sleep while hanging from a tree limb thanks to their unusual locking mechanism. They’ve even been seen to hang upside down after passing away!