96 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



outer pair white at base of outer and at tip of inner webs, and 

 with white or whitish diagonal central streak (of varying size) at 

 base ; wing-feathers black, with distal halves of outer webs fringed 

 yellowish and basal parts of inner webs fringed white, with band 

 of white showing below coverts on outer webs of 4th to 10th 

 primaries ; inner secondaries tipped and edged chestnut-buff ; 

 primary-coverts black, edged buff ; greater coverts black, outer 

 ones edged and tipped whitish and inner chestnut-buff ; median 

 coverts whitish-buff ; lesser coverts bright orange-buff, with 

 black bases. This plumage is acquired by complete moult in 

 Aug. -Sept. Summer. No moult but abrasion produces remark- 

 able change on upper-parts. In much worn examples (June and 

 July) whole head becomes glossy blue-black, nape marked grey, 

 mantle blue-black, wings and tail black, with scarcely any 

 edgings, remains of tips of greater coverts and median coverts 

 nearly white, lesser coverts and scapulars more yellow and 

 paler than winter, buff on throat, breast, flanks, and under 

 tail-coverts much paler. N.B. The effect of abrasion begins to 

 show generally in Feb. or March, but individual variation is 

 considerable. 



Adult female. Winter. Like male, but duller and with no 

 blue-black, dark portions of feathers of crown and mantle being 

 brown-black ; ear-coverts greyish-brown ; sides of neck and centre 

 of nape greyer than male ; scapulars and lesser wing-coverts 

 especially with smaller and duller chestnut-buff tips ; throat and 

 breast paler than male. Summer. No moult. Abrasion pro- 

 duces little change compared to male, but upper-parts (especially 

 crown) become more uniform brown-black by wearing off of 

 buff tips. 



Nestling. Down, white ; distribution, inner and outer supra- 

 orbital, occipital, humeral, spinal, ulnar, ventral, femoral, and 

 crural (C. B. Ticehurst, Brit. B., n, p. 193). 



Juvenile. Closely resembling female but rump and belly 

 tinged yellow, greater and median coverts black-brown, with 

 buffish-white tips. 



First winter and summer. Male and female. Apparently like 

 adults. The juvenile body -feathers and wing-coverts are moulted 

 in Aug.-Sept., but not primary-coverts, wing- or tail-feathers. 



Measurements and structure. <$ wing 89-94 mm., tail 55-62, 

 tarsus 17-19, bill from feathers 11-13 (14 measured). $ wing 

 83-89. Primaries : 1st minute and hidden, 3rd longest, 4th often 

 equal but usually 1-2 mm. shorter and equal to 2nd, 5th 3-4 shorter, 

 6th 12-14 shorter ; 3rd to 5th emarginated outer webs. Secondaries 

 about equal 9th primary, tips square, slightly notched. Tail 

 rather deeply forked. Bill thick, tapering gradually to point. 

 Good many short nasal and rictal bristles. 



Soft parts. Bill blue-black (summer), yellow with black tip 

 (winter) ; legs and feet brownish-flesh ; iris brown. 



