Pygmy Three Toed Sloth: Bradypus pygmaeus

pygmy three toed sloth in a tree

The Pygmy Three Toed Sloth was only quite recently declared to be a new species.

In 2001 scientists made this decision, mainly because the pygmy sloth is such a little cutie – with little being the operative word.

How big are pygmy sloths?

Pygmy sloths are about 40% smaller and lighter than their sister species, the Brown Throated Sloth. They are also approximately 15% shorter.

Their length is 48 – 53 cm, and they weigh between 2.5kg – 3.5kg. So teeny!!

Where do pygmy sloths live?

The only place in the world that you will find pygmy three toed sloths is on a little island called Isla Escudo de Veraguas. It is the furthest outlying island in the Bocas del Toro archipelago, which is a chain of islands that was separated from Panama, due to rising sea levels, about 9000 years ago.

Isla Escudo de Veraguas is only 4.3 square kms in area (1.7 sq miles)

The other islands in the Bocas del Toro archipelago are home to sloths who are also smaller than average. But it’s only on Isla Escudo de Veraguas that the sloths have been deemed sufficiently small to be classified as a separate species.

This island is also home to species of hummingbirds and bats, that can be found nowhere else.

Up until recently, it was thought that the pygmy three toed sloths only lived on the red mangroves on the outer edges of the island. However, a biologist named Bryson Voirin placed radio collars on 10 sloths in mangroves and then tracked them for a period of three years. 3 of the sloths stayed in the mangroves. 5 moved out of the mangroves and hung out in some other tree species at the mangroves’ edge. 4 adventurous pygmys travelled as far as 200 meters inland. Quite a distance if you’re a tiny little slow moving sloth!

What lives on pygmy sloths?

A pygmy sloth’s coat is home to just one type of green algae, the Tricophilus species. This algae gives the little pygmy a nice green tinge, which comes in handy as a camouflage.

But it is also home to almost 40 other creatures! This is more than any other species of sloth has crawling around in its fur.

What do pygmy three toed sloths eat?

Pygmy three toed sloths eat the leaves of the red mangrove trees (Rhizophora mangle). No other sloths eat this kind of leaf.

The red mangrove leaf is not great, nutritionally speaking, and it’s also quite coarse.

What do pygmy sloths do?

The pygmy three toed sloth lives in trees, and spends about 15-20 hours a day hanging around in them.

On the ground, they’re realllllly slow. Clocking in at 0.24km hour, they’re one of the slowest animals in the world.

Put them in water however, and boy do they go!!! (Not really, but they are about three times faster in water). Pygmy sloths do seem to like to swim more than any other sloth, and they’re the only sloths that swim in salt water. Roughly a third of a sloth’s body mass is the contents of its stomach. Because leaves generate quite a lot of gas while they’re being digested, sloths are actually a bit like a pool floatie – the air inside them helps them to be bouyant!

Are pygmy three toed sloths really different to their bigger cousins?

Some researchers believe that pygmy sloths are really just a smaller version of brown-throated three toed sloths.

Are pygmy sloths endangered?

In 2012, only 79 pygmy three toed sloths were found living on Isla Escudo de Veraguas. This has resulted in them being listed as critically endangered. The majority of these 79 sloths were found living in the mangroves at the edge of the island. It is hoped that there are actually more living in the forests further inland, where they are much harder to see and track. Due to the difficulties involved in finding animals in dense rainforests, biologist Bryson Voiring actually estimates that the population is more likely to be between 500 to 1500. Even so, this is still an extremely small number for a whole species of animal.

Living an isolated existence on a little island has resulted in inbreeding, which means the genetic diversity of the pygmy three toed sloth is ever decreasing.

Tourism development is also a threat to this species. There have been proposals to develop a marina, casion, hotel and airstrip on the island.

Although no people actually live on Isla Escudo de Veraguas, indigenous people from Panama often camp there to fish. They cut down trees for their huts and firewood, and also eat sloths when they don’t catch enough fish. As mangrove trees are cut down, gaps in the canopy appear. This means the sloths have to travel on the ground more often and this puts them at risk of being eaten by feral cats and other predators. Although the Panamanian government has listed Isla Escudo de Veraguas as a National Park, it doesn’t enforce laws about cutting down the mangroves.  Biologist Bryson Voirin believes that unless this changes, and the pygmy three toed sloth is given some more protection, they may only have a few years left on this planet.



Recommended Reading

Mongabay interview with Bryson Voirin

Keeping pygmy sloths afloat

Wikipedia

More endangered pygmy sloths in Panama than previously estimated

Sloth Species: What are the different types of sloths?

Are there different species of sloths?

How many types are there?

What do people mean when they talk about species of sloths – do they mean the two and three fingered types?

Let’s have a closer look at the relationship between the different sloth species to get a better understanding of our two and three fingered friends.

Biological classification chartSloths and Evolution

You might be quite surprised to learn that two toed sloths are actually not all that closely related to three toed sloths. In fact, they’re about as closely related as you and I are to baboons.

The last time two toed and three toed sloths shared a common ground dwelling ancestor was about 30 million years ago (about the same time that us human types split from our baboon relations (although perhaps it doesn’t feel like it at some Christmas get togethers?)

It is thought that three toed sloths were the first to climb up into the trees to get a good view. The two toed sloth made its tree-change millions of years later!

What this means is that they’ve been evolving separately, although quite similarly, for all that time. This is called convergent evolution and is of quite a lot of interest to some scientists. The different number of fingers, and some differences in the way their muscles connect to their bones, is the giveaway that they are actually quite distant relatives who have each found their own special ways to live in the trees.

What’s pretty weird though, is that they both climb down from the trees, putting their lives at risk, to poop (and do the subsequent poop dance) once a week. This peculiar habit has evolved not just once, but twice. Holy sloth dung, that’s pretty amazing!

Order

So, two-toed sloths are quite distant relatives of three-toed sloths. If you have a look at the chart above, they both belong in the same order (four categories from the bottom).

The order is called Pilosa and it is one the smallest orders in the mammal class. It consists of just two suborders:

  • Folivora – sloths
  • Vermilingua – anteaters and armadillos

Fun fact – Folivora means ‘leaf eater’ and Pilosa means ‘hairy’.

Family and Genus

Moving down the rung of the biological classification chart we come to Family. Here’s where sloths get split up into five different groups. What’s terrible, though, is that three of the families are extinct. So that leaves us with two:

  • Bradypodidae – Three toed sloths are the only members of this family (and genus Bradypus)
  • Megalonychidae – This family gets split into two genus:
    • Megalonyx – an extinct genus of ground sloths.
    • Choloepus – Two toed sloths

Species

Finally we get to answer your question about how many species of sloth there are!

The two different existing sloth genus, Bradypus and Choloepus, are each split into different species.

Bradypus (Three Toed Sloth)

There are four species of three toed sloths:

  • Brown Throated Sloth (Bradypus variegatus)
  • Pale Throated Sloth (Bradypus tridactylus)
  • Maned Sloth (Bradypus torquatus)
  • Pygmy Three Toed Sloth (Bradypus pygmaeus)

Choloepus (Two Toed Sloth)

There are two species of two toed sloths:

  • Linnaeus’s Two Toed Sloth (Choloepus didactylus)
  • Hoffmann’s Two Toed Sloth (Choloepus hoffmanni)

So there you have it! If you’d like to read more about each species of sloth, then follow the links on each species name.

 

Sloth cuddling with its mom
Photo by Eric Kilby 

Differences between Two Toed and Three Toed Sloths

Clearly – a major difference is that two toed sloths have two toes, and three toed sloths have three. But it’s important to note that we are only actually talking about their ‘fingers’ here. Both types of sloth have three claws on their hind legs. This is the reason that you’ll notice people starting to refer to them as Three Fingered and Two Fingered Sloths.

Another significant difference is that two toed sloths have 5 or 6 vertebrae in their necks. Most mammals have 7. Three toed sloths have 9! This makes them able to turn their head 270 degrees, which comes in very handy when they go for a swim as they are able to keep their head out of the water easily.

Three toed sloths have small tails, but their two fingered friends have no tail at all.

Two toed sloths are larger. They’re generally 58-70 cm long and weigh 4-8 kgs. Three toed sloths are only about 45 cm long and weigh 3.5-4.5 kg.

Two toed sloths are mostly nocturnal. Three toeds are diurnal (which means they’re active in the daytime).

References

National Geographic

Two toed sloth -Wikipedia

Three toed sloth – Wikipedia

Sloths in the wild: Where do sloths live?

You’re planning your next world wide trip and want to make sure you stop in at the right places so that you can visit all the
sloths. Or maybe your friend said to you today, hey friend – where can sloths be found? and you were embarrassed to admit that you didn’t know the answer. Well, we’re glad you are here because we are on a mission to answer the very important where do sloths live question for you.

As you know (or if you don’t, it’s ok – don’t panic, you can read all about it here), there are different types of sloths in the world. So lets talk about where each type of sloth lives in the wild.

Pygmy Three-Toed Sloth

If you want to visit the Pygmy Three-Toed Sloth (Bradypus pygmaeus) (also known as the monk sloth or dwarf sloth) then you’ll need to book yourself a ticket to Isla Escudo de Veraguas. This is a Carribean island of the Republic of Panama which is only 4.3 square kms (1.7 sq mi). Once you’re there, find your way to the red mangroves. Hopefully then, with quite a lot of luck, you’ll find one of the remaining Pygmy Three-Toed Sloths in the world. In 2012 it was estimated that only 79 existed. This means, of course, that they are critically endangered.

Map of the areas that pygmy three toed sloths live
Photo credit

Brown-Throated Sloth

The Brown-Throated Sloth  (Bradypus variegatus) is a three-toed friend who prefers to hang out in the neotropical ecozone of Central and South America.

The most common and widespread of the three-toed sloths, it can be found in Honduras, Nicaragua, Costa Rica, Panama, Venezuela, Colombia, Ecuador, Bolivia, Brazil and eastern Peru. People have thought they’ve seen Brown-Throated Sloths north of the Amazon Rainforest and east of the Rio Negro – but most likely those poor sods had them confused with the Pale-Throated Sloths (they do look very similar, we can’t blame them too much).

Covering such a large area, it’s not too suprising that the Brown-Throated Sloth can be found in lots of different environments. Dry forests, evergreen ones – even natural areas that have been messed with by humans. 1200m (3,900ft) is about as high above sea level as they’ll get, but some adventurous individuals have been found up even higher.

Map of where Brown Throated Three Toed Sloths live
Photo credit

Maned Three-Toed Sloth

In the 1950s,The Maned Three-Toed Sloth (Bradypus torquatus) could be found in the Bahia coastal forests of Bahia, Rio de Janeiro and Espirito Santo. Now, thanks to deforestation and hunting, they can only be found in the Atlantic coastal rainforest of southeastern Brazil.

Maned Three-Toed Sloths like it wet. They live in areas with no dry seasons, and annual rainfall of at least 120cm. However, as they don’t mind munching on quite a range of leaves, they can also be found in semi-deciduous and secondary forest.

Area map of Maned Sloth
Photo credit

Pale-Throated Sloth

The Pale-Throated Sloth (Bradypus tridactylus) lives in tropical rainforests in northern South America. More specifically, have a look for them in Suriname, French Guiana, Brazil (north of the Amazon River), Guyana and western parts of Colombia and Venezuela.

Pale Throated Sloth Area Map
Photo credit

Linnaeus Two-Toed Sloth

The Linnaeus or Linne’s Two-Toed Sloth (Choloepus didactylus) live in the tropical rainforests of Colombia, Guyanas, Peru, Ecuador, Venezuela and Brazil (north of the Amazon River). It is possible that they also live in parts of Bolivia. If you see some on your travels there, please be sure to let us know.

Map showing where Linne's Two Toed Sloth live
Photo credit

Hoffmann’s Two-Toed Sloth

The Hoffmann’s Two-Toed Sloth (Choloepus hoffmanni) live in tropical rainforests ranging from sea level up to about 10,800 ft, or 3.3km, above sea level. They are actually separated into two different areas of Central and South America, divided by the Andes. One group can be found ranging from western Ecuador up to eastern Honduras. The other group inhabits the areas of western Brazil, eastern Peru and northern Bolivia. I wonder if they have different accents.

Hoffmans Two Toed Sloth Area Map
Photo credit