SILVER GULL. 
towards the end which occupies both webs, shghtly fringed with black on the 
inner one ; the second primary has a Hne of white near the base which occupies 
the shaft and a small portion each side of it, a mirror near the tip similar in shape 
to the one on the first primary but more broadly margined with black on the inner 
web ; the third primary has a similar hne of white from the base to beyond the 
middle of the feather, and another elongated spot on the inner web which is joined 
by the continuous white shaft, also tipped with white ; the fourth quill is white 
on the outer web for the greater part of its length, towards the end it crosses on 
to the inner web : the basal portion of the inner web is greyish-brown near the 
shaft with a subapical black band and white tip ; the fifth primary is white on the 
outer web nearly the whole length, dark grey and fringed with black on the inner 
web, with a subapical black band and white tip ; the sixth quill is blue-grey 
fringed with black on the inner web towards the end and a narrow subapical black 
band and white tip ; the seventh primary blue-grey with a very shght fringe of 
black on the inner web near the tip ; secondaries entirely blue-grey ; bill and 
feet red ; iris white, eyehd red. Total length 440 mm. ; culmen 36, wing 309, 
tail 120, tarsus 50. 
Adult female. Similar to the adult male, but smaller. 
Immature. Differs from the adult in having the tips of the feathers on the nape, hind- 
neck, and mantle brown ; the lesser wing-coverts brown tipped with white and 
fringed on the sides more or less with ochreous-buff, the greater coverts grey with 
a subapical brown spot and white tip ; bastard-wing dark brown on the inner web ; 
the secondaries grey with subapical brown marks and tipped with white ; the 
innermost secondaries brown with grey bases irregularly marked and fringed with 
white at the tips, also a slight mottling of buff ; some of the scapulars similarly 
marked but paler ; the feathers of the rump grey with subapical brown spots and 
fringed with buff at the tips ; some of the upper tail-coverts blackish at the tip ; 
tail-feathers white with a subapical dark band mottled with buff and tipped with 
white. As the bird advances in age the brown of the upper wing-coverts seems 
to be the last to change. 
Nestling. Does not appear to have been described. 
Nest. “ Some were very elaborate structures, although out on the shingly slopes they 
were merely deep indentations, with a ridge of pebbles and a few straws or frag- 
ments of dry seaweed round the eggs. On the rocky headlands the eggs were 
deposited in natural hollows in the rocks.” (Hull.) 
Eggs. Clutch, two to three ; ground-colour greenish-buff, blotched with dark brown 
and lavender; axis 57-58 mm., diameter 37-38. “From pale ohve-green ground 
sparsely to thickly covered with sepia and black markings, blotches, spots or hair 
fines, to the deep red-brown ground bearing similar markings. Two noticeable 
variations were seen — one with very deep-green ground having a broad ring of 
black round the thick end, and another with umber ground capped with black, 
gradually merging into the brown, but without other markings. 
“ Mutations ; pale blue, absolutely devoid of markings ; deep blue ground fairly 
well covered with sepia spots and small blotches ; glossy white ground, sparsely 
streaked and spotted with pale red and purplish-red suffused markings, and.\^ few 
dull red spots distributed over the whole shell ; warm pink ground colour, very 
richly marked with deep red streaks, spots and blotches. 
“ Vary very considerabty in size and shape, some being long and tapering, while 
others were short and swollen. 
“Measurements: 1.78-2.43 (1.26) in. x 1.31 (1.09) inches.” ^HuU.) 
Breeding-season. “End of August to October” (Hull). 
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