Regarding the grouse roosting near an owl:

I have read of prey fish gathering around a predator fish in terms of
signaling to the predator that it has been detected, and thus, pursuit
will be less likely to result in capture. Don't small birds do this with
accipiters?

A second theory might be that by grouping, each grouse reduces the
probability of an attack on itself through dilution effects (e.g.,
Hamilton 1971, Bertram 1978, Viscido et al. 2001). And perhaps an attack
on a group is less likely to succeed simply because the scattering of
prey may be more confusing to the predator?

Regarding Pine Siskins:

During the recent heavy and incessant rains, I observed a siskin perched
the entire day on or near my front porch. It obviously wasn't in the
best of health, and no other siskins were around. I could approach it
closely, but that's not too unusual for siskins. A few days later, I
noticed what looked like this same "weak" individual and one other
feeding on the ground near my feeder. The fact that there was no flock
around reinforced my feeling that both were probably less than healthy.
I doubt a dead siskin would last long in my yard with the Doug squirrels
and raccoons and crows making the cleanup rounds day and night.

Finches: I always have more Purple Finches than House Finches during the
breeding season. I live on Cooper Point sort of between the golf course
and Evergreen. There is a large undeveloped, early-successional Doug-fir
forest lot across the street from my particular yard, which may make a
difference? I'll try to do more observations this breeding season.

Angela Percival
Olympia, WA
Angela at Stillwatersci dotcom

------------------------------
Message: 5
Date: Wed, 14 Jan 2009 15:59:17 -0800
From: "Paul Webster" <paul.webster at comcast.net>
Subject: Re: [Tweeters] Waterville Plateau and Okanogan Highlands Owls

...But a few moments later someone located a half-dozen Sharp-tails in a
tree relatively close to the owl. Why would this be? Perhaps they feel
safe near this big predator if there are several of them? Perhaps the
owl won't attack a group of them? Or perhaps it's because it was daytime
and the owl hunts only by night? Does anyone know?

Paul Webster
------------------------------
Message: 13
Date: Wed, 14 Jan 2009 23:08:04 -0800
From: "William Markey" <wmarkey at clearwire.net>
Subject: [Tweeters] Pine Siskin mortality

When I was filling feeders yesterday, I found two dead Pine SIskins.
One on
the ground and one on a tray feeder. Today, I found another on the
ground.

Has anyone noticed any dead birds around their feeders?
-
Will Markey
Auburn (Soos Creek), WA