Scientists say rattlesnakes have developed a clever way of convincing people that danger is closer than they think.
The sound of tail trembling increases as the person approaches, but suddenly shifts to a much higher frequency.
In tests, the rapid change in voice led participants to believe that the snake was much closer than it actually was.
Researchers say the trait evolved to help snakes avoid being trampled.
The sound of a rattlesnake’s tail has always been a cliché.
Tale strands consist of the rapid vibration of hard keratin rings on the tip of the crawler’s tail.
Keratin is the same protein that makes up our nails and hair.
The key to the noise is the snake’s ability to vibrate its tail muscles up to 90 times per second.
This powerful vibration is used to warn other animals and humans of their presence.
Despite this, rattlesnakes are still responsible for the majority of the approximately 8,000 bites people in the United States experience each year.
Researchers have known for decades that a rumble can change in frequency, but little research has been done on the importance of a shift in sound.
In this study, scientists conducted experiments by rounding the human-like torso of a western diamondback viper and recording the reaction.
The closer the object is to the snake, the higher the frequency of the crackle to about 40 Hz. This was followed by a sudden jump in sound to a higher frequency range between 60-100 Hz.
To find out what the sudden change meant, the researchers continued working with human participants and a hypothetical snake.
Participants experienced an increase in crackle speed with increased loudness as they approached.
The scientists found that when the sudden change in frequency occurred at a distance of 4 metres, the participants thought it was much closer, about 1 metre.
The authors believe that the switch in sound is not just a simple warning, but a complex communication signal between species.
“The sudden switch to high-frequency mode is a clever cue that deceives the listener about their true distance from the source of the sound,” said senior author Boris Chagno of Karl Franzens University in Graz, Austria.
“The misinterpretation of distance by the listener creates a margin of safety for the distance.”
The authors believe that the snake’s behavior takes advantage of the human auditory system, which has evolved to explain increased loudness as something moving faster and closer.
Dr. said. what’s up
“Snake rumbles along with mammalian auditory perception develop through trial and error, giving those snakes the best ability to avoid being trampled.”
The study was published in the journal Current Biology.
Follow Matt on Twitter Embedded Tweet.
