740 A PRACTICAL HANDBOOK OF BRITISH BIRDS. 



Second winter and summer. — As adult but outer five primaries 

 (i.e. 2nd to 6th) with varying amount of black, outer webs of 2nd 

 to 4th usually with distal half black extending somewhat on to inner 

 webs along shafts, and tips black with apex white, 5th and 6th with 

 subterminal black band across both webs, otherwise white but 

 sometimes black descends towards base along shaft ; outer primary- 

 coverts often tinged brown along shafts. 



Measurements and structure. — $ wing 295-315 mm., tail 117- 

 126, tarsus 48-55, bill from feathers 33-37 (9 measured). $ wing 

 290-315, bill 30-36. Primaries : 1st very small, narrow and about 

 three-fourths primary-coverts, 2nd longest, 3rd as long or 4-5 mm. 

 shorter, 4th 14-20 shorter, 5th 30-40 shorter. Rest of structure as 

 Bonaparte's Gull, but bill stout, upper mandible considerably 

 dilated laterally except at tip which is much compressed and strong 

 and sharply decurved, gonys comparatively short and angle fairly 

 prominent. 



Soft parts. — (Ad. summer) bill, legs and feet, and orbital ring 

 dark red, bill with slight dusky subterminal band ; iris brown. 



Characters. — No subspecies. Distinguished from L. ridibundus 

 by stout bill, in adult by white primaries, in young by outer 

 primaries having dark brown shafts and broad blackish band on 

 inner webs adjoining shafts and extending to tips and by brown 

 (instead of white) coverts along front edge of wing. Differing from 

 L. ichthyaetus in its much smaller size. 



Breeding-habits. — Breeds on low-lying islets in salt-lagoons and 

 shallow lakes. Nest. — Slight, built of stalks, coarse grass, and some 

 feathers in lining. Eggs. — Usually 3, sometimes only 2 ; light 

 stone or yellowish-white in ground, with numerous small spots and 

 streaks of dark brown and also many small ashy-grey markings. 

 Average of 100 eggs, 53.73x38.11. Max.: 61.9x38.3 and 53.2 X 

 42. Min. : 47.8x37.2 and 52.8x34.9 mm. Breeding -season. — 

 About last fortnight of May and early June. Incubation. — No 

 details. Single brooded. 



Food. — Probably very varied but records scanty. Insects, chiefly 

 coleoptera (especially water-beetles) are largely taken ; also 

 mollusca (Helix pisana, etc.). 



Distribution. — England. — Nine or more. Immature, Barking 

 Creek (Essex), Jan. 1866. Adult, Breydon (Norfolk), Dec. 26, 1886 

 (Saunders, p. 667). One Yorks. coast Nov., 1895 (Birds Yorks., 

 p. 675). One Littlestone (Kent), Sept. 8, 1913 (Brit. B., vm, p. 13). 

 Several Bye (Sussex) July, 1915, one shot 15th, two 16th, and one 

 21st (T. Parkin, t.c, ix, p. 69), one reported seen Hastings (Sussex) 

 Nov. 11, 1915 (id., t.c, ix, p. 214). [Two said Falmouth (Cornwall) 

 Mar., 1851, cf. Brit. B., n, p. 328.] 



Distribution. — Abroad. — Inhabits Mediterranean (breeding only 

 certain in eastern parts), Bosporus, and Black Sea, and reaches in 



