THE BEITISH LESSER BLACK-BACKED GULL. 757 



160, tarsus 59-66, bill from feathers 50-55 (12 measured). $ wing 

 405-420, bill 46-49. Structure as in L. f. affinis. 

 Soft parts. — As in L. f. affinis. 



Field -characters. — Differs only from L. f. affinis in colour of 

 mantle which is slate-black like that of Great Black-backed and not 

 slate-grey. 



Breeding-habits. — Similar in habits to British race. Eggs. — 

 Also similar. Average of 22 Scandinavian eggs, 66.77x46.21. 

 Max.: 75.5x48.7. Min. : 57.5x46.8 and 64.2x44 mm. Breeding- 

 season. — From early May to late June but rather later in north, 

 rarely before June. Incubation. — By both sexes. Period not 

 exactly ascertained. Single brooded. 



Food. — Varied, probably differing little from that of British race, 

 but mainly fish. Naumann also mentions small mammals such as 

 mice, dead birds, worms, insects (orthoptera, coleoptera, etc.), and 

 eggs of other birds. Has been seen to pursue and kill a Lark. 



Distribution. — Great Britain. — Passage -migrant and occasional 

 winter- visitor. Apparently scarce and few positive records ; mostly 

 of single birds or two and three only : Lanes., Oct. 20 to March 21, 

 Norfolk, May, Suffolk, Aug., probably Kent, Oct., Sussex, March 

 (flock ten adults), StirUngshire, Sept., Fifeshire, July, Wigtown- 

 shire, Nov. 



Distribution. — -Abroad. — Breeds in northern Europe from Dwina 

 to Scandinavia. Winters from Baltic to Mediterranean, Algeria 

 (once), Italy, Egypt, to Red Sea and Persian Gulf, south to E. 

 Africa. 



455. Larus fuscus affinis Reinhardt— THE BRITISH LESSER 

 BLACK-BACKED GULL. 



Larus affinis Reinhardt, Vidensk. Meddel. Kjobenhavn for 1853, p. 78 



( 1 854 — Greenland). 



Larus fuscus affinis Reinhardt, Iredale, Bull. B.O. Club, xxxi, p. 69. 



Larus fuscus britannicus Lowe, Brit. Birds (Mag.), vi, p. 2 (1912 — British 



Isles, type Caithness, Scotland). 



Larus fuscus Linnaeus, Yarrell, 111, p. 624 ; Saunders, p. 675. 



Description. — Adult male and female. Winter. — Crown and sides 

 of head white closely streaked black-brown, nape and hind-neck 

 same but streaks widening out to blotches ; throat lightly and 

 finely streaked brown ; mantle, back, scapulars, and wing-coverts 

 slate-grey (varying somewhat in shade but always darker than 

 L. a. cachinnans and never so dark as L. marinus), lower scapulars 

 with long white tips ; rump, upper tail-coverts, whole of under- 

 pays and tail white ; primaries : 1st (undeveloped) slate-grey with 

 most of outer web white, 2nd (outer) brown-black with base of 

 inner web dull grey (much darker than Herring-Gull) extending in 

 varying degree along inner edge towards tip, tip (40-55 mm.) white 

 with black subterminal band (usually broader and with narrower 



