Dr. Tiana Pirtle

Wait, wait, wait, wait, wait, wait, wait.

Wait, wait, wait, wait, wait, wait, wait.

What does the alpaca penis look like? Terrifying. It's long and thin and it has a collagenous hook on the bottom. Alpacas are quite unusual in the mammal world in that most penises stay in the vagina, deposit the sperm within the vaginal canal. The cervix will often kind of function as a bit of a a quality control checkpoint and the sperm have to make it through the cervix.

What does the alpaca penis look like? Terrifying. It's long and thin and it has a collagenous hook on the bottom. Alpacas are quite unusual in the mammal world in that most penises stay in the vagina, deposit the sperm within the vaginal canal. The cervix will often kind of function as a bit of a a quality control checkpoint and the sperm have to make it through the cervix.

The trapdoor of the cervix, yes. Whereas for these guys, the penis punctures through, the little hook pokes through the cervix and deposits the sperm straight into the uterus. Ooh, okay.

The trapdoor of the cervix, yes. Whereas for these guys, the penis punctures through, the little hook pokes through the cervix and deposits the sperm straight into the uterus. Ooh, okay.

Does feel efficient. Which is, if I'm gunning for the male alpaca, good strategy, I would say. Good work, Evolution. Yeah.

Does feel efficient. Which is, if I'm gunning for the male alpaca, good strategy, I would say. Good work, Evolution. Yeah.

And, you know, this is potentially because male alpacas are what we call dribble ejaculators. Hello now. Dribble ejaculators. So the ejaculate dribbles out very slowly. So mating can take up to an hour in alpacas. It's like anywhere from 20 to 60 minutes. And it happens in a very reclined repose. The female alpaca will sit on the ground.

And, you know, this is potentially because male alpacas are what we call dribble ejaculators. Hello now. Dribble ejaculators. So the ejaculate dribbles out very slowly. So mating can take up to an hour in alpacas. It's like anywhere from 20 to 60 minutes. And it happens in a very reclined repose. The female alpaca will sit on the ground.

The male will get on top of her and sometimes she'll lay down on her side, have a nap, wait for him to finish his job. And so other species, the ejaculate comes out with force. Get familiar with those species.

The male will get on top of her and sometimes she'll lay down on her side, have a nap, wait for him to finish his job. And so other species, the ejaculate comes out with force. Get familiar with those species.

So, you know, needs a little bit of force to get through the cervix. Whereas I guess, you know, if you're dribbling, you might as well put it where it needs to go. Ah! Of course, that makes sense. I guess this nondescript normal vagina can look the way it does because the female has a high degree of control behaviorally. So if she's not intimating, she'll just stand up and walk away.

So, you know, needs a little bit of force to get through the cervix. Whereas I guess, you know, if you're dribbling, you might as well put it where it needs to go. Ah! Of course, that makes sense. I guess this nondescript normal vagina can look the way it does because the female has a high degree of control behaviorally. So if she's not intimating, she'll just stand up and walk away.

Or if she doesn't want it in the first place, she just won't lay down. So she hasn't necessarily needed to evolve all these fancy bells and whistles to stop sperm from getting to where she doesn't want it to go.

Or if she doesn't want it in the first place, she just won't lay down. So she hasn't necessarily needed to evolve all these fancy bells and whistles to stop sperm from getting to where she doesn't want it to go.

Because she can just get up and lay. Oh, that's so interesting. So we find that in the animals, like to go back to the duck, where it is more forcible and the males are really coercing that sexual behaviour, then you have to evolve a vagina that can handle that, that can sneakily... Well, that will give you the final say.

Because she can just get up and lay. Oh, that's so interesting. So we find that in the animals, like to go back to the duck, where it is more forcible and the males are really coercing that sexual behaviour, then you have to evolve a vagina that can handle that, that can sneakily... Well, that will give you the final say.

Right, but with some animals like alpacas, the sort of evolutionary arms race actually comes from the behaviour. Presumably, yeah. That you can just walk away, I'm done with this dribble. So it is interesting. We do often see, as you've talked about at the beginning of the show, you know, we often see sex as this battle where the slutty male is fighting to impregnate.

Right, but with some animals like alpacas, the sort of evolutionary arms race actually comes from the behaviour. Presumably, yeah. That you can just walk away, I'm done with this dribble. So it is interesting. We do often see, as you've talked about at the beginning of the show, you know, we often see sex as this battle where the slutty male is fighting to impregnate.