Spruce forest blankets lowlands in the eastern third of the archipelago, while to the west, tundra prevails. A backbone of mountains rising to over 4,000 feet runs the length of Kodiak Island. Eight hundred miles of coastline with associated shallows and marshes exist on the Kodiak Refuge alone. In winter the area is important to sea ducks and other water birds whose combined populations number well over a million birds. A wide variety of upland and marine habitats, and temperatures moderated by the Gulf of Alaska, give Kodiak the greatest diversity of wintering birds in the State.
Summer brings nesting birds from land and sea.
Bank Swallows arrive from South America and puffins fly in from deep North Pacific waters. Many breeders are year-round residents. While Kodiak is not in a major migratory bird pathway, a variety of migrants can be seen in small numbers. This checklist contains 237 species that have been recorded in the archipelago. Most of these have also been found on the Kodiak refuge.