Length to end of tail 50, to end of wings 50, to end of claws 65; extent of wings 75; wing from flexure 18 3/4; tail 6 3/4; bill along the back 5 10/12, along the edges 7 3/4, its depth at base 1 5/12; tarsus 7 1/2; middle toe 4 1/4, its claw 9/12. Weight 7 1/4 lb.
The Young are at first covered with white down, and when fledged are of the same colour. An individual just able to fly was of the following dimensions.
Length to end of tail 43 1/2, to end of claws 56; wing from flexure 18; bill 5 4/12; along the edge 7 1/4; tarsus 6 1/2; middle toe 4 1/4, its claw 3/4. The serrature of the middle claw is distinct at this age.
In this species, the skin is uncommonly tender, and of a yellow colour.
THE WHITE-WINGED SILVERY GULL.
Larus leucopterus, Faber.
PLATE CCLXXXII. Adult Male, and Young.
I have not met with this species farther south than the Bay of New York. During the winter it is not rare about Boston and farther eastward. At the approach of summer, before the pairing of the Herring Gull, Larus argentatus, the White-winged Gulls collect in flocks, and set out for the distant north, where they breed.
The flight of this species so much resembles that of the Herring Gull, that were it not for its smaller size, and the different colour of its wings, it could not be distinguished from the other. It is less shy, however, proceeds farther up the rivers and salt-water creeks, and alights oftener on the water as well as on the salt-meadows, than that species. While at Portland in Maine, I observed a good number of these Gulls flying over the inner harbour close to the shores, descending towards the water, and picking up garbage in the manner of the Herring Gulls, with which they associated. Their notes were not so loud, nor so often heard.
I was surprised to find but very few on the coast of Labrador, and these did not seem to be breeding, for although we carefully watched them, we did not succeed in finding any nests.
Larus leucopterus, Ch. Bonaparte, Synops. of Birds of the United States, p. 361.