. A practical handbook of British birds . ing primaries mottled grey ; primaries : 1st (un-developed) slate-grey with outer web white except at tip, 2nd(outer) brown-black, inner web grey at base and narrowly edgedwhitish, tip (50-80 mm.) white (often more or less mottled grey),3rd same but with grey of inner web extending further (to varyingdegree) towards tip, base of outer web fringed grey, white tip usuallyshorter and with subterminal black band varying greatly in widthand usually much reduced or absent on outer web, 4th with only 762 A PRACTICAL HANDBOOK OF BRITISH BIRDS. apex (10-15 mm.)
. A practical handbook of British birds . ing primaries mottled grey ; primaries : 1st (un-developed) slate-grey with outer web white except at tip, 2nd(outer) brown-black, inner web grey at base and narrowly edgedwhitish, tip (50-80 mm.) white (often more or less mottled grey),3rd same but with grey of inner web extending further (to varyingdegree) towards tip, base of outer web fringed grey, white tip usuallyshorter and with subterminal black band varying greatly in widthand usually much reduced or absent on outer web, 4th with only 762 A PRACTICAL HANDBOOK OF BRITISH BIRDS. apex (10-15 mm.) white, occasionally white subterminal spot oninner web, grey of inner extending sometimes far towards tip butvarying, rest of primaries slate-grey to blackish slate-grey tippedwhite, 5th and 6th with black subterminal band extending somewhatup outer web with white line or patch at junction of grey and black,7th with subterminal black band broken, often reduced to spot andsometimes absent, rest with no black ; secondaries slate-grey with. The Great Black-backed Gull (Lams marlnus). Second (outer) primary of: 1. Juvenileand 1st winter. 2. 2nd winter. 3. 3rd winter. 4th. Adult. long white tips and mottled white on inner webs ; primary-covertsand all wing-coverts slate-black but small coverts along edge andbend of wing white. This plumage is acquired by complete moultJune to Nov. sometimes Dec. and occasionally outer primary stillwith sheath in Jan. Summer.—The body-feathers are moultedJan-March, but not wing- or tail-feathers nor wing-coverts. Aswinter but whole head and neck pure white, descending further onto mantle than in winter. Nestling.—Like that of L. a. argentatus but black-brownmarkings on head often smaller and ground-colour of upper-partsusually paler or purer grey (not so buffish), under-parts also usuallyslightly paler and centre of breast and belly whitish. Juvenile.—Like that of L. a. argentatus but under-parts whiteand less mottled, brown markings being few
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, bookyear1920
