Flying in a flock and in an organized way is a strategy used by migratory birds to spend less energy and cover greater distances. Such flights are common among large birds, such as geese and swans, and seabirds, such as cormorants and pelicans. The energy savings are such that, at the end of the day, the birds reach up to 70% further than if they flew in disarray. The positioning also helps for the birds to keep an eye on each other, since neither leaves the other’s sight. “Another differential for birds that migrate together, even out of formation, is the issue of survival. When in a group, they are more protected from predators, which get confused when attacking a bird and causing a flock of others around it”, explains Roberto Cavalcanti, from the zoology department at the University of Brasília (UnB).
impeccable platoon
Birds like Canada geese flee the winter to feed by traveling thousands of kilometers without leaving the line
NATURAL AERODYNAMICS
When the bird tears the air in front of it, a void, called a vacuum, forms behind it for an instant. Birds at the back take advantage of this, as the layer of air to break through is less dense. In addition, the wings also displace the air around them, causing a whirlpool, or vortex.
GENTLE ON POULTRY
The air displacement caused by the front bird makes the bird behind obtain the same flight performance by flapping its wings less often. Three birds flying together are enough to assemble a platoon in which each bird uses 40% less energy. With less effort, they also slow down your heart rate
ESCAPE ROUTE
Birds that migrate at night are guided by the stars, while diurnal birds use the Sun as a route reference. Geographic features, such as the outline of the coastline or the course of rivers, also indicate the best path. Pigeons, in turn, follow their course according to the Earth’s magnetic poles!
CONSTANT ROTATION
The bird that commands the formation is the one that wears out the most, while those that are in the center of each “wing” are the ones that benefit most from the displacement of air from the vortices. When the leader gets tired, it migrates to one of the ends and one of the birds in the second row takes the lead. This is repeated several times during the flight.
FLIGHT MENU
Months before migrating, the birds reinforce their diet to accumulate fat and even double in size. This tasty effort helps to withstand hunger and fatigue during the long journey. Some birds, like the thrush, feed on insects before leaving and, during the trip, they eat plants and fruits.