Many migrating birds travel thousands of kilometres between their breeding and wintering grounds.

The longer version

Long-distance migration works because birds store fat before departure. Fat packs roughly twice the energy per gram that carbohydrate or protein does while carrying little water weight, so a small bird can nearly double its body mass and then fly for days while burning that reserve.

Some routes cross oceans, deserts and mountain ranges without a stop, running to thousands of kilometres each way. Birds preparing to leave eat almost continuously and shrink parts of the digestive tract to save weight. Early naturalists thought small birds hibernated in mud, since they vanished each autumn and no one could imagine such a flight.

Where this entry sits

Here you will find feathered trivia about flight, migration, nests, eggs, and the songs birds sing. Expect short surprising facts on penguins, owls, hummingbirds, and other familiar birds from gardens, forests, wetlands, and distant coastlines. The full list sits on the Birds page, where every entry is listed in order.