Weird little leporids

Rabbits are the most freaky of all mammals (right, Chris?) They’re thriving, though—they’re all over my lawn, and if this summer is anything like last year, I’ll have to go out about once a week and scrape one off the road running by my house.

I did not know that interesting fact about their scrotum, though.


  1. Carlie says

    Interesting. Watership Down was my favorite book that I had to read in high school (the “rabbity epic”, as the lit teacher called it), and I always shuddered at the thought of making it into a cartoon. I can’t imagine that the movie version could come anywhere near the excellence of the book.

  2. says

    Also, the females have hypertrophied Skene’s glands, compared to other species. That means that female rabbits have significant, detectable prostate organs.

    Freaky little mammals, all right.

  3. David Wilford says

    Carlie, I read Watership Down when it first came out in paperback (I still have it even) and it was a favorite of mine too. I later saw the film when it came out and while it wasn’t the book of course, it did get the feel right and I recommed it to you. Art Garfunkel even does a beautiful job of singing the movie’s theme song, “Bright Eyes”, that works wonderfully in the film itself and isn’t merely something that’s tacked on for commercial purposes.

  4. says

    it seems half the problem isn’t lagomorphs but the propensity of taxonomists to insist a hierarchy of mutually exclusive species is the best way to organize biological lineage. admittedly, such abstractions are highly compatible with human thinking and may work well for 95+% of species. but for the other 5%, perhaps they oughtn’t be forcibly “orthogonized”.

  5. says

    I tried to reconfirm the prepenile scrotum statement — which I had also heard — by means of empirical observation of male rabbit reproductive morphology, but my observations were inconclusive.

    In other news, does anyone have tips for stopping bleeding from large bite and scratch wounds to the face? I’m, um, writing a paper. Yeah. That’s it.

  6. says

    P.S. Hints about good ways to extract carrots that have been jammed where the sun don’t shine would also be helpful. Thanks in advance.

  7. says

    Another odd thing about rabbits is that while other animals typically overshoot when correcting a salt/water inbalance, rabbits don’t. The difference between rabbits and other animals is, in a leading researcher’s words, “striking”. From my site:

    “The intriguing data on the capacity of adrenalectomized rabbits to repair body deficit precisely without excess intake are dealt with in Chapter 14 bearing upon satiation behaviour.”

    Denton quote, Chapter 14, pg. 255:
    “Wild rabbits, sodium-deficient as a result of adrenal insufficiency, take 9-12 h to correct deficit whether large or small. That is, the rate of drinking is determined by the amount of deficit. The precise correlation between deficit and intake is striking.”

  8. Left_Wing_Fox says

    David: Have you seen “Wallace and Gromit: Curse of the Were Rabbit” yet? There’s a “Watership Down” gag in therre that I think only a handful of people on earth caught.

  9. David Wilford says

    Left_Wing_Fox, I saw Curse of the Were Rabbit in the theater, and do recall the Watership Down gag. I’m sure I missed tons of others though, which is why I need to get around to watching the DVD!

  10. ulg says

    A final weird rabbit fact: Male Rabbits lack a baculum . Strangely enough, human males also lack a baculum, despite having invented the term ‘boner’.

  11. says

    Rabbits. Who’d have thought?

    Watership Down (the book) is amazing, not only because the epigraphs familiarized me with all kinds of literature and poetry about a decade before I actually encountered any of it in school. I mean, a fantasy about rabbits, quoting Auden, Mozart, Plato, Dylan Thomas, and Blake? Wow.

  12. Carlie says

    I didn’t catch the reference myself, but I heard something about the song on the radio when Gromit was in the car alone – was that it?

  13. says

    Is the lack of a baculum in humans basal or derived? What is the baculum status among the other primates?

    I’m no baculum expert, so I defer to anyone with more specific knowledge on basal vs. derived ([1] and [4] look interesting), but a quick PubMed search turns up the following, which confirms the presence of a baculum for woolly spider monkeys [2] and macaques [3].

    1: J Androl. 2005 Sep-Oct;26(5):624-8. Distal ligament in human glans: a comparative study of penile architecture. Hsu GL, Lin CW, Hsieh CH, Hsieh JT, Chen SC, Kuo TF, Ling PY, Huang HM, Wang CJ, Tseng GF. “A distal ligament in the human glans penis replaces the os penis that is present in dogs or rats, also termed the baculum, but retains collagen types I and III as common structural and interlocking components, respectively.”

    2: Folia Primatol (Basel). 2004 Mar-Apr;75(2):61-9. Observations on genital morphology and anatomy of a hybrid male muriqui (genus Brachyteles). “In addition, the occurrence of a baculum (os penis) is confirmed for this genus, and the first description of its morphology is provided.”

    3: Horm Behav. 1997 Apr;31(2):126-35. The socioendocrinology of adolescent development in male rhesus monkeys (Macaca mulatta). Dixson AF, Nevison CM. “Maternal rank was also found to correlate with circulating testosterone levels, testes weights, growth of the baculum (os penis), and maintenance of body weight in adolescent sons during the mating season.”

    4: J Steroid Biochem Mol Biol. 1991 Dec;39(6):873-81. Differentiation of mesenchymal tissues during phallic morphogenesis with emphasis on the os penis: roles of androgens and other regulatory agents. Williams-Ashman HG, Reddi AH. “This article reviews various aspects of differentiation and growth of phallic mesodermal tissues with special reference to the os penis. In many species of certain mammalian orders the penile interior contains an os penis or baculum with bona fide bone. Mechanisms of phenotypic sex differentiation and the androgenic regulation of morphogenesis of genitourinary tracts of both sexes are first overviewed. Thereafter the various mesodermal tissues in fully developed penes and clitorides are discussed. The developmental fate of mesenchymal cells in the fetal genital tubercles is then considered in detail, including considerations of epithelial-mesenchymal interactions. The review concludes with a discussion of the possible roles of certain polypeptide growth factors acting in concert with androgenic steroids. Special emphasis is placed on the potential role of bone morphogenetic proteins in formation of the os penis in a restricted number of eutherian mammalian taxa.”

  14. Left_Wing_Fox says

    When Gromit is sitting in the car waiting for Wallace, he fiddles with the radio, and manages to tune into the Watership Down theme “Bright Eyes” by Art Garfunkel, just before the Were Rabbit strikes. :)

  15. KeithB says

    What a coincidence:
    Just this morning I ran across a review for this:

    Consider yourself lucky, PZ.

    Also, at the Page Museum at the La Brea Tar Pits they have a wall with dozens of Dire Wolf fossils. (They find a *lot* of Dire Wolves – they had a wall with hundreds of skulls!)

    Anyway, each one had the baculum just kind of hanging there. I thought it odd, since I don’t think I had ever seen one in a fossil display before…but thanks to Pharyngula, I knew exactly what it was. Are baculums usually left out of the exhibits? (“What is that thing hanging down below, Daddy?”)

  16. quork says

    Rabbits are the most freaky of all mammals

    Surprising. I thought YECs were the most freaky of all mammals.

  17. says

    Having had pet rabbits for years, I can confirm that particular bit of freakiness, though it hadn’t actually struck me at the time. Their anatomy is different enough in that area from larger mammals (they don’t really have a scrotum, the testes just protrude a bit from the lower abdomen) that you don’t just look at it and think “Hey, those things are the wrong way around!”

  18. thwaite says

    QrazyQat noted the Buffy episode in which Anya gave musical vent to her characteristic bunny-phobia…

    for the pop-culture trivia fans, this was the Buffy musical episode which appeared in season six. The show’s premise is that everybody slowly realizes they’re singing their lines, not speaking normally. In the Buffy universe this could imply anything from demons to ??? at work. As they first realize the problem and stand about singing their working hypotheses (scientific in their own way), the arias’ tempo is changed to a rock-rhythm in which Anya speculates:

    Bunnies aren’t just cute like everybody supposes!
    They got them hoppy legs and twitchy little noses!
    And what’s with all the carrots?
    What do they need such good eyesight for, anyway?
    Bunnies! Bunnies! It must be bunnies!
    Or maybe midgets…

    Quite funny and endearing in context, but you had to have been there…

    References as always:

  19. says


    Thank you.

    What about the great apes?

    Further on the subject, have you seen the work done on the jointed os-penis of the sasquatch?