Want to know where a whale has been on its long-distance oceanic travels? Try listening to its songs, say scientists from the University of St. Andrews. New research, published in Royal Society's journal Open Science, reveals that migrating humpback whales swap songs during their journey in the South Pacific.
"Male humpback whales perform complex, culturally transmitted song displays. Our research has revealed the migration patterns of humpback whales appear to be written into their songs," explains Dr. Ellen Garland of St. Andrews. "We found similarities in songs from the Kermadec Islands and songs from multiple wintering locations."
The Kermadec Islands, north of New Zealand, are a recently discovered migratory stopover in the South Pacific. That region's whale songs were compared to ones being sung in several wintering locations, from New Caledonia to the Cook Islands. The similarity in songs suggest a cultural exchange was taking place as the whales migrated during the fall of 2015.
"Our best analogy is hit human fashion and pop songs," Garland told New Scientist. "We can pinpoint a population a whale has likely come from by what they are singing." Scientists believe male humpbacks sing for a variety of reasons: to attract mates, to navigate new neighborhoods, or even when they've lost a loved one.
Whale songs are a relatively new discovery for humans. In 1967, two biologists revealed that male humpbacks produce complex sounds featuring repeated "themes" that can last up to 30 minutes. At the time, the gentle giants were at the brink of extinction because commercial whalers were hunting and killing them by the tens of thousands each year. Fortunately, thanks to pop culture and a best-selling LP of whale songs that debuted after the study, the International Whaling Commission banned commercial hunting of humpbacks, followed by actions to protect all baleen whales and sperm whales in 1986.
Today, humpback numbers hover around 80,000, down from a pre-whaling population of 125,000. Other populations, however, remain endangered or vulnerable to oil spills, fishing gear and climate change.