Sloth Versus Giant Tortoise

Sloth Versus Giant Tortoise

Wait — we’re comparing a sloth with a reptile? It’s never been done before! What could a sloth possibly have in common with a reptile? On the face of it, there’s not much that a warm-blooded sloth could share with a cold-blooded reptile. But these slow and charismatic creatures might be more similar than you’d think.

There are just two surviving species of giant tortoise: the Galápagos giant tortoise and the Aldabra giant tortoise.

The Aldabra giant tortoise is now found in the wild only in the Seychelles, although they used to be found on many islands in the western Indian Ocean.

In the Galápagos Islands in the Pacific Ocean, there are two distinct types of Galápagos giant tortoises: domed tortoises and saddlebacks.

Are sloths and giant tortoises related?

No! Giant tortoises are reptiles in the order Testudines, whereas sloths are mammals in the order Pilosa. Reptiles and mammals diverged from one another around 325 million years ago, during the time the supercontinent Pangaea existed.


Galapagos Giant Tortoise Chelonoidis nigra. Santa Cruz Island, Galapagos Islands, Ecuador

Where do they live?

Giant tortoises used to inhabit every continent apart from Antarctica, but today they’re found only in the Galápagos Islands of Ecuador, and the Aldabra Atoll islands in the Seychelles.

Sloths and Galápagos giant tortoises both once shared the same landmass. Scientists believe that Galápagos tortoises most likely migrated from South America to the Galápagos 2 to 3 million years ago. But that’s where the similarities end when it comes to the habitats of sloths and giant tortoises.

Tree-dwelling sloths need a warm and humid habitat, whereas Galápagos giant tortoises live generally in dry and arid climates. Aldabra giant tortoises live in scrubland, mangrove swamps, and open grassy areas.


Three-fingered sloth in the canopy. Suzi Eszterhas.

How heavy are they?

A giant tortoise has yet to be seen climbing a tree! They prefer to stay firmly on the ground. In fact, they have little choice. These stocky tortoises really are giants, weighing up to around 700 pounds. But that’s still nothing compared to the prehistoric ground sloth Megatherium, which weighed up to 4 tonnes!



Their thick, sturdy legs help them to carry around this weight, and as their shells are made up of honeycomb structures that enclose small air chambers, the shell itself doesn’t present the tortoises with too much of a problem when it comes to carrying it around.


giant tortoise
Aldabra Giant Tortoise Geochelone gigantea

How long do they spend resting?

As giant tortoises are cold-blooded, they like to spend a good amount of time basking in the sun. They sunbathe for 1—2 hours after dawn to absorb the sun’s heat through their shells before foraging 8-9 hours a day. In total, they rest or sleep for nearly 16 hours per day.

Sloths by comparison sleep for just 8—10 hours a day.



Sun seekers

Like tortoises, sloths are poikilotherms — animals that are unable to regulate their body temperature.

Although sloths live in warm, tropical environments and have thick coats to help them thermoregulate, they’re unable to shiver when cold, so need to bask in the sun to warm up — much in the same way that giant tortoises do.

If sloths become too cold, they will stop being able to digest food and can starve to death, even on a full stomach!


sloth basking
Sloths also bask under the sun / Photo by Cristhian Chentiko


Like sloths, giant tortoises will seek shade to help them to cool down, but even better is a muddy puddle to wallow in — perfect to escape the midday heat.


Sloths and tortoises, who is the slowest?

It’s a close call. The sloth boasts the title of the world’s slowest mammal moving at a mere 0.27 km per hour, while the giant tortoise races ahead at a heady 0.3 km per hour.

Like the sloth, giant tortoises have a very slow metabolism. It takes them up to 21 days to digest food, while the sloth, which boasts the lowest metabolic rate of any mammal, takes 30 days to digest just one leaf!


What do they eat?

Giant tortoises are predominantly herbivores. Aldabra giant tortoises eat grasses, leaves, woody plant stems, and fruit, but they’ve occasionally been observed eating small invertebrates and carrion, including the bodies of other dead tortoises! You wouldn’t catch a sloth doing that.

The diet of a Galápagos tortoise consists of cacti, grasses, leaves, lichens, milkweed, fruit, and prickly pear cactus. They’ve been found to play a key part in shaping their ecosystem by dispersing plant seeds in their dung.


Galapagos Giant Tortoise Chelonoidis nigra. Santa Cruz Island, Galapagos Islands, Ecuador. Suzi Eszterhas.

Little water is available in the giant tortoise’s natural habitat, so they get most of their moisture from their food. This is similar to sloths, obtaining most of the water they need from the foliage they eat.

Amazingly, the slow metabolism of the giant tortoise and their ability to store large amounts of water means that they can survive up to a year without eating or drinking!


How long do sloths and giant tortoises live?

Although no one knows how long sloths actually live for, it’s suspected that they might live to well over 50 years old in the wild — an impressive age. But that’s nothing compared to giant tortoises.


sloth fest sloth selina


They are among the world’s longest-living animals, with an average lifespan of 100 years or more. Lonesome George, a Galápagos giant tortoise, died at 152. A spring chicken compared to Jonathan the Aldabra giant tortoise, who recently celebrated his 190th birthday.


Are they social?

Like sloths, giant tortoises like to lead peaceful and quiet lives. Their lives revolve around eating, relaxing in the sun, or wallowing in puddles. Aldabra giant tortoises and domed tortoises in the Galápagos are more social and often found in herds, in contrast to more solitary and territorial saddleback tortoises.


giant tortoises
Galapagos Giant Tortoise Chelonoidis nigra. Santa Cruz Island, Galapagos Islands, Ecuador

What problems do sloths and giant tortoises have in common?

Sloths and giant tortoises both face threats from habitat loss due to human development.

Galápagos giant tortoises have historically suffered huge declines due to exploitation by whalers, pirates, traders, and fur sealers. They were a source of fresh meat that could be kept alive for months on end without any food or water — ideal for long days out at sea. They were also killed for their oil, which could be used for burning lamps.


giant tortoise
Galapagos Giant Tortoise Chelonoidis nigra. Santa Cruz Island, Galapagos Islands, Ecuador.


The introduction of different species have also had a terrible impact on giant tortoise populations. Feral dogs can attack tortoises, rats predate tortoise eggs while livestock such as cattle and horses trample their nests. Goats compete with the tortoises for food, and fencing and roads affect migration their migration routes.

Two species of giant tortoise are sadly thought to have gone extinct: the Floreana giant tortoise and the Pinta tortoise. The last known Pinta tortoise was Lonesome George, who died in June 2012.


What can be done to protect them?

In Ecuador, the Galápagos National Park was established in 1959 in an effort to protect its unique flora and fauna. Scientists have collected eggs from the wild in the park and incubated them at the Charles Darwin Research Station. Bringing the eggs into captivity ensures that the newly hatched tortoises can grow big enough to escape attacks from rats and dogs when they’re released into the wild. Eradication campaigns are also being undertaken to remove introduced species such as rats.

Scientists are also working to better understand the tortoise’s migration routes, in an effort to protect more of their habitat. As with sloths and any other animal, the better we understand them and their needs, the better we are able to help them and ensure their survival.


-Samantha Stocks

SloCo Collaborator

Sloth Versus Capybara

Sloth versus Capybara

The sloth and the capybara, do they have anything in common? What is a capybara, anyway? Aren’t they, like, exotic-looking giant rats?


Capybaras are indeed rodents, the largest in the world, and they are native to South America, so they do share a lot of territory with sloths! They’re both mammals, they both can swim (in fact, the capybara is semi-aquatic), they’re both vegetarians, and they both look great in pictures!


capybara scale

Are sloths and capybaras Related?

Not for about 100 million years. Like so many mammals, the capybara said goodbye to the Xenarthra superorder when Atlantogenata (including manatees, shrews, elephants, and of course our favorite sloths) split from Boreoeutheria (including cats, dogs, rabbits, monkeys, and rodents).

Basically, the easy way to remember if sloths are related to other mammals is: no, unless it’s another Xenarthra. Everyone else split up before the dinosaurs went extinct.

Where do they live?

Both sloths and cavys (the family that includes capybaras, guinea pigs, and wild cavys) evolved in South America, and capybaras live there still. So do many sloths, but sloths also branched out and now live in parts of Central America too!


Are they social animals?

Sloths definitely are not social, but capybaras are very gregarious. In the wild, the biggest group of sloths that seek association with each other is a mother and her baby, but capybaras form groups of 10-40 individuals that may merge into much larger groups during the dry season.



Like sloths, when in heat capybaras make a whistling noise (actually, in sloths it sounds more like a scream or bird cry), but unlike sloths, capybaras only mate in water.


capybara with animals
Capybaras are known for being one of the friendliest animals, usually sharing spaces with other species. In this photo a capybara with a smooth-billed ani and a wattled jacana. Pantanal, Brasil.

Who sleeps more?

Sloths sleep eight or nine hours per 24-hour cycle, and capybaras also sleep in small naps throughout the day, staying most active around dawn and dusk. The more interesting question is: where do they sleep? Sloths sleep hanging upside down in trees, and capybaras often sleep in the water!



What do they eat?

Both sloths and capybaras are vegetarians, eating a lot of leaves (almost exclusively leaves, in the case of sloths), and capybaras also eat bark, fruit, reeds, and grass. The name Capybara comes from tupí and means “grass-eater”.


sloth mother feeding her baby leaves
Baby sloths learn from their mother what leaves are good to eat

Both animals have specialized adaptations to help them digest the tough cellulose found in their diets: sloths ferment it in their large stomachs, and capybaras are autocoprophagous, meaning that they digest their food twice by eating it again after they poop it out once.

How do scientists study sloths and capybaras?

Capybaras do pretty well in captivity, and many studies are conducted on captive animals. Scientists in Japan actually developed an objective classification for how much capybaras enjoy bathing in hot springs (answer: a lot).



Sloths are best studied in the wild, though they are sometimes hard to find, whereas the abundant capybara is easier to spot, observe, and genetically test.

What problems do sloths and capybaras have in common?

Like all wild animals, sloths and capybaras face problems with deforestation and loss of habitat. Capybaras, however, have adapted better than sloths to human encroachment on their environment and can be found in zoos, parks, farms, and even urban neighborhoods.

Are they endangered?

Both capybaras and a few species of sloths are listed by the IUCN as “least concern”, but in the case of sloths, the populations are likely declining significantly, whereas, in the case of capybaras, we are happy to report that they are indeed probably doing very well. The capybara’s ability to live alongside humans has helped them adapt to our changing world.


What can be done to protect both species?

Capybaras are actually doing pretty well, though as aquatic animals they benefit from all initiatives that help protect rivers, lakes, wetlands, and water sources. They are threatened in some areas by hunting.

Sloths need forests to survive, and since rainforests make great watersheds, you can help both sloths and capybaras by saving the rainforest. Both animals face ever-increasing levels of habitat urbanization, and you can also assist by supporting organizations that help them adapt. Perhaps sloths have a thing or two to learn from capybaras-as scientists, we know we do!

Sloth versus Giraffe

Sloth versus Giraffe

This month we’ve got another weird one for you as we compare the world’s tallest mammal with the world’s slowest: yes, that’s right, we bring you Sloths vs Giraffes!

They’ve both got long necks! They both make some weird noises! Let’s take a look and see what giraffes have in common with sloths… and what they don’t.

Are sloths and giraffes related?

Trick question, sloths are hardly related to anybody except anteaters and armadillos, and them only barely. Giraffes are ungulates (hoofed mammals) of the superorder Laurasiatheria, originally from the supercontinent of Laurasia, which used to be part of Gondwana. Giraffes and sloths haven’t been related to one another for about 100 million years.


Longer or more?

It’s a common misconception that giraffes’ long necks must have more neck vertebrae than any other mammal. After all, a giraffe’s neck can easily reach 2 meters (6 ft) long! Giraffes in fact have seven cervical (neck) vertebrae, the same numbers as humans, dogs, and most mammals. The only difference is that in giraffes, the bones are stretched very long to enable the tall neck that lets the giraffes browse the tops of trees.

giraffe skeleton
Image: Gordon Johnson on Pixabay


Giraffes’ long necks aren’t just used to reach tasty treats; they also fight with them. Male giraffes establish dominance with other males by pushing each other with their necks, and sometimes swinging and butting each other with their necks and ossicones (the short horns on top of their heads). Recent research indicates that these dominance battles may have been the original driver of the long necks, with the treetop grazing abilities being a side effect.



Sloths use their impressive claws when they need to fight, and their necks are not as proportionally long as a giraffe, but some sloths actually do have more neck bones. While most mammals (including the giraffe) have seven cervical vertebrae, two-fingered sloths have six, and three-fingered sloths have nine! Sloths’ elongated necks can rotate 270° and are useful for scanning their surroundings and keeping their heads above water while swimming.



Where do they live?

Sloths live in trees, and giraffes live on the ground. More specifically, sloths live in trees in tropical rainforests in the Western Hemisphere, and giraffes live on the ground in sub-Saharan Africa.

What do they eat?

Sloths and giraffes are both big consumers of tree products. Sloths eat leaves, whereas giraffes eat tree leaves, twigs, and bark, and also feed on shrubs, grass, and fruit. They have occasionally been known to chew bones, which don’t grow on trees. Giraffes eat about 34 kg (75 lbs) of foliage daily.


Giraffe at Mala Mala reserve, South Africa. Photo: Suzi Eszterhas

Who sleeps more?

For the first time in a while, we’ve found an animal that sleeps less than our relaxed sloth! Giraffes sleep about four and a half hours per night  – mostly standing up, they only lie down for short periods of time. They spend most of their time chewing cud.

Are they social?

Unlike our solitary sloths, giraffes are quite social animals. They have long-lasting fission-fusion social groups that merge and split up in complex ways, usually based on sex and family ties. It’s possible that some giraffe herds are much larger than previously thought, as giraffes can use their great height to see and monitor other herd members from quite far away. Group sizes of more than 100 individuals have been observed.


A group of Giraffes , Okavango Delta, Botswana. Photo: Suzi Eszterhas


Like sloths, mother giraffes give birth to a single baby at a time and raise them without the help of the father. Unlike sloths, female giraffes may babysit each other’s offspring. Female sloths scream when in heat in order to attract males, whereas giraffes make a low humming noise that humans care barely hear, and we aren’t entirely sure why.

Do they have parasites?

Sloths have an entire ecosystem living in their fur, but most of the moths, algae, and fungi that live there have a symbiotic relationship with the sloths. Giraffes have as many as 11 chemicals in their fur that combine to repel many kinds of insects!

How do scientists study them?

Wild giraffes are recorded by ground survey methods such as mark-recapture photo surveys. Each giraffe has a unique pattern of spots, much like a human fingerprint, that is stable over time and a good way to recognize individuals. Sloths are studied exclusively by researchers in the field, as the thick jungle canopy prevents aerial observation. Both animals have different behaviors and feeding habits in captivity.


What problems do they have in common?

Like sloths and so many other wild animals, giraffes suffer from deforestation and habitat loss. Giraffes currently inhabit only 10% of their ancestral range, the other 90% has been lost to humans and habitat fragmentation. Giraffes are also hunted for bushmeat, which is sometimes sold as “beef”.

Habitat fragmentation can lead to inbreeding, though sloths may be more at risk for this than giraffes. The West African giraffe population rebounded from 49 individuals to a healthy population of over 600, proving that these are very resilient animals that only need us to give them a chance!


Lewa Conservancy, Kenya. Photo: Suzi Eszterhas

What is the IUCN classification?

Giraffe populations are a little easier to estimate than sloth populations, but both are declining. Sloths range from “least concern” to “critically endangered” depending on the species.  The IUCN still recognizes only one species with 9 subspecies.



But according to The Giraffe Conservation Foundation’s peer-reviewed research, Giraffes have four different species with a variety of subspecies, some of which are “vulnerable”, and some of which are “critically endangered”.



The Nubian giraffe has lost 95% of its population in the last 30 years. Populations that benefit from good conservation are actually increasing, though some of these numbers may be due to better survey methods. With a current best population guess at 117,000 there are approximately half as many giraffes left on planet Earth as Ferraris.

What can be done to protect both species?

Don’t eat them, give them space, and don’t buy their bones. You probably aren’t tempted to go down to your local supermarket for a can of Sloth Soup, and if you live outside of Africa there isn’t much access to giraffe bushmeat, but you can support sustainable agriculture and initiatives to end poverty, which keeps people from being so desperate that they have to eat and exploit animals better left alone.

The Giraffe Conservation Foundation, much like the Sloth Conservation Foundation, works to help protect their respective species from extinction, so check out their amazing work and support them! A huge thanks to our colleagues from GFC and their valuable contributions to this ‘Sloth Versus Giraffe’.

Tall or small, neotropical or African, black-tongued or pink, both of these amazing animals help make our world what it is. Don’t let sloths or giraffes suffer from habitat loss or face extinction! We owe it to them, and to ourselves, to keep our world rich with diversity.

Sloth versus Cheetah

Sloth versus Cheetah

Ready! Get set! Go….odbye!

It’s a good thing this isn’t a race, because if it were, it wouldn’t be much of a contest between the slowest mammal and the fastest; after all, the sloth is outpaced by some species of plants, whereas the cheetah travels at speeds only matched by humans on the freeway.


In fact, if they were vehicles, cheetahs would be the muscle cars of the animal world, whereas sloths would be kind of like those floating innertubes that go around Lazy Rivers at theme parks.

If not speed, then do these two animals have anything at all in common?


Are sloths and cheetahs related?

Cheetahs are members of the family Felidae, most closely related to jaguarundis and cougars and somewhat more distantly related to the common house cat. Sloths and cheetahs last shared an ancestor about 90 to 100 million years ago, before Tyranosaurus Rex first terrorized the Earth.




Both are in the mammalian infraclass Placentalia (an infraclass is in between a class—mammalia—and a clade—Boreoeutheria, for the cheetah, and Atlantogenata, for the sloths), but other than that they aren’t very close. Sloths are an old species, having been around for some 30+ million years, whereas cheetahs are comparatively young species at only about 3 to 3.5 million years old.


Savannahs and Jungles

Sloths and cheetahs live on completely different halves of the world: in fact, that’s what the two names of the clades Boreoeutheria and Atlantogenata refer to. Sloths like to live in tall trees of the Central and South American jungles, whereas cheetahs like to live in savannahs, mountains, and valleys of Africa and Iran with thin vegetation. It turns out when you can go from 0 to 60 mph in under 6 seconds, trees become obstacles very quickly. Sloths, on the other hand, go from 0 to 60 in approximately never and are therefore better adapted to the forest.


Cheetah mother w 4.5 month old cubs on a termite mound, Ngorongoro Conservation Area, Tanzania. / Brown-throated sloth in the South Caribbean of Costa Rica. Photo: Suzi Eszterhas

Are they social animals?

Cheetahs were once thought to be solitary animals, much like sloths, but recent observations have revealed that cheetahs actually have a rather complex social structure. Sometimes cheetahs will be loners, but males frequently associate in groups called “coalitions”, usually but not always consisting of siblings.


Cheetah Conservation Fund, Namibia.


Females live with their current litter of kittens and will often be friendly with their daughters, sisters and mothers. Sloths will peacefully share the same tree with other sloths, but almost never interact with each other outside of mother-child pairs and very brief mating encounters.

Do sloths sleep more than cheetahs?

Cheetahs may move faster than sloths, but they make up for it by sleeping more! Cheetahs spend most of their day resting (when they aren’t setting land speed records, that is), and about 12 hours out of every day is dedicated to snoozing.



This is still better than the common house cat, who sleeps up to 16 hours a day, but much lazier than that sloth, who sleeps only 8 to 10 hours out of 24.



What do they eat?

Like all cats, cheetahs are carnivores. They eat small to medium sized prey, mostly ungulates (hooved mammals), but will occasionally eat rabbits, livestock, and melons. Scientists think the melons are eaten for their water content, which can be scarce in some of the more arid areas of the cheetah’s habitat.



Sloths only eat melons in captivity, and they probably aren’t good for them. One dietary preference that sloths and cheetahs have in common is that neither one eats humans! The cheetahs probably could if they wanted to, but happily for us, they just want to be left alone.

How do scientists study cheetahs and sloths?

Humans have long admired the sleek, speedy cheetah, and historical records of them go back for millennia. In fact, the most difficult thing about the history of the cheetah is human’s annoying habit of referring to all big cats with a few interchangeable names: basically every cat that doesn’t wear a collar and go by Mrs. Tiddles has been called, at some point, a “leopard”, making specific details hard to discern.


Cheetahs at Masai Mara Conservancy, Kenya. Photo: Suzi Eszterhas


Scientists who study cheetahs are challenged by the large territories occupied by the big cats, which are up to 7,063 km2 (2,727 sq mi)! However, cheetahs are much less cryptic than sloths—just look for the only thing on the savannah streaking by at up to 128 km/h (80 mph)—and cheetahs have benefited from a very good PR campaign since the 1970s, though they are still killed for their fur and interactions with livestock in much of Africa. Sloths, on the other hand, have only recently come to the interest of scientists, social media, and the general public.



What problems do they face and what is their conservation status?

As with so many wild animals, both sloths and cheetahs face a lot of difficulties with habitat loss. Wild creatures need wild spaces, and you don’t get much more wild than either sloths or cheetahs! Habitat fragmentation is a particular problem for both animals, leading to dangerous levels of inbreeding.



Unlike sloths, cheetahs are social enough to tame, though they don’t do very well in captivity. Specifically, cheetahs rarely mate in captivity, and their kittens have a very high mortality rate—which is probably the reason they have never been fully domesticated. Both animals suffer from illegal trafficking and the pet trade, though public campaigns have reduced this considerably for cheetahs in recent decades.

The IUCN lists cheetahs as “vulnerable”, whereas the Endangered Species Act goes one step further and lists them as “endangered”. Most sloth species are listed (probably incorrectly) as “least concern”, though both cheetahs and sloths have species that are critically endangered. The pygmy sloth falls into this category, and the Asiatic cheetah has only 12 individuals left in the wild.

What can we do to help cheetahs and sloths?

Sloths and cheetahs are both resilient, adaptable animals that can thrive if only given the chance to do so! The African Wildlife Foundation and the Cheetah Conservation Fund are two organizations working with these amazing cats, and of course, your friends here at SloCo dedicate our days to saving sloths. The most important thing YOU can do is to support organizations that keep the wilderness intact, promote scientific initiatives that find peaceful compromises between humans and wildlife, and of course, never buy or handle wildlife that was never meant to be a pet.

No matter whether you identify with the speed and agility of the cheetah or the Pura Vida relaxation of the sloth, we have so much to learn from our fellow animals, and our world is always enriched by the amazing diversity that life brings us!

Sloth versus Aardvark

Sloth versus Aardvark

Welcome to the latest version of “Sloths Versus”, your monthly introduction to strange creatures of all kinds, where we (virtually) travel around the world to find out that sloths are indeed one of the weirdest animals out there. In this edition we bring you… the aardvark!


This famous blue character from The Pink Panter, it’s an aardvark!


The aardvark doesn’t just win at being at the head of the alphabet, it is a pretty strange creature too. Does it have anything in common with our friends the sloths? A bit, but mostly on technicalities. Read on to find out!



So are sloths and aardvarks related?

Nope, not at all! Hailing from Africa, where it is also called the “Cape anteater” or the “African ant bear”, the aardvark (Orycteropus after) eats as many termites as it does ants. Sloths live near ants and termites, as they share trees in the rainforests, but sloths ignore the bugs in favor of the leaves.


Aardvark in burrow/ Photo: Louise Joubert


The word “aardvark” actually comes from the Afrikaans word “erdvark”, which means “ground pig” because of their burrowing habits. They aren’t pigs though. Aardvarks are in an order all by themselves, and have no close living relatives!

A family of one

Just as the sloth has only a few cousins, to whom they aren’t very related, the aardvark is also a bit of an only child. They are distantly related to elephant shrews and manatees, as they are all in the clade Afrotheria, which means “from Africa”, so that’s a lot of different mammals.


Photo: African Wildlife Foundation


Aardvarks last had a living relative in the middle of the late Cretaceous, over 80 million years ago. That makes the two species of sloths, who had a common ancestor about 28 million years ago, look like twins! Afrotheria (which includes aardvarks) and Xenarthra (which includes sloths) diverged about 90 million years ago.

Antisocial Social Club

One thing aardvarks and sloths have in common is that they are both a bit anti-social. While sloths may share trees with other sloths without being particularly social, aardvarks only bother with other aardvarks when it’s time to mate.



Like sloths, they have only one baby at a time, so when we say they are only children, that covers both their evolutionary history AND their actual childhood!



Ants, leaves, and… cucumbers?

Sloths are strict folivores that eat only leaves, whereas aardvarks are insectivores that eat ants and termites. And when we say eat, we mean eat; they can consume as many as 50,000 bugs in one night! The sloth’s philosophy of vegetarianism might have one small thing in common with the aardvark, as for some reason the aardvark eats exactly one kind of vegetable: the cucumber.

Image: Sydney M. Stent –


Not just any cucumber though, a special kind called (you guessed it) the aardvark cucumber, Cucumis humifructus. The cucumber fruits underground, where it is found by burrowing aardvarks, which consume it for the water content, and spread the seeds as they pass through its digestive system.

Unexpected skills

Sloths and aardvarks don’t drink much water, so it’s a bit surprising that they are both strong swimmers! Though sloths live high in the canopy and aardvarks live in holes in the ground, they both can get out and swim across rivers when necessary, which just goes to show that there’s no real excuse not to know how to swim.



Are sloths and aardvarks endangered?

Another thing that aardvarks and brown-throated three-fingered sloths have in common is that they are both listed by the IUCN as “Least Concern”—and in both cases, that might not be true. Sloths are so hard to find and study that we don’t really know how many wild sloths there are, and populations are very probably declining. Pygmy and maned sloths are both critically endangered.


Aardvarks, likewise, are hunted by humans who like their meat but don’t like the holes they dig, and kill off their food sources with insecticides. When the humans come in, the sloths and aardvarks leave, and if we’re not careful, they soon won’t have anywhere to go.

Help advaarks and sloths!

The African Wildlife Foundation is one of a few organizations working to help conserve the aardvarks and make sure they don’t suffer from the same habitat loss that faces sloths.

If you’d like to help these weird and wonderful creatures, get in touch with conservation organizations that can tell you how! Whether they live high in the trees or burrow deep underground, wild creatures deserve us to respect their wild spaces.


Sloth versus Pangolin

Sloth versus Pangolin

The humble sloth vs the armored pangolin, what have these two unusual mammals got in common?

Pangolins are sometimes called “scaly anteaters”, because they A) have scales, and B) eat ants. If you remember our Sloth vs Anteater blog, you may be tempted to think the pangolins, like the furry anteaters, are distant cousins of the sloths, but in fact, they aren’t very related at all.


pangolin anteater
Giant Anteater (Myrmecophaga tridactyla) and SundaPangolin (Manis javanica).

Similar but not related

In fact, of all the placental mammals, sloths and pangolins are as distantly related as can be: they last shared a common ancestor about 90 to 100 million years ago. That means they’ve spent about half of all mammalian existence doing their own thing.



Scientists once thought that the sloth’s order Xenarthra and the pangolins order Pholidota (which means “clad in scales” in Ancient Greek) were closely related, probably because pangolins look very much like you’d expect if you crossed a furry anteater with an armadillo (which can’t be done, trust us), but now that they have genetic sequencing available, the two orders have been reclassified.


armadillo pangolin
Armadillos and Pangolins are very similar. In the photos, Six-banded Armadillo (Euphractus sexcinctus) and Chinese Pangolin (Manis pentadactyla).


Mammals have fur… except pangolins

One thing sloths and pangolins have in common is that they are both mammals, even though the pangolin is sometimes mistaken for a medieval suit of armor and the sloth meets several criteria to be in fact classified as a plant. (No, really, there are species of plants to move faster than sloths do. The Venus flytrap closes in milliseconds, and the dogwood bunchberry flower explodes in fractions of milliseconds. You can’t make this stuff up.)

Like most mammals, sloths have fur, and unlike most mammals, pangolins have scales. These scales aren’t like fish scales or reptile scales though, they are made of keratin, like fingernails. Imagine having fingernails all over your whole body! You’d spend a fortune at the salon.


sunda pangolin scales
Pangolin scales are made of keratine.


They use these scales for defense by curling up into a ball and wrapping their thick tails around their faces, making it hard for predators to eat them. This is a very different method of defense than sloths use, which is to stay very still and blend into the rainforest canopy.


pangolin sleeping
Chinese pangolin (Manis pentadactyla). Three-month-old orphaned baby (named Gung-wu) sleeping. Gung-wu is the offspring of parents rescued from poachers. Taipei Zoo, Taipei, Taiwan

Smelly Pangolin

One thing that’s quite different about sloths and pangolins is the way they smell; sloths have almost no discernible body odor (see “possibly a plant”, mentioned about), while pangolins have scent glands similar to those of a skunk, which is quite noxious and may aid in driving off predators.

Species of pangolin

There are eight extant species of pangolin. They comprise the Chinese pangolin, Indian pangolin, Sunda pangolin, and Philippine pangolin, which inhabit Asia, and the white-bellied pangolin, black-bellied pangolin, giant pangolin, and Temminck’s pangolin, which occur in Africa.




The most trafficked animal in the world

This distribution has kept the sloth out of the crosshairs of Chinese traditional medicine, which unfortunately has many recipes for parts of the pangolin, especially the scales. Pangolins have the unfortunate distinction of being the most trafficked animal in the world, with over 100,000 animals sold on the black market each year. 



Thai Van Nguyen, Executive Director of Save Vietnam’s Wildlife, holding a three-month-old Sunda Pangolin baby that was rescued from poachers and is in rehabilitation. Cuc Phuong National Park, Vietnam


Like the sloth, they do not breed well in captivity, meaning that nearly all captive and traded animals are kidnapped from the wild. It is estimated that more than a million pangolins have been snatched from the wild in the past decade. There are eight species of pangolins, and each of them is listed by the IUCN as vulnerable, endangered, or critically endangered.



Perhaps the best thing that sloths and pangolins have in common is that both of them have friends in the fields of wildlife conservation who are dedicated to their survival.


pangolin baby
Twelve-day-old orphaned baby (named Gung-wu). Gung-wu is the offspring of parents rescued from poachers.


Multiple rescue centers in Taiwan have helped the pangolin population rebound in that country, and international organizations like Save Pangolins or the Pangolin Crisis Fund work across borders and even continents to make sure these amazing animals live to see another day.

So let the forces of Sloth Conservation and Pangolin Conservation join together to celebrate World Pangolin Day, because no matter if you have skin, scales, or fur, we’re here for you.


-SloCo Team

Sloth versus Anteater

Sloth versus Anteater

In this episode of “sloths vs” we are taking a look at another member of the Xenarthra; the anteater. Anteaters are in fact the sloth’s closest living relative, though by “close” we don’t actually mean very close.

Anteaters and sloths last shared a common relative about 60 million years ago. Compare that to humans, who split off from the bonobo/chimpanzee lineage about 4.5 million years ago, and sloths and anteaters look like kissing cousins at best.

Sloths and anteaters make up the Pilosa branch of the Xenarthran clade. Pilosa means “the ones with hair”, because sloths and anteaters are furry, and are separate from the armadillos, which… aren’t.


Although armadillos have some hair…

Leaves versus Ants

The most obvious difference between sloths and anteaters is that sloths eat leaves (which is what the suborder Folivora means in Latin) whereas anteaters eat insects, which is why their scientific suborder is named Vermilingua, meaning “worm tongue”.

Wait, what? Are anteaters actually Harry Potter villains or something?

Actually, they get the name Vermilingua not from their diet but from their very, very long tongues, which are anchored somewhere around their breastbone and can be up to 60 cm (2 ft) long.


anteater tongue


In case this isn’t weird enough, their tongues are also covered in backward-facing spines, probably to make up for the fact that they have no teeth, so the tongue just has to do all the work itself,  and extra sticky saliva for lapping up all those ants and termites. They can also flick their tongue back and forth about 150 times per minute. That’s more than twice per second!

The sloth, we are happy to report, has a normal-looking tongue that mostly stays inside their mouths, is lacking in spines and gluey secretions of any kind, and looks incredibly pink and cute when they are babies.


mom and baby tongue

Body Temperature

Like sloths, anteaters have a cooler-than-average body temperature that can fluctuate by a large margin. They both have poor eyesight that is compensated for by an excellent sense of smell, and all species of anteater except the giant anteater are, like sloths, excellent tree climbers. This is helpful because in the jungle there are a lot of bugs in trees, especially termites and other social insects that the anteater prefers.



The tails

The tree-climbing anteaters (which are the northern and southern tamandua and the silky anteater) all have long, prehensile tails, as compared to the sloths, of which only the three-fingered have a tail worth talking about, and it is short and stubby. It doesn’t help at all with climbing trees, though it does help with going to the toilet.


Anteater Myrmecophaga Tridactyla, Hanging from a Tree Trunk, Upside Down at the Foot of the Arenal Volcano Stock Image - Image of anteater, anteaters: 169601205

The best pet?

For all their differences in appearance, the sloth and the anteater actually have quite a lot in common. Finally, it would be remis of us not to mention another very important similarity in the Pilosa suborder, which is that anteaters and sloths both make very poor pets.

They have specialized diets and require wild, natural environments to thrive. Also, the giant anteater has been known to kill people. It’s pretty rare (in fact, only three people in recorded history have died this way) and in all cases, the anteater was found “not guilty by reason of humans being incredibly dumb”, but those claws are no joke, and giant anteaters can weigh up to 50 kg (over 100 lbs), so don’t mess with them.



(Sloths have never been known to kill humans, which proves that either they are kind creatures that mind their own business, or else that they are secretly very deadly and we just never find the bodies.)

Sadly, just like sloths, the illegal pet trade affects both sloths and tamanduas. In the case of both northern and southern tamanduas this is a big problem, according to Dr. Aurnaud Debiez from the Instituto de Conservação de Animais Silvestres (ICAS) in Brazil.  Both species are in high demand in countries like the United States where the legislation about wildlife as pets desperately needs to be updated to address current trends and threats.

Open arms for a hug?

Another common misconception about sloths and tamanduas is the idea that they open their arms for hugs. For both species, this open-armed posture is actually a response to feeling stressed or threatened: it makes them look bigger and keeps their claws out and at the ready. So if you see one of these animals with their arms spread wide, they aren’t looking for a hug, they are actually asking for space!


anteater standind meme
Not looking for a hug!

How to help sloths and anteaters

In fact, if you like sloths and anteaters, the best way to support them is to help make sure they have a home to live in! The wildlands of Central and Sloth America are home to sloths, anteaters, and so many more species that we literally haven’t even discovered all of them yet. We haven’t even discovered all of the sub-species of sloths and anteaters yet, and more research is urgently needed.

The giant anteater, like the maned sloth, is classified by the ICUN as “vulnerable” (which means they could use our help), while the arboreal anteaters as well as the brown-throated, pale throated, and both species of two-fingered sloths are listed as “least concern” (and we’d like to keep them that way). The pygmy sloth is critically endangered, which means they need protection right away.

Let’s work together to keep these strange creatures happy in their homes. Save the forests, and save the world!


-Ames Reeder

Urban Sloth Project

Sloth versus Snow Leopard

Sloth versus Snow Leopard

The sloth and the snow leopard (Panthera uncia) seem like two animals that have absolutely nothing in common. After all, they live on opposite sides of the planet from each other, prefer habitats that couldn’t be more different without being under water, and one is a small herbivore that eats leaves while the other is a large predator that eats whatever it wants.

Superficially, they couldn’t be more different animals, but we think that if the sloth and the snow leopard ever sat down to have a cup of tea together, they’d have more to talk about than you’d think!


Are they related?

Both animals are in the class Mammalia, subclass Theria, and infraclass Placentalia; this means they are both furry mammals that carry their young in their wombs and basically aren’t platypuses.

Other than that, they haven’t shared a common ancestor since the time of the dinosaurs. Although snow leopards live exclusively in the mountains of South and Central Asia, their ancestors evolved in the Americas, not so far from the South American ancestors of the sloth!


snow leopard
Facebook: Snow Leopard Conservancy / Photo: Rafael Kettsyan

Where do they live?

Sloths and snow leopards are both remote creatures that are difficult for scientists to study. The sloth lives deep in the hot trackless jungles of the New World, while the snow leopard lives high in the mountains of Asia, where the air is thin, dry, and cold.

Some populations of snow leopards also come down into the Gobi Desert following herds of wild sheep and goats. All of these regions are difficult for humans to navigate and study, and the animals that live there remain largely mysterious to science.

Though separated by a distance of over 15,000km (nearly 10,000 miles), both animals prefer habitats far off the beaten path!


snow leopard
Photo: Snow Leopard Conservancy

Do they make friends easily?

Like sloths, snow leopard territories overlap with each other, but neither animal interacts much with others of their kind except when mating.

Both sloth and snow leopard mothers raise their young on their own, a process that takes about a year for sloths and up to two years for snow leopards.

Young sloths will sometimes have a home range initially near their mothers, and young snow leopards will sometimes come back to visit before they are fully mature. Though sloths have a lot of tolerance for sharing trees with other sloths, they would likely identify with the snow leopards’ drive for independence.


snow leopard
Photo: Suzi Eszterhas


Who sleeps more?

The sloth has a reputation for sleeping a lot, but this reputation is owed to lazy human researchers, not to the sloths themselves! Sloths only sleep for eight to ten hours per day, whereas most cats sleep for 12-16 hours every day.

Scientists aren’t sure if snow leopards follow this pattern, because it is very hard to observe the elusive snow leopard all day long, but it is very likely that snow leopards actually sleep more than sloths.

Sloths even “cat-nap” more frequently than snow leopards do, with short rest periods throughout the day, whereas the snow leopard is primarily active during dawn and dusk, though they have also been observed during the late afternoon.


snow leopard

How about those tails?

This is one area where snow leopards and sloths couldn’t differ more! Snow leopards have long, thick, furry tails which they use as a rudder while running up and down mountains. They also use these tails as mufflers to wrap themselves up when the weather turns freezing cold.

Three-fingered sloths have short, stubby tails they only use when going to the bathroom, and they wouldn’t know what to do if the weather ever froze. Sloths would just turn instantly into popsicles; unlike the hot-blooded cats, they cannot regulate their temperature very well.


snow leopard tail
Photo: Suzi Eszterhas

Whos fur is thicker?

Sloth and snow leopards both have thick fur coats they depend on for survival. Like all mammals, thermoregulation is hugely important to their survival, and their fur is important insulation and camouflage.

The dense, beautiful snow leopard pelt is the longest and thickest of any felid. This fur is much sought after by humans, though hunting snow leopards is illegal in all 12 countries where they reside.

Sloth pelts, on the other hand, would never become a fashion statement for humans—only the sloths think that green algae, anti-cancerous fungi, and a whole colony of sloth moths count as haute couture!


snow leopar baby
Photo: Suzi Eszterhas

What do they do about humans?

The biggest concern that sloths and snow leopards have in common is their relationship to humans. Both animals are threatened by habitat loss, both animals and illegally hunted for the pet trade, and both animals suffer from human ignorance about their needs and habits.

Sloths are often mischaracterized as lazy and diseased, when in fact they don’t sleep much more than humans, and the anti-microbial properties of their fur have great potential for fighting diseases that threaten humans!

Snow leopards are incorrectly thought to be dangerous to humans and a threat to livestock, when in fact snow leopards are very shy and try to avoid confrontations with humans at almost all costs. These big cats would stay away from people if they had anywhere to go.



Neither sloths nor snow leopards make good pets, but luckily they both make excellent virtual adoptions! There are organizations all over the world fighting to understand and protect these awesome animals, such as  Snow Leopard Conservancy, and both benefit from humans that help spread awareness and fight for their right to exist.

One thing we’ve all got in common is this earth, and saving the world for one species saves it for us all!

Read More: Sloth versus Koala