Subject: [Tweeters] Birds fighting mirrors and windows
Date: Mar 11 07:55:28 2005
From: David White - drmwhite at nets.com


Rob Sandelin wrote:

> It is really astonishing to me that birds not only whack themselves silly>
fighting reflections, but that they do it for such long periods of time. > I
imagine this is most of the> active breeding season, and I assume such birds
are out of the gene pool,> , are> these the total nimrods of the bird world?

As Jeff Kozma commented, these are the highly aggressive birds, defending
their territory. Whether or not they remove themselves from the gene pool is
an open question, but I imagine these birds would not be so insistent unless
they have a territory and a mate to defend.

Are they "nimrods"? This is an interesting question. I don't have a
Webster's handy, but my impression is that American usage carries a bit more
negative freight (something like 'dim bulb') than the British definition; my
Concise Oxford Dictionary defines "nimrod" as a "great hunter or sportsman."

Clearly, that's not what Rob meant! But I think the heart of the question is
whether this is maladaptive behavior, and I imagine that it probably is.

Mirrors are something that rarely exist in nature (quiet pools of water
might qualify, tho I've never seen a bird attacking its refletion, say, in a
birdbath, and if one did I would think the disruption of the image could
easily be construed as victory).

Hence: these territorial birds are responding to a new factor in their
environment, and the extent to which it may be deleterious is unknown. I
doubt that anyone has ever had the time to watch male birds who do & don't
attack mirrors, to see how much time mating & contributing to the brood they
each spend.

And it gets complicated. If mirror-attackers are simply spending defense
time at the mirror, and otherwise fulfilling their other duties, it's one
thing--but yet we'd also have to consider whether they're focusing so much
on the mirror as to allow philandering males to sneak in and dilute their
contribution to the gene pool.

Things we'll probably never know.

David White
Santa Fe NM/Auburn WA
mailto:drmwhite at nets.com

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