How do migrating birds navigate?
The world champion migrant may be the Arctic Tern, which breeds in the Arctic and “winters” in extreme southern South America and Antarctica. In contrast, Blue Grouse in the mountains of North America move as little as a kilometer down the slopes to a lower altitude for the winter months and then return up the mountainside in the spring. While a Blue Grouse may not have much trouble finding its way up and down the hill, most other migratory species face a daunting challenge that may involve ocean crossings and journeys of thousands of miles. Longer lived species such as geese, swans, and cranes migrate as family groups. The young may learn the migration route from their elders. Most migratory songbirds must make their first long journey on their own. Some species of brood parasites, such as the European Cuckoo, are not even reared by their own parents, yet they still migrate according to the pattern of their true species. Navigation skills for these birds must be inherited rather than
