Some animal species like birds, insects and mammals undertake marathon journeys of long distances that extend over weeks or months as part of their annual routine. This is known as migration. The exact reason as to what prompts the migration is not yet known. But, reasons like changes in weather, scarcity of food and variations in temperature are believed to be the major reasons that initiate migration. Migrating animals may move horizontally or vertically as part of migration, but return to their favored place to lay eggs or give birth to young ones.
Animals have the special ability to sense the changing seasons. Also, they become cautious when food supply drops. More concentration of animals or birds in limited area is another reason that prompts migration. While these are compelling reasons for migration, the secret behind following the same route year after year is still a mystery to be fully resolved.
It is believed that the migrating animals genetically inherit the knowledge from their parents. It is thought that these animals follow the magnetic field of earth for navigation. A molecule has been identified in the brains of migrating birds that reasonably explains the connection between the brain of the bird and the magnetic field of earth.
Sea turtle hatching, emerging on moon lit beaches and then heading towards sea to join the regular migration route is believed to be following the magnetic field of earth. Zambian mole rats also come under this category.
Arctic tern, Caribou, Gray whale, Hummingbird and Salmon fish are some of the major species of animals that travels thousands of kilometers as part of annual migration. How do birds prepare themselves for migration?