OWLS AND DIURNAL BIRDS OF PREY, 357 
at the base. The naked portion is covered in front with 
transverse plates, and behind with smaller polygonal scales, 
The toes are moderate, the claws slim, curved, and sharp. 
In their habits all the species are very similar. They are 
generally seen flying over marshes or open grassy lands with 
heavy flaps of the wings, beating up and down for their prey, 
which consists largely of frogs, reptiles, insects, and small 
mammals. They are somewhat crepuscular, and generally 
perch and roost on or near the ground. In many species the 
male and female have a very different plumage, and the best 
way to identify the various forms is by the “notch” or 
indentation in the outer web of the larger primaries. This 
“notching * is characteristic of the larger wing quills in most 
birds of prey. From the base to this wavy indentation the 
barbs of the quill are set at an angle of about 45° to the shaft. 
From the “ notch ” to the tip the barbs, though no shorter in 
length, are set at a much more acute angle, thus considerably 
reducing the width of the web. 
Rough Key to Species. 
A.—Outer web of second, third, and fourth quills notched ; | 
fifth quill not notched. 
(1) Tarsus over 2°5 in length ; notch on second quill 
close to tip of greater coverts. 
Circus macrurus (Pale Harrier). 
(2) Tarsus under 2°5; notch on second quill about 
an inch beyond tip of greater coverts. 
C. cineraceus (Montagu’s Harrier). 
B.—Outer web of second to fifth quills notched. 
(1) Wing under 15 in length. 
C. melanoleucus (Pied Harrier). 
(2) Wing 16 or over. 
C. eruginosus (Marsh Harrier). 
7 6(21)20 
