314 
SWAIN SON'S HAWK 
Light stage. 
Color. Adult male. Above, dark-brown everywhere, lightest on the head, becoming darker on the wings and ashy 
on the tail, with the feathers more or less edged with rufous, especially on the neck. The wings are obscurely barred with 
dusky and the tail is tipped with whitish and is crossed with about twelve wavy lines of dusky. Concealed patch on oc¬ 
ciput, white. Sides and base of upper tail coverts, white, barred with rufous and sooty-brown. Beneath, everywhere, 
white, pure on the throat but tinged on the remaining under portions with yellowish-rufous, while the breast is banded 
with reddish-brown, which has an ashy overwashing, but every feather of this portion is streaked in the centre with dark- 
brown. The sides, flanks, and under tail coverts, are barred with rufous. There is a spot of black on the tips of the un¬ 
der wing coverts. 
Adult female. Much darker above than the above described and the lower portions are strongly tinged with rufous, 
barred with a deeper shade of the same color. The flanks are barred and streaked with dark-brown. Otherwise as in 
the male. 
Young. Quite similar to the adult above but much more decidedly rufous, and the outer webs of primaries and tail 
are edged with ashy. Below, yellowish-rufous, tinged with ashy, thickly, marked with drop-shaped spots of brown which 
crowd together on the breast so as to form a band. The flanks are also barred with dusky. 
Dark stage. 
Color. Adult. The throat, under wing and under tail coverts are as in the light stage but the remaining portions 
are very dark-brown, or nearly black, but the bandings on the wings and tail are as described. There are occasionally 
rufous markings below, especially in the female. 
Young. Very dark, but showing strong traces of rufous on both surfaces. Bill and iris, brown, cere, greenish, and 
feet, yellow, in all stages. 
OBSERVATIONS. 
The young is the “ Bairdi ” of authors, while the dark type is “ insignatus ”. There is considerable variation in plum¬ 
age, for specimens occur in all gradations between the light and dark stages; but this species may be recognized by the 
white throat, incision of but three outer quills, combined with the size and colors as described. Distributed throughout 
Western North America. Rare in Illinois and accidental in Canada and Massachusetts. 
DIMENSIONS. 
Average measurements of male specimens from Western North America. Length, 19 - 55; stretch, 47'85; wing, 15 25; 
tail, 7‘00; bill, ‘82; tarsus, 2*52. Longest specimen, 20'63; greatest extent of wing, 48 50; longest wing, 15 50; tail, 8'50; 
bill, "85; tarsus, 2 - 60. Shortest specimen, 18 75; smallest extent of wing, 47’25; shortest wing, 15 00: tail, 7'50; bill, ‘80; 
tarsus, 2’45. . 
Average measurements of female specimens from Western North America. Length, 20*25; stretch, 49*25; wing, 10*00; 
tail, 8*50; bill, *95; tarsus, 2*60. Longest specimen, 21*50; greatest extent of wing, 5T00; longest wing, 10*50; tail, 9*32; 
bill, TOO; tarsus, 2*70. Shortest specimen, 18*80; smallest extent of wing, 47*00; shortest wing, 15*50; tail, 8*25; bill, ‘85; 
tarsus, 2-50. 
DESCRIPTION OF NESTS AND EGGS. 
Nests, placed in trees or bushes; they are quite bulky structures, composed of sticks and twigs, arranged in a com 
pact manner. 
Eggs, four to six in number, varying from spherical to oval in form, yellowish-white in color, spotted and blotched irreg¬ 
ularly and rather faintly with reddish-brown, with occasional markings of purplish. Dimensions from 1'75 x2'30 to 182 
x2 32. 
HABITS. 
The first record of the occurrence of this species east of the Mississippi, was made from 
a specimen taken in the vicinity of Montreal, Canada, about the year, 1854, nothing more 
being heard of it in this section until one was obtained in Salem, Massachusetts, in 1873. 
Then Mr. E. W. Nelson found them breeding on Fox Prairie, Illinois, in 1875 aud obtained 
four specimens, and Mr. William Brewster makes record of a specimen which was taken 
at Wayland, Massachusetts, in September, 1876. Thus we are obliged to give Swainson’s 
Hawk a permanent place in our fauna, although it is yet very rare east of the Mississippi. 
