シャドーイング練習: 5 Gross Gifts Animals Give Their Mates - 動画で英語スピーキングを学ぶ

練習モードを選ぶ

各モードは全画面の練習ルームで開きます。

115 文

文が短すぎたり長すぎる場合は、Editをタップして調整してください。

Thanks to Brilliant for supporting this episode of SciShow.

Go to Brilliant .org slash SciShow to get 20 % off an annual premium subscription for yourself or someone else.

Humans have some odd customs around gift -giving and courtship.

I mean, chocolate is this one specific tropical bean that's been fermented, roasted, and mixed with sugar.

But on a date, it tends to go over pretty well.

However, humans aren't the only ones who bring gifts to a potential mate.

Gift -giving is a behavior that occurs in many species across the animal kingdom.

And these gifts do more than make a good first impression.

They generally provide substantial benefits that ensure a better outcome for the pair's offspring.

But the gifts themselves can be, well, chocolate they ain't.

So from poison to mucus and a few bodily fluids in between, let's explore a few creatures who take gift -giving to a whole new level.

Six -spot burnet moths bestow upon their potential mate a toxic gift—actual poison.

These critters have a deadly talent that develops when they're just a wee caterpillar.

They're able to produce hydrogen cyanide, a chemical that, in high enough concentrations, can even be deadly to a potential predator.

These critters incorporate some of the toxins that plants make as a chemical defense against pests, and their bodies convert them into hydrogen cyanide.

This chemical causes them to have an unpleasant taste, so predators tend to steer clear.

The red spots on the moths' bodies serve as a warning sign to keep away.

And during the mating process, the male moths are able to transfer some of their cyanide to the females.

Not to kill them, mind you.

Instead, researchers believe they are passing it along for additional protection against potential predators.

This gift is like the insect equivalent of gifting a couple dozen roses,

because the process of creating the cyanide is fairly energetically costly for the moths.

Female moths are capable of producing cyanide too and actually emit plumes of it to attract a mate,

but the males still gift them a little extra during courtship,

which allows the females to put their energy into laying eggs while keeping their defenses up.

The female also uses some of that poison to coat her eggs with as an added layer of protection against potential predators.

And researchers have found that the females value how much cyanide is gifted to them,

preferentially choosing a male based on how large his cyanide gift was.

Which may mean that these moths are becoming more toxic over time, as the females are constantly selecting for large cyanide gifts.

Now, the red velvet mite goes to great lengths to woo a mate.

The male doesn't just bring a gift, he builds a beautiful, intricate space for his potential mate.

And this little mite creates an elaborate setup out of sticks, leaves, grass, and sperm.

Researchers tactfully refer to this as a love garden.

The sperm is dotted all over the sticks and grass,

acting as both decoration and a sticky web holding all of the pieces of the meticulously designed space together.

Once constructed, the male leaves an intricate path of silk leading up to the space for a mate to find.

Then he sits in front of his masterpiece until a potential mate wanders by and notices his handiwork.

And when a potential mate does come along,

the male will perform a little dance in front of the space as a way of capturing her attention

and enticing her into coming closer.

And if the female mite is intrigued, she will enter the garden he's created to investigate the space further.

If the female sits down in that space, the sperm can impregnate her.

Unfortunately, the competition for a mate can be stiff among mites.

That same trail he wove for his mate to find can be discovered by another male instead.

The other male will immediately tear down the garden and build up his own in its place,

as a way of ensuring that it's his sperm that contributes to the next generation.

So red velvet mites have to be fancy and quick in order to catch a female before the competition swoops in.

Now, it does make sense for sperm to be involved during courtship, but that's far from the only bodily fluid on offer.

For example, some creatures will offer up their own blood to their mates during the mating process.

Ground crickets give their mates access to their blood, or rather their hemolymph, which is the insect equivalent of blood.

Male ground crickets have evolved large spurs on their tibia for female ground crickets to chew on during mating.

That gives the female access to the male's hemolymph in the process.

Researchers believe that this gift provides specialized nutrition to the females, who gain access to nutrients that they might otherwise be lacking in their diets,

including protein, fats, and carbohydrates.

This comes in handy for the female, particularly during egg -laying, which is energetically costly.

In fact, researchers have found that female ground crickets have a preference for large males over smaller ones, because the larger the male,

the more hemolymph a female can get from his spur during mating.

While it's likely this is not really a very pleasant experience for the male, it's a sacrifice that makes sense for the survival of his offspring,

because a well -fed female will have more energy to put towards high -quality eggs.

As a result, much like the burnet moths are selecting more poisonous mates,

the female ground crickets are shifting the size of the overall population towards larger males.

Now, a gift of blood might be too much of a sacrifice to make, so how about some spit instead?

While hocking up a big loogie in front of a date is typically considered bad form among humans,

that's pretty much what male scorpionflies will do for their potential mates.

Scorpion fly males have evolved enlarged salivary glands, specifically for the ability to produce large balls of spit.

Interestingly, only well -fed scorpion flies have the ability to produce spit balls.

Those that are malnourished will choose to offer up a dead bug instead.

Now, if you ask me, either of these gifts sounds less than appealing, but researchers believe that much like our cricket example,

scorpion flies offer spit to provide the females with additional nutrients prior to egg -laying.

Which is why a dead bug proves to be a decent substitute for a giant ball of spit

if a male is unable to produce any spit himself.

The female snacks on the spit during the mating process, which ensures she's well -fed enough to pass the male's genes along to the next generation.

And sometimes, whether they can't make spit or just want to avoid making it in the first place,

male scorpionflies will pretend to be females and steal the spit snack right out from under a competitor.

The females select a mate based on their ability to produce a lot of spit it.

The more spit, the more likely they are to prefer that individual.

And I say cheers to that.

Now, our next animal has quite a pointed way of interacting with its mate.

Mutual stabbing, with a snot -coated dagger.

While this sounds awful, this is a behavior frequently observed in land snails.

And this isn't just a gentle poke.

Researchers have observed snails retracting rapidly after being stabbed, suggesting that this is a fairly painful process.

Yet it's a behavior that they frequently frequently perform during mating.

Most land snails are hermaphrodites, which means they have both sperm and egg -producing reproductive organs.

And during the mating process, some species of snails will stab each other with what researchers refer to as love darts.

These love darts are made up of a hard piece that makes them sharp and dagger -like, and they're also coated in mucus.

The hard part can be made up of a few different compounds, depending on the species of snail.

Some use calcium carbonate, while others use a more flexible material like chitin or cartilage.

Now, these darts are not to be confused with a penis.

Each snail has one of those, too.

And the snails can mate without the love darts.

Once they use the dart, the snails need some time to regrow it, sometimes taking up to a week to generate another one.

But researchers have found

that snails who mated shortly after being stabbed by a love

dart were twice as likely to sire offspring as those who weren't stabbed.

So scientists believe the love darts are a way to encourage successful reproduction.

The mucus on the darts contains a pheromone -like compound that targets the snail's egg -producing organs,

encouraging them to store the sperm they're receiving from the other snail.

All of these gifts sound fairly unusual from a human perspective, but they're particularly interesting to consider from an evolutionary point of view.

100

These unique choices for gifts play important roles in mate selection

101

and have probably helped to determine the evolutionary history of these species.

102

With the exception of the land snails, most of the females are actively selecting for mate that produces their preferred gift in the right size,

103

shape, or quantity.

104

Researchers are always eager to learn more about the process of gift -giving in creatures,

105

since very little is known about how these abilities evolved and were selected for with time.

106

But if you ask me, I might just stick to bringing flowers and chocolate on a date.

107

That said, if you're looking for gifts for this holiday season, Brilliant is great for the relentlessly curious person in your life.

108

Brilliant's online courses in math, science, engineering, and computer science are designed to help you learn through interactivity.

109

It gives you the satisfaction of letting you work through problems yourself, with explanations for any time you get stuck.

110

Courses are even available offline through their iOS and Android apps,

111

so you or your lucky gift recipient can keep learning on the go or with a spotty internet connection.

112

The first 200 people to sign up at brilliant .org .scishow can save 20 % off an annual premium subscription to Brilliant,

113

which you can also apply toward a gift subscription.

114

So thanks for checking them out.

115

We'll be right back.

アプリをダウンロード

流暢に話すために必要なすべて

AI発音採点文ごとに採点

IPA練習すべての音をマスター

単語学習自分の単語帳を作る

単語ゲーム遊びながら覚える

QRをスキャン

Download on theApp Store Get it onGoogle Play

同じチャンネル

FOR YOU

このレッスンの語彙とスピーキングのポイント

このスピーキングレッスンは、動画「5 Gross Gifts Animals Give Their Mates」を教材にしています。繰り返し出てくる語は次のとおりです：gift, female, mate, male, snail。この動画には、シャドーイング用の文が95文、単語が1754語あります。音声の長さは8:49です。話す速さは速く、1分あたり約199語です。音のつながりや弱く発音される音が多くなります。英語の頻出3,000語に含まれる単語は74%だけなので、語彙は難しめです。

この動画の重要語彙

動画に出てくる覚えておきたい単語15語を、発音と意味つきで紹介します。

単語	発音	意味
spit 動詞	/spɪt/	つばを吐く, 吐く
snail 名詞	/sneɪl/	蝸牛, カタツムリ
researcher 名詞	/ˈɹiˌsɝ.t͡ʃɚ/	研究員, 研究者
stab 動詞	/stæb/	刺す
select 動詞	/sɪˈlɛkt/	選ぶ
coat 名詞	/ˈkoʊ̯t/	コート, 外套
predator 名詞	/ˈpɹɛd.ə.tɚ/	天敵
poison 名詞	/ˈpɔɪ.zən/	毒
subscription 名詞	/səbˈskɹɪpʃən/	定期購読, 購読
offspring 名詞	/ˈɔfspɹɪŋ/	胤, 子孫
dagger 名詞	/ˈdæɡɚ/	短剣, 短刀
encourage 動詞	/ɪnˈkʌɹ.ɪd͡ʒ/	勇気付ける, 奨励する
refer 動詞	/ɹɪˈfɜː/	問い合わせる
grass 名詞	/ɡɹɑːs/	草, 雑草
sacrifice 名詞	/ˈsæk.ɹɪ.faɪs/	犠牲, 生贄

動画に出てくる句動詞

単語	意味
get off 動詞	降りる

この動画の文法

話し手がよく使っている文型を、動画の実際の表現とともに紹介します。

文型	動画での表現
受動態 be + 過去分詞 — 誰がするかより、何が起きるかに焦点を当てる	been fermented · is gifted · is dotted
現在完了形 have/has + 過去分詞 — 過去の出来事が今も関係している	that's been fermented · have found · have evolved
関係詞節 who / which + 節 — 人や物について情報を加える	ones who bring · hemolymph, which is · laying, which is

注意したい発音

話し手はthey're, aren't, ain'tなど、短縮形や弱形を14回使っています。聞こえたとおりの短い形で発音しましょう。

「th」の音: mathematics /mæθ(.ə)ˈmæt.ɪks/, moth /mɔθ/
「sh」と「zh」の音: subscription /səbˈskɹɪpʃən/, evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/, sharp /ʃɑɹp/, shortly /ˈʃɔɹtli/, unusual /ʌnˈjuːʒ(u)əl/
長い単語（アクセントの位置に注意）: evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/, unusual /ʌnˈjuːʒ(u)əl/, explanation /ˌɛkspləˈneɪʃən/, establishment /ɪˈstæb.lɪʃ.mənt/, investigate /ɪnˈvɛs.tə.ɡeɪt/

日本語話者が苦手な音：

/r/ と /l/ の区別 — /l/ は舌先を歯茎につけ、/r/ はどこにもつけない: evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/, shortly /ˈʃɔɹtli/, trail /tɹeɪl/, rapidly /ˈɹæpɪdli/, explore /ɪkˈsploɹ/
/v/ — /b/ にならないように、上の歯を下唇に当てる: evolve /ɪˈvɑlv/, observe /əbˈzɜːv/, evolutionary /ˌiː.vəˈluː.ʃən.ɛɹ.i/, velvet /ˈvɛlvɪt/, survival /sɚˈvaɪ.vəl/
/f/ — 「フ」ではなく、上の歯と下唇で出す: offspring /ˈɔfspɹɪŋ/, refer /ɹɪˈfɜː/, sacrifice /ˈsæk.ɹɪ.faɪs/, fluid /ˈflu.ɪd/, confused /kənˈfjuːzd/

この動画での練習方法

まず声を出さずに動画を最後まで聞き、知らない単語をメモします。
まず0.75倍速で一文ずつシャドーイングし、慣れてきたら通常の速度に戻します。
自分の声を録音して元の音声と比べます。spit, snail, researcherなどの単語に特に注意しましょう。

シャドーイングとは？英語上達に効果的な理由

シャドーイング（Shadowing）は、もともとプロの通訳者養成プログラムで開発された言語学習法で、多言語習得者として知られるDr. Alexander Arguelles によって広く普及されました。方法はシンプルですが非常に効果的：ネイティブスピーカーの英語を聞きながら、1〜2秒の遅延で声に出してすぐに繰り返す——まるで「影（shadow）」のように話者を追いかけます。文法ドリルや受動的なリスニングと異なり、シャドーイングは脳と口の筋肉が同時にリアルタイムで英語を処理・再現することを強制します。研究により、発音精度、抑揚、リズム、連音、リスニング力、そして会話の流暢さが大幅に向上することが確認されています。IELTSスピーキング対策や自然な英語コミュニケーションを目指す方に特におすすめです。

シャドーイングのやり方: ステップ別の完全ガイドを読む →

シャドーイング練習: 5 Gross Gifts Animals Give Their Mates - 動画で英語スピーキングを学ぶ

練習モードを選ぶ

アプリをダウンロード

同じチャンネル

Two Different Things Are Killing Sharks

Why Do We Sneeze?

What’s Ruining Our Ruins?

The Science Behind The Odyssey's Greatest Challenge

Do Penguins Control the Weather?

Ticks Can Spread An Allergy To… Red Meat?

The Most Important Picture in the History of Science

Why Can’t We Have Unicorns?

Does Aloe Really Treat a Sunburn?

What's Really Behind The Adderall Shortage?

The ONE Disease That Smoking Can Help Treat

How Onions ACTUALLY Make You Cry (And How to Stop Them)

おすすめ動画

Happy Brain Chemicals: dopamine, serotonin, oxytocin, endorphin

02-4New Concept English e02 Spare that spider

Why The Entire Ocean Is Terrified of Sperm Whales

神奇的植物自卫术 - Valentin Hammoudi

Katie Vaca is afraid of cats until she makes her first cat friend | The Moth

Queen Ant Clones Another Species

Color in Nature – Quiz Edition

1,000 Flies vs. Venus Fly Trap

MinuteEarth Explains: Cats vs Dogs

The real reason cheese is yellow

The American Bullfrog

Why Don't Snakes Poison Themselves?