142 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



a white region with few dark marks ; long feathers on sides of 

 breast covering flanks dark brown tipped rufous or buff and with 

 varying amount of spots and bars of rufous and white ; lower flanks 

 and belly usually regularly barred white or creamy and dark brown 

 but sometimes white with varying amount of irregular dark brown 

 spots or marks ; feathers of tibia and half-way down tarsus in front- 

 dark brown tipped and spotted and sometimes barred rufous or 

 buff ; under tail-coverts as belly but usually with fewer dark bars 

 or marks ; axillaries and under wing-coverts barred dark brown 

 and often rufous and white, under wing-coverts covering base of 

 primaries with blackish tips forming a dark patch ; tail-feathers 

 with narrow buff tips and broad dark brown subterminal band and 

 rest of feather narrowly barred (bars about 5 mm. wide), dark brown 

 and greyish-brown or dull grey, these paler bands becoming whitish 

 or white on inner edges of inner webs, bases of feathers under 

 coverts white or whitish and not uncommonly tail is more or less 

 strongly tinged with rufous ; primaries with long purplish-black 

 tips, outer four or five with greyish tinge on outer webs and inner 

 webs white, rest and secondaries brown with dark brown bars, 

 edges of inner webs and bases white ; wing-coverts as mantle. 

 This plumage is acquired by complete moult from April to Oct. 

 or Nov. N.B. — An albinistic variation which seems more frequent 

 on Continent than in British Isles has upper-parts brown, feathers 

 broadly edged white and crown with much white ; upper tail- 

 coverts often white and tail usually white at base ; under-parts 

 white or creamy-white with varying number of brown streaks. 

 A melanistic and apparently scarcer variation is almost entirely 

 very dark brown or blackish. 



Nestling. — At first down (a) fairly long with silky hair-like 

 tips, covering bird fairly well but rather sparse on under-parts and 

 three-fourths of tarsus bare. Varying pale brownish-grey to pale 

 bumsh-grey on upper-parts, round eye usually darker, sides and 

 under-parts white and usually small white patch at back of crown. 

 Very short tufts of down (b) white. Later thickly covered with 

 longer and coarser down (c) which replaces down (b) (exactly as 

 in Peregrine, see p. 108). Down (c) dark greyish-brown to paler 

 bufnsh-grey, concealing most of down (a) when fully grown. 



Juvenile. — Much like adult and when worn difficult to dis- 

 tinguish. Crown more streaked with white or cream ; mantle, 

 scapulars and wing-coverts not so uniform, feathers having edgings 

 of whitish, buff or rufous-buff ; under-parts with fewer dark mark- 

 ings than is usual in adults and these usually in form of streaks of 

 varying width and very rarely definite bars on belly where markings 

 are usually in form of irregularly shaped spots ; tibial feathers 

 barred ; some adults indistinguishable from juveniles on under- 

 parts ; tail usually not with a distinctly broader subterminal band 

 and only occasionally with rufous tinge. 



First winter. — Like juvenile. 



