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Lady Wieners of the Spotted Hyena

August 26, 2014

My lab mates and I frequently discuss weird stuff during lunch. Last week, however, our topic really took the cake. Someone informed us that female hyenas have pseudo-penises. Now, I know my posts can be a bit colorful at times, but this one might be more graphic than others. Sorry mom and dad, but the topic of this post is LADY WIENERS.

The female hyena, ladies and gents.

So yes, my lab mate was correct. The female spotted hyena has what appears to be a very large penis dangling from her nether region. In fact, even weirder, the organ is essentially an enlarged clitoris. In hyena clans the females are the dominant sex and not surprisingly they have high levels of testosterone. The formation of their pseudo-penis is linked to this hormone, as females with higher testosterone have larger peens. Here’s a super gross picture of a dissected female reproductive tract for your viewing pleasure.

Cunha et al, 2003 (Journal of Morphology)

The science version of a dick pic.

So… it gets weirder. Both male and female hyenas have spines on their dingalings that make intercourse a painful act. The spikes are made of the same stuff as fingernails (keratin), if you needed extra convincing of how unpleasant it would be. Fun fact: house cats have them too!

I don’t know if the other obvious problem has occurred to you yet, but my first thought was: how exactly do they have sexytimes if everyone is sporting an outtie? Turns out the female has to be flaccid so the male can insert his penis into her penis, and he has to do it at all sorts of wacky angles. In fact, males have to practice unsuccessfully for months before they learn how to do it right. It’s no small risk for these guys either – not only because females are the more aggressive and dominant sex, but don’t forget that her (now kinda inside-out) dong has spikes on it.

Now – we aren’t done yet. What about the babies? Where do they come out? WELL GUYS… she has to push them out of her seven inch pseudo-penis. Seriously. In real life. How did evolution let this happen?! The mortality rate for pups born to first time mothers is very high, because the babies literally suffocate inside of their mother’s penis. And yes, they tear that shit open on their way out, too.

So there you have it. The female reproductive system of the spotted hyena. Hopefully none of you will be scared away from reading my posts because of this – it’s just so crazy and unbelievable that I couldn’t help but share.

PS – if you’re like me and weirdly interested in learning more, watch the sweet video National Geographic made about it!

PPS – I hope you all realize my search history is now full of terms like “penile spines” and “female penis” and “wiener vs. weiner” lol


From → Biology

  1. This is a serious question about lady dicks – do they have any hypotheses about why this occured in evolution?

  2. From what I can tell, it’s not that the pseudo-penis was specifically selected for, just that it hasn’t been selected against. It’s more likely a side effect of the female dominance in hyena packs – the more testosterone a female has, the more likely she will be the alpha and produce offspring. (Although mortality rate is high for pups, it doesn’t appear to be enough to select against the pseudo-penis trait).

    Embryos of both sexes start off identical until certain cues trigger development of sex organs, and the high circulating levels of testosterone drive development of an enlarged clitoris. This organ derives from the same population of undifferentiated stem cells as the male penis, and therefore the presence of male sex hormones cause the clitoris to take on a rather convincing phallic shape.

    In sexually dimorphic species all individuals have the genetic blueprints to make either boy parts or girl parts. The organs that actually develop are often dictated by levels of sex hormones. However, there are genetic disorders that can cause males to develop female genitals (or vice versa). For example, XY males with an SRY mutation develop female genitals, while XXY individuals can develop female, male or intersex traits. Genetics be cray!

  3. Jake Hyer permalink

    This paper: is about administering anti-androgens to pregnant spotted hyenas, which actually serve to “feminize” males, which in this context gives them a urogenital configuration that is closer to the female pseudo-penis. Anti-androgen treatment also fails to prevent development of the pseudo-penis in females. Finally, the pseudo-penis begins to form before gonadal differentiation. Testosterone surely has a role in the dominance and aggressiveness of the females, but formation of the pseudo-penis seems to be more complicated than just a testosterone effect. Fun fact: males and females lick the clit of the dominant female in greeting displays, but males never get any dome because they are at the bottom of hyena society.

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