188 
333. Cooper’s Hawk, chicken hawk. Accipiter cooperi. L, 15*50. A rather 
small Hawk, between the Sharp-shinned and Goshawk in size (Figure 202 — 4). Almost 
exactly similar in colour and plumage sequence to the Sharp-shinned Hawk (See Plate 
XXV A and description of that species) but larger. 
Distinctions. Easily separated from the smaller Falcons, the Sparrow Hawk, and the 
Pigeon Hawk, by its accipitrine characters of round wing and untoothed bill (Figures 
205 and 206, compare with 228 and 229). 
Most likely to be confused with the 
Sharp-shinned or Broad-winged Hawks. 
Usually separated from the Sharp- 
shinned by larger size; but a small male 
may measure closely to the size of a 
large female of that species. A bird 
over 16 inches will be this species; 
under 14, a Sharp-shinned. The tarsus 
of Cooper’s Hawk is heavier and the 
tail is rounded instead of being square 
or slightly forked when closed (Figure 
209, compare with 208). 
Occasional very large females may 
approach a small Goshawk in size. A 
bird 19 inches or under will be a Cooper’s 
Hawk. In no plumage does it resemble 
the adult Goshawk, but juveniles of the 
two species have a very similar color- 
ation. The best distinction other than 
size is the feathering of the leg. In 
Cooper’s Hawk, less than one-half of the 
tarsus is feathered, in the Goshawk, one- 
half or over (Compare Figures 209 and 
211). The Cooper’s Hawk is also 
similar in size and colour to the Broad- 
winged Hawk. The latter, however, is 
a Buteo and not an Accipiter. with a 
deeper wing and a chunkier build. The best colour distinction, however, is the under- 
wing surface. In Cooper’s Hawk it is sharply and regularly barred to the primary tips, 
in tne Broad-winged it is mostly creamy white with but suggestions of bars. In Cooper's 
Hawk the first five primaries are emarginate, in the Broad-winged but three (Compare 
Figures 209 and 215). 
Figure 209 
Specific details of Cooper’s Hawk; 
foot and tail; scale, I; 
wing tip; scale, J. 
Figure 210 
Cooper’s Hawk (juvenile); scale, 
Appearance in Sight. 
Field Marks. A small Hawk between the Sharp-shinned and Broad- winged in size 
(Figure 202 — 4). Short, round wings regularly barred below, long tail (Figure 210), and 
flight— when not under a burst of speed, a series of quick even strokes and short sails — 
