Above water, they are like bellowing Wookies. Beneath the ice, they are like sifting, chatting robots. Either way, Weddell’s seals in Antarctica should have no problem finding work in the future Star Wars project.
“Weddell’s seal calls create an almost incredible landscape, another under the ice,” Paul Cziko, a visiting professor at the University of Oregon and lead author of a new study describing the sounds of strange seals, said in a statement ““ It looks like you’re in the middle of an inner space battle Star Wars, laser carriage and everything. “
The catch: You had to be a stranger (or droid) to hear them; these sci-fi sounds are completely inaccessible to human ears.
Cziko and his colleagues were able to discover the other sounds after two years of listening to Weddell’s seals (Leptonychotes weddellii) with a special hydrophone (underwater microphone) installed in the McMurdo Strait at Antarctica in 2017.
Before the researchers began recording, scientists knew about the 34 sealskin sightings that could be heard in human ears. Now, the team’s research – published online Dec. 18 in Journal of the American Acoustical Society – adds nine new types of ultrasonic coatings to the seals’ repertoire. These sounds include trills, whistles and chirps with a foreign sound, sometimes made up of many harmonious tones.
People hear in the sonic range of 20 to 20,000 hertz (or 20 kilohertz), the researchers noted. Most modern seal sounds were above 21 kHz, with some consistently rising to 30 kHz.
(McMurdo Oceanographic Theater)
Above: Visual representation (spectrogram) of one of the nine types of ultrasonic calling. The U-shaped features in the upper half of the plot are part of the U101 call type.
One loud whistle reached 49.8 kHz, the team wrote – and when seals matched multiple tones, the resulting sound could exceed 200 kHz. (That is far beyond the range of cats, dogs and even some bats.)
What are these high frequency communications about? The researchers are unsure; To date, scientists have never detected ultrasonic calls in seals (or in other steep mammals, such as sea lions or walruses).
A diver in the McMurdo Strait at Antarctica is watching a Weddell seal. (McMurdo Oceanographic Theater)
According to Cziko, the sounds could simply be bonus conversation elements to “stand out over all lower frequency sounds, as a switch to a different channel for communication.”
It is theoretically possible that the sounds are involved in an echo, the biological sonar that animals such as dolphins and bats use to find their way around dark places. But so far, there is no evidence that seals use echolocation, the researchers said.
However, the out-of-character behavior would not be for seals that can dive more than 1,900 feet (600 meters) underwater and hunt in the winter darkness of Antarctica, the team said.
We see Wookie trying to do that.
This article was originally published by Live Science. Read the original article here.