When humpback whales are hunting together at the bottom of the ocean, they make “tick-tock” noises to call other nearby whales over for a late-night feeding.
Scientists have known that humpback whales have a trick or two when it comes to finding a quick meal at the bottom of the ocean during the day. But how they pinpoint that meal at night, with little or no available light, has been a mystery.
New research suggests whales work together by emitting specific auditory cues as they search the deep ocean for prey.
“Humpback whales are known to cooperate with others to corral prey near the surface,” says Susan Parks, assistant professor of biology at Syracuse University.
“Recent studies suggest they may cooperate (with each other), when feeding on bottom prey, as well.”
‘Tick-tocks’ call whales to dinner
For a new study published in Scientific Reports, reseachers spent the past decade monitoring humpback feeding behaviors in the Gerry E. Studds Stellwagen Bank National Marine Sanctuary, off the coast of Massachusetts.
Whales were tagged with special underwater recording devices to determine how specific acoustic sounds correlated with successful seafloor feeding.
The findings show that whales make “tick-tock” noises while hunting together at night in deep, pitch-black water, but are silent when hunting alone.
On the menu? Mostly sand lance—eel-like fish known to bury themselves in the sand of the ocean floor. The research suggests that whales’ vocal sounds may help flush the sand lance 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 behavior suggest that other whales who overhear the sounds are attracted to them and may eavesdrop on other whales hunting for food,” Parks says.
Researchers from Oregon State University, the Gerry E. Studds Stellwagen Bank National Marine Sanctuary, and the Whale Center of New England are coauthors of the study.
Source: Syracuse University