Do sloths have tails?

The sloth is a really primitive creature in terms of both anatomical and physiological traits, compared to the vast majority of mammals.

When you look at external characteristics such as olfaction and eyesight, while considering the kind of environment they live in, you can’t help but prove this claim. Sloths are really behind the times, battling with may archaic features and challenges they ought to have upgraded a long time ago!

And when you study well their anatomy and physiology, you can’t help but discover that the modern day sloths are nothing but vestigial remains of what used to be a ground dwelling beast; fully of eyesight, voracious appetite and a perfectly working metabolism.

Anyways, in this article, our main goal is to continue with our study on the external features of sloths, particularly those on the lower part of their bodies. We are going to be investigating whether or not sloths have tails and what the functions of these tails are or why they are there if they are functionless and are yet, still present.

Do sloths have tails?

All modern day species of sloths have tails, but the extent to which these tails protrude vary greatly across families and the various species within each family.

Two fingered sloths have inconspicuous tails that are widely considered vestigial: serving no purpose at all, whereas three fingered sloths have tails that are functional and range between 3 to 5 cm in total length.

Just for clarity sake, the modern species of sloths exist only in the two aforementioned families: the two fingered and three fingered family.

The mysterious tail of sloths

Almost all species of sloths have stubby little tails that are evidence of a much more prominent and larger sprout from their ancestral forefathers.

Evolution has told us a very interesting story, that the ancient species of sloths dating several million years ago (with some being large enough to rival the sizes of modern day elephants), were much more wide spread on terrestrial lands and possessed huge, long tails that were relative in proportion to their body size; the tails were long enough that they even touched the ground.

Some paleontologists are of the opinion that the stout tails were used by the giants sloths in combination with their robust hind feet to support their massive bodies when reaching into the trees to forage: such was the strength and thickness of this sprout.

In modern day sloths however, the tails are very much greatly reduced to the extent that it’s possible to handle captive sloths for the first time and hardly even recognize they have tails without any prior knowledge. In some species, the tails are essentially short vestigial structures that have turned functionless over the course of their land to tree migration.

The drastic reduction in the length of tails of modern sloths can be clearly understood by the narrative surrounding their migration from land into the trees.

While on land sloths relied constantly on their tails for support along with their hind feet, but when they migrated into the trees, they simply outgrew, function-wise, the purpose for these tail and so decided to get rid of the tail to maximize energy expenditure (through reducing the amount of tail muscles the body would have to maintain) and prevent extra burden of weight.

As a result, sloths began evolving smaller and smaller tails as they themselves shrank considerable over the course of time (due to their new habitat that demands smaller size for agility). Today, the tails in sloths are very little and in some almost completely gone. 

The tails of the different species of sloths

Moder group of sloths, both the three fingered and two fingered variety all have tails, but the extent to which the tails protrude differ greatly by family and even by species within each family. The tails of sloth is nothing like you would expect of an arboreal mammal, for example howler monkeys.

The tails of sloths are stubby, thick and short and can span a maximum of 5 cm in length. Generally, three toed sloths have the longer tails and two toed have variety have the shortest, sometimes even considered not to have any at all due to how inconspicuous the structures are.

Here are the total range spans of the tails of the different species of sloths:

Two fingered family (Megalonychidae)

  1. Hoffmann sloths (choloepus hoffmanni: tail is a vestigial structure (about 1 to 2 cm in length)
  2. Southern sloths (choloepus didactylus): tail is a vestigial structure about 0.5 to 1 cm in length.

Three fingered family (Bradypodidae)

  1. Manned sloths (Bradypus torquatus): they have the longest tails of the three fingered family: the range is from 4.8 to 5 cm
  2. Pygmy sloths (Bradypus pygmaeus): 3 cm tails
  3. Brown throated sloths (Bradypus variegatus): 3 cm tails
  4. Pale throated sloths (Bradypus tridactylus): almost no tails

Do sloths use their tails?

Interesting enough, since all species of sloths migrated into the trees and begun to get rid of their redundantly heavy and extra burdening tails, it would be expected that any structure that would’ve remained today would be vestigial and have no practical functions at all.

While such is the case with the two toed variety, the same isn’t for the three toed sloths. Their stubby little tails are employed in the pooping process to dig holes into the ground to contain their droppings. Two toed sloths leave their litters flying on the ground since their tails aren’t as prominent and any attempt to dig on the litters would only bless their buttocks with a painful scratch.

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Cite this Article (APA Format)

Bunu. M. (2020, May 4). Do sloths have tails?. Retrieved from

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