FALCO. 15 
Genus FALCO. 
The genus Falco was established by Linneus in 1766, in his ‘Systema 
Nature,’ i. p. 124. At the present day it is impossible to make even a 
guess at the species which Linneeus considered typical; but as the deci- 
piter falco of Brisson is the Peregrine Falcon, this species may safely be 
accepted as the type. 
The true Falcons may always be distinguished by their long pointed 
wings, the first primary being nearly equal to the third, and much longer 
than the secondaries. The bill is deeply notched. The lower half of the 
tarsus is entirely covered with small hexagonal reticulations, and is never 
feathered. The tail is somewhat rounded. . 
This genus is almost cosmopolitan in its range, being only absent from 
the Pacific islands. Of the British species of this genus, four breed in our 
islands, and four or five more are accidental visitors. 
Most of the Falcons feed on small mammals and birds; but some occa- 
sionally eat insects. 
Their nests are generally placed in trees or rocks, but sometimes on the 
ground. The eggs vary from white, more or less richly marked with red- 
brown, to an almost uniform red-brown. ; 
In the genus Falco the female is always larger than the male, and in 
some species differs from her mate in the colour of her plumage; but even 
in these cases very old females sometimes assume the plumage of the male. 
The young in first plumage always differ from their parents. They retain 
their immature dress through their first winter, and moult into the adult 
plumage during the following summer. 
