Hens control fertilization?

Discussion in 'Random Ramblings' started by LittleChickenLady, Aug 30, 2011.

  1. LittleChickenLady

    LittleChickenLady Chillin' With My Peeps

    Mar 4, 2011
    Clanton, Alabama
    Anybody else see this article?

    "Chickens have their own battle of the sexes, and scientists have discovered a secret strategy used by hens to control who fertilizes their eggs: After mating, hens can eject the sperm of less desirable, low-status roosters.
    A new study has shown that, during an average ejection, a hen jettisons 80 percent of the sperm a rooster deposits in her reproductive tract. This has a huge impact on the competition among males fighting to father her future chicks, according to study researcher Tommaso Pizzari, an evolutionary biologist and university lecturer at Oxford University in the United Kingdom.

    "It is beginning to appear females can play a much more subtle, but powerful, role in the battle for fertilization," Pizzari told LiveScience.com.

    A few things to know about chicken sex : Both sexes are promiscuous, mating with multiple partners. Hens, however, often don't have a choice in mates. They prefer males at the top of the pecking order, but other roosters with lower status will force the hens — about half their size — to mate. Rather than attempt to fight off the undesirable mates, hens appear to have developed a more subtle way to reject them.

    Scientists already knew that hens could eject sperm, but in the recent study, they set out to find evidence that hens were actively using this technique to control fertilization.

    Using chickens from a flock that lived in a semi-feral setting, similar to their wild ancestors, the red jungle fowl, Pizzari and other scientists led by Rebecca Dean, who conducted the study while at Oxford and is now at University of Uppsala in Sweden, mated hens with various roosters; the scientists ranked roosters' social status from 1 to 6, with 1 being the most dominant. They then videotaped any sperm ejection that followed the mating and collected the results. To determine how this compared with the total sperm the roosters had deposited, the researchers captured all of their semen during another set of controlled mating attempts.

    Their results confirmed that sperm from the least desirable, low-status roosters suffered the most for several reasons.

    When mating with a series of roosters, hens ejected more semen from the later mates. Since lower-status roosters don't get the first shot at the hens, for this reason alone, their sperm are more likely to be ejected, Pizzari explained. But even controlling for mating order, status had a strong effect on whose sperm the hens kept. In addition, lower status roosters were more likely to ejaculate more semen in one shot, and the team found that hens were more likely to eject larger ejaculations.

    "It is likely in more natural situations, subdominant males are disadvantaged in many ways," Pizzari said.
    The study appears in the September 2011 issue of the journal The American Naturalist."

    I thought it was pretty interesting.

  2. pbjmaker

    pbjmaker Overrun With Chickens

    May 9, 2008
    Central Iowa
    I wonder if my hens are completely rejecting my roo - my eggs haven't been fertile in awhile. I know for a fact they have ZERO respect for this particular roo and have been known to beat on him occasionally.

    For awhile he even resorted to trying to mate young ducks [​IMG]

    He earned his name Rodney cuz he don't get no respect.
  3. ChooksinChoppers

    ChooksinChoppers Chillin' With My Peeps

    Mar 24, 2011
    Ocala, Florida.
    Either that or Rodney is shooting blanks [​IMG]
  4. I have WHAT in my yard?

    I have WHAT in my yard? Chillin' With My Peeps

    Jun 24, 2008
    Eggberg, PA
    I wonder if that's whats wrong with my hens lately. They have zero respect anymore for my Romeo, but he is still their only option. My last two hatches were duds. If the hens are broody with only one male would they still reject his sperm?? Or is he shooting blanks? Or are they rejecting him cause he's shooting blanks?

    I dunno what to do, I really love Romeo and really need a roo that can produce. He HAS fathered chicks, just not recently....

    He currently has three males that are not his sons in the flock that I am thinking I might let grow up to see if they can get the deed done.....
  5. pbjmaker

    pbjmaker Overrun With Chickens

    May 9, 2008
    Central Iowa
    Quote:Rodney is a white silkie so.....

    Same here IhWimY. He is the only thing going out there. He can usually "get with" the bantam birds but even then nothing happens. I have two arucana hens and I would love fertile eggs from them!
  6. I have WHAT in my yard?

    I have WHAT in my yard? Chillin' With My Peeps

    Jun 24, 2008
    Eggberg, PA
    Nasty ole hens! My Romeo took on a fox in a one on one battle last year. Lost most of his back end but by golly he beat off that fox and saved his ladies! And this is how they repay him! [​IMG]


    DH thinks the fox might have ripped up more than we knew at the time. [​IMG] Now I am bummed because we never let his sons live. [​IMG] Who knew?
  7. pbjmaker

    pbjmaker Overrun With Chickens

    May 9, 2008
    Central Iowa
    I just went and checked on the two eggs I'm letting my frizzle banty sit on and they are both fertile! One is from my splash silkie so I will get a miscolored but otherwise pure silkie from Rodney at least! He somehow knows that my splash is the only silkie and is totally obsessed with her and even cuddles her at night.

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