Humpback whales make “tick-tock” noises while hunting together at night in deep, pitch-black water which help draw their prey — eel-like fish — out of hiding, a new study has found.
Susan Parks, assistant professor of biology in the College of Arts and Sciences at Syracuse University, and colleagues have been studying how humpback whales pinpoint their meal at night, with little or no available light.
“Humpback whales are known to cooperate with others to corral prey near the surface. Recent studies suggest they may cooperate [with each other], when feeding on bottom prey, as well,” Parks said.
Parks was part of a collaborative multi-institutional consortium that has spent a decade monitoring humpback feeding behaviours in the Gerry E Studds Stellwagen Bank National Marine Sanctuary, off the coast of Massachusetts.
Whales were tagged with special underwater recording devices so Parks could determine how specific acoustic sounds correlated with successful seafloor feeding.
The investigation found that whales make “tick-tock” noises while hunting together at night in deep, pitch—black water, but are silent when hunting alone.
Parks suggests that whales’ vocal sounds may help flush the sand lance — eel-like fish known to bury themselves in the sand of the ocean floor — out of hiding to where they’re scooped up and eaten.
The clock-like sounds created by whales may also serve as a dinner bell of sorts for other nearby whales during late-night feedings.
“Hints of behaviour suggest that other whales who overhear the sounds are attracted to them and may eavesdrop on other whales hunting for food,” Parks added.
The findings are published in the journal Scientific Reports.
