A new study is first to find that a humpback whale’s song structure is directly connected to its movement through water
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A new study has found a previously unknown link between the structure of a humpback whale’s song and the whale’s movement through the water. The study, published in Current Biology and led by PhD graduate Julia Zeh at Syracuse University, shows that specific whale vocalisations are tied to certain parts of a dive, offering a new perspective on the importance of whale song.
To gather the data, researchers attached sound-and-movement suction tags to 16 humpback whales off the coast of Maui using long poles and drones. Once attached, these tags captured a whale’s sounds and movements, collecting data that researchers could then analyse.
In this study, researchers were able to discern what the whales are physically doing while they sing. Sound is described as a crucial part of the species’ survival, as it is how they find mates, much like the way certain male birds choreograph ‘dances’ for a prospective partner.
Humpback whale songs are made up of a series of distinct sections, known as ‘themes’, which are typically repeated for two to four minutes before the whale moves on to another. The researchers found that particular themes were associated with particular depths, suggesting that the whales stick to different sections of their song as they move through the water, rather than altering their pitch in response to water pressure.
Humpback whales must regularly dive underwater and return to the surface in a process known as a dive cycle. A typical dive involves descending, spending time underwater – often searching for food – then ascending and pausing at the surface to breathe and recover.
While earlier researchers had noted that only certain themes occurred as whales approached the surface, it hadn’t previously been thought that the structure of an entire song could mirror an entire dive cycle.
What determines a humpback whale’s song during a dive?
While similar recurring themes were sung when whales remained at relatively constant depths, the greatest variability was observed at greater depths. Zeh believes that this may be more strongly shaped by the whale’s pursuit of a mate. By contrast, shallower parts of the dive are limited by factors such as the environment or the whale’s physiology, including the demands of managing oxygen and buoyancy while singing.
Each male humpback’s song could be a signal of its individual qualities, according to the findings of the study.
As varied sounds are highly concentrated near a whale’s deepest points in the water column, this may suggest that deeper waters are where males are most likely to attract a mate.
These findings not only help scientists better understand whales’ vocal behaviour but also have practical implications for whale research. Acoustic monitoring is already a common tool for tracking whale populations, but understanding how song relates to movement could allow researchers to determine a whale’s depth or position directly from a recording.
In turn, this could help scientists establish a clearer baseline for normal humpback behaviour, providing an essential reference point for detecting when whales are disturbed by human activity such as vessel traffic or ocean noise.
However, the study was conducted in Hawaii, so there are some doubts over whether the same findings would apply to humpbacks in other parts of the world, where patterns of human activity in the ocean differ.
Ultimately, Zeh’s work opens a new avenue for studying how physiology, environment and the social transmission of song interact to shape one of nature’s most complex learned behaviours. Framing whale song through movement also offers a model that researchers can apply not only to future humpback studies but potentially to the study of complex acoustic communication across species.
