Western Bird Guide: Birds of the Rockies and West to the Pacific

by Charles K. Reed

GLAUCOUS-WINGED GULL.

44. Larus glaucescens. 25 to 27 inches.

The primaries are the same color as the mantle on this gull except that the primaries are tipped with white. They breed in large numbers both on the rocky cliffs and on the low sandy islands of the Aleutians. On the cliffs large nests of seaweed are built, while on the low sandy islands no attempt is made at nest building.

Nest.—Two or three eggs are the usual complement, of a greenish brown ground color with various shades of brown spots, most thickly covered on the larger end (2.75 × 2.05).

Range.—North Pacific coast, breeding from British Columbia northwards, and wintering to southern California.

SLATY-BACKED GULL.

48. Larus schistisagus. 27 inches.

This large gull, with its almost pure white head and neck and slaty colored back, is one of the prettiest. They often nest in colonies with other gulls, building their small mounds of seaweed on the higher parts of the islands.

Nest.—Usually contains sets of two or three grayish colored eggs, spotted with dark brown and lavender (2.90 × 2.00).