video covers the ins and outs of hyena genitalia, so if that's not something you're keen

これからハイエナの生殖器を解説するので そういう話題はちょっと...という方は

to learn about, you can check out some of our other videos.

他の動画を選んでください

But from the comments on our recent hyena video, we learned that a lot of people are

でも先日のハイエナの動画のコメント欄をみると

really curious about what, exactly, is going on with hyena genitalia.

みなさんハイエナの生殖器に興味津々みたいですね

And they're not alone - everyone from Aristotle to Hemingway to a host of modern scientists

実際、アリストテレスやヘミングウェイから 現代の科学者まで、みんな不思議に思ってきました

has been interested in why, exactly, female spotted hyenas seem to have penises.

なぜブチハイエナのメスには ペニスがあるように見えるのでしょう？

Females urinate through these 7-inch long phalluses, and they're fully erectile.

メスは18cmもある''ペニス"から排尿し 勃起もします

But since they don't deliver sperm, they aren't actually penises - they're elongated

ただし射精はしないので、厳密にはペニスではなく

clitorises.

巨大化したクリトリスです

Spotted hyenas are the only hyena species to sport these so-called pseudopenises, and

4種いるハイエナのうち 偽陰茎をもつのはブチハイエナだけ

while a few other female mammals have male-like genitalia, the spotted hyena's is the most

メスがオス的な生殖器をもつ哺乳類は 他にもいくつかいますが

male-like by far - complete with a pseudoscrotum.

偽陰嚢まであるブチハイエナには及びません

All the female reproductive parts are there, but the entrance is so unwieldy that females

体内の生殖器官はふつうの哺乳類と同じですが 外部生殖器がとても変わっていて

have to mate - and give birth - through what's essentially a penis.

メスは交尾も出産もこの"ペニス"を通じておこないます

Mating via pseudopenis is about as awkward as you might imagine [speak slowly].

偽陰茎を使った交尾はかなりぎこちないものです

In order to make sex possible, the female actually has to retract her pseudopenis, so

メスが偽陰茎を萎縮させないと 交尾ができないので

male hyenas can't force females to have sex.

オスがメスに交尾を強制することは不可能です

And speaking of which, we got a lot of comments about female hyenas forcing sex on males,

ちなみに、メスがオスを襲うの？というコメントが 多数ありましたが

but there just isn't any evidence that this ever happens.

そういう事例は確認されていません

Then, there's giving birth, which involves forcing a 4-pound cub through an inch-wide,

出産時には体重1.8kgの胎児が

23-inch-long birth canal, which is...not easy.

幅2.5cm、長さ58cmの産道を通るので かなり大変です

For first-time moms, somewhere around 60 percent of cubs get stuck in this gauntlet and suffocate

初産では胎児の約60%が産道に詰まってしまい

before they're even born.

窒息し死産になります

And a dead cub stuck in a mom's pseudopenis can be fatal for her, too.

偽陰茎に胎児が詰まると メスにとっても命に関わります

A hyena's pseudopenis actually has to rip for her to give birth successfully, which

偽陰茎の一部が裂けると、無事出産できるだけでなく

leaves behind a stretchy patch that does make birth easier the next time.

癒えた裂け目が伸縮部分になるので 翌年以降は出産が楽になります

In our earlier video, we talked about why it sucks to be a male hyena, but there's

以前の動画では オスハイエナは楽じゃないと言いましたが

also a lot that sucks about being a female hyena.

メスはメスで大変なのです

So why do they have such incredibly unwieldy genitalia?

こんなやっかいな生殖器をもっている理由は？

Is fending off male suitors so critical that pseudopenises evolved as protection?

つきまとうオスを退散させるための防護器官？

Doubtful - females are dominant enough to keep suitors in check without any help.

いいえ、メスはオスよりも優位なので 偽陰茎がなくても追い払えます

Are female hyenas trying to confuse others into thinking they're males?

では、オスに擬態しているのでしょうか？

Probably not - even experienced humans can tell what's pseudo and what's not, and

これもなさそうです 人間でも慣れれば雌雄の区別はできますし

hyenas have lots of other ways of distinguishing females from males.

ハイエナは匂いなど他の手段でも 雌雄を区別しています

So far, we just don't have a convincing explanation for why nature has also given

結局、メスハイエナに"ペニス"がある理由の説明は

female hyenas the shaft.

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