Found in large numbers off the West Coast of North America in winter, when they are gray above and white below. They are smaller than Common Loon with a shorter bill. Also, note overall dark head with a clearly demarcated white throat and short bill. During the breeding season, they have a silvery head, black-and-white stripes on neck, and white patches on back. Frequently dives to catch fish; often found in loose flocks with species of loons. Breeds on lakes and ponds in tundra. Rare stray to inland reservoirs and lakes during migration and winter.