The so-called “Western Pacific Biotwang” is more horror movie than Nashville ballad. A low moan at the beginning is typical of baleen whales, but it was the end that caught the ear of OSU researcher Sharon Nieukirk.
“What makes this call special is the second part, and the way it sweeps way up and it sort of has that metallic twang sound to it,” she said.
This high-pitched sound has been heard coming from minke whales on Australia’s Great Barrier Reef.
“Not many animals make a call with this frequency sweep - that goes from such a low frequency to a very high frequency,” Nieukirk said.
The OSU scientists used a sensor attached to an underwater glider to record in the Mariana trench near Guam. They were doing whale surveys for U.S. Navy to inform how military training exercises are done in the region.
Nieukirk says the sound likely had not been identified previously because of the way scientists analyze acoustic data from the ocean. Usually they look at the low-, middle-, and high-pitched sounds separately.
“In this case, you have to look at all parts simultaneously in order to identify the call in the data,” she said. “It is possible that others have recorded it in the past, and just didn’t put the pieces of this puzzle together.”
Now that the call and the whale that is likely making it have been identified, other scientists can start looking for the new song as well.
The OSU research was published in The Journal of the Acoustical Society of America.