The researchers think the shift occurred gradually as populations rebounded after the general suspension of whaling in the 1960s.

According to research led by Associate Professor Rebecca Dunlop from The University of Queensland’s School of Biological Sciences, male whales along the eastern coast of Australia have shifted their focus from singing to fighting in order to attract mates.

The study analyzed nearly two decades of humpback whale behavior data and suggests that singing may no longer be a popular tactic for seduction.

When compared to a non-singing male, a singing male whale was nearly twice as likely to be seen attempting to mate with a female in 1997, according to Dr. Dunlop.

But by 2015 it had reversed, with non-singing males approximately five times more likely to be documented seeking to pair than singing males.

“It’s quite a big change in behaviour so humans aren’t the only ones subject to big social changes when it comes to mating rituals.”

The shift, according to the researchers, occurred gradually as populations rebounded after the general end of whaling in the 1960s.

“If competition is fierce,” according to Dr. Dunlop, “the last thing the male wants to do is advertise that there is a female in the area, because it might attract other males which could out-compete the singer for the female.”

“By switching to non-singing behaviour, males may be less likely to attract competition and more likely to keep the female.

“If other males do find them, then they either compete or leave.

“With humpbacks, physical aggression tends to express itself as ramming, charging, and trying to head slap each other.

“This runs the risk of physical injury, so males must weigh up the costs and benefits of each tactic.”

Male whales are reportedly less inclined to sing while with other males.

“Singing was the dominant mating tactic in 1997, but within the space of seven years this has turned around,” Dr. Dunlop adds.

“It will be fascinating to see how whale mating behaviour continues to be shaped in the future.”

Co-author Associate Professor Celine Frere noted that prior research by UQ’s Professor Michael Noad revealed that between 1997 and 2015, the whale population increased from 3,700 whales to 27,000 whales.

“We used this rich dataset, collected off Queensland’s Peregian Beach, to explore how this big change in whale social dynamics could lead to changes in their mating behaviour,” adds Dr. Frere.

“We tested the hypothesis that whales may be less likely to use singing as a mating tactic when the population size is larger, to avoid attracting other males to their potential mate.”

The study was published in the journal Communications Biology.

Source: 10.1038/s42003-023-04509-7

Image Credit: Getty