The two represented in the plate were drawn at Boston, at the approach of spring, when the old birds had already assumed the pure white of the head. This species was so abundant on several of the islands of the Bay of Boston, that several basketfuls of them were procured in the course of a few excursions. When one fell to the water, the rest would hover about and around the boat, until many were shot from a flock. The case was the same, while we were in some of the harbours of Labrador.
Larus tridactylus, Lath. Ind. Ornith. vol. ii. p. 817.—Ch. Bonaparte, Synopsis of Birds of the United States, p. 359.—Swains. and Richards. Fauna Bor. Amer. part ii. p. 423.
Kittiwake Gull, Nuttall, Manual, vol. ii. p. 298.
Adult in Summer. CCXXIV. Fig. 1.
Bill shorter than the head, strong, nearly straight, compressed. Upper mandible with the dorsal line nearly straight and slightly declinate, until towards the end, when it is decurved, the ridge convex, the sides slightly convex, the edges a little inflected, straight, towards the end declinate and arched, the tip rather obtuse. Nasal groove narrow, rather long; nostril in its fore part, lateral, longitudinal, linear, wider anteriorly, open, and pervious. Lower mandible with a slight prominence at the end of the angle, which is long and narrow, the dorsal line then nearly straight and ascending, the sides convex, the edges sharp and inflected.
Head rather large, oblong, anteriorly compressed. Neck of moderate length. Body rather full. Wings long. Feet of moderate length rather strong; tibia bare below; tarsus somewhat compressed, covered before and behind with numerous broad scutella, the sides reticulated; hind toe rudimentary, with a minute knob in place of the claw; the fore toes rather long and slender, the fourth longer than the second, all scutellate above, and connected by reticulated entire membranes, the lateral toes margined externally with a narrow membrane. Claws small, compressed, slightly arched, rather obtuse.
The plumage in general is close, elastic, very soft and blended, on the back somewhat compact. Wings very long, rather broad, acute, the first quill longest, the other primaries rapidly graduated; secondaries broad and rounded, the inner elongated and narrow. Tail of moderate length, even, of twelve rounded feathers.
Bill pale greenish-yellow. Edges of eyelids crimson; iris reddish-brown. Feet black. The head, neck, rump, tail, and lower parts generally are pure white. The back and upper surface of the wings light pearl-grey. The first five quills are black at the end, the first on its outer web also, the fifth with a small white tip, the tips of all the other quills more or less white.
Length to end of tail 18 inches, to end of wings 20, to end of claws 17; extent of wings 36 1/2; wing from flexure 12, tail 7; bill along the back 1 1/2, along the edge of lower mandible 2 2/12; tarsus 1 7/12; middle toe its claw 4/12. Weight 1 1/2 lb.
Young bird in January. Plate CCXXIV. Fig. 2.