Sometimes, a hamster mom looks at her adorable little babies and is like, 'I just want to

ハムスターのお母さんはときどき かわいいわが子を「食べちゃいたい」と思うようです

gobble you up'—except not in a cute way...more in an “I'M ACTUALLY ABOUT TO EAT YOU”

ただし比喩ではなく、文字通りの意味で

way.

00:00:14,900 --> 00:00:21,120 ハムスターだけではありません ブタ、昆虫、鳥、ヘビ、サル、魚も

Hamster moms are not alone—pigs, bugs, birds, snakes, primates, and fish all occasionally

時にわが子を食べることが知られています

nom on the next generation.

これは理屈にあいません

Which is weird.

わが子を食べるなんて極悪非道！ というのではなく

Not just because we humans consider it deeply wrong to eat our own babies, but also because

子を残すことは ほぼすべての生物の究極目標なのですから

making babies is the primary goal of virtually all life, so eating them, and the genes they

わが子を食べ、自分の遺伝子を絶やすのは 完全に自殺行為のはずです

carry, seems like the ultimate act of self defeat.

でも、自滅的衝動に駆られては すぐに死に絶えるだけですから

But self-defeating impulses have a pretty straightforward way of dying out, so the fact

さまざまな動物が時に わが子を食らうことには

that species across the animal kingdom occasionally cannibalize their young suggests that it can

何か戦略的利点があるはずです

sometimes be a successful strategy.

たとえばハムスターは 子食いで個体数を抑制しています

For instance, hamsters appear to use baby-eating as a form of crowd control: females with litters

8〜9頭の子を産んだ母親は 平均で2匹の子を食べます

of 8 or 9 pups eat two of them, on average.

そこに研究者がさらに2匹足すと 母親は4匹の子を食べます

And when scientists have tried adding a couple pups to the litter, the hamster moms eat four.

逆に2匹減らすと 母親は子食いをしなくなります

But removing a few pups the day they're born pretty much stops the cannibalism before

つまりハムスターは 世話が十分行き届くよう、子の数を抑制して

it starts—suggesting that a hamster mom eats her young to keep her litter small enough

遺伝子が次世代に 引き継がれる可能性を上げるのです

that she can provide for the survivors and ensure they grow up to pass on their genes.

ある種のトカゲは緊急事態にだけ わが子を食べます

Other critters, like the Long-tailed Sun Skink, chow down on their babies only in emergencies.

卵を狙う天敵が何度もやってくると 母親は先手を打ち

When predators repeatedly threaten to eat the mother's eggs, she beats them to it

自分で自分の卵を食べるのです

and eats them all herself.

これは理にかなっています 卵がどうせ食べられてしまうなら

Which actually makes sense: if the eggs are doomed to become someone's lunch, making them

自分で食べてしまえば 次の繁殖のための栄養にできるからです

HER lunch helps prepare the mama skink for another round of reproduction.

時に子供は邪魔になります だから消えてもらう、という種も

And sometimes, kids, you know, get in the way, so they just have to go.

ある種のハゼのオスは 短期間にひとつの巣のなかで

The male sand goby fertilizes eggs from multiple females over a short period of time and cares

複数のメスの卵に放精し、世話をします

for them all together in one nest.

すべての卵が孵化するまで 次の繁殖はおあずけ

In order to mate again, he has to wait for all his eggs to hatch, so he sacrifices the

だからぐずぐずしている卵は片付けて 次のお相手探しに向かうのです

slowpokes to free himself up for more baby-making.

このように、動物界では 資源、エネルギー、機会を最大限に活かして

In short, for critters across the animal kingdom to maximize the resources, energy and opportunities

次世代に遺伝子を残すためには 「お子様ランチ」を食べるのが

they need to pass on their genes, sometimes it does make sense to order off of the kid's

有利になることもあるのです

menu.

00:02:22,320 --> 00:02:23,920

This video was sponsored by Audible.com, the leading provider of audiobooks, with over

00:02:23,920 --> 00:02:28,690

250,000 downloadable titles.

00:02:28,690 --> 00:02:34,230

Annnd, on the topic of eating one's own kind, maybe you'll want to check out Audible's

00:02:34,230 --> 00:02:38,850

audiobook version of “Miracle in the Andes,” the harrowing first-person account of a high-altitude

00:02:38,850 --> 00:02:40,099

plane crash in the mountains of Peru, and the 72-day-long struggle for survival that

00:02:40,099 --> 00:02:43,900

followed.

00:02:43,900 --> 00:02:47,710

Download “Miracle in the Andes,” or another book of your choice for free, by going to

00:02:47,710 --> 00:02:49,430

audible.com/minuteearth and signing up for a 30-day trial membership.

And thanks for watching!