0:00:00.992,0:00:02.142
Hello.

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Well, I'm here to talk to you[br]about my animal muse:

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the sloth.

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(Laughter)

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I've been documenting the strange lives[br]of the world's slowest mammal

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for the last 10 years.

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I still remember the first time I saw one.

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I was fascinated by their freaky biology.

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I mean, what's not to love[br]about an animal that's born

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with a fixed grin on its face?

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(Laughter)

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And the need to hug.

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Audience: Awww.

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But sloths are massively misunderstood.

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They've been saddled with a name[br]that speaks of sin

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and damned for their languorous lifestyle,

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which people seem to think[br]has no place amongst the fittest

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in the fast-paced race for survival.

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Well, I'm here to tell you[br]that we've got this animal all wrong,

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and how understanding[br]the truth about the sloth

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may help save us and this planet[br]we both call home.

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I traced sloth-based slander

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back to a Spanish[br]conquistador called Valdés,

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who gave the first description of a sloth[br]in his encyclopedia of the New World.

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He said the sloth was,

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"The stupidest animal[br]that can be found in the world ...

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

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(Laughter)

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Tell us what you really think, Valdés.

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(Laughter)

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I'd like to have a word[br]about Valdés's drawing skills.

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(Laughter)

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I mean, what is that?

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(Laughter)

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I've never seen an illustration[br]of a sloth that's more useless.

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(Laughter)

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But I mean, on the plus side,

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he has given the sloth[br]a remarkably humanlike face,

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and sloths do have remarkably[br]humanlike faces.

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

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(Laughter)

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But then, sloths do bear an uncanny[br]resemblance to the The Beatles.

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(Laughter)

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Particularly pleased[br]with Paul, actually, on there.

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But like The Beatles,[br]sloths are also extremely successful.

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They come from an ancient line of mammals[br]and they were once dozens of species,

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including the giant ground sloth,[br]which was the size of a small elephant

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and one of the only animals big enough[br]to eat avocado pits whole

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and disperse them.

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So ... [br](Laughter)

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Some of you have worked it out already.

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(Laughter)

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That means that without sloths,

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there might be no avocado on toast today,

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leaving hipsters everywhere[br]totally bereft of breakfast.

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(Laughter)

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(Applause)

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Today, there are six surviving species[br]and they fall into two groups.

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You've got your Bradypus[br]three-toed sloths,

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they're the ones with the Beatles haircuts[br]and the Mona Lisa smiles.

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Then, there are the two-toed sloths.

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They look a little bit more like a cross[br]between a Wookiee and a pig.

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They live in the jungles[br]of Central and South America,

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and they're extremely prolific.

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There was a survey[br]that was done in the 1970s

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in a Panamanian tropical forest

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that found that sloths were the most[br]numerically abundant large animal.

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They took up one quarter[br]of the mammalian biomass.

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Now, that's an awful lot of sloths

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and suggests they're doing[br]something very right indeed.

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So what if, rather than deriding[br]the sloth for being different,

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we tried to learn from it instead?

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We humans are obsessed with speed.

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Busyness is a badge of honor,

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and convenience trumps quality[br]in our quest for quick.

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Our addiction to the express life[br]is choking us and the planet.

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We idolize animals like the cheetah,[br]the Ferrari of the animal kingdom,

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capable of doing naught to 60[br]in three seconds flat.

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Well, so what?

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(Laughter)

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(Applause)

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So what?

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The sloth, on the other hand,

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can reach a leisurely 17 feet a minute

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with the wind behind it.

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(Laughter)

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But being fast is costly.

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The cheetah is speedy,[br]but at the expense of strength.

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They can't risk getting in a fight,

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so they lose one in nine kills[br]to tougher predators like hyenas.

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No wonder they're laughing.

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(Laughter)

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The sloth, on the other hand,

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has taken a more stealthy[br]approach to dinner.

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They survive by capturing and consuming

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static leaves.

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(Laughter)

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

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so they're loaded full of toxins[br]and very hard to digest.

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So in order to consume them,

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the sloth has also[br]had to become an athlete --

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a digesting athlete.

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(Laughter)

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The sloth's secret weapon[br]is a four-chambered stomach

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and plenty of time.

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They have the slowest[br]digestion rate of any mammal.

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And it can take up to a month[br]to process a single leaf,

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which gives their liver plenty of time[br]to process those toxins.

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So, sloths aren't lazy.

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No, they're busy.

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Digesting.

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(Laughter)

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Yeah, really busy.

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(Laughter)

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Hard at work, that sloth,[br]very hard at work.

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And of course, leaves[br]have little calorific value,

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so sloths have evolved to spend[br]as little energy as possible.

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They do about 10 percent of the work[br]of a similar-sized mammal

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and survive on as little[br]as 100 calories a day,

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thanks to some ingenious adaptations.

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The Bradypus, three-toed sloths,

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they've got more neck bones[br]than any other mammal,

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even a giraffe.

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Which means they can turn their head[br]through 270 degrees

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and graze all around them,

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without having to actually bother[br]with the effort of moving their body.

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(Laughter)

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It also means that they are[br]surprisingly good swimmers.

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Sloths can bob along in water

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three times faster[br]than they can move on land,

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kept afloat by ...

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trapped wind.

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(Laughter)

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So --

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(Laughter)

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sloths are the only mammal that we know of[br]that don't do flatulence.

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When they need to expel gas,

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it's actually reabsorbed[br]into their bloodstream

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and expelled orally[br]as a sort of mouth fart.

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(Laughter)

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Turning their lives upside down[br]saves further energy.

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They have about half the skeletal muscle[br]of a terrestrial mammal.

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They don't really have so many[br]of the extensor muscles

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that are the weight-bearing muscles;

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instead, they rely on retractor muscles[br]to pull themselves along.

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They have long, hooked claws[br]and a high fatigue resistance,

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so they can literally hook on and hang[br]like a happy, hairy hammock,

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for hours on end.

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And sloths can do almost anything[br]in this inverted position.

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They sleep, eat and even give birth.

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Their throat and blood vessels[br]are uniquely adapted

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to pump blood and to swallow food[br]against the force of gravity.

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They have sticky bits on their ribs

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that prevent their enormous stomach[br]from crushing their lungs.

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And their fur grows[br]the opposite direction,

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so they can drip dry[br]after a tropical drenching.

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The only problem is,[br]if you turn a sloth the other way up,

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gravity removes its dignity.

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Audience: Awww.

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They can't hold themselves upright.

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And so they drag their bodies along[br]as if mountaineering on a flat surface.

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And I think this is why[br]the early explorers like Valdés

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thought so poorly of them,

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because they were observing sloths[br]the wrong way up and out of context.

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I've spent many happy hours[br]mesmerized by moving sloths.

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Their lack of muscle hasn't impeded[br]their strength or agility.

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

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(Laughter)

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with the core control of a tai chi master.

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This one has fallen asleep mid-move,[br]which is not uncommon.

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(Laughter)

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But you're probably wondering:

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How does a dangling bag[br]of digesting leaves avoid being eaten?

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Good question.

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Well, this is one[br]of the sloth's main predators.

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It's the harpy eagle.

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It can fly at speeds[br]of up to 50 miles per hour,

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has talons the size of a grizzly bear's,

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razor-sharp eyesight,

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and that ring of feathers focuses sound

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so that it can hear[br]the slightest leaf rustle.

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The sloth, on the other hand,[br]has poor hearing, bad eyesight,

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and running from danger[br]is clearly not an option.

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No, they survive by wearing[br]an invisibility cloak

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worthy of Harry Potter.

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Their fur has grooves[br]that attract moisture

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and act as tiny hydroponic[br]gardens for algae,

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and they also attract[br]a host of invertebrates.

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So they are their own, slow-moving,[br]miniature ecosystem.

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They become one with the trees.

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And we think that[br]their movements are so slow,

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they slip under the radar[br]of the monstrous harpy

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as it's flying about the canopy,[br]scanning for action.

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Sloths are stealth ninjas,

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and they rarely leave[br]the safety of the canopy --

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except to defecate,

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which they do about once a week[br]at the base of a tree.

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Now, this risky and energetic behavior[br]has long been a mystery,

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and there are lots of theories[br]as to why they do it.

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But I think they're leaving surreptitious[br]scented messages for potential mates.

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Because, you see, sloths are generally[br]silent, solitary creatures,

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except for when the female is in heat.

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She will climb to the top of a tree[br]and scream for sex.

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In D-sharp.

0:10:50.751,0:10:52.728
(Laughter)

0:10:52.752,0:10:53.902
Don't believe me?

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(Sound of sloth scream)

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D-sharp.

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This and only this note[br]will get the male's attention.

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It mimics the sound[br]of the kiskadee flycatcher.

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So the female remains covert,

0:11:06.883,0:11:10.146
even when yodeling for sex[br]at the top of her lungs.

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Her clandestine booty calls[br]will carry for miles across the canopy,

0:11:15.436,0:11:18.922
and males will beat[br]a slow path towards her.

0:11:18.946,0:11:23.239
(Laughter)

0:11:23.263,0:11:27.978
I think scented messages in her dung[br]will help send Romeo up the right tree

0:11:28.002,0:11:31.859
so that he doesn't waste precious energy[br]scaling the wrong one.

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Sex, by the way, is the only thing[br]that sloths do swiftly.

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I've seen them do it in the wild,

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and it's over and done[br]within a matter of seconds.

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But then, why waste precious energy on it,

0:11:44.085,0:11:46.093
particularly after that journey?

0:11:46.117,0:11:47.799
(Laughter)

0:11:47.823,0:11:49.101
Unlike other mammals,

0:11:49.125,0:11:54.268
sloths don't also waste time maintaining[br]a constant warm body temperature.

0:11:54.292,0:11:55.982
Energy from the sun is free,

0:11:56.006,0:11:58.276
so they bask in the sun like lizards

0:11:58.300,0:12:03.466
and wear an unusually thick coat[br]for the tropics to keep that heat in.

0:12:03.490,0:12:07.561
Sloths have a freakishly low metabolism.

0:12:07.585,0:12:10.157
And we think that this might be[br]one of the reasons

0:12:10.181,0:12:12.646
that they can sometimes[br]recover from injuries

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that would kill most animals.

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This sloth recovered[br]from a double amputation,

0:12:18.355,0:12:21.982
and I've known sloths[br]that have managed to survive

0:12:22.006,0:12:24.379
even power line electrocutions.

0:12:24.680,0:12:30.196
And we now think that a low metabolism[br]may well be key to surviving extinction.

0:12:30.631,0:12:34.101
Researchers at Kansas University[br]who were studying mollusks

0:12:34.125,0:12:38.553
found that a high metabolism[br]predicted which species of mollusk

0:12:38.577,0:12:39.958
had gone extinct.

0:12:41.609,0:12:44.585
Sloths have been around on this planet[br]in one shape or another

0:12:44.609,0:12:47.251
for over 40 million years.

0:12:47.768,0:12:52.156
The secret to their success[br]is their slothful nature.

0:12:52.490,0:12:56.339
They are energy-saving icons.

0:12:57.022,0:12:59.427
And I founded the Sloth[br]Appreciation Society

0:12:59.451,0:13:05.283
to both promote and protect[br]their slow, steady, sustainable lives.

0:13:06.712,0:13:08.712
I'm a pretty speedy character.

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I'm sure you've guessed.

0:13:10.990,0:13:14.728
And the sloths have taught me[br]a lot about slowing down.

0:13:14.752,0:13:17.149
And I think that the planet would benefit

0:13:17.173,0:13:22.125
if we all took a slowly digested[br]leaf out of their book.

0:13:22.752,0:13:26.783
How about we all embrace our inner sloth

0:13:26.807,0:13:28.370
by slowing down,

0:13:28.394,0:13:29.909
being more mindful,

0:13:29.933,0:13:32.401
reducing wasteful convenience,

0:13:32.425,0:13:35.128
being economical with our energy,

0:13:35.152,0:13:37.171
recycling creatively

0:13:37.195,0:13:39.869
and reconnecting with nature.

0:13:40.520,0:13:43.090
Otherwise, I fear,

0:13:43.114,0:13:46.438
it will be us humans that turn out to be

0:13:46.462,0:13:50.109
"the stupidest animals[br]that can be found in the world."

0:13:51.622,0:13:53.246
Thank you very much.

0:13:53.270,0:13:54.668
May the sloth be with you!

0:13:54.692,0:13:58.047
(Applause)