Sloths have the slowest metabolic rate of any non-hibernating land mammal. This sometimes makes people think that they are lazy, unmotivated, and not very good at what they do. In fact, being slow is an incredibly successful strategy for survival: sloths have survived on this planet for almost 64 million years!
Contrary to their reputation, sloths don’t sleep that much at all – research has shown that on average, wild sloths only sleep for 8-10 hours a day. In comparison, the similarly sized howler monkeys that sloths share their environment with sleep for 15 hours a day, while koalas will regularly snooze for 20 hours.
Cathemerality, sometimes called metaturnality, means that an animal sleeps at irregular intervals throughout the day. Sloths take short naps during the day and night, and spend the rest of their time feeding, grooming, moving, or observing their environment.
5.2 Toilet habits
In an optimal environment with lots of trees, sloths don’t like to come down to the ground, and will only do so for one reason – to go to the bathroom. In the wild, they do this approximately once every 5 days, although in captivity they often do it more often.
Fun fact – sloths can lose up to one-third of their body weight in one toilet session!
No one knows why sloths come down to the ground to go to the bathroom – on the surface, this seems like a risky waste of energy when sloths’ entire lives revolve around conserving energy.
Scientists have a few hypotheses why sloths might have this unusual habit, such as: by only pooping on the ground, they avoid leaving a scent trail in the trees for predators, to help the sloth moths lay eggs and find new hosts, or to use pheromones in the feces to communicate with other sloths.
If sloths left pheromone trails in the branches of the trees, other sloths might not find them– but each tree has only one trunk, which limits the number of places another sloth might have to look for scent markers. This theory is supported by the fact that female sloths in heat descend to the ground to defecate once per day instead of once per week.
Three-fingered sloths use their short tails to dig a hole and bury their feces by doing something which is known as the ‘poop dance’.
Sloths are excellent swimmers. In fact, they swim through water three times faster than they can move on the ground! Three-fingered sloths are more inclined to swim than two-fingered sloths.
While it seems unlikely that an animal that specializes in hanging out upside down in trees would be well adapted to moving through the water, living in the rainforests of Central and South America means that swimming is essential for survival.
In these regions, vast rivers fragment the forest, leaving gaps in the canopy that could act as a barrier to tree-dwelling creatures. Monkeys are able to leap from branch to branch to cross over the rivers, but sloths cannot jump, and they must swim to reach new territories.
The sloth’s enormous stomach creates so much gas from digesting leaves that it acts as a giant flotation device. Their long necks allow them to keep their nose high above the water like a snorkel.
Since sloths can float and breathe easily, they do not need to paddle their limbs fast to stay afloat, and once in the water they can bob along and use their long arms to control the direction of travel. Pygmy sloths are the only sloth species known to swim in saltwater.