Bird Migration
Bird migration is one of the most astonishing feats in nature. Some birds fly thousands of kilometers non-stop braving rough weather and other hazards! Their strength and bravery are to be admired and respected.
For centuries the study of bird migration has been riddled with mystery and unanswered questions: Where do birds go? How far do they fly? Why do birds fly in V formation? Scientists are tapping new technologies to find the answers.
What is Migration? Migration is the movement of a bird or an animal from one region to another. This happens at regular periods of time, and during a particular season. Somebirds migrate across oceans, mountains and the equator.
Why do birds migrate? The reasons are complex and not fully understood. But a simple explanation is food and a safe place to breed. Birds migrate to a warmer climate in the winter to avoid losing their food supply under snow and ice.
How fast do migratory birds fly? Great Snipe is the fastest migratory bird ever discovered. Scientists found that the birds fly non-stop over a distance of around 7000 km from Sweden to Central Africa at a phenomenal speed of 100km per hour.
How high do birds fly? The highest honours go to a Ruppell’s griffon vulture. Alas, while cruising over the Ivory Coast at an altitude of 37,900 feet in 1975, this poor soul was sucked into a jet engine. That’s one high and mighty trip.
What’s the record for the longest migration on the planet? The Arctic Tern (Sterna Paradisaea) is an elegant flyer performing an annual long-distance migration between the Arctic and the Antarctica and back. The longest journey recorded for the Tern was 81,600 km. The Arctic Tern has the longest annual migration of all the animals in the world. When added up over a lifetime, the total journey for the bird is the equivalent of three trips to the moon and back.
How long do migratory birds fly non-stop? Some birds fly for several days in a row without stopping, sleeping or eating! The Bar-tailed Godwit was named the ‘endurance champion of the animal kingdom’ after it completed a nine-day non-stop 11,000 kilometer flight across the Pacific Ocean.
How do birds find their way? Navigation is complicated because it requires three things: birds must know their current location, their destination and the direction they must take to get there. Birds acquire directional information from five primary sources: (1) topographic features like hills, rivers and buildings (2) stars (3) sun (4) Earth’s magnetic field and (5) odours.
When the sky is cloudy and birds cannot see the sun or stars, they rely on their sense for the Earth’s magnetic field. They are sensitive to the angle at which lines of magnetic force meet the Earth’s surface, which changes at different latitudes. Some birds that were captured, shipped to areas outside of their flyway, and released have still been able to reorient themselves and fly to their original destination!
Why do birds fly in V formation?
One of the joys of the changing seasons is watching migratory birds make their journey in the impressive V formation. Migratory birds take advantage of each other’s wingtip vortices by flying in a V formation. It helps all other birds except the leader to fly easily in the up-wash from the wing of the bird ahead.
The first bird in the pointing tip of V has to work the hardest since it flies through undisturbed air. When the lead bird is tired, it will move out of the lead position and fall back into one of the lines of the V. Another bird will rapidly move forward to take the lead position to maintain the V formation.
How do the birds prepare themselves for migration? The endurance displayed by the migratory birds is amazing. Eating right and gaining endurance seems to be the buzzword of birds prior to migration, according to the latest research.
Tiny Sandpiper which migrates 3000 km with 3 days of non-stop flight has an amazing feat of endurance among the small birds. Just before the onset of migration, the sandpipers start eating mud shrimp. Mud Shrimp is loaded with omega-3 fatty acids. Within a short period of two weeks this frantic eating doubles the sandpiper’s bodyweight.
Bird migration is one of nature’s greatest miracles. It is fun to observe these tiny creatures and to know about their bravery and stamina. The epic flights of migratory birds connect us all - crossing our borders, cultures and lives.
