Jim,

Apology accepted. As most of the people on TWEETERS probably know (I've been
a member for 10 years), I am a professional biologist with a Ph.D. in
ornithology, and I am certainly not an anti-evolutionist. Among other things
that I did in my career with the B.C. government, I wrote one detailed
report on Spotted Owls and compiled a comprehensive bibliography of the
species, so I do have some specialized knowledge of the species' biology,
although I haven't studied them in the field myself.

I'd like to address a couple of points you raised. In relation to Kirtland's
warblers, it is generally recognized that a shortage of its preferred
habitat (5 to 10-year-old jack pine stands) was one of the main reasons for
its rarity, and steps were taken to increase this habitat in Michigan and
Wisconsin. However, cowbird parasitism became so severe that the warblers
would probably have gone extinct without cowbird control BEFORE an increase
in habitat could be accomplished. Cowbirds don't seem to like really large
areas of young jack-pines, so hopefully if large enough areas are created,
the cowbird problem will decrease.

New habitat can be created for Kirtland's Warblers in 10 years or less, by
clearing a forest and planting young jack pines. Unfortunately, it isn't so
easy to create new Spotted Owl habitat; because they prefer old-growth
forest, it would take 200-300 years to create new habitat from scratch.

The actions that were taken during the 1990s (e.g. the Northwest Forest
Plan) should have slowed, if not stopped, the decline of Spotted Owls in the
Northwest. Unfortunately, the sharp decline seems to have continued unabated
in most areas, even without further habitat loss. Barred Owls seem to have
displaced Spotted Owls from most forests, even old-growth forests, below
2000 feet altitude, and even many forests above that level. It really looks
like Barred Owl competition, not habitat loss, is the main cause of the
continuing Spotted Owl decline in the last 10-15 years. Habitat preservation
or creation alone will not save the Spotted Owls.

This brings up your second point: whether or not Barred Owls are "native" to
Washington. They first arrived here only in the 1970s, so they were not part
of the ecosystems in which Spotted Owls evolved. Until about the 1940s,
Barred Owls were unrecorded west of the Rockies. It could be debated whether
or not their range expansion was caused or assisted by humans. Although
there is little critical evidence one way or the other, my belief is that
extensive logging in central B.C. and the growth of second-growth deciduous
and mixed stands, which Barred Owls prefer over pure conifer stands, was a
key factor in the Barred Owl's spread across the Rockies and into Washington
and Oregon by way of British Columbia.

Whatever the cause of the Barred Owl's range expansion, they are here in
large numbers now, and they are certainly having a detrimental effect on
Spotted Owls (and probably on Western Screech-Owls as well). Even if the
decision is made to try to control Barred Owl numbers in some areas, it
would not be possible (or desirable) to do this throughout the area where
they overlap the (Northern) Spotted Owl's range. It may be that despite all
we can do, Northern Spotted Owls will disappear from most or all of their
range, except in the few areas where Barred Owl control is carried out. I
think we owe it to the Spotted Owls to at least attempt the experiment,
rather than to just stand idly by and watch as Northern Spotted Owls slide
downward toward extinction.


Wayne C. Weber
Delta, BC
contopus at telus.net





-----Original Message-----
From: tweeters-bounces at mailman2.u.washington.edu
[mailto:tweeters-bounces at mailman2.u.washington.edu] On Behalf Of Jim Greaves
Sent: December-10-09 2:38 PM
To: tweeters at u.washington.edu
Subject: [Tweeters] Re: Kirtland's and cowbirds

I have no problem with the gist of what is said about cowbird
control. But, keep in mind that the "god" of Kirtland's Warblers came
out years ago opposed to cowbird control because he contended it
didn't really work. Habitat loss is the key. Without retaining and
increasing the appropriate pine forests for Kirtland's, they will
always be in short supply, endangered, and in need of aggressive
(assertive?) protection from those ecological elements that benefit
from humans to the detriment of other native birds and wildlife.
Also, I apologize for my stupid comment about Mr. Weber being an
"anti-evolutionist" - I was in error and only being flippant - Jim
Greaves, Thompson Falls MT

At 01:00 PM 12/10/2009, tweeters-request at mailman2.u.washington.edu wrote:
>Message: 14
>Date: Thu, 10 Dec 2009 10:23:43 -0800
>From: "Wayne Weber" <contopus at telus.net>
>Subject: RE: [Tweeters] RFI killing barred owls to save spotted owls
> in Cle Elum area
>To: "TWEETERS" <tweeters at u.washington.edu>
>Message-ID: <004201ca79c5$e815ee30$b841ca90$ at net>
>Content-Type: text/plain; charset="us-ascii"
>
>Jo and Tweeters,
>
>There should be nothing disturbing about this proposed action. It has been
>proposed and seriously considered by wildlife agencies for quite a few
>years. Spotted Owls are threatened, Barred Owls are not; Spotted Owls are
>native to Washington and Oregon, Barred Owls are not.
>
>For comparison, the Kirtland's Warbler exists today only because many
>thousands of cowbirds, which were parasitizing them and severely reducing
>their breeding success, were trapped and killed on the breeding grounds.
The
>cowbird control program continues, although the restoration of suitable
>breeding habitat for Kirtland's Warblers may soon decrease or eliminate the
>need for cowbird control.
>
>Wayne C. Weber
>Delta, BC
>contopus at telus.net