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A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



webs and tips, paler brown inner webs and whitish at extreme base ; 

 secondaries black-brown, inner ones with narrow white fringes at 

 each side of tip ; primary-coverts as primaries ; wing-coverts brown^ 

 black, feathers narrowly fringed white on each side of tip giving 

 appearance of diagonal short streaks on greater and median but 

 smaller and more spot-like on lesser. This plumage is acquired by 

 complete moult Oct -Dec. Primaries, primary-coverts and second- 

 aries are moulted simultaneously but wing-coverts normally. 

 Summer. — Another complete moult similar to that of autumn 

 takes place March-May, sometimes not completed June. Crown 

 somewhat glossy dark grey, streaked blackish, each feather having 

 greyish -black centre ; whole of back of neck extending to sides of 

 upper -mantle black, streaked white, each feather having even white 

 margin on each side of web ; upper-mantle black-brown, washed 

 grey and spotted greyish -white, each feather having at tip a pair 

 of small greyish-white spots as in winter but smaller and less pure 



Feathers from mantle of: (A) Black-throated Diver (Colymb'us a. arcticvs), juvenile. 

 (B) Juvenile, (C) Adult, winter, of the Bed-throated Diver (C. stellatus). 



white, a few similar feathers on sides of mantle, otherwise rest of 

 upper-parts usually unspotted glossy black-brown (frequently a 

 few spotted winter feathers are retained and some of these lose 

 white spots by abrasion) ; lores, sides of head, chin, sides of throat 

 and sides of neck uniform dark ash-grey ; down middle of throat 

 long patch of dark chestnut (feathers with grey bases), narrow on 

 upper part and increasing to full width of throat at base ; immedi- 

 ately below this and on sides of upper-breast feathers narrowly 

 streaked black-brown ; rest of breast and belly white ; feathers of 

 flanks black-brown more or less edged white and sometimes with a 

 few small grey spots ; under tail-coverts mixture of brown and 

 white ; axillaries and under wing-coverts as winter ; tail-feathers 

 black-brown very narrowly tipped paler brown (some old winter 

 white-tipped feathers often retained) ; wing-feathers as winter ; 

 wing-coverts much more narrowly and less distinctively fringed 

 greyish-white rather than white and lesser coverts with small 

 greyish spots or fringes and sometimes uniform black-brown. 



