Humpback whales are famous for their complex and captivating songs, which can last for hours and travel across vast distances. But why do these marine giants sing, and how do they adapt to the changing soundscape of the ocean?
The Mystery of Whale Songs
Mike Doherty/Unspalsh
Scientists have been studying humpback whale songs for decades, but they still do not fully understand their function and meaning.
Some hypotheses suggest that the songs are used for mating, navigation, communication, or social bonding. However, none of these explanations can account for all the variations and patterns observed in whale songs.
One of the most intriguing aspects of humpback whale songs is that they change over time and space. Humpback whales in different populations sing different songs, and they also modify their songs within and between seasons.
Moreover, the songs can spread rapidly among whales, creating a cultural phenomenon known as song convergence.
Anke Kogler, a former doctoral student at the University of Hawaii at Manoa, who led a groundbreaking study on humpback whale singing behavior, said that the songs are "a dynamic and ever-evolving acoustic display".
She added that the songs are "presumed to play an important role for breeding", but the exact mechanisms are still unknown.
They found that the whales move their singing away from shore during the day and return to the nearshore in the evening.
The researchers used a combination of underwater listening devices and visual surveys to track the movements and acoustic patterns of the whales.
They speculated that the whales' daytime offshore movement is an adaptive behavior to reduce the interference from other whales and noises nearshore, where whale density is high.
They also suggested that the whales move closer to shore around sunset to avoid the offshore evening chorus of other animals, such as dolphins and fish.
Marc Lammers, a research ecologist with NOAA's Hawaiian Islands Humpback Whale National Marine Sanctuary and a co-author of the study, said that the whales' movement may be aimed at increasing the efficiency of their acoustic display, ensuring that other whales hear their songs.
He said that the study was "the first effort of its kind" to use specialized acoustic sensors to localize individual singers close to shore and understand their daily variations in behavior.
The study, published in Royal Society Open Science, highlights the significance of the acoustic environment for humpback whales and their singing.
It also opens up new avenues for understanding how these whales adapt and harmonize with their surroundings, and how human activities may affect their acoustic communication.
Humpback whales are ecologically, economically, and culturally important in Hawaii, and their singing is iconic around the world. By unraveling the mysteries of their songs and movements, scientists hope to gain a deeper appreciation of these magnificent creatures and their role in the ocean.
