746 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



webs of 5th and 6th, while 7th to 11th are mostly dull grey with 

 shafts, subterminal marks and edges of outer webs brown ; 

 secondaries dull grey with whitish tips and bases and brown 

 subterminal marks which (except in outer feathers) extend towards 

 base on outer webs, innermost feathers brown tipped dull white ; 

 primary-coverts dark brown ; coverts along edge of wing brown 

 with white bases not entirely concealed ; greater coverts buffish- 

 grey, tipped buff, outer webs especially of outer feathers usually 

 grey-brown, innermost feathers as rest of coverts brown edged 

 buff. 



First winter. — Varying number of the juvenile body -feathers 

 are moulted Aug. to Oct.,, but always some and usually many are 

 retained while wing- and tail-feathers and wing-coverts are not 

 moulted. New feathers like adult winter but lower part of back of 

 neck streaked as crown and always some and usually many retained 

 juvenile feathers on upper- and under -parts ; wings and tail as 

 juvenile. First summer. — Much as first winter but a few more body- 

 feathers are moulted April-May and mantle is usually purer grey 

 and under-parts purer white but crown streaked and still a good 

 many juvenile body-feathers retained as also all wing- and tail- 

 feathers and wing-coverts. 



Second winter and summer. — Moults as adult but distinguished 

 by varying but considerable amount of black-brown on primary- 

 coverts, along edge of wing and usually some spots at bend of wing, 

 some brown edgings or tips to median and lesser coverts (especially 

 latter), usually some brown edgings to under wing-coverts, some- 

 times some on flanks, occasionally some black marks on tail- 

 feathers but usually these are pure white, primaries browner, not so 

 black as in adult, with much smaller white tips, smaller mirror on 

 3rd, more black at tip of 7th and usually some black on 8th, second- 

 aries usually as adult but occasionally with dark brown subterminal 

 marks. 



Third winter and summer. — Probably usually indistinguishable 

 from adults but birds with fine brown-black shaft-streaks on 

 primary-coverts but otherwise like adults may be in third winter. 



Measurements and structure. — $ wing 340-371 mm., tail 133- 

 147, tarsus 48-55, bill from feathers 32-36 (12 European measured). 

 $ wing 330-365, bill 29-33. Primaries : 1st narrow, pointed and 

 about two-thirds primary-coverts, 2nd longest, 3rd 1-5 mm. shorter, 

 4th 18-2 5* shorter, 5th 45-53 shorter. Rest of structure as Bona- 

 parte's Gull but bill stouter and more sharply decurved at tip. 



Soft parts. — Bill (ad.) yellow-green, upper mandible and tip 

 purer yellow, (juv. and 1st winter) blackish with dull flesh base, 

 (2nd winter) pale slate with subterminal dusky band and yellowish 

 tip ; gape and inside mouth (ad.) orange-red ; legs and feet (ad.) 

 green-yellow, marked blue-grey, (juv.) yellow-flesh, (2nd winter) 

 pale slate, webs tinged yellow ; iris brown to whitish or yellowish - 

 white ; eyelids and orbital ring (ad.) vermilion, (juv. and 1st winter) 

 dusky-brown, (2nd winter) tinged orange. 



