Sperm whales headbutt each other, research reveals

The idea of a huge whale crashing head-first into another might sound like a scene from a horror story, but new research shows that these ocean giants really do headbutt one another.

Researchers at the University of St Andrews have obtained clear evidence of sperm whales striking each other with their heads.

For years, sailors told tales of whales ramming objects, with some even claiming the animals could sink ships. Those accounts went on to inspire famous works such as Moby Dick.

Science now lends support to the old stories. Using modern technology, researchers have confirmed that whales use their heads to deliver powerful blows, linking real animal behaviour with historical accounts.

Capturing sperm whales headbutting

The research team studied whales in the Azores and the Balearic Islands alongside the University of the Azores and Asociación Tursiops.

Drones allowed the scientists to watch the whales from above, giving them a clear view of activity close to the surface.

The footage showed whales approaching one another and making contact with their heads. Some also hit each other’s bodies. During these encounters, the whales rolled, opened their jaws and made sounds.

The aerial perspective revealed details that observers watching from boats would usually miss.

What happens during headbutting

Three clear instances of the behaviour were recorded. In one, two similarly sized whales swam towards each other and collided head-first. A third, larger whale remained close by but did not take part in the contact.

In another encounter, two young males moved around a smaller female. One changed course and hit her with his head, pushing her body sideways through the water.

The third case involved repeated contact between two whales. One followed and struck the other several times, even hitting the other whale’s head with its tail. The encounter showed that the behaviour can be repeated and vary in intensity.

Fighting and social behaviour

The researchers found that headbutting is not necessarily aggressive. It may sometimes be social interaction or rough play, and many of the whales involved were young or not yet fully grown.

Scientists also recorded clicks and “codas” during the encounters. These sounds form part of whale communication, indicating that the animals were interacting in more than one way at once.

The study suggests that the behaviour could help young whales practise skills important for adult life.

How powerful are the impacts?

The headbutts are forceful. Scientists estimated that some collisions occur at speeds of up to 12.9 kilometres per hour (8 miles per hour, or 3.6 metres per second). Such impacts can generate very large forces.

In one instance, the force reached approximately 200,000 newtons. Larger adults might produce even stronger impacts, potentially reaching 1,000,000 newtons.

The findings show that sperm whales can deliver powerful blows with their heads and help explain how whales in the past may have damaged ships.

What this means for whale society

Headbutting may influence the way whale groups function. Sperm whales, particularly females and young animals, live in close social groups, and forceful or aggressive actions could disrupt harmony within them.

Young males may become more aggressive as they grow, which could eventually lead them to leave the group. A similar pattern occurs in animals such as elephants, whose young males move away as they mature.

Headbutting may have a role in this important stage of life.

The significance of filming whale headbutts

Lead author Dr Alec Burlem, who worked on the study while at the University of St Andrews, described the importance of the discovery.

“It was really exciting to observe this behaviour, which we knew had been hypothesised for such a long time, but not yet documented and described systematically,” he commented.

The finding confirms a behaviour that had long been suspected and raises new questions about whale life.

What comes next

Scientists still do not fully understand why sperm whales headbutt one another. The behaviour could be connected to competition, communication or practice for adulthood, and further observations may help provide answers.

“This unique overhead perspective for observing and documenting near-surface behaviour is just one of the ways drone technology is transforming the study of wildlife biology,” added Dr Burlem, who is now at the University of Hawaii.

“It’s exciting to think about what as-yet unseen behaviours we may soon uncover, as well as how more headbutting observations may help us to shed light on the functions the behaviour may serve. If there are people out there with similar footage, we would be very keen to hear from them,” said Dr Burlem.

As the research continues, scientists expect to uncover more hidden behaviours. What once sounded like a sea story is now supported by science, illustrating how much remains to be learned about ocean life.