Even without ears, snakes hear airborne sounds
A Burmese python ( file photo)
Popular belief is that snakes are deaf since they do not have external ears.
People think they only feel vibrations coming from the ground, says Professor Christina Zdenek, from the University of Queensland in Australia, in a statement.
The Professor and her colleagues conducted a series of experiments to prove once and for all that snakes can hear airborne sounds.
To crack the mystery, Professor Zdenek and her colleagues conducted over 300 experiments with 19 snakes from 5 different genera.
“Our work is the first to use unanesthetized, freely moving snakes.
—Christina Zdenek, University of Queensland
The team placed the reptiles in a soundproof room to observe their individual responses to three sounds, each comprising a range of frequencies from 1 to 50 Hz, from 150 to 300 Hz and from 300 to 450 Hz.
For comparison, the frequency of the human voice is between 100 and 250 Hz, and that of chirping birds is around 8000 Hz. One of the sounds produced vibrations on the ground, while the other two were only airborne. .
Observed behaviors were body, head and tongue movements, and whistling.
Our research reveals that they [snakes] respond to sound waves traveling through the air, and possibly even human voices, says Professor Zdenek, lead author of the work published in the journal PLOS ONE.
Collected observations show that snakes react to airborne and terrestrial sounds, at least in the frequency range of 0 to 450 Hz.
In addition, researchers have established that behavioral responses are highly species-dependent.
For example, the Woma python (Aspidites ramsayi)tends to move more and move closer to a sound, as the taipan moves away from it, notes Pr Zdenek.
< p>“The Woma python is a large nocturnal snake that does not have many predators, so it is less cautious and tends to approach sound.
—Christina Zdenek, University of Queensland
In addition, it exhibits an interesting behavior called periscopic, during which it raises the front third of its body in a movement reminiscent of curiosity.
The taipan, smaller than the python, reacts more cautiously to sound and seems more defensive. In its natural environment, the taipan must constantly monitor predators such as raptors, especially during the day. Because of this, it tends to shy away from sound, she adds.
Dr. Zdenek believes her study puts to rest the myth of snake deafness.
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They hear sounds, but certainly not as well as you and me, says the researcher, who adds that snakes can only pick up low frequencies below 600 Hz.
We know very little about how most snake species orient themselves in different environments around the world.
Our results improve our still limited understanding of snakes, which could help humans better understand their behavior and thus avoid their bites, estimates the researcher.
- There are more than 3400 species of snakes in the world, including about 500 venomous.
- They can live in the most extreme climates, with the exception of polar climates and subpolar.
- In Canada, there are 26 native species and one apparently hybrid species. The majority of snakes live in the south of the country.
< li>They are found in several types of environment, from tropical forests to desert, from rivers to the sea.
