The elks, also known as North American red deer or wapitis, manage to roar and whistle at the same time, resulting in the vocalization known as a bugle. The findings are published in the Journal of Experimental Biology.
Bugling bull elk:
“Larger animals tend to have deeper resonances and lower voices,” lead author David Reby from the University of Sussex explained in a press release.
The paradox has puzzled scientists for decades, so when Reby’s colleague Megan Wyman returned from a trip recording deer bellows in New Zealand, Reby knew that they might have a chance to finally solve the mystery.
While studying these and other recordings of the animals, another stroke of good luck happened — at least for the researchers.
A member of the research team, Yann Locatelli, learned that a male elk in the herd at France’s Muséum National d’Histoire Naturelle had died. The natural death gave the scientists a chance to study the elk’s anatomy underlying calls.
All of the analysis allowed the team to determine that elks whistle while simultaneously roaring through their vocal chords. The call includes an unnatural sounding, high-pitched shriek that reaches frequencies up to 4000 Hz.
The high and low pitched sounds can shift independently. For example, sometimes the high-pitched wail rises and falls while the tone of the lower-pitched roar remains constant. The vocal folds vibrate and produce a call that matches the animal’s size, while the bull simultaneously produces a high-pitched, high-volume, wraith-like cry by whistling.
Physicist Joel Gilbert, also on the research team, calculated how the air released by the bull might vibrate in the animal’s oral cavity. He realized that the jet of air could hit the elk’s soft palate (known as the velum) in much the same way that air in a flute vibrates.
Like a wind instrument musician, the process requires the elk to make some skillful mouth and other facial movements, too.
Read more at Discovery News
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