Dear Tweets,

I am curious if anyone else has had a good chance to study this
individual and what they think the identification is; I jumped the gun
earlier on my assigning this bird outright as a Krider's Red-tailed- I
now want to be a little more cautious.

This was my description: An adult type Red-tailed with dark eye;

1. Tail was extensively white at the base, but strongly washed in bright
rufous distally- there was also a narrow dark brown subterminal band,
and white terminal band. From a distance in flight this individual's
tail
appeared white with a smudgy greyish subterminal band, and very like a
Harlan's should look. The tail may have had other dark but indistinct
banding, but I do not recall any streaking or flecking.
2. Strong reddish-brown tones to the browns of the upperparts.
3. Extensive white in the scapulars and coverts, forming a pale 'v' down
its back.
4. Wing-tips fell short of the tail.
5. Very white head, appearing white cleanly streaked in dark brown.
6. Bright white underparts, with little streaking- probably the bird's
most striking character. There was no rufous or buff wash and no breast
band.

This is what is generally said about the two forms in the literature:

Harlan's Hawk - light-phased birds: From Wheeler and Clark:
blackish-brown upperparts with some white scapular markings and vry
white underparts that lack the rufous of other races. Dark belly band is
light to moderate, and dark patagial marks are pronounced. Tails are
whitish to grayish...shows either dark mottling, usually with a smudgy
darker terminal band, or dark banding and sometimes has a rufous cast
becasue of intergrading with other Red-tails. Wingtips fall somewhat
short of tail tip. These birds show a large range of variation, some
approaching Krider's in many respects. Harlan's Hawk have been reported
in Washington state at least since the 70's, and Bud Anderson has
informed me that he has seen light phased birds on at least three
occasions in the past in Western WA. Light-phased birds are very rare
(less than 1% according to some sources) and have in the past been been
attributed to polymorphism (pure Harlan's variant) or to integration
with "krideri" (Krider's) or calurus (Western Red-tailed).

"Krider's"- Wheeler and Clark state that this form is not a race, but a
whitish form of borealis (Eastern Red-tailed). Typical adults have
upperparts heavily mottled in white, often including an all-white head.
Underparts are completely white, with little or no rufous wash on neck
and never show a belly band or flank barring. White underwings usually
show faint patagial marks. Tail is usually basally white and outer half
pale rufous. The brown in Krider's upperparts is said to be similar to
borealis, described as hair to russet brown with russet-brown or
cinnamon margins. Krider's apparently breeds in the northern Great
Plains, and winters form South Dakota and southern Minnesota southe to
central Mexico, although distribution is poorly known, and pattern of
vagrancy unknown. Pale individuals show up in various parts of the
southeast; it is not known if these are Krider's. I have not been able
to find any records of this form for the west coast.

So, I believe this bird can be safely called a light phased Red-tailed
Hawk, a tentative light-phased Harlan's, a tentative out-of range
Krider's, or an unusual intergrade (harlani x "krideri"??). I would urge
someone out there to try and photograph this bird and I would like to
read what others have seen and what they feel is a good assessment of
this individual.

Selected Sources:

Traverner, P.A. 1027. A study of Buteo borealis, the Red-tailed Hawk and
its varieties in Cannon. Canada Deptartment of Mines, Victoria Memorial
Museum. Museum Bulletin, No 48, Biological Series No. 13.

Mindell, D.P. 1985. Plumage variation and winter range of Harlan's Hawk
(Buteo jamaicensis harlani). American Birds, Vol. 39 (2) 127-133.

Lish, J.W. and W.G. Voelker. 1986. Field Identification aspects of some
Red-tailed hawk subspecies. American Birds, Vol 40 (2) 197-202.

Preston, C.R. and R.D. Beane. 1993. Red-tailed Hawk (Buteo jamaicensis).
The Birds of North America, No. 52.

Wheeler, B.K. and W.S. Clark. 1995. A Photographic Guide to North
American Raptors.
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______________________________
Alan J. Knue
bluecrow at home.com
Seattle, WA