A R CHIB LITE O LAGOPUS. 
317 
ARCHIBUTEO LAGOPUS. 
Rough-legged Hawk. 
Archibuleo lac/opus Gray, List Genera of Birds; 1855, 3. 
DESCRIPTION. 
Sp. Ch. Form, very robust. Size large. Sternum, stout, rather wide, with the marginal indentations quite small. 
Tongue, quite fleshy, widening toward tip which is rounded but not bifid. Sterno-trachealis, weak. The glands of the 
proventriculus are arranged in five longitudinal, pyramid-shaped ridges. Coeca, very small. Sexes, similar in color. 
Light stage. 
Color. Adult. Above, everywhere uniform dark-brown, with the feathers more or less edged with whitish and ru¬ 
fous. Outer edges of primaries, ashy, while the inner webs and under surface are white, and the entire wing is obscurely 
barred with dusky. The tail is tipped with yellowish-white, and the base and nearly all the lower portion are white, the 
whole being banded with dark-brown. Sides and base of upper tail coverts, also white, and the remaining portions are 
banded with it. Sides of head, yellowish-white, streaked with sooty-brown. Beneath, everywhere pale yellowish-white, 
broadly streaked in a band on the breast with dark-brown. There is a broad continuous band of dark-brown crossing the 
middle of the body, and the under wing coverts are streaked with dusky and the tips are black. The tibia is finely barred 
W'ith wavy lines of rufous and dark-brown. The throat is also streaked with dark-brown. 
Young. Quite similar to the adult but much more decidedly rufous above and below. The top of the head is very 
light, only being narrowly streaked with brown. 
Dark stage. 
Color. Adult. Uniform sooty-black everywhere, excepting under portions of wings, base of tail, and irregular mark¬ 
ings on it, all of which are white. 
Young. Very dark, like the above described, but more or less streaked, spotted, and mottled on both surfaces with 
brown and rufous. Bill, black, orange at base of lower mandible, cere and feet, orange, iris, brown, in all stages. 
OBSERVATIONS. 
It is extremely difficult to give an idea of the variable plumage of this species. I have described the extremes, but there 
are all gradations between and in some specimens the three colors, black, white, and rufous, are almost indescribably 
mixed and in others, appear in patches. Sometimes the tibia is unspotted, being either yellowish-rufous or decidedly red¬ 
dish. The light stage b the typical lagopus of authors and previous to 1873 the dark stage was considered a species, and 
called u Sanc/i Johannis". In spite of this variation in plumage, no one in our section will fail to recognize this fine bird 
by the wholly feathered tarsus, size, and colors as described. Distributed asa summer resident throughout North America, 
north of latitude 45°; wintering in New' England and southward, at least into Pennsylvania. 
DIMENSIONS. 
Average measurements of female specimens from Eastern North America. Length, 22'30, stretch, 53 - 15; wing, 16 - 55; 
tail, 9 25; bill, ’95; tarsus, 2-75. Longest specimen, 2^'25; greatast extent of wing, 53‘80; longest wing, 17-25; tail, 9 75; 
bill, POO; tarsus, 3 00. Shortest specimen, 21 - 45; smallest extent of wing, 52 00; shortest wing, 16 00; tail, 9 00; bill, ‘90; 
tarsus, 2‘50. 
Average measurements of male specimens from Eastern North America. Length, 2(r35; stretch, 52 00; wing, 16’15; 
tail, 8 45; bill, - 95; tarsus, 2*65. Longest specimen, 2115; greatest extent of wing, 52"25; longest wing, 16 25; tail, 8’50; 
bill, 1‘00; tarsus, 2 - 75. Shortest specimen, 19 50; smallest extent of wing, 5P75; shortest wing, 15‘85; tail, 8*35; bill, *85; 
tarsus, 2‘40. 
DESCRIPTION OF NESTS AND EGGS. 
Nests, placed in trees or on rocky cliffs; they are very bulky structures, composed of sticks and twigs, arranged in a 
compact manner, lined with leaves etc. 
- Eggs, four to six in number, varying from spherical to oval in form, ashy or yellowish-white in color, spotted and blotched 
irregularly and rather faintly with reddish-brown and umber, with frequent markings of purplish. Dimensions from 
P75x212 to P82x2 26. 
HABITS. 
When the brighter and warmer days of early November have past and the icy winds, 
blowing from the northward, constantly remind us, with ever increasing force, that the 
