GLAUCOUS GULL.

42. Larus hyperboreus. 28 inches.

This is one of the largest of the Gulls; mantle light gray; it is distinguished by its size and the primaries, which are white to the tips. It is a powerful bird that preys upon the smaller Gulls, eating both the eggs and young.

Nest.—Of seaweed on ledge of sea cliff, eggs three in number, in shades of light drab to brown, spotted with brown and black.

Range.—Arctic regions, in winter south to San Francisco Bay.