Hi Tweeters,

I had another thought about jaegars, one which I brought up in my last
posting, but failed to discuss, as I thought it was already too long.
But I think the term 'persistence' certainly applies to jaegars as well.
When the old routine of 'following the researchers to rob nests' fails
(like when we would catch them doing it), these birds would resort to
robbing eider mothers of their broods. I recall on one occasion a
Parasitic who dive-bombed a female Spectacled Eider who was hiding all of
her chicks underneath her wings. This jaegar went on for at least twenty
minutes before I lost interest and had to move on (sorry, I don't know
the outcome). I think in many cases their refusal to cease and desist
results in a good meal. Another curious phenomenon, though is the close
association of eider nests to jaegar nests. The eiders actually seek out
their enemies nesting sites because the jaegars defend a large territory
from other critters like gulls, snowy owls, and Arctic foxes. They also
have the nice character to not eat the birds nests within these
territories. The down-side of course is that when the young hatch, mom
has to get them safely out of the jaegars territory, without them being
eaten. So there are costs and benefits to that scenario as well. All in
all it's a dog-eat-dog world out there, or at least a bird-eat-bird world.

Mike Smith
University of Washington
whimbrel at u.washington.edu