There is documented video footage showing a Barred Owl coming in and
attacking a stuffed Northern Spotted Owl (SPOW). The Barred Owls come into
the call of the SPOW. When they do, they do so silently and approach from
behind the dummy and strike it violently from behind. Is this intended to
kill the SPOW....yes. If it were only to drive the bird away, why would the
Barred approach silently from behind and why strike it so hard that it
knocks the stuffed SPOW off its perch? They are now expanding the research
by applying pressure plates to the stuffed SPOW to see the actual force of
the impact. I have not seen the results from this research yet.

So yes, Barred Owls do infact kill SPOW. If they don't actually kill them,
the more aggressive Barred Owls simply drive them away.

Some of the research also suggests that SPOW are starting to avoid calling
back in response to call surveys. This stems most likely from fear of being
attacked from Barred Owls.

SPOW also are attacked and killed by Northern Goshawks, but SPOW have also
been found preying on the young of Northern Goshawks...so that contest maybe
a tie. Yet, these species often nest within the same stand, with SPOW often
taking over abandoned goshawk nests.

Finally, Barred Owls occupy a much smaller home range that SPOW, with 4-5
Barred Owls (or more) occupying the same area as one SPOW home range. The
generalist diet of Barred Owls is thought to account for this, since they
can find a wide variety of prey items in a much smaller area than the
specialist SPOW whose main prey is the northern flying squirrel, and in some
areas, dusky-footed woodrat and red-backed voles.

Jeff Kozma
Yakima

j kozma at charter dot com


----- Original Message -----
From: <mgd at myuw.net>
To: "Tweeters" <tweeters at u.washington.edu>
Sent: Friday, May 04, 2007 9:24 AM
Subject: [Tweeters] Barred Owl removal


It?s been very interesting to read all the comments on this issue. I think I?ll
take the opportunity weigh in with my thoughts.

My concern is that if a Barred Owl (BAOW) removal plan is implemented, that
this decision will be made based on politics, not science.

We know that BAOWs are appearing in pristine old-growth forests that used to
have Spotted Owls (SPOW).
Did the Barreds eat the Spotteds?
Did they displace them (which means the Spotteds were probably eaten by
Goshawks or Great Horned Owls)?
Did the Spotteds perish from predators or starvation and the unoccupied
territory then became occupied by Barreds?

Do we know any of this? The answers to these questions are important for
assessing whether or not a removal plan would or even could be successful.

It would be incorrect to assume that SPOWs would automatically reoccupy an
area. How many are even in that particular region? Is there even a local
population that could be a source of dispersing young owls?

I'm not opposed to a removal plan if it is based on scientific information
about both species' biology and population dynamics, and that there's a
valid scientific plan to study the effects.

Mike Donahue
Seattle






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