104 BULLETIN 17 0, UNITED STATES NATIONAL MUSEUM 



so that probably it varies usually from 30 to 32 days but is at times a 

 little longer or shorter. Interesting observations on the development 

 of a young kestrel in captivity have been made by A. Geoffrey Leigh 

 (1911). 



Plumages. — We do not propose to describe the plumage in detail, 

 as full descriptions can be found in Witherby's Handbook (1924) and 

 other works. The male in full plumage is recognizable in the field by 

 his brown coloration and slate-gray head; tail and rump also are 

 slate-gray, with a conspicuous black subterminal band on the tail. 

 The back of the male is chestnut-brown, with blackish markings on 

 the feathers, which distinguish it at once from the lesser kestrel. The 

 hen lacks the slate-gray and has the mantle thickly barred with black, 

 bill horn blue, dark at tip, and feet yellow. 



Food. — To a very great extent the kestrel feeds on small mammals, 

 especially rodents, and is therefore on the whole a most useful bird. 

 It does not as a rule attack the larger mammals, such as the rabbit, 

 though it has been known to kill a young one, and also a young leveret, 

 and has been recorded as carrying off a weasel. The staple food, is, 

 however, the long- and short-tailed field mouse, while bank-vole, house 

 mouse, mole, shrew, rat, and exceptionally bats (noctule and pipistrel) 

 are taken. In some districts where mice are scarce small birds are 

 frequently captured, such as house sparrow, skylark, greenfinch, gold- 

 finch, linnet, yellow bunting, pipits, hedge sparrow, starling, thrush, 

 blackbird, fieldfare, lesser redpoll, and, surprising to say, swift. 

 Though as a rule confining its attacks to small birds, there are cases 

 on record of attacking sandpiper, wounded redshank, young lapwing 

 and snipe; and it has been seen devouring wood pigeon and hooded 

 crow, though it is very doubtful whether it is capable of killing the 

 latter. It is generally harmless to game, but single birds may develop 

 the habit of taking very young pheasants, grouse, and partridges. 

 Other animals recorded as food are frogs, lizards, adder, slow-worm, 

 beetles (Geotrupes, Melolontha, etc.), Orthoptera, caterpillars, and 

 earthworms. 



Behavior. — This species hunts openly, skimming over the country- 

 side fairly high in air and hovering over some spot in a meadow, 

 where he can perhaps detect a mouse running about in the grass. A 

 suspicious movement below induces a drop to closer quarters and then 

 a swift descent, which may or may not be successful. If the latter, 

 up he goes again and resumes his beat until at last his stoop secures a 

 victim. When after a bird, he flies it down, and I have seen one in 

 pursuit of sparrows come swiftly around the corner of a barn into a 

 crowd of noisy, quarreling sparrows and at once produce a headlong 

 flight in all directions and a resultant silence. This open chase is 

 quite unlike that of the European sparrow hawk, which flies low, only 

 rising to top a hedge, and seeks to take its prey on the ground or 





