----- Original Message -----
From: "Stan Kostka" <lynnandstan at earthlink.net>
To: "tweeters" <tweeters at u.washington.edu>
Sent: Sunday, September 23, 2001 11:35 AM
Subject: Re: A few bluebirds and a kestrel on the prairie


> I am intrigued by this distinction, nest box vs tree cavity, and Im
> glad to hear someone make it.
>
> Why do the catch regulations regarding salmon make distinctions between
> hatchery and wild fish. ? Is there some "real" quantifiable difference
> ? One might assume so since some wild salmon must be released while
> the hatchery fish can be taken.

I'm not sure that the two cases, hatchery fish and birds who use nestboxes,
really have that much in common. Hatchery fish are much more suspect, as it
were, for there is very little that is natural about their reproduction and
early rearing.

Hatchery fish result from eggs and sperm from fish selected by hatchery
managers from fish who have made it back to the hatchery. The female fish does
NOT find an appropriate gravel bed, she does not make her nest, etc., etc.,
etc. The male does not chase other males away before and after fertilizing the
eggs. The young hatch in tanks and are raised in tanks and fed salmon chow for
a year or so before they are released. They mostly all survive, not just the
wily ones. In short, throughout the mating/hatching/smolt phase, a period
where natural selection should be acting in critical ways, the process is
entirely artificial. It should come as no surprise that a smaller percentage
of hatchery fish heading out to the ocean return, as compared to wild fish.

In contrast, when providing a bird box, all we are providing is an artificial
home. Before we came and cut down all of the trees, there were plenty of snags
along the shores of all the large lakes and the Sound, and there were
undoubtedly plenty of nest holes for swallows and swifts to fight over. Now,
nest hole competition is probably much more of an issue. As for bluebirds, at
times we may have disproportionately aided them at the expense of other
species. I would guess that by 1927, when 40 acre family farms covered much of
the United States, that there were more bluebirds than before or since. But I
doubt we did much to change selection processes, except perhaps the species
aggregate definition of a perfect nest hole.

== Michael Hobbs
== Kirkland WA
== hummer at isomedia.com