The intentional rattle of a rattlesnake is an effective acoustic alarming gesture: anyone who knows what is good for them and what venom can even be dangerous to humans, prefers to quickly disappear as soon as they hear a normal rattle. We do. This helps the snake to snap as close as you get – and eventually resorted to an effective acoustic trick that had previously been overlooked, as now discovered by a team of researchers from the Ludwig Maximilians University and the Technical University of Munich at the University of Munich. In the case of the team. Graz Report in the Journal “Current Biology”.
Rattlesnakes native to the Americas rattle with their distinctive mobile structure of hollow, loosely interlocking old horn segments at the end of the tail, which produces a rattle that can be heard over several meters. Basically, the frequency of the noise increases in the same way that the spacer beeps when reversing in a parking space: the closer the snakes are, the louder the sounds follow each other.
This can also be shown well in experiment, describe first author Michael Forsthofer and his colleagues: they documented the rattle frequencies of 25 Texas rattlesnakes. (Crotalus atrox)that he tested in person on a small platform while the prosthesis slowly approached. The rattle frequency increased continuously from 40 to 50 Hz. Apparently at this stage snakes send a message about how close they are to a slowly approaching object. But then there was always a very sudden jump: from a certain distance, the snakes began to rattle very quickly, at 60 to 100 Hz.
Why do queues reliably change frequency so abruptly? The German-Austrian team speculates that this behavior may have worked as a psycho-acoustic trick in addition to the warnings already sent. To a listener who nevertheless comes close to the snake, the astonishing increase in frequency should be interpreted as if he suddenly came very close to the snake from one moment to the next – possibly good for a venomous snake.
