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  • Hello.

  • Well, I'm here to talk to you about my animal muse:

  • the sloth.

  • (Laughter)

  • I've been documenting the strange lives of the world's slowest mammal

  • for the last 10 years.

  • I still remember the first time I saw one.

  • I was fascinated by their freaky biology.

  • I mean, what's not to love about an animal that's born

  • with a fixed grin on its face?

  • (Laughter)

  • And the need to hug.

  • Audience: Awww.

  • But sloths are massively misunderstood.

  • They've been saddled with a name that speaks of sin

  • and damned for their languorous lifestyle,

  • which people seem to think has no place amongst the fittest

  • in the fast-paced race for survival.

  • Well, I'm here to tell you that we've got this animal all wrong --

  • and how understanding the truth about the sloth

  • may help save us and this planet we both call home.

  • I traced sloth-based slander

  • back to a Spanish conquistador called Valdés,

  • who gave the first description of a sloth in his encyclopedia of the New World.

  • He said the sloth was

  • "the stupidest animal that can be found in the world ...

  • I have never seen such an ugly animal or one that is more useless."

  • (Laughter)

  • Tell us what you really think, Valdés.

  • (Laughter)

  • I'd like to have a word about Valdés's drawing skills.

  • (Laughter)

  • I mean, what is that?

  • (Laughter)

  • I've never seen an illustration of a sloth that's more useless.

  • (Laughter)

  • But I mean, on the plus side,

  • he has given the sloth a remarkably humanlike face,

  • and sloths do have remarkably humanlike faces.

  • This sloth I photographed in Costa Rica, I think looks a lot like Ringo Starr.

  • (Laughter)

  • But then, sloths do bear an uncanny resemblance to the The Beatles.

  • (Laughter)

  • Particularly pleased with Paul, actually, on there.

  • But like The Beatles, sloths are also extremely successful.

  • They come from an ancient line of mammals, and there were once dozens of species

  • including the giant ground sloth, which was the size of a small elephant

  • and one of the only animals big enough to eat avocado pits whole

  • and disperse them.

  • So ... (Laughter)

  • Some of you have worked it out already.

  • (Laughter)

  • That means that without sloths,

  • there might be no avocado on toast today,

  • leaving hipsters everywhere totally bereft at breakfast.

  • (Laughter)

  • (Applause)

  • Today, there are six surviving species, and they fall into two groups.

  • You've got your Bradypus three-toed sloths,

  • they're the ones with the Beatles haircuts and the Mona Lisa smiles.

  • Then, there are the two-toed sloths.

  • They look a little bit more like a cross between a Wookiee and a pig.

  • They live in the jungles of Central and South America,

  • and they're extremely prolific.

  • There was a survey that was done in the 1970s

  • in a Panamanian tropical forest

  • that found that sloths were the most numerically abundant large animal.

  • They took up one quarter of the mammalian biomass.

  • Now, that's an awful lot of sloths

  • and suggests they're doing something very right indeed.

  • So what if, rather than deriding the sloth for being different,

  • we tried to learn from it instead?

  • We humans are obsessed with speed.

  • Busyness is a badge of honor,

  • and convenience trumps quality in our quest for quick.

  • Our addiction to the express life is choking us and the planet.

  • We idolize animals like the cheetah, the "Ferrari of the animal kingdom,"

  • capable of doing naught to 60 in three seconds flat.

  • Well, so what?

  • (Laughter)

  • (Applause)

  • So what?

  • The sloth, on the other hand,

  • can reach a leisurely 17 feet a minute

  • with the wind behind it.

  • (Laughter)

  • But being fast is costly.

  • The cheetah is speedy, but at the expense of strength.

  • They can't risk getting in a fight,

  • so they lose one in nine kills to tougher predators like hyenas.

  • No wonder they're laughing.

  • (Laughter)

  • The sloth, on the other hand,

  • has taken a more stealthy approach to dinner.

  • They survive by capturing and consuming

  • static leaves.

  • (Laughter)

  • But you see, leaves don't want to be eaten any more than antelope do,

  • so they're loaded full of toxins and very hard to digest.

  • So in order to consume them,

  • the sloth has also had to become an athlete --

  • a digesting athlete.

  • (Laughter)

  • The sloth's secret weapon is a four-chambered stomach

  • and plenty of time.

  • They have the slowest digestion rate of any mammal.

  • And it can take up to a month to process a single leaf,

  • which gives their liver plenty of time to process those toxins.

  • So, sloths aren't lazy.

  • No, they're busy.

  • Digesting.

  • (Laughter)

  • Yeah, really busy.

  • (Laughter)

  • Hard at work, that sloth, very hard at work.

  • And of course, leaves have little calorific value,

  • so sloths have evolved to spend as little energy as possible.

  • They do about 10 percent of the work of a similar-sized mammal

  • and survive on as little as 100 calories a day,

  • thanks to some ingenious adaptations.

  • The Bradypus, three-toed sloths,

  • they've got more neck bones than any other mammal,

  • even a giraffe.

  • Which means they can turn their head through 270 degrees

  • and graze all around them,

  • without having to actually bother with the effort of moving their body.

  • (Laughter)

  • It also means that they are surprisingly good swimmers.

  • Sloths can bob along in water

  • three times faster than they can move on land,

  • kept afloat by ...

  • trapped wind.

  • (Laughter)

  • So --

  • (Laughter)

  • sloths are the only mammal that we know of that don't do flatulence.

  • When they need to expel gas,

  • it's actually reabsorbed into their bloodstream

  • and expelled orally as a sort of mouth fart.

  • (Laughter)

  • Turning their lives upside down saves further energy.

  • They have about half the skeletal muscle of a terrestrial mammal.

  • They don't really have so many of the extensor muscles

  • that are the weight-bearing muscles;

  • instead, they rely on retractor muscles to pull themselves along.

  • They have long, hooked claws and a high fatigue resistance,

  • so they can literally hook on and hang like a happy, hairy hammock

  • for hours on end.

  • And sloths can do almost anything in this inverted position.

  • They sleep, eat and even give birth.

  • Their throat and blood vessels are uniquely adapted

  • to pump blood and to swallow food against the force of gravity.

  • They have sticky bits on their ribs

  • that prevent their enormous stomach from crushing their lungs.

  • And their fur grows the opposite direction,

  • so they can drip dry after a tropical drenching.

  • The only problem is, if you turn a sloth the other way up,

  • gravity removes its dignity.

  • Audience: Awww.

  • They can't hold themselves upright.

  • And so they drag their bodies along as if mountaineering on a flat surface.

  • And I think this is why the early explorers like Valdés

  • thought so poorly of them,

  • because they were observing sloths the wrong way up and out of context.

  • I've spent many happy hours mesmerized by moving sloths.

  • Their lack of muscle hasn't impeded their strength or agility.

  • Nature's zen masters of mellow move like "Swan Lake" in slow mo --

  • (Laughter)

  • with the core control of a tai chi master.

  • This one has fallen asleep mid-move, which is not uncommon.

  • (Laughter)

  • But you're probably wondering:

  • How does a dangling bag of digesting leaves avoid being eaten?

  • Good question.

  • Well, this is one of the sloth's main predators.

  • It's the harpy eagle.

  • It can fly at speeds of up to 50 miles per hour,

  • has talons the size of a grizzly bear's,

  • razor-sharp eyesight,

  • and that ring of feathers focuses sound

  • so that it can hear the slightest leaf rustle.

  • The sloth, on the other hand, has poor hearing, bad eyesight,

  • and running from danger is clearly not an option.

  • No, they survive by wearing an invisibility cloak

  • worthy of Harry Potter.

  • Their fur has grooves that attract moisture

  • and act as tiny hydroponic gardens for algae,

  • and they also attract a host of invertebrates.

  • So they are their own slow-moving, miniature ecosystem.

  • They become one with the trees.

  • And we think that their movements are so slow,

  • they slip under the radar of the monstrous harpy

  • as it's flying about the canopy, scanning for action.

  • Sloths are stealth ninjas,

  • and they rarely leave the safety of the canopy --

  • except to defecate,

  • which they do about once a week at the base of a tree.

  • Now, this risky and energetic behavior has long been a mystery,

  • and there are lots of theories as to why they do it.

  • But I think they're leaving surreptitious scented messages for potential mates.

  • Because, you see, sloths are generally silent, solitary creatures,

  • except for when the female is in heat.

  • She will climb to the top of a tree and scream for sex.

  • In D-sharp.

  • (Laughter)

  • Don't believe me?

  • (Sound of sloth scream)

  • D-sharp.

  • This and only this note will get the male's attention.

  • It mimics the sound of the kiskadee flycatcher.

  • So the female remains covert,

  • even when yodeling for sex at the top of her lungs.

  • Her clandestine booty calls will carry for miles across the canopy,

  • and males will beat a slow path towards her.

  • (Laughter)

  • I think scented messages in her dung will help send Romeo up the right tree

  • so that he doesn't waste precious energy scaling the wrong one.

  • Sex, by the way, is the only thing that sloths do swiftly.

  • I've seen them do it in the wild,

  • and it's over and done with in a matter of seconds.

  • But then, why waste precious energy on it,

  • particularly after that journey?

  • (Laughter)

  • Unlike other mammals,

  • sloths don't also waste time maintaining a constant warm body temperature.

  • Energy from the sun is free,

  • so they bask in the sun like lizards

  • and wear an unusually thick coat for the tropics to keep that heat in.

  • Sloths have a freakishly low metabolism.

  • And we think that this might be one of the reasons

  • that they can sometimes recover from injuries

  • that would kill most animals.

  • This sloth recovered from a double amputation,

  • and I've known sloths that have managed to survive

  • even power line electrocutions.

  • And we now think that a low metabolism may well be key to surviving extinction.

  • Researchers at Kansas University who were studying mollusks

  • found that a high metabolism predicted which species of mollusk

  • had gone extinct.

  • Sloths have been around on this planet in one shape or another

  • for over 40 million years.

  • The secret to their success is their slothful nature.

  • They are energy-saving icons.

  • And I founded the Sloth Appreciation Society

  • to both promote and protect their slow, steady, sustainable lives.

  • I'm a pretty speedy character.

  • I'm sure you've guessed.

  • And the sloths have taught me a lot about slowing down.

  • And I think that the planet would benefit

  • if we all took a slowly digested leaf out of their book.

  • How about we all embrace our inner sloth

  • by slowing down,

  • being more mindful,

  • reducing wasteful convenience,

  • being economical with our energy,

  • recycling creatively

  • and reconnecting with nature.