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WebExtra Feature—supporting material for "Comparison of Harlan's with Western & Eastern Red-tailed Hawks" Birding Volume: 42 Number: 2 Pages: 30-37.
 

Harlan's Hawk Photo Captions

Fig. 1 – Adult light-morph Harlan's Red-tailed Hawk, California, January. A slightly atypical individual with much red in the tail and a thick subterminal band. White is limited to the base of the central tail feathers, and gray mottling is somewhat restricted on the base of the outer tail feathers. We consider this a Harlan's, but it does have overlapping traits with Eastern. Photograph by Brian Sullivan.

Fig. 2 – Adult light-morph Harlan's Red-tailed Hawk, Mississippi, December. White-headed, reddish-tailed (and whitish-tailed) Harlan's pose several questions. They have not been seen at Gunsight Mountain, AK, so one could surmise that white-headed Harlan's are not breeding in southwest or west-central Alaska. These white-headed birds could represent Harlan's from the southeast part of their range, which could extend into northern Alberta and some of which may be intergrades with Krider's. Interestingly, light-morph Harlan's outnumbered dark-morphs in the Mississippi Delta region 4:1; a ratio that is well off the population average of 1:10, suggesting the ratio may differ regionally. Photograph by Brian Sullivan.

Fig. 3 – Adult light-morph Red-tailed Hawk (left), Utah, November. A difficult adult to classify in that it has a red tail with limited brownish-gray mottling at the base and white breast as on Harlan's, but buffy leggings and strong rufous tone on the underwings; two characters that favor Eastern. This bird is a Harlan's or possibly a Harlan's x Eastern intergrade. Right, an Eastern-looking bird, note unbanded retained juvenile P8-10 but whitish chest. This bird is an Eastern or possibly a Harlan's x Eastern intergrade. Alaska, April. Photographs by Jerry Liguori.

Fig. 4 – Adult light-morph Western Red-tailed Hawks showing variation in tail pattern (note lighting). The bird at left, a Utah breeding bird, has white highlights in the tail, a trait rarely shown in Western. The bird at right is more typical, but the tail appears to have white highlights only because it is backlit and fanned. Left, May, photograph by Adam Hutchins. Right, Utah, November, photograph by Jerry Liguori.

Fig. 5 – Two examples of adult light-morph Red-tailed Hawks that are not Harlan's showing clear white breasts. The bird at left is a Utah breeder. The bird at right, a Utah wintering bird, is interesting as it appears to look more like an Eastern than the expected Western in Utah. Left, Utah, April. Right, Utah, December, both photographs by Jerry Liguori.

Fig. 6 – Two examples of adult dark-morph Harlan's Red-tailed Hawks with rufous-brown wash on the breast. It is unknown whether Harlan's with rufous breast represent intergrades, or if these are within the range of typical variation. Harlan's that do show fully rufous breasts often have boldly banded tails. Left, Alaska, April, photograph by Jerry Liguori. Right, Oklahoma, January, photograph by Jim Lish.

Fig. 7-10 – Four examples of adult Red-tailed Hawks showing intermediate characters between Harlan's and Western. It is unknown whether this is simply variation within Western, or whether these birds represent Harlan's x Western intergrades. However, all three birds are similar to the Utah breeder in Fig. 11c of Birding. Note bottom bird has retained juvenile P10 that lacks banded tip typical of Harlan's. Top; Oklahoma, January, photograph by Larry Hancock. Second, California, January, photograph by Brian Sullivan. Third, Oklahoma, January, photograph by Larry Hancock. Bottom, Nevada, October, photograph by Anna Peterson.

Fig. 11-14 – Adult dark-morph Western Red-tailed Hawks showing variation in tail pattern, which can range from dark brick red to a more washed out orange, but most are heavily banded with wide subterminal band. Note displaced central tail feather showing white on bottom right. Body plumage ranges from all blackish brown to brown with clear vinaceous tones on the breast. The color on the breast is shared by some dark Harlan's. Top left, California, January, photograph by Brian Sullivan. Top right, a Utah breeding bird, May, photograph by Jerry Liguori. Middle left, a Utah breeding bird, May, photograph by Adam Hutchins. Middle right, bottom left, bottom right, Oklahoma, January, photograph by Larry Hancock.

Fig. 15-16 – Adult light-morph Red-tailed Hawks showing white tail bases. The bird on top is at least part, and perhaps all Krider's showing more typical Krider's underparts. The bird on bottom is likely a Krider's x Eastern intergrade. Both captured at New York, April, photographs by Jerry Liguori.

Fig. 17-19 – Adult Eastern Red-tailed Hawks showing mild Harlan's-like tail characteristics. The bird at left is more like the Canadian form described as B. j. abieticola, and has one retained juvenile tail feather, but the adult tail feathers have dark barring concentrated at the base. The bird at middle is a typical Eastern, but shows some longitudinal grayish-brown tail markings similar to some Harlan's. The bird at right is a heavily marked Eastern showing minor longitudinal grayish tail markings. Left and middle, New York, April, both photographs by Jerry Liguori. Right, Minnesota, September, photograph by Stephen Wilson.

Fig. 20 – Adult light-morph Red-tailed Hawk presumably of the Canadian form B. j. abieticola. This bird is a heavily marked extreme of this form. Note very heavily marked underparts, mixed throat and boldly banded tail. This form has been considered as a valid subspecies, an intergrade between Eastern and Western, or a heavily marked Eastern. More research is needed to resolve this issue. Minnesota, October, photograph by Stephen Wilson.

Fig. 21 – A typical light-morph Western Red-tailed Hawk with strong rufous wash on the underparts, and Western tail pattern with some gray at the base. A small amount of gray at the tail base (typically much more obvious on Harlan's) is not unusual in the Western subspecies. Nevada, October, photograph by Jerry Liguori.

Fig. 22-25 – Adult Western Red-tailed Hawks showing tail plumage overlap with typical Harlan's. The first three birds are typical in body plumage for light-morph Western, but show minor grayish tones on the outer tail. The bottom bird shows white highlights in the tail, but is a typical Western otherwise. Top, Nevada, September, photograph by Jeremy Russell. Second, Nevada, October 1999, photograph by Jerry Liguori. Third, Nevada, October, photograph by Kara Donohue. Bottom, Montana, September, photograph by David Ellis.

Fig. 26-29 – Adult dark-morph Western Red-tailed Hawks showing variation in tail pattern on individuals with vinaceous (not rufous-orange) breasts. The top bird has strong vinacous-rufous tones, and is somewhat intermediate in this regard. It also shows white highlights in the tail. The second bird shows faint vinaceous breast coloration, and a red, unbanded tail. The third bird has a vinaceous breast, but a more typically banded tail. The bird on bottom shows a similar breast, but wavy tail bands and faint grayish tones. Top, Nevada, October, photograph by Sarah Frey. Second, Nevada, October, photograph by Jerry Liguori. Third and bottom, Nevada, October, photographs by Jeremy Russell.

Fig. 30 – Adult dark-morph Red-tailed Hawk. This bird shows mostly Western characteristics but is difficult to classify. It has wholly brown underparts, and a mostly red tail. The slight black mottling on the tail may suggest Harlan's ancestry, yet it's impossible to know for sure. Colorado, December, photograph by Stephen Wilson.

Fig. 31 – Second-year dark-morph Red-tailed Hawk. This bird has thick tail bands with hints of gray and white with a slightly smudged tip, a retained juvenile tail feather that has wide dark bands, and importantly three retained outer primaries that are boldly banded indicating Harlan's ancestry. This bird is wholly, or mostly Harlan's, but has much red in the tail. Montana, September, photograph by Stephen Wilson.

Fig. 32 – Adult dark-morph Red-tailed Hawk with dark brown body, slightly rufous underwing coverts, but some suggestion of white mottling on the breast possibly due to being handled. The tail pattern is a little too confused to safely fall within the variation of Western. This bird is atypical of Western or Harlan's and may be a Harlan's x Western intergrade. Montana, September, photograph by Stephen Wilson.

Fig. 33-38 – Adult Harlan's Red-tailed Hawks. These birds all fall within the typical range of what we consider to be Harlan's. Note variable tail pattern, flight feather banding, blackish tones to dark morphs, and snow white underparts of light morphs.
(33, 37) Nevada, January, photographs by Al Hinde.
(34) Minnesota, November, photograph by Stephen Wilson.
(35, 36) Montana, October, photographs by Stephen Wilson.
(38) Colorado, January, photograph by Stephen Wilson.

Fig. 39 – Adult Eastern Red-tailed Hawk, Gunsight Mountain, Alaska, photograph by Jerry Liguori. Note typical Eastern plumage below, and the unmarked red tail with thin subterminal band. The authors observed several typical Eastern Red-tailed Hawks during mid-April on migration in central Alaska, perhaps the first documented for the state.

Fig. 40-43 – These Adult light-morph Red-tailed Hawks all show characters consistent with northern breeding Eastern Red-tailed Hawks (B. j. abieticola), and are inconsistent with the known variation in Harlan's. These are perhaps the only photographs of Eastern and Western Red-tailed Hawks from central Alaska, and possibly indicate that these two subspecies occur more widely in Alaska than previously thought. Note heavily marked bellies, buffy tones underneath, and multiple tail bands and darkish throats (not seen on light-morph Harlan's) on several. Bottom photo is of two individuals that are possible Easterns, but most likely Westerns. All photographed at Alaska in April by Jerry Liguori except bottom right by Brian Sullivan.

Fig. 44 – Adult dark-morph Western Red-tailed Hawk, Gunsight Mountain, Alaska, mid-April, photograph by Jerry Liguori. At least 32 birds showing characters of rufous or dark-morph Westerns were seen on migration in Alaska in 2009. Many birds were too distant to categorize but this distant bird clearly shows the all red tail typical of Westerns, and rufous breast.

Fig. 45-46 – Adult rufous-morph Western Red-tailed Hawks, Gunsight Mountain, Alaska, April. These four birds all show orange-rufous breasts and typical Western tail patterns. Photographs by Jerry Liguori.