This article was originally posted in Indonesian at Antara News,
and translated into English by EAAFP Secretariat.
Bogor (ANTARA News) – Have you ever noticed that birds fly in flocks during migration? They usually make a particular formation, the most frequent is the letter V.
From aerodynamic and energy efficiency point of view, flying in a letter V formation has an incredible impact. This formation can minimalize the energy used by birds by enhancing the aerodynamics due to reduced air turbulence.
Jihad, Bird Conservation Officer of Burung Indonesia, said that when the birds are flapping their wings, an air vortex will appear at the wingtips. This vortex causes the air behind the bird to be pushed downwards. Meanwhile, the air at the side and rear of the bird will be pushed upwards. The combination of these will rotate in the opposite direction at the tip of the right wing and left wing. “Because of this, when there are other birds flying next to a bird, the second bird will get a free ‘ride’ and save energy”, said Jihad.
Jihad also said that in the V formation, the bird in the front or the leader of the formation loses energy. Because of this, birds take turns and change position as the leader of the formation to save energy.
“This formation is usually used by ducks or swans when they migrate in the winter, to save energy”, Jihad said.
He explained that the strategy of the birds to save energy while flying has inspired humans. The V formation for example, is used by fighter pilots to save fuel while flying. While the use of thermals by raptors is adapted by humans in the sport of paragliding.
“Not only is it inspiring to learn how birds save energy in the air, it is also inspiring how they save energy on the land”, he said.
According to Jihad, Eiji Nakatsu (Chief Train Technician from Japan who is also a bird watcher), found inspiration from kingfishers, which are capable of diving at high speed from the air into the water to catch fish while only causing a slight splashing of water. It means that kingfishers can move from one medium (air) to another (water) almost without making any waves.
This high speed movement from one medium to another is similar to what the Japanese Shinkansen bullet trains are exposed to, when they enter a tunnel, because of the sudden change in air pressure.
“According to Nakatsu, the shape of snout of the Shinkansen series 500 train was adapted from the kingfisher’s bill. This design has 30% less air resistance, uses 15% less electricity, and goes 10% faster compared to trains of a previous design”, said Jihad.
Burung Indonesia is a part of Birdlife International. To celebrate Earth Day, Burung Indonesia engages people to conserve the Earth and save the energy as the birds do.