Under Antarctica's ice, Weddell seals produce ultrasonic vocalizations
EUGENE, Ore. -- Dec. 21, 2020 -- Weddell seals are chirping, whistling and trilling under Antarctica's ice at sound frequencies that are inaudible to humans, according to a research team led by University of Oregon biologists.
Two years of recordings at a live-streaming underwater observatory in McMurdo Sound have captured nine types of tonal ultrasonic seal vocalizations that reach to 50 kilohertz. Humans hear in the sonic range of 20 to 20,000 hertz, or 20 kilohertz.
The discovery is detailed in a paper published online Dec. 18 ahead of print the Journal of the Acoustical Society of America.
Weddell seals (Leptonychotes weddelii), the world's southernmost-ranging mammal, thrive under the continent's sea ice, using their large teeth to create air holes. They can dive to 600 meters in search of prey and remain submerged for 80 minutes. Researchers had first identified 34 seal call types at sonic frequencies in 1982, tying the sounds to social interactions.