Friday Weird Science: The Hyena Mating Game

Sep 25 2009 Published by under Friday Weird Science, Natural Sciences

Editor's Selection IconThis post was chosen as an Editor's Selection for ResearchBlogging.org (w00t!)
Today's post comes to you courtesy of Laelaps. Sci's been wanting to cover sex in other species for a while now (I mean, it's so WEIRD!), and Laelaps has kindly provided a whole series of great articles!!! This is good, as Pubmed is not particularly informative on other species. The weird science is flowing today. Or maybe oozing. I imagine weird science likes to ooze.
So. Hyenas. Having sex. Which they don't really seem to do very often. And there's a good reason. The females don't have it very easy. What they have...is masculinized genitalia.
Warning: pics below the fold. Does it count as NSFW if it's a hyena pseudopenis?
ResearchBlogging.org Szykman et al "Courtship and mating in free-living spotted hyenas". Behavior, 2007
And these scientists are DEDICATED. I know it takes a long time for me to get through grad school, but these folks spent 11 YEARS making various trips to watch hyenas on the savannah. While it's a much better and more exciting location than my graduate work calls for, it still might get kind of old. Eternal vigilance with low hope of success must grind you down after a while. Their perseverance impresses me.


The hyena
hyena1.jpg
Cute, huh? Looks kind of witty. Anyway, hyenas are Crocuta crocuta of the order Carnivora. They are apparently related to civets, and related to dogs, but more closely related to things like meerkats. They hunt for themselves sometimes, but do a lot of scavenger work, and have some amazing bone-crushing teeth. Interestingly, hyenas live in large social groups (the one that these scientists studied was between 45-79 individuals, and a group of hyenas is called a clan), and the females are typically dominant over the males. The females are also larger, and just as well armed with claws and teeth as the males. She won't just turn you down for a date, she will BITE YOUR HEAD OFF FOR ASKING.
All this makes for a bit of fear on the part of the males wanting to mate. But then, it gets worse. Here's why:
hyena2.jpg
The Female Hyena.
No really. That's not a penis. It's a pseudopenis caused by elongation of the clitoris. There is no vagina, rather the labia majora (which would normally be split down the middle to form a vagina) are fused together to form a fake scrotum. So this means that the female must copulate, urinate, and GIVE BIRTH through that pseudopenis. And we thought humans had a hard time.
And there's something else about this. The pseudo-penis is stretchy and can accommodate the male's penis. But you'll note that it's kind of...pointing the wrong way. So for a male to mate successfully, he's got to get his penis inside the pseudopenis of a female who is bigger, has teeth and claws, and may not like him very much.
The scientists set out to study how this happened, and how the males got close to the girls. It turns out that each spotted hyena population has two sets of males, the locals (those born there), and the immigrants (those coming in from other clans). Normally, the males born in the clan grow up, and then go out on their own to seek another clan, though some do stay. Those that stay don't really get much mating in, however. It's the immigrants that do most of the work. Genetically, this is probably a good thing, as you wouldn't want lots of clan inbreeding.
So the immigrants are most successful, but it turns out the females themselves are not so awful. During their estrous cycle, they will actually welcome male attention, or at least they won't bite the heck out of the guy. And when she's at the right time, it goes like this:
The beginning:
Male sniffs or licks female or female's urine. Realizes this is a good one and starts hanging around. Hangs around more and more as estrous approaches. Several males might be hanging out. She is much hotter if she's also high ranking, the low ranking females don't get as much attention.
Displaying interest (wanna go out with me?)
There are a varieties of ways of doing this:
1) Male does something called "approach-avoid display, but which I imagine looks a lot like a very silly dance. Usually the female is lying down, and the male will get within about 10m, and then take a few steps back. Few steps forward...few steps back. Few steps forward, now stomp! Slide to the left! Slide to the right! Turn around and do it again!

2) The male can "present", holding himself steady while the female checks him out. Males are understandably skittish at this time, after all, those big teeth are near your penis.
3) Then there's other weird dance steps. The male will look at the female and cross his front legs. He'll groom his front legs. He'll bow and groom. He'll pat the ground. He'll do just about anything short of actually waving his penis at her.
4) Attempted mount. These are usually very fast and he never quite gets there.
The Lady
If the female sees this performance, and if it is to her liking, she'll take a receptive stance. This involves holding her head down and bracing her legs for what is bound to be a series of awkward maneuvers.

Gettin' it On

The male approaches, the female holds position. He's up, he's ON!!! But only sort of. He's on like this:
hyena3.png
(The look on his face says "a little to the left...wait...")
So you'll notice he's kind of squatting under the female. This is to get his penis to insert into her pseudopenis. This can take several minutes, and can often be unsuccessful. But once he gets it in there, he mounts up, pulling her pseudopenis backward with him to face the other way (it normally faces front). No data on how the female feels about this, she's just staying put (he hopes).
hyena4.png
(lemme hear ya say "YEAH")
Here we are! Often there are several of these sessions, short or long (long mounts are better to actually achieve insertion), during which the male starts thrusting. But this doesn't always go well. There are often other hyenas around, and other males will try to butt in. If they are higher ranking, they can just hop on and replace the current male, though the male can try his luck again later while the bigger male is between sessions.
Anyway, if all goes well, the male thrusts furiously, ejaculation occurs, and you get this:
hyena 5.png
(Someone needs a cigarette)
This is this "post-ejaculatory rest" during which I imagine there might be a hyena version of pillow-talk. Male hyenas are apparently capable of multiple ejaculations, which they always rest after.
One of the interesting things about the spotted hyena is this: though the females are dominant, the males do almost all of the approaching for mating. The female is receptive in that role, though she might start hanging around some males as estrous approaches. For the male, this creates some conflicting problems. He wants to mate (duh). But that will BITE HIM. This, plus the difficult body structures, make it really hard to get successful copulation. And even if copulation is successful, fertilization often isn't.
Luckily, it appears that young hyenas get a lot of practice. There's a great deal of play mounting in young spotted hyenas, which may help train them for what they're going to eventually have to accomplish. Interestingly, the sons of high-ranking female hyenas tended to mount the most, and so may have the most success later.
The females are rarely receptive, usually ignoring the males entirely, if not being aggressive, and the males are both trying to get it on, and really hesitant about getting their butts kicked. This is made harder by the fact that, unlike other species (like cats and dogs) female hyenas never really show much mating interest other than the mating posture. They might follow the guy around a little, but there's none of the rolling around and playing and presenting that occur in other species.
And of course, lots of mounts take a long time, and thus it's kind of dangerous. Aside from the possibility of some other male claiming your mate, there's the possibility of getting eaten while you're not really focusing. So the scientists hypothesize that a lot of mating may take place in hidden areas (thickets) or at night. They have in fact seen animals doing a few short mounts and then heading off into the bushes. Presumably this can help shield them from predators somewhat.
The crazy, crazy world of hyena mating. I thought the human dating world was bad!!
Szykman, M., Van Horn, R., Engh, A., Boydston, E., & Holekamp, K. (2007). Courtship and mating in free-living spotted hyenas Behaviour, 144 (7), 815-846 DOI: 10.1163/156853907781476418

18 responses so far

  • Laelaps says:

    Great post, Sci! And thanks for the hat-tip. Believe it or not, I adopted a spotted hyena in Tracey's honor as part of her Christmas gift. I wonder how "little Tracey" is doing these days...
    I have been meaning to write something about sex-differentiation in spotted hyenas for a while. Maybe this post will finally motivate me to do it!
    And I just wanted to add something about hyena evolutionary relationships. Hyenas belong to the larger group of mammals called the Carnivora, which is split into two groups; the Feliformia ("cat forms") and Caniformia ("dog forms"). Hyenas are on the cat side (feliforms), which itself can roughly be split between cat-like forms and mongoose-like forms. Hyenas are on the "mongoose" side of the feliform split and are closely related to civets and mongooses. (Weasels are actually more closely related to dogs. Go figure.) Hyenas might seem dog-like, but seals are more closely related to dogs than hyenas are.

  • abb3w says:

    What, no mention of hot hyena lesbian same-sex mounting for dominance displays?

    • Pride says:

      The female hyenas seem to have no sexual pleasure whatsoever, it seems that sex only hurts them and because of that the male that have sex can't be any loser... They have sex for reproduction purposes.

  • Sanity Jane says:

    So this means that the female must copulate, urinate, and GIVE BIRTH through that pseudopenis.

    That's why she's so MEAN.
    /punchline

  • Noam GR says:

    That female is not enthused. She's just wants to get it over with.
    ... who says science is not relatable :s
    --
    http://noamgr.wordpress.com

  • Luna_the_cat says:

    Oh, hyenas are fascinating beasts. Love this whole description of the mating game, too....
    The only thing I'd add is that, the way I read the taxonomy, hyenas are equally related (or unrelated) to cats and mongooses (and civets, genets, linsangs and fossa), given that they are all members of suborder Feliformia. Or is there a better clade description which gives quantitative genetic distance?

  • Laelaps says:

    Luna; The way I read it, there are two major clades containing extant animals within the Feliformia. One contains the cats and their nearest relatives and the other contains hyenas, mongooses, viverrids, etc. This would place hyenas closer to mongooses and viverrids than to felids. Also, within this clade hyenas form the sister group to a clade composed of mongooses and fossas, so I think it is justified to say that they are more closely related to them than to cats. I am not working from the Linnean system of taxonomy but from a phylogenetic tree like the one here. I am basing how "close" on group is to another on common ancestry, i.e. hyenas and mongooses shared a more recent common ancestor than with felids, thus making them evolutionarily closer to mongooses.

  • Luna_the_cat says:

    Laelaps -- I worked my way through that, and I see what you mean, but to be honest I found the proposed phylogeny as confusing as it was enlightening. Do you have any recommended resources that dig into Carnivora phylogeny with more detail about reasoning, and with graphics....?

  • Errol Wood says:

    I much giggled but I suppose that was the point in part... I heard about the female hyena's mock penis but wasn't privied to much you wrote - I thank you once again.
    I have a soft spot for hyena and given the chance, they'd probably feel the same for me.
    Many people find them repulsing... au contraire... hyenas are to my mind, the ultimate beast, so beautiful and they're not too, too bothered with occasional annoyances like lions... just don't fear 'em much. Anyway, thanks for the info. Later.

  • elena says:

    thats so nasty i want to see it for real

  • tory says:

    How, how WIERD! and also fascinating!
    My big question: Why / how did this pseudopenis evolve?
    Thanks, Sci, you sure took my mind right off the other topics that had been whirling around in there.

    • Pride says:

      The masculinized genitalia is probably a undesirable side effect from the need of becoming stronger by dramatically increasing the testosterone levels...

  • katharina says:

    heyanas are tha cutest I am studying them

  • katharina says:

    ps will you write to me and tell me more about...hyenas

  • john says:

    am curious to understand how hyeans mate

  • Ernie says:

    Do female hyenas use their clitoris for insertion into the another females clitoris or into anuses of males or females?

  • […] which can grow up to 7 inches long. She doesn’t use it to penetrate a male; in fact, the male must penetrate her pseudopenis with his actual one. Later, she gives birth through […]