Some, like willow ptarmigan, migrate only a few miles from mountain tops to more sheltered subalpine or forest areas. Other birds migrate thousands of miles. Each spring they return to Alaska, thus, making an annual trip of 20,000 miles. Even Alaska's smallest birds, rufous hummingbirds, migrate over 1,000 miles to winter in California and Mexico. All of Alaska's tiny warblers migrate long distances, too.
Blackpoll warblers migrate to South America for the winter.
Townsend's warblers winter along the west coast of North America from California to Central America, and wilson's warblers make a long journey to Mexico and Central America. Several small Alaskan birds including the arctic warbler, yellow wagtail, and bluethroat migrate to Asia to winter. Golden plovers head to Hawaii and the West Indies, while the bar-tailed godwit migrates to the south Pacific. Most of Alaska's waterfowl head to the central valley of California or parts of Mexico, although the eiders, oldsquaw, scoters, scaups, and some other diving ducks spend their winter off the southern coasts of Alaska. Clearly, birds leave Alaska in winter to visit places where the winter weather is warmer, water is open, and food, particularly insects, is more available.