Humpback whales move daytime singing offshore, research reveals

JANUARY 24, 2024

by Marcie Grabowski, University of Hawaii at Manoa



Singing whale. Hawaiian Islands Humpback Whale National Marine Sanctuary (NOAA permit 782-1719). Credit: Hawaiian Islands Humpback Whale National Marine Sanctuary

Humpback whale singing dominates the marine soundscape during winter months off Maui. However, despite decades of research, many questions regarding humpback whale behavior and song remain unanswered. New research has revealed a daily pattern wherein whales move their singing away from shore throughout the day and return to the nearshore in the evening.

The findings were led by the University of Hawaiʻi, in partnership with NOAA's Hawaiian Islands Humpback Whale National Marine Sanctuary, and published in Royal Society Open Science.

"Singers may be attempting to reduce the chances of their song being drowned out among the cacophony nearshore when whale numbers are high," said Anke Kügler, lead author of the study who was a doctoral student in the Marine Biology Graduate Program at UH Mānoa at the time of the research. "Further, we documented humpback whales moving closer to shore around sunset, possibly to avoid the offshore evening chorus of other animals."

By using a combination of underwater listening devices and visual surveys, the research team was able to track both the physical movements and the acoustic patterns of whales in the high-density breeding grounds found in Hawai'i.

"This dynamic onshore-offshore movement of singers may be aimed at increasing the efficiency of the whales' acoustic display, ensuring that other whales hear their songs," said Marc Lammers, study co-author and research ecologist with NOAA's Hawaiian Islands Humpback Whale National Marine Sanctuary.

More:
https://phys.org/news/2024-01-humpback-whales-daytime-offshore-reveals.html