Hi Everyone,

Many Maryland eBird users have noted that there have been two forms of Red-tailed Hawk listed as options on our eBird checklists: Red-tailed Hawk (Eastern) and Red-tailed Hawk (Canadian). The former is the expected breeding and wintering subspecies in our area. The latter is a rare but regular (and poorly understood) form in the Eastern U.S. 

Here are some notes on the "Canadian" form compiled by Marshall Iliff:

"Red‑tailed Hawk (Buteo jamaicensis abieticola)
Regular. Migrant and winter visitor.

An uncommon to rare migrant and wintering (Oct-Apr) subspecies in Maryland, abieticola breeds in the spruce-fir forests of eastern Canada but is highly migratory and winters extensively throughout the East. Dickerman & Parkes (1987) report two Dorchester County specimens: an adult from E. New Market, 10 Mar 1980 (USNM 598208) and an immature from Cambridge, 30 Nov 1980 (USNM 598209). This form is documented with several photos from Washington (J.L. Stasz), Anne Arundel (M.J. Iliff), and Harford counties (M.J. Iliff). It may winter more commonly in western Maryland and least commonly on the Eastern Shore. Liguori (2001) points out that peak spring migration of this form is somewhat later (mid- to late Apr) than for borealis (late Mar to early Apr).  

Although Preston & Beane (1993) say that this subspecies 'is not generally recognized,' it is fairly distinctive and I follow Todd (1950) and Dickerman & Parkes (1987) in giving it full treatment. Adults should generally be field identifiable, and differ from borealis Red-tailed Hawks in having dark throats, darker backs, extensive heavy black streaking on the belly which often forms a thick belly band or an almost entirely dark belly, and more strongly-marked chests which are often heavily marked with broad, indistinct streaks and washed strongly with orangeish or rufous (Parkes 1996, Liguori 2001, M.J. Iliff pers. obs.). Some individuals have narrow bands on the tail, and such individuals are essentially identical to light morph calurus Red-tailed Hawks, which are probably not safely separable in the field (Liguori 2001). Abieticola also molt more slowly, and typically retain more flight feathers during a given molt period than do borealis (Liguori
 2001). Figures #10-14 and #21 in Liguori (2001) are some of the only published photos available for this form, and he provides important cautionary notes on the identification of this form."

As addressed by Marshall, there is contention about the validity of the subspecies. However, these birds are quite distinctive and, if anything, their uncertain status makes it all the more important that we track sightings of them. 

To date, I have photographed one bird that might be ascribed to this form:
http://www.billhubick.com/images2/red-tailed_hawk_dark_so_md_20081123.jpg

Because this is a rare form in Maryland, we have decided to remove the option "Red-tailed Hawk (Canadian)" from the default Maryland eBird checklists. This will help ensure that it is not erroneously reported for normal Red-tails. To add this subspecies to your checklist, click "Rare Species", then in the "Add Species" box, start typing "Red-tailed Hawk". It will list the various options, from which you can select "Red-tailed Hawk (Canadian)". If you are reporting this form, please take a moment to describe any features that led to the ID as a non-Eastern Red-tailed Hawk. The dark throat alone is probably good enough to warrant the report. As always with subspecies, documentation via photos or video is valuable.

In summary, I hope everyone will keep an eye out for this poorly understood form and report it when observed. I will remove the form from the default county checklists today, so it will no longer be shown unless you manually add it. Many thanks!

Good birding!

Bill

Bill Hubick
Pasadena, Maryland

http://www.billhubick.com