[birdky] LATEST BIRD QUIZ SOLUTION

From: "Palmer-Ball, Brainard (EEC)" <Brainard.Palmer-Ball@xxxxxx>
To: "BIRDKY" <birdky@xxxxxxxxxxxxx>
Date: Thu, 18 Feb 2010 10:09:45 -0500
Most who have emailed me back regarding the identity of the mystery
raptor at the KOS photo quiz link:
 
http://www.biology.eku.edu/kos/whatisit.htm

came to the same conclusion that I had initially ... this is a juvenile
"Krider's morph" Red-tailed Hawk. However, a few other photos of the
bird (now posted at the same link ... you might have to hit Refresh in
order to see them), show some additional characters. Suspecting this
would not be judged by authorities to be a "pure" Krider's morph, I
asked Brian Wheeler for a few comments on the ID of this bird ... his
reply follows:

        "This bird is a paler borealis [here borealis = normal eastern
Red-tail] but not a full Krider's because the tail is still mainly dark.
The tail is very rufous and solidly colored on the dorsal side as on a
typical borealis.  A "good" Krider's has white on at least the basal 1/3
to 1/2 of the tail. Head and belly are nice Krider's type but scapulars
not white as on many. This bird no doubt has a mix of both typical
borealis and Krider's , but it is far from "pure."  This also nicely
shows the rufous tail variant of juvenile Red-tails well. My friends
Jerry Liguori and Brian Sullivan spent time in eastern Montana and North
Dakota this summer and found many very pale Krider's (nesting) and many
intergrades with calurus and typical borealis.The birds in my books are
classic, including the older A Photographic Guide images.--BW"

Krider's Red-tailed Hawk is a curious form; it is found breeding only in
a specific geographic region (northern Great Plains) so one might think
individuals showing this distinctively pale plumage could be classified
as a subspecies of Red-tailed Hawk. However, even in the limited region
where Krider's birds breed, "classic" looking birds make up only a
portion of the population ... most look like normal Red-tails. This
being the case, you can imagine there are many individuals that are
intermediate in appearance between "classic" Krider's and "normal"
eastern Red-taileds. Many Red-tails that breed in the northern portion
of North America migrate south during fall to winter in the southern
U.S., including KY & TN. Wintering birds that show varying degrees of
influence of Krider's form are annual in occurrence in our area;
however, as you can imagine, it requires a pretty good look to determine
that an individual bird is something pretty "pure." 

One other note regarding the quiz bird of which some may not be aware
... this bird can be aged a juvenile in the original photo by the pale
iris (eye) color. As most raptors age, the color of their eyes changes
... in Red-tailed Hawks this is basically from pale gray/yellow to dark
brown.

I would like to thank Brian Wheeler for his comments on the identity of
this bird, and to Ed Schneider of Nashville, Tennessee, for the photos,
which he recently took in Cheatham County, TN. These are certainly the
nicest images of a "Krider's-ish type" Red-tail I've seen in the east
...kudos to Ed!
 
BPB
[birdky] LATEST BIRD QUIZ SOLUTION

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