Animals travel immense distances across continents in search of new habitats, to feed or for breeding. Their ability to find their way on these incredible journeys has long puzzled scientists.
The fact that animals travel from one habitat to another is known by all. Migration of animals, ranging from individual trekkers to herds of thousands, tells us that they have an amazing sense of direction which enables them to chart their route over long distances. But what it is that guides them has long mystified scientists. Even today they can only guess how these creatures travel such long distances every year.
The North American monarch butterfly undertakes a journey that would make the toughest traveller exhausted. It travels from Eastern North America almost 8000 km to California and New Mexico.
Whales are also incredible aquatic migrators. The arctic grey whale travels up to 10,000 km sough on an annual basis to breed. This journey from the Arctic Circle to the subtropics is the longest undertaken by such a mammal. We all know birds migrate. What most people don’t realize is the astounding distances these birds travel. Arctic terns leave their summer breeding grounds in the Arctic every autumn and fly to the Antarctic before making the long journey back in the spring. This entire trip, which circumnavigates the Earth, is around 30,000 to 40,000 km in length. Many other birds make similar journeys. Flocks of ducks, geese and swans migrate regularly.
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Scientists have long been puzzled by the way in which animals on land, in the water and in air make these long journeys crossing continents. They wonder how the animals make these journeys without getting lost. These creatures do not use visual landmarks to guide them. Today it is believed that the animals use their body clocks which are influenced by light and darkness. The relative position of the sun in the sky also plays an important role in establishing directions.
Scientists feel that the Earth’s magnetic field may also help animals to know where they are. Much more study and research will have to be done, however, before scientists learn everything about the migratory habits of animals and birds.