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Sloths are famous for being the slow-coaches of the animal kingdom – indeed, they hold a record for their leisurely pace among mammals. 

But there’s much more to these speed-challenged jungle-dwellers. For instance, did you know they’re pretty good swimmers – moving about three times faster in water than they do on land? Or how about that some of the fungi that grow in their fur could have potential disease-fighting capabilities?

So what better way to mark International Sloth Day (20 October) than to kick back and celebrate a few records held by these treetop critters…

Largest sloth

Largest sloth

Imagine a sloth that weighs as much as an African elephant and stands as tall as a giraffe on its hind legs!

The Florida ground sloth was really that huge… but unfortunately/fortunately (depending on your opinion!), you’re not going to bump into one of these when visiting the Sunshine State, as they died out at least 300,000 years ago.

If you’re wondering how such a big beast got into the treetops like today’s sloths, they didn’t; they actually lived underground in what are now considered the largest animal burrows. A few of these cave-sized tunnels are still intact today in South America.

Smallest sloth

Smallest sloth

At the other end of the scale, of the six living species, the pygmy three-toed sloth is the most diminutive member of the family.

Measuring around 50 cm (1 ft 7 in) in length and weighing in the range of 2.5–3.5 kg (5 lb 8 oz–7 lb 11 oz), they’re about the same size as a domestic cat. With less than 100 left in the wild – only found on the tiny island of Escudo de Veraguas off Panama – this critically endangered creature is also the rarest sloth.

It’s one of the many threatened animals receiving much-needed help from ZSL’s Edge of Existence programme, whose chief scientist we interview in Guinness World Records: Wild Things.

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Slowest mammal

If all the world’s mammals were to take part in a 100-m sprint, odds are that the three-toed sloth would cross the finish line last.

While the world’s fastest man, Usain Bolt (JAM), covered that distance in a lightning-quick 9.58 sec, the sloth would take almost 50 min to complete the race at its average speed.

While on the ground, three-toed sloths travel at just 1.8–2.4 m (6–8 ft) per min, they’re slightly quicker in the rainforest canopy, where they can reach “blistering” speeds of 4.6 m (15 ft) per min! Even this top rate is still around five times slower than a drifting iceberg…

Discover why Sir David Attenborough has a soft spot for sloths in Guinness World Records: Wild Things. To learn about more incredible animals check out the Wild Things page.

Wild Things