Neglected sending this to the whole group, as intended.
Dave
From: daleatherman@msn.com
To: quetzal65@comcast.net
Subject: RE: [cobirds] Boulder surprising hawk kill
Date: Fri, 27 Feb 2015 10:28:38 -0700
Dave
From: daleatherman@msn.com
To: quetzal65@comcast.net
Subject: RE: [cobirds] Boulder surprising hawk kill
Date: Fri, 27 Feb 2015 10:28:38 -0700
David, Nick, Gary, et al,
Interesting observations, all. I would throw in seeing a Northern Pygmy-Owl fly past with a Steller's Jay in its talons one time in Rist Canyon west of Fort Collins. The owl is 2.5 oz (70g), the jay 3.7 (105g). The literature talks about a pygmy-owl that was threatening a Dusky Grouse (1050g) , but that report was unclear as to whether it was a predator-prey thing or territorial harassment thing. For sure, hunger and brood protection are both strong motivators.
As for Sharp-shin numbers, I was always under the impression the majority migrate south. Maybe how many stick around is somehow driven by autumn weather and the sudden cold snap we had in early November made up the minds of birds sitting on the fence, so to speak. Sort of like kestrels, Great Blue Herons, meadowlarks and other semi-hardy species that we have a few of in winter, but not in bulk. Just a thought.
Dave Leatherman
Fort Collins
Subject: Re: [cobirds] Boulder surprising hawk kill
From: quetzal65@comcast.net
Date: Fri, 27 Feb 2015 10:04:41 -0700
CC: cobirds@googlegroups.com
To: djwaltman@comcast.net
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Interesting observations, all. I would throw in seeing a Northern Pygmy-Owl fly past with a Steller's Jay in its talons one time in Rist Canyon west of Fort Collins. The owl is 2.5 oz (70g), the jay 3.7 (105g). The literature talks about a pygmy-owl that was threatening a Dusky Grouse (1050g) , but that report was unclear as to whether it was a predator-prey thing or territorial harassment thing. For sure, hunger and brood protection are both strong motivators.
As for Sharp-shin numbers, I was always under the impression the majority migrate south. Maybe how many stick around is somehow driven by autumn weather and the sudden cold snap we had in early November made up the minds of birds sitting on the fence, so to speak. Sort of like kestrels, Great Blue Herons, meadowlarks and other semi-hardy species that we have a few of in winter, but not in bulk. Just a thought.
Dave Leatherman
Fort Collins
Subject: Re: [cobirds] Boulder surprising hawk kill
From: quetzal65@comcast.net
Date: Fri, 27 Feb 2015 10:04:41 -0700
CC: cobirds@googlegroups.com
To: djwaltman@comcast.net
Sharpies take Eurasian Collared-Doves on a regular basis. The dove is almost 50% larger than the hawk by mass. This brings up a question: why are there not more Sharp-shinned Hawks around? There must be more influential constraints on the hawks population than winter food supply. Any thoughts on what those constraints might be?
Nick Komar
Fort Collins CO
Sent from my iPhone
Sent from my iPhone
I just witnessed a Sharp-shinned Hawk successfully kill a Steller's Jay. It's sitting on the ground eating the jay right now. The Steller's Jay is about the same size as the hawk, although the Sharp-shinned would outweigh the jay at about 5 oz. vs.3.7 oz. I'm amazed that a Sharp-shinned Hawk would go for a bird that large.David WaltmanBoulder County foothills, 1/2 between Boulder and Lyons
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