Bats use the same aerodynamic techniques as insects to keep themselves floating in the air during slow or stationary flights, according to a study published today in the journal Science . When these mammals flap their wings, unfolding them fully and bending them downwards, they produce an air movement similar to a small whirlwind , which generates an upward vertical thrust.
Scientists already knew that insects produce these whirlwinds permanently with their wings while they fly. But they doubted if that same mechanism could be used by heavier animals, such as bats.
To verify this, a team of American and Swedish researchers has studied three Glossophaga bats from South America, which are two inches long and feed mainly on flower nectar. The scientists measured the airflow around their wings inside a wind tunnel using artificial fog and recording the movement of the fog particles. In this way they were able to show that these mammals have a flight capacity ten times higher than normal, comparable to that of light hummingbirds.
