Western Diamondback Rattlesnake: A Unique Evolutionary Trick One of the rattlesnake species known for using frequency jumps to deceive ears.
Scientists believe that rattlesnakes “tear apart” the keratin structure on their tails to warn enemies, gradually increasing the frequency as the attacker approaches.
Rattlesnakes use auditory illusions to deceive humans.
However, researchers have now discovered that the rattlesnake may have another trick in its arsenal: a sudden frequency jump in the rattling sound it uses to mislead listeners.
“Our data shows that the sound of the rattlesnake, long understood for decades as a simple warning signal of the snake’s presence, is actually a much more complex communication signal,” said Professor Boris Chagnaud, a senior researcher in neurobiology at the University of Graz in Austria.
To understand the reasons behind this phenomenon, he and his team recorded the frequency of the rattling sound as various objects were brought closer to the snake.
When threats first approached, the rattling increased steadily to a frequency of 40 Hz, but as objects drew nearer, the frequency suddenly jumped from 60 to 100 Hz.
Chagnaud suggests that rattlesnakes create this strange auditory illusion to establish a “safe distance” between themselves and potential attackers.
He stated: “Like other snake species, rattlesnakes, of which there are many in North America, are more concerned with not being detected than confronting any other animals besides their prey. Although rattlesnakes can defend themselves with venom, these snakes try to avoid using it whenever possible.”
Chagnaud adds: “Snakes do not just rattle to announce their presence; they have developed a creative solution: a sound-based distance warning device similar to those found in cars when reversing. The results of thousands of trials show that they do this to avoid being stepped on.”
