Saturday, June 18, 2011

Bufflehead Behavior

Last spring I searched for duck pairs.  The perfect Bufflehead photograph has eluded me.  This photo, from the Dennison sewage ponds, is perhaps my best attempt.  This male swam near two hens.  Suddenly one of the females lit out after the male, apparently chasing him away.  Later she joined the other female. You can see the action in the photograph below.

As best I can guess, this behavior may be an example of a "Following Display."  Females often run on the water to catch up with a displaying male. This display is considered to be evidence that the birds are paired (Gauthier 1993).  The only problem with my hypothesis is that the male in my photo seems to be running from the female for dear life!

Update:  Bill Marchel points out that the bird chasing the male below is most likely a second-year male that has not molted into breeding plumage.  Sibley's guide indicates that some young males do not transition to breeding plumage until their second July.  Sex is told by the shape of their face patch--much longer and less oval than that on a female.  The bird above is probably a female, the birds below, males. In fact, the behavior I saw did seem to be more like male to male aggression than the cementing of a pair bond.

1 comment:

  1. Thank you for sharing that most informative description of that behavior.

    Regards,

    Jonathan J. Weber
    Northwestern New York State

    ReplyDelete