Some species of bats have learned to use their echolocation in stealth mode
As shown by the results of research published by the Royal Society of London, bats of the kind of gray mumps use an unusually wide range of ultrasonic signals for navigating in the dark – from a shrill scream to a quiet whisper.
To learn more about the features of this biosensor, the researchers installed infrared cameras and ultrasonic microphones to record the voices of bats flying in the autumn over the coast of California.
Studies of sounds continued for five nights. Approximately half of the 80 flights were shorter, faster and quieter than the voices of other species of bats. Usually, as the mice approach the object, the intensity of the signals increases, but here, literally halfway to the obstacle, the gray night shocks did not make any sounds at all.
Such a hidden mode of flight explains a lot – in particular, quite a lot of collisions of mice with wind turbines. And the sounds are so quiet that they sharply reduce (about 3 times) the ability of bats to detect obstacles.
A legitimate question arises: Why do we need this “conspiracy”? Scientists suggest that by doing so, animals avoid unnecessary encounters with aggressive congeries during the mating season. In this case, the opportunity to hear the opponent is reduced from 92 to 12 meters. Apparently, this is a kind of tactic of behavior of male rivals.