Forgot the Foto.
On Sun, Jan 14, 2018 at 8:25 PM, Robert O'Brien <baro@xxxxxxx> wrote:
Well, the officials are calling the election early in favor of the
peregrine.
Since I voted for both falcons, I couldn't lose. But here's what stumped
me. (Get it?)
The bird on the stump sure seems to have a tail extending considerably
further than the wings. I could argue this point from the photos but I
won't bore you.
Now the _one_ definitive mark to separate these two species is a much
longer
tail than the folded wings in Gyrfalcon. This is sometimes said in field
guides
to be so because the Gyr has a longer tail. But I checked this and it
really ain't so.
The Gyr has shorter _wings_, proportionately to body size. On a flying
falcon,
they are basically indistinguishable by tail proportions. See statistics
below.
Now, there could be some argument about the fuzzy stump fotos, which
don't involve any measurements, but it remains a conundrum to me.
Bob OBrien
To check on proportions I copied 7 photos each of flying falcons from the
internet
and measured their full body + tail length and the length of the tail
beyond where the
secondaries 'connect' to the body. It is easy to identify that point.
Here are the statistics. There is a slight difference, with Gyr being
longer but not
statistically significant and in any even difficult to discern visually
when seen by eye.
Average ratio of tail to body length in flying falcons. % Standard
Deviation in the average %
36.1 13.4 PEFA
39.4 8.6 GYR
On Sun, Jan 14, 2018 at 5:24 PM, Jeff Gilligan <jeffgilligan10@xxxxxxxxx>
wrote:
I am in agreement with Dave.
Jeff Gilligan
On Jan 14, 2018, at 5:29 PM, David Irons <LLSDIRONS@xxxxxxx> wrote:
Definitely an mmature female Peregrine Falcon.
Dave Irons
------------------------------
*From:* obol-bounce@xxxxxxxxxxxxx <obol-bounce@xxxxxxxxxxxxx> on behalf
of Robert O'Brien <baro@xxxxxxx>
*Sent:* Monday, January 15, 2018 12:12 AM
*To:* obol
*Subject:* [obol] PEFA or GYR ?
I spent the day at the coast Jan 2, finding some interesting things and
taking a lot of photos. While searching for WW Crossbills I stopped by
Parking Lot C (SJCR). Not much was going on there birdwise
but the waves/winds/tides on the Jetty were truly spectacular.
While watching the weather I caught a glimpse of an
apparently large falcon fly low in from the east and rather clumsily
land on the distant Salicornia flats. It didn't seem to have captured
anything, looking more like it had a previous kill there. Anyhow
it was out of sight even in the low vegetation.
I've been birding a long time so I easily make snap IDs (some of
which I soon or later regret). Gyrfalcon was my reaction.
Although the bird was not visible now, several minutes
later it took off, flying farther to the west, eventually landing on a
very distant
stump. I took some flight photos (here highly magnified), decided it
was a peregrine and went back to my crossbill search.
Last night I looked at the photos; so, this is a quiz of sorts.
What do you think? If so inclined email me privately your thoughts.
If otherwise inclined reply to this post with your analysis.
I'll post the summarized responses, if any, and describe what
had stumped me.
Bob OBrien
PS If you can tolerate this sort of arm-chair birding you might
also review Mike Patterson's recent blog post, quite apropos to
my falcon encounter.
http://www.surfbirds.com/community-blogs/northcoastdiaries/
North Coast Diaries | Natural History along the Oregon ...
<http://www.surfbirds.com/community-blogs/northcoastdiaries/>
www.surfbirds.com
Back in the very early 1990’s I set up a mist-net in my back yard and
started banding Pine Siskins. I don’t remember how many I banded, maybe a
couple hundred.
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