THE YELLOW-LEGGED HERRING-GFLL. 755 



moulted Dec. to March and sometimes (perhaps as a rule) inner 

 wing-coverts and innermost secondaries are also moulted but not 

 rest of wings nor tail. Plumage as winter but head entirely white 

 as in summer L. a. argentatus. 



Nestling. — Like that of L. a. argentatus but black-brown spots 

 and blotches on head smaller and less numerous,, dark markings 

 on rest of upper-parts small and ill-defined and often almost 

 obscured by buff -grey, except blotches on wings, which are usually 

 distinct. 



Juvenile. — Like that of L. a. argentatus but portion of tail- 

 feathers proximal to black subterminal band usually whiter and 

 with fewer dark markings (sometimes outer -feathers white except 

 for subterminal band) but owing to individual variation this 

 character is not a certain means of identification. 



First winter. — Crown whiter less streaked, mantle and scapulars 

 paler and under-parts rather whiter than in L. a. argentatus. First 

 summer. — As above but crown usually quite white or with a few 

 pale brown streaks, new feathers of mantle and scapulars paler and 

 greyer. Moults as in L. a. argentatus. 



Second winter and summer. — Like L. a. argentatus but proximal 

 part of tail-feathers usually with fewer black bars and markings, 

 crown in winter only faintly streaked and under-parts usually purer 

 white. 



Third winter and summer. — Differing from adult in same way 

 as in L. a. argentatus. 



Measurements and structure. — $ wing 425-465 mm. (juv. 430- 

 455), tail 155-180, tarsus 65-73, biU from feathers 53-65 (juv. 50- 

 57) (12 measured). 2 wing 420-445 (juv. 400-445), bill 50-58 (juv. 

 45-57). Structure as L. a. argentatus. 



Soft parts.— As L. a. argentatus but in adult legs and feet pale 

 yellow sometimes tinged flesh, in 3rd winter and summer pale 

 salmon or pale creamy-flesh with grey tinge ; younger birds as 

 L. a. argentatus. 



Breeding-habits. — Nests in colonies, often on rocky islands, but 

 also on flat islets, sand-banks and among reeds. Exceptionally 

 breeds on roofs of fishers' huts. Nest. — Large, built of any available 

 material, heath, algse, grass, and shore-wrack of any kind as well 

 as dead stalks, plants, etc. Eggs. — Usually 3, but sometimes 2 only, 

 like those of Herring-Gull, but red type not recorded. Average of 

 100 eggs, 70.87x49.24. Max. : 86.8x46.5 and 70.3x53.3. Min. : 

 63x47.7 and 65.8x44.3 mm. Breeding -season. — From early April 

 onward in Mediterranean, but eggs may be found till June as nests 

 are often robbed. Incubation. — Probably resembles Herring-Gull 

 but no reliable observations. Single brooded. 



Pood. — Little definitely recorded ; but fish, stranded or captured 

 alive, insects, including orthoptera, dead birds, and marine inverte- 

 brata from shore, have been noted, and on one occasion the writer 



