What helps the tundra swan survive in the tundra?

The tundra swan only lives in the tundra during the summer months. It migrates in the spring. Tundra swans have heavy amounts of down that keep them warm in the chillier parts of the summer. They nest on the swampy ground near tundra lakes and still waters. It's prime feeding ground with some of the thickest populations of mosquitos and berries in the world. So they can easily reer their young. Once their young are older in the fall they migrate to warmer climates.