Name: 8 Animal Friendships That'll Give You All the Feels
Uploaded: 2021-06-02T13:04:42.000Z
Duration: 13 min 21 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

In the wild, it's easy to imagine that every species is out for itself.

But animals of different species form all sorts of relationships in nature,

That's what you call mutualism: a relationship where both organisms benefit from the arrangement.

Kind of like a “You scratch my back, I'll scratch yours,

because neither of us can scratch our own backs cuz our arms are wrong.”

Such animal partnerships show just how interconnected the animal kingdom really is.

So today, we're gonna talk about 8 unexpected but very real animal duos,

from hunting partners to grooming buddies,

these animals make interspecies friendship look easy.

Coyotes and badgers are both common predators in much of North America.

But rather than fight for food, the two have been known to work together as hunting partners.

You see, badgers generally hunt ground squirrels underground.

They put dead ends in their tunnels, then scare them into that trap and dig them out.

Sounds terrible. They are not friends. Not friends.

Coyotes hunt these squirrels above ground

by waiting until they venture far enough from their tunnels to pounce.

And because their styles are so different,

if these two predators team up, they can both benefit.

When squirrels detect a badger, they often run above the ground to escape,

And when squirrels detect a coyote, they usually retreat to their tunnels,

putting them right where the badger wants them.

A 1992 study found that when working together,

coyotes captured 34% more squirrels than working alone.

And while it's harder to count the prey badgers catch when they're in the dirt,

badgers that work with coyotes spend more time underground.

Biologists' figure that's because they're hunting more or eating more,

Both of these species are pretty smart and social and live fairly long lives,

so it's not too surprising that they're able to form this kind of relationship.

But scientists don't see these pairings everywhere.

They seem to occur more often where there are more coyotes and badgers,

which makes sense, because there are a ton of them around, they're bound to run into each other.

And that means there's more opportunity for an accidental assist to lead to a lasting partnership.

They also seem to happen in areas where there's a lot of dense, small bushes.

These make it harder for both hunters to succeed solo,

so the benefits of teaming up are all that more appealing.

It's not just predators that work together though.

Prey species can also team up for extra protection.

One of the most well-studied mutualisms is one that occurs

between snapping shrimps and gobies, a kind of small fish.

Dozens of species of these animals pair up.

The shrimp is really good at digging, so it digs and maintains a burrow for the both of them.

The goby, meanwhile, has better long-distance eyesight, so it watches out for predators.

And in many pairings, the two communicate through touch.

The shrimp taps the goby with its antennae to let it know that it's there,

and the goby flicks its tail to tell the shrimp that trouble's brewing.

Some species in this setup are obligate partners,

meaning they literally don't make it if they don't have their brother from another  mother,

or like, I guess brylum from another phylum.

Even when the partnership is optional, though,

biologists have found that if you take away a shrimp's fish buddy, it eats less,

presumably because it's more worried about being vulnerable while foraging.

And in studies, gobies that don't pair with shrimps tend to disappear.

Without their well-maintained panic room, they just get eaten.

Of course, it's not always a single shrimp-fish pair:

both the shrimps and the gobies will live with their mates, too,

bringing the twosome to a foursome, or even a fivesome,

since the shrimps frequently form thruples instead of couples.

This partnership makes a lot of sense from an evolutionary perspective.

Gobies are generally fond of hiding places,

so it seems like they'd dart into a shrimp burrow on occasion.

And the shrimps probably wouldn't mind that,

if having a goby roommate meant knowing when to duck underground.

Then over time, selection favored individuals that formed partnerships,

and the species began to influence each other's evolution, or to co-evolve.

Some scientists think they're seeing this happen in real time.

They've found species of shrimps and gobies that are doing their individual jobs together,

but without the specific communication system.

So basically, it's the beginning of what is expected to be a beautiful friendship.

Sometimes, though, a burrow isn't cozy enough.

Sometimes what you really need is a turtle butt. Take it from oceanic crabs.

They have been known to make a home on the butts of sea turtles,

specifically, the little area between the tail and the upper shell.

See, the crabs can't swim very far, so they live on anything that floats.

But they prefer places where they can hide, which makes turtle butts the obvious choice.

The crabs on turtles tend to be big and healthy, suggesting they get plenty of food.

They're also more likely to be monogamous, since there's room for two and only two.

And the females are more likely to be brooding eggs;

a clear sign to biologists that turtle butt is awesome habitat.

For awhile, it wasn't clear what, if anything, the turtles got out of having these rear-end residents.

Scientists used to think that the crabs ate the turtle's poop,

which would have made this a strictly one-sided relationship.

But studies of the crab's stomach contents revealed that

they actually feed on barnacles and other organisms that attach to turtles.

Since these can damage the turtle's shells and make it harder to swim,

the crabs provide a valuable cleaning service.

They're like live-in maids. On your butt.

Some rove beetles live in the fur of small South American mammals, especially rodents.

At first, scientists thought these beetles were parasites,

though that would have made them the world's only blood-sucking beetles.

But back in the 1980s, a pair of biologists questioned this idea.

The mice didn't seem to care that the beetles were there,

which is weird, because these are not small beetles.

They're about a centimeter long, on a roughly fifteen centimeter-long mouse.

The beetles could even walk across their faces and the rodents didn't do a thing about it.

But, when the scientists placed these beetles on another mouse species, things were totally different.

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8 Animal Friendships That'll Give You All the Feels

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