THE COMMON GULL. 747 



Characters and allied forms. — L. c. major (Siberia) is larger 

 with higher and thicker bill ; L. c. brachyrhynchus (western N. 

 America) has grey on primaries extended further towards tips and 

 usually patch of white immediately proximal to black tip. Size 

 and in adult greenish -yellow bill and grey and black primaries 

 (outer with white "mirrors") and in young mottled crown, dark 

 primaries without white and dark edge of wing and mottled under - 

 wing distinguish species. 



Field -characters. — Rather larger and of more robust build than 

 Black-headed, but decidedly smaller than Herring-Gull. Adult has 

 greenish feet and bill, latter lacking Herring-Gull's red spot on gonys. 

 Mantle paler grey than in Kittiwake. Large white subterminal 

 wing-tip, smaller in Herring-Gull and lacking in Kittiwake, is a 

 marked character in flight. Ash-brown plumage of juvenile not 

 unlike that of Herring and Lesser Black-backed Gulls, but bird is 

 more bullet-headed and much smaller. More of an inland feeder — ■ 

 particularly on pastures — than the larger Gulls. Its varied vocabu- 

 lary includes a wailing " kee-yah " similar to that of other Gulls. 

 Alarm-note a clamorous " yak, yak, yak." 



Breeding-habits. — Frequently breeds on low islets in lochs, but 

 also on grassy hills and on boggy moorlands or hillsides near sea, 

 usually in small or medium-sized colonies. Nest. — Variable in size, 

 built of heather, grass or sea-weed as obtainable. Eggs. — Usually 

 3 but sometimes 2 only (exceptionally 4) varying from dark to light 

 olive in ground (occasionally pale greenish or bluish) with blotches, 

 spots and a few streaks of dark umber-brown. Average of 100 eggs, 

 58.41x41.34. Max.: 64.8x41.3 and 64.4x45. Min. : 53.3x41 

 and 56.4x36 mm. Breeding-season. — Latter half May and early 

 June as a rule in British Isles, but occasionally early May. Incuba- 

 tion. — Share of sexes and periods seem not to be definitely known. 

 Single brooded. 



Food. — Almost omnivorous : carrion, small mammals (young 

 voles, etc.), small birds (such as Meadow-Pipit), and eggs of many 

 species (Red-throated Diver, Lapwing, Oyster-Catcher, Dunlin, 

 Ringed Plover, and Terns), fish, mollusca (slugs, Cardium edule, 

 etc.), worms (Lumbrici, etc.), insects (coleoptera, diptera, orthoptera, 

 larvse of lepidoptera, and hymenoptera), spiders, Crustacea, milli- 

 pedes, and harvesters. Also vegetable matter : potatoes, turnips, 

 grass, seeds, and grain, fragments of sea-weed and moss. 



Distribution. — England and Wales. — On all coasts and often 

 inland. Young birds frequent all summer, especially in north. 

 One pair has bred Fame Isles (Northumberland), since 1910, and 

 possibly once previously, one pair bred English side of Solway, 1914, 

 and 3 or 4 pairs on Dungeness beach (Kent), 1919, and since, but 

 has not bred elsewhere. Some winter -visitors are immigrants from 

 Continent, birds ringed in Baltic and Denmark having been re- 

 covered in Norfolk, Hants., and Gloucester. Scotland and Ireland. — ■ 



