When it comes to sloths, there’s more than meets the eye. We know them as those super slow and lazy animals (their name literally means “laziness”). But as it turns out, their fur plays a pretty cool role in harbouring a whole ecosystem of algae, fungi and insects.
Unlike typical animal hair, sloth hairs have a unique structure. Their hair has grooves or cracks that have the capacity to hold water, allowing algae and fungi to grow within those grooves.
And an animal that benefits from this hairy ecosystem are sloth moths.
Sloth moths have evolved to exclusively inhabit the fur of sloths. They find refuge in the coarse hairs of sloths, where they not only benefit from protection against predators but also establish a reproductive strategy tied to the sloth's habits.
Due to their low nutrient diets, sloth have very low metabolic rates. This means they have very little energy to do anything else besides eating and resting.
Yet despite their limited energy levels, once a week sloths make a dangerous trek to the forest floor to take a shit. Not only does this whole process use up a lot of energy, but it also exposes the sloths to predators near the ground.
And this is where the sloth moths come in.
The female sloth moth lays its eggs in the sloth’s shit, providing a nutrient-rich environment for the larvae to develop. The larvae are coprophagal, meaning they exclusively feed on sloth poop (sounds delicious, doesn’t it?). Once the larvae develop into moths, they fly up into the trees to find another sloth to inhabit and the cycle repeats.
But what’s in it for the sloths?
Well, it’s theorised that the sloth moths add nitrogen to the sloth’s fur, aiding in the cultivation process of algae and fungi that allows the sloth to camouflage into their environment. On top of that, the algae are also a vital food source for sloths. As it turns out, the algae contain the same amount of protein and carbohydrates as the tree leaves that sloths typically eat.
Plus, the algae also contain three to five times more fat, providing the necessary supplements to the sloth’s otherwise poor diet.
So, to sum this mutually beneficial relationship, sloth moths provide nitrogen in turn for protection, and the sloth gain some free food out of it. Which is conveniently located on their fur. Now that’s pretty cool. While also really emphasising how lazy sloths are.