The humpback whales, once on the brink of extinction due to unrestricted commercial whaling practices, have slowly grown back in numbers thanks to the untiring efforts of conservationists and international protection.

The main breeding ground of the whales in the North Pacific region has been the main Hawaiian Islands. But research conducted by scientists at the Hawaii Institute of Marine Biology (HIMB) and the National Oceanic and Atmospheric Administration (NOAA) shows that these grounds extend throughout the Hawaiian archipelago and into the Papahanaumokuakea Marine National Monument, also known as the Northwestern Hawaiian Islands (NWHI).

Dr. Marc Lammers, lead scientist of the project and a researcher at HIMB explains “these findings are exciting because they force us to re-evaluate what we know about humpback whale migration and the importance of the NWHI to the population.”

This startling revelation came to light when researchers deployed instruments known as Ecological Acoustic Recorders (EARs) in both the Northwestern Hawaiian Islands and Main Hawaiian Islands to record the occurrence of humpback whale song as an indicator of winter breeding activity. Song is produced by male humpback whales during the breeding season in winter. Researchers are unsure why male humpbacks produce song, but many believe that it is a display to other males.

Approximately 8,500 to 10,000 whales migrate to Hawaii each winter. The rest of the population migrates to the Philippines, Taiwan, the Mariana Islands, Mexico, Baja California and other Pacific locations.