The retina is twice as thick as that of a human and can focus rapidly and efficiently. Swan eyes are able to adjust quickly to different levels of light. The western Tundra Swan population nests in Alaska. While in Alaska the Tundra Swan eats a great deal. They are lining their bodies with fat for energy during the fall migration.
Swans begin migrating shortly after the hours of daily sunlight start to decrease in the fall.
Three month old cygnets, baby swans, migrate south with the others. They follow their parents closely. It takes about 15 to 20 feet of open water for the swans to gain enough speed to launch themselves into the air. Tundra Swans fly in a V formation. The V formation gives each bird extra lift from the slip stream of the bird in front.