On Fri, 19 Jul 1996, Michael Patrick wrote:
> The problem with all this intervention (small though it is) could be that
> I've now weakened the genetic pool of pine siskins by allowing poor nest
> building genes to enter the breeding population. The birds may also have
> some sort of distorted view of human beings too.

Michael- great story and kudos for your ingenuity. Many birds learn
during their first or second nesting seasons that certain areas are
unsuitable for nesting, or that nests have to be built a certain way. I
found a Killdeer nest right in the middle of a baseball field (during a
little league practice on the field) at the Native Heritage school in
Seattle. People use this field every day, you gotta wonder what on Earth
was the Killdeer thinking? The empty nest a few days later confirmed its
fate. But this is surely not a wasted effort by the birds, they will know
not to nest there again. Or if they do, then they are being selected
against and future Killdeer generations will be spared from this sort of
nest failure. Same is true for your siskins. You surely haven't 'hurt'
anything, but merely put off the inevitable. If the parents didn't learn
this year, maybe they will next year. Or if it's an inherent genetic
predisposition towards sloppy nest-building, they and their young who
inherit it will lose in the big game of reproduction eventually.

-------------
Michael R. Smith
Univ. of Washington, Seattle
whimbrel at u.washington.edu
http://salmo.cqs.washington.edu/~wagap/mike/mike.html