Birds fly better after a full meal!

A bird's flight may well be better fueled by a tummy full of food. That birds fly best after a full meal seems to be the latest observations made by bird watchers armed with a scientific pair of goggles. This seems rather paradoxical when one observes that at least when it comes to humans and other species, nature recommends an empty stomach before any form of exercise. A bird's beak full of food may however be a different metabolic story altogether - especially for the long distance fliers who brave the cold winds to fly thousands of kilometres.

For many a migratory bird, there is recent evidence which makes it look like accumulation of fat helps to fuel their long distance migratory flights. That explains the secret of how they can sustain continuous flying for thousands of kilometres. Anders Kvist and co-investigators at University of Lund have been studying flying efficiency in red knots, a family of birds that tend to double up in weight before taking off on a transcontinental flight. Their normal intercontinental flight is a long one - all the way from Siberia to Africa.

The typical V formation that many bird leaders guide their flocks to follow may be not an interesting pattern to make clouds look attractive but a terrific way to conserve energy. Birds fly V because that's a bonus energy saver - with energy savings of as much as 11-14% . Back benchers in the V shape get to glide a lot more than the ones right at the front.

This interesting study on V shaped patterns and flight was led by Henri Weimerskirch, chief biologist at the National Centre of Scientific Research at Villiers en Bois, France. The puzzle of the magic V in the sky which has been speculated upon for aerodynamic and energy efficiency has at last been solved after 100 years of contemplation, debate and persistent observation by generations of enthusiastic bird watchers and aerospace engineers.

Reference for further reading:
Kvist, A., Lindstrom, A., Green, M., Piersma, T. & Visser, G. H. Carrying large fuel loads during sustained bird flight is cheaper than expected. Nature, 413, 730 - 732, (2001). Weimerskirch, H., Martin, J., Clerquin, Y., Alexandre, P. & Jiraskova, S.. Energy saving in flight formation. Nature, 413, 697 - 698, (2001).