58 BRITISH BIRDS 
Higgs. Usually 2-3. Much like those of the two preceding 
species, but more boldly marked and larger. Av. size, 
3x2:13 in. Laying begins April-May. One brood usual. 
114. Glaucous-gull [Larus glaucus Brimnich]. Winter 
visitor, chiefly to our north and east coasts. Occurs in 
summer, but not to breed. 
Bird. Length 29 in., therefore about the same size as the 
preceding species, from which it may be distinguished in adult 
plumage by the entire absence of black. Mantle and wings 
mostly pearl-grey ; rest of plumage white. Legs pink. Beak 
yellow with patch of orange on the angle of the lower 
mandible. Size apart, No. 114 applies also to the rarer Iceland- 
gull (22 in.), which is also a winter visitor. 
The young is mottled greyish-buff, which grows paler until 
the plumage becomes wholly white in the fourth year, to be 
followed by the grey and white of the adult stage. 
115. Kittiwake [Rissa tridactyla tridactyla (Linneeus)}. 
Resident and widely distributed. Strictly marine. _ 
Bird. Length 16 in. Same size as the blackheaded-gull, 
but distinguished both from it and the common-gull by the 
vestigial hind-toe—usually a warty excrescence with a small 
claw—by the black or dark grey legs, and, in flight, by the 
conspicuous black triangular tip to the wings; also by its 
note, Kitti-way-¢k, which gives it its name. Mantle and wings 
mostly bluish-grey, rest of plumage white. Beak greenish- 
yellow, black in the fledgling, and the inside of the moutha 
gorgeous orange-red, yellow in the fledgling. Fledgling and 
immature birds have a more or less complete dark collar, a 
greyish-black band on the wings and dark rim to the tail, but 
resemble the adults in the general white-grey of the plumage, 
thus differing conspicuously from other young gulls. 
Nest. Place: on ledges of cliff faces or walls of sea-caves. 
Material: sea-weed, grass, moss, earth. Usually a solid 
structure. Species nests in colonies, often with razorbills, 
guillemots, puffins, and gannets. 
Eggs. 2-3. Greyish-white to olive-buff, spotted and 
blotched with dark brown and ash-grey. Av. size, 2°21 x16 
in. Laying begins end May to early June. One brood. 
(3) Family: Laride. (c) Subfamily: Stercorartine—Skuas 
116. Great-skua, bonxie, skooi [Megalestris skua (Briin- 
nich); Megalestris catarrhactes (Linneus)|. Breeds in Shet- 
land. Elsewhere winter visitor to our coasts. __ 
Bird. Length 21 in. Recognised by the hooked upper 
mandible and bluish cere, the general umber-brown of the 
plumage, and the large white patch across the dark brown 
