Ferruginous Hawk
Buteo regalis
Summary 6
The ferruginous hawk (ferruginous = from Latin ferrum – iron, ferrugin-, iron rust, iron-rust color – reddish-brown), Buteo regalis (Latin, royal hawk), is a large bird of prey and belongs to the broad-winged buteo hawks. An old colloquial name is ferrugineous rough-leg, due to its similarity to the closely related rough-legged hawk (B. lagopus).
Identification 7
The male and female have identical markings. The main difference is size, with the female being somewhat larger. Perched birds have a white breast and body with dark legs. The back and wings are a brownish rust color. The head is white with a dark streak extending behind the eye. The wingtips almost reach the tip of the tail.
The underside is primarily light colored with the dark legs forming a "V" shape. The reddish upper-back color extends to the inner wing-coverts or "shoulders." The primary remiges (pinions) are dark gray with conspicuous light "windows" in the inner primaries. Three prominent light areas on the upper surface stand out as two "windows" on the outer wings and a rufous rump mark, perhaps the most significant feature of a flying ferruginous hawk. The underwings are whitish overall with rufous markings, particularly in the patagial area. This gives a smudgy appearance to the wings, but less dark than in a red-tailed hawk. The ferruginous hawk is noticeably longer winged than a red-tailed hawk, although the wings appear slenderer than the latter species the total wing area of the ferruginous is considerably more. However, the Red-tail can be nearly as bulky and heavy. Dark "comma"-shaped markings are prominent at the wrists. The ferruginous hawk is one of the only two hawks that have feathers that cover their legs down to their toes, like the golden eagle. The other is the rough-legged buzzard (Buteo lagopus). The pale morph of the closely related but more slender rough-legged species is best distinguished by its darker coloration, with a broad black tail band and a dark band across the chest. The dark morph Rough-leg is more a slaty coloration than the more brownish dark morph ferruginous. Swainson's hawks and especially rough-legged buzzards can be nearly as long-winged but are less bulky and heavily built than the ferruginous. Among the normal standard measurements, the wing chord measures 415 to 477 mm (16.3 to 18.8 in), the tarsus measures 81 to 92 mm (3.2 to 3.6 in) and the tail measures 224 to 252 mm (8.8 to 9.9 in). Additionally, the grasp is 94 to 125 mm (3.7 to 4.9 in) and the third toe 29.5 to 45 mm (1.16 to 1.77 in), indicating that the ferruginous hawks has the largest and most robust feet of any of the world's Buteos. Compared to other Buteos, the ferruginous has a larger bill, at 37.6 to 49.5 mm (1.48 to 1.95 in), with a much wider gap when the bill is opened, at 42.7 to 57 mm (1.68 to 2.24 in).
In-flight, these birds soar with their wings in a dihedral.
Voice 7
The voice is not well-described in literature. Alarm calls consist of kree – a or ke – ah and harsh kaah, kaah calls, the latter resembling some vocalizations of the herring gull. One description referred to the "wavering" alarm call and "breathy" notes, while other authors describe screams similar to those of the red-tailed hawk (B. jamaicensis).
Sources and Credits
- (c) dplawrance, some rights reserved (CC BY-NC-ND), uploaded by dplawrance
- (c) Jamie Chavez, some rights reserved (CC BY-NC), https://www.flickr.com/photos/almiyi/32930841388/
- (c) Greg Lasley, some rights reserved (CC BY-NC), uploaded by Greg Lasley
- (c) Mathesont, some rights reserved (CC BY-NC), https://www.flickr.com/photos/44055945@N06/8252608509/
- (c) Donna Pomeroy, some rights reserved (CC BY-NC), uploaded by Donna Pomeroy
- Adapted by Hayden Wright from a work by (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Buteo_regalis
- (c) Wikipedia, some rights reserved (CC BY-SA), https://en.wikipedia.org/wiki/Ferruginous_hawk
