144 
FALCONIFORMES 
easily distinguished from the other falcons by their large size, but are otherwise character- 
ized by the tarsus being feathered for one-half its length instead of only one-third, and the 
first primary being equal to or shorter, instead of equal to or longer, than the third. 
The Gyrfalcons were most highly regarded for hunting by the falconers 
of old and by the exacting laws of the times their use was restricted to 
persons of the highest rank. They combined all the spirit and hardihood 
of the smaller species with greater size and strength and hence were adapted 
for the largest game to be taken with hawks. The Gyrfalcons are of 
far northern distribution in Canada and are very rare within the limits 
of settlement, rarely troubling poultry yards or game coverts; otherwise 
a war of extermination would probably have to be waged against them as 
they undoubtedly can be very destructive. 
There is considerable difference of opinion about the relationship of 
the various forms of Gyrfalcon and no arrangement of them so far advanced 
seems to meet with general approval. The last Check-list (1931) recog- 
nizes only a single species in the New, and the Old, Worlds, instead of two 
as heretofore. 
353. Gyrfalcon. i.e gerfaut. Falco rusticolus. L, 22. A large falcon. Mostly 
white, sometimes almost immaculate; almost solidly black or anything intermediate 
between these. Adults may have a de- 
cidedly barred back, but juveniles are much 
softly striped below and extensively feather 
edged with light above. 
Distinctions. As a falcon, by toothed 
bill and pointed wings. As a gyrfalcon, by 
large size and, in one subspecies, by general 
whiteness. 
Field Marks. A very large falcon, 
said to resemble a goshawk in action. May 
be very black or very white. In the latter 
case may have a strong resemblance to a 
Snowy Owl, but note small head. 
Distribution. The Arctic regions of 
both hemispheres. In winter may appear 
almost anywhere in Canada. 
Nesting. On cliffs, or in trees. 
Subspecies. The Check-list recognizes 
three subspecies in America. The White 
Gyrfalcon (le Gerfaut blanc) Falco rusti- 
colus candicans. Predominantly white, 
sometimes almost immaculate, with sparse 
or scattered dark flecks on wing tips, wings, 
or back, and a sharply shaft-streaked crown 
(Figure 212a). The hick of markings on the 
undertail-covcrts separates this from other 
races with which it may almost intergrade. 
It breeds in the eastern Arctics to western 
Europe. All other American Gyrfalcons 
are ascribed to the Black Gyrfalcon (le 
Gerfaut noir) F. r. obsoletus, and the 
Figure 213 Asiatic Gyrfalcon F. r. uralensis; the latter 
Gyrfalcon; scale, C appearing in western Alaska and wandering 
occasionally south to Washington. It may 
occur on our west coast. The Black Gyrfalcon includes the birds covered in former editions 
of this work as F. r. obsoletus, F. r. gyrfalco, and F. r. rusticolus. The wisdom of this course 
may be questioned and the writer in inclined to restrict F. r. obsoletus to the very black 
birds of Labrador and to include the others under F. r. rusticolus. 
