132 
FALCON IFORMES 
SUBSPECIES. The American Rough-leg (la Ruse pattue d’Am&ique) Buteo 
lagopus sandi-johannis is separated from the European Rough-leg by being double instead 
of single phased, and thus presents an analogous case to that of the Eastern and Western 
Red-tailed Hawks where the same distinction occurs. 
This is an early spring and late autumn visitor to our marshes where 
it is to be seen beating up and down over the sere surface, dropping occa- 
sionally into the grass, and then resorting to some nearby fence-post or 
other little elevation to devour its catch. More commonly, however,. it is 
noted circling in large, loose flocks, so high in the air as to be seen with 
difficulty, and slowly drifting north or south on its migrations. 
Economic Status. Its talons are small and weak for so large a bird, 
and it confines its attentions to small mammal game. It may sometimes 
pick up a wounded bird left by the shooters, but occasions of its taking 
anything of economic value are practically unknown. 
Though one of our largest hawks, it is among the three least harm- 
ful. Of 45 stomachs examined: 40 contained mice; 5, other mammals; 
1, lizard; 1, empty. A record like this is enough to condemn the indis- 
criminate killing of hawks. It is a mouse-hawk par excellence. It also 
feeds on grasshoppers and has been known at times to do most excellent 
work controlling plagues of these destructive insects. 
348. Ferruginous Rough-leg. squirrel hawk, gopher haw k, chap-haw k, 
la buse pattue couleur de ROUILLE. Buleo regalis. L, 24. Plate XV A. A character- 
istic light plumage is shown in the plate. There is also a complete '“black” phase, that 
is inseparable in colour from the dark Swainson’s Hawk. A lighter coloration has all the 
underparts pure, uniform white, very slightly streaked, and the pantaloons or thighs 
white, or heavily barred with dark rusty in striking contrast with the white abdomen and 
breast. The whole tail may be white, but usually darkens slightly towards the tip 
(Figure 193). 
Ferruginous Rough-legged Hawk; scale, 
Appearance in flight of extreme light phase. 
Distindions . Easily recognized as a Rough-leg by its feathered tarsi (Figure 190'. 
The breast show T s a large amount of pure white, which the American Rough-leg never does, 
and it never has the general ochraceous tone nor the sharply defined, dark, abdominal 
band of that species. The tail is white, often gradually darkening towards tip, but never 
with w T ell-defined, dark, terminal band. In no plumage has it the patternless intermixture 
of black and light seen in the adult American Rough-leg. The most certain and final 
distinction, however, between these two species, is the shape of the bill. That of the 
Ferruginous when examined from above is wide and heavy at the base instead of narrow 
and constricted, and presents a "frog-mouth” appearance (Compare Figures 195 and 192). 
