Subject: [Tweeters] unusual bird behavior
Date: Nov 25 20:43:42 2010
From: Jeff Kozma - jcr_5105 at charter.net


Thanks, Joe and Dan, for your replies. I have been thinking about this all afternoon and one thing I noticed is that when a kestrel hunts birds in my yard, it makes a pass over my feeder area, the birds scatter into the shrubs and trees, and the kestrel goes on its way if it doesn't connect with a bird. Sometimes it will perch on the fence or on a roof top, but then really doesn't pursue the birds. The birds seem to also know that the kestrel won't dive into vegetation after them like a Sharp-shinned Hawk (SSHA) will. The birds in the vegetation will move around and call scolding at the kestrel. However, when a SSHA hunts in the yard, birds scatter into any cover and freeze instantly. SSHA will dive into shrubs, run on the ground under vegetation then fly up in too it to get birds to flush. Even when a SSHA makes a kill, eats the bird, and then leaves, I often will flush birds out of vegetation in my yard for sometimes 20 or 30 minutes after the SSHA has left...birds that were obviously hiding when the SSHA was dining, but still felt they didn't want to appear when the SSHA is present. Perhaps SSHA are really much more perceived as potential danger than a kestrel...because with a kestrel, they simply have to dive into cover to escape...not so with a pursuing SSHA.

Anyway, it has been great fun to speculate on this behavior and I feel fortunate to be able to witness such natural events from only a few feet away behind glass. Pretty special. Too bad I didn't get to see how the kestrel caught the bird and how the other birds reacted. I only saw the aftermath. By the way, the bird captured was a male House Finch. Since I counted 122 House Finches in my yard today at one time, I guess one less won't be missed!

Jeff Kozma

Yakima


From: Joseph BC Mackie
To: notcalm at comcast.net ; Jeff Kozma
Cc: Tweeters
Sent: Thursday, November 25, 2010 7:00 PM
Subject: Re: [Tweeters] unusual bird behavior


Hello Birders,

Over a few years of observation, my impression has been that prey of falcons and accipters are generally quite perceptive, i.e., if the predator has been successful in its hunt and is actively feeding or recently satiated, they seem to resume foraging with apparent immunity to the presence of said predator. They can tell if they're imminent potential targets or not by the behavior of the predator.

Cheers,
Joe Mackie
Bellingham
----- Original Message -----
From: notcalm at comcast.net
To: Jeff Kozma
Cc: Tweeters
Sent: Thursday, November 25, 2010 6:09 PM
Subject: Re: [Tweeters] unusual bird behavior


Hello Jeff,


Wow. How special to have a Kestrel in your yard!



I have observed Merlins and many Peregrines and a few Coopers and Sharp-shinned be near flocks of birds and the prey species and others appear more vigilant but continue feeding. After a falcon completes giving chase, the birds will land and begin feeding, sometimes close to where the Falcon is eating. I wonder how the birds were behaving before the Kestrel gave chase?


My observations and speculation have been that birds become hyper-vigilant and often more vocal when birds of prey are nearby in preparation for chase, but often remain feeding if they are on prime feeding grounds and quickly return following the chase to feeding at the same site if it provides a scarce or rich food source.


Like my Robin story yesterday, bare ground was very scarce, but a large group of them appeared and fed when I accidentally removed snow from small area of grass next to our driveway. They fed voraciously, in an unusually linear, dense cluster. Your rich and scare food source was probably necessary and the birds needed to stay. Perhaps if this was Summer and food was abundant they would have left.


Last year, I was filming a tightly clustered group of Pectoral Sandpipers in a Marsh, when a Merlin took one right in front of me, within seconds, a young Peregrine chased the Merlin, which dropped the SP. The peregrine then ate within close range of the original SP feeding site. The Pectorals took flight and landed within a short time (seconds) and distance and resumed feeding.


Dan Reiff
----- Original Message -----
From: "Jeff Kozma" <jcr_5105 at charter.net>
To: "Tweeters" <Tweeters at u.washington.edu>
Sent: Thursday, November 25, 2010 4:16:27 PM
Subject: [Tweeters] unusual bird behavior


Hi Tweeters,

When the weather gets really cold, and especially with snow on the ground, I
sometimes get a kestrel that visits my yard to attempt to pick of a bird to eat.
This afternoon, I looked out the window and saw the usual juncos and House
Finches feeding in the yard. I looked on the other side of my feeding area and
there was a male kestrel on the ground that was in the middle of eating a bird
it had caught. It was almost completely plucked and about half eaten so I
haven't identified the bird caught yet. What I was amazed at was that the birds
feeding in the yard were acting like it wasn't there. When it took off to my
neighbors roof to finish eating the bird, the birds in the yard never flushed
and kept on feeding like nothing was going on. Do birds not perceive the
kestrel as a threat? When a Sharp-shinned Hawk is in the yard eating a bird,
other birds completely disappear and do not return until the hawk has been gone
for some time. I know that kestrels prey on birds (although this is the first
time I have seen a kestrel eating an adult bird in my yard), especially young
birds and nestlings. I am totally perplexed as to why the birds in my yard
ignored the kestrel.

Any thoughts?

Jeff Kozma

Yakima (Terrace Heights)

j c r underscore 5105 at charter dot net



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