Name: なぜこれらの蛾はコウモリから逃げないのか (Why These Moths Don't Run Away from Bats)
Uploaded: 2021-01-14T10:28:17.000Z
Duration: 6 min 33 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：

Thanks to Brilliant for supporting this episode of SciShow.

Go to Brilliant.org/SciShow to learn more about gifting a Brilliant Premium subscription this month.

Being attacked by a predator can be scary, but a new study in the journal Frontiers in

Ecology and Evolution helps us understand how some animals can keep cool under even

Even weirder, it turns out we can gain insight into how an animal would behave, even if we

They contain chemicals that make them toxic, nasty-tasting, or otherwise unpleasant to

be around, which is a great defense against predators.

It's so reliable that many of these animals are aposematic, meaning they have bright colors

or other signals that warn predators to keep away.

Aposematic animals tend to be relatively sluggish in their day-to-day movements.

After all, there's no need to rush if most predators won't mess with you.

But being under direct attack from a predator is a different story.

This study aimed to find out if animals with chemical defenses are able to remain relaxed

To do so, the researchers tracked the behavior of 5 different species of tiger moths.

These moths have a remarkable ability to detect the echolocation of predatory bats.

If a moth hears a bat coming, it can take evasive maneuvers by spiraling or diving out

But this comes with a cost: quick, panicky flight can make it easier to get yourself

lost, get stuck on a spider web, or draw the attention of other predators, not to mention

So if a moth has another line of defense — say, chemical grossness — it may be best for

To observe the moths' behavior, the researchers released a bunch of moths in an outdoor arena

Over three years, they observed more than 300 bat-moth interactions.

Each time a moth was caught, the researchers observed whether the bat ate them or spat

This data let them grade the moths on a spectrum of palatability, or tastiness.

The researchers also observed whether the moths tried to avoid the bats, or whether

they just kept flying pretty normally under attack.

That let them rank the moths according to nonchalance.

They found that the less palatable species were also cooler under pressure.

It seems those chemical defenses allow the moths to save energy on evasive maneuvers.

This is pretty exciting because it means we might be able to predict animals' behavior

Researchers could study a bug in a lab, or even a museum specimen, and based on its chemical

makeup, predict how it would act to avoid predators.

This is not only much easier than observing bugs under attack, but it could be done for

And it's not just tiger moths that do this.

Similar bat-avoiding behavior is seen in many species of beetles, mantises, lacewings, and

These findings could open up a whole new way to study aerial predator-prey interactions.

And while those researchers were exploring ecological dynamics in the air, another group

of scientists have presented findings on the importance of microbial ecosystems beneath

Soil is obviously super important for life.

It not only provides a home for lots of living things, but also contains the nutrients necessary

for plants and other organisms to thrive.

A new study in the journal PNAS sheds new light on the ways bacteria are responsible

It's a mixture of minerals, water, air, and organic matter, both alive and dead.

Beneath all that life-rich soil is a subsoil made of crumbly rocks, and beneath that is

Soil contains minerals that life needs — things like phosphorus and potassium.

Those are generally thought to come from down in the bedrock.

But plant roots and wind erosion can only break down rocks near the surface, and bedrock

So these scientists set out to explore how microbes deep underground might contribute

To do so, they drilled a bunch of core samples from the soil and bedrock at the Luquillo

Critical Zone Observatory in Puerto Rico.

They ground up samples of the bedrock, added soil bacteria to some of the samples, and

then let all of the samples sit in the lab for 864 days.

After this extensive waiting period, they observed that the rocks had experienced some

chemical breakdown, but only if the bacteria were present.

What's more, the bacteria had increased in abundance.

Despite being in a dark room with no organic food sources, they were thriving.

The bacteria in question are chemolithotrophs, meaning they get their energy through chemical

reactions with inorganic materials in their environment.

Genetic analysis of these soil bacteria found that they produce special proteins on their

cell surface that allow them to swipe electrons from the iron in certain minerals, using those

In the process, they accelerate the chemical weathering of the rock, breaking it down and

releasing all those wonderful nutrients that become part of the soil.

For example, we don't how quickly this bacterial weathering occurs in nature, or how this microbial

action varies at different levels of soil.

But one thing is clear: these bacteria are a major player in the breakdown of rocks,

meaning we have them to thank for the abundance of minerals in soil that help give life to

It takes a long time to degrade bedrock into soil, but the time for holiday shopping is

One quick way to check someone off your list is with a premium subscription to Brilliant.org.

If your loved ones are excited by science, math, and learning, they might really enjoy

the daily challenges and in-depth courses offered by Brilliant.

Brilliant's thought-provoking content breaks up complex ideas into bite-sized, understandable

chunks that will lead them from curiosity to mastery.

If you're interested, check out brilliant.org/SciShow and grab a gift subscription to help your

loved ones spark a lifelong love of learning.

字幕リスト動画再生

なぜこれらの蛾はコウモリから逃げないのか (Why These Moths Don't Run Away from Bats)

bunch

present

nasty

metabolism