Subject: Re: kingbirds
Date: Jun 12 13:37:19 1995
From: Don Baccus - donb at Rational.COM


>I meant to mention after my trip to the Columbia Basin that Common Raven
>nests were common on the big power towers near Dodson Road. Here's a
>significant nest predator that's been aided and abetted in its occurrence
>by humans.

Yes, indeed, to such an extent that they've become a real problem
in some areas.

Malheur NWR now practices raven control (by a corvid-specific
poison placed in chicken eggs, for those worried about non-target
species being impacted) in some years, at least. They now nest
on power poles in numbers far above those of several decades ago,
and have been one factor in the decline of the Greater Sandhill
Crane in the area. There were documented pairs of Greater Sandhill
which had not succesfully fledged young in over a decade due to
raven and coyote predation. While the latter is largely due to
grazing and haying practices on the refuge (gawdamnit) the former
is not.

PAS was involved in the decision-making process on this issue,
and after some deep thought and lobbying by the independent biologist
who'd studied the crane out there for over ten years (C.D. Littlefield,
one very strange dude who does know a lot about crane) we concurred
with the decision to implement predator control.

Relunctantly. Doubly so in the case of coyotes, since changes in
grazing and haying practices could've removed the need to do so
(or, at least, reduced the need). Such changes were not politically
achievable, however. Since I've brought this up, I should point
out the relationship: haying occurs before the sandhill chicks have
fledged, and drainage of the flooded areas occurs even earlier. This
gives the coyotes access (they don't swim to prey that often, though
I'm sure they've been known to) and the reduction of cover after
haying leaves the young crane with no effective escape.

Raven predation crane eggs probably needs no explanation to this
group.


- Don Baccus, Portland OR <donb at rational.com>