Headbutting whales. Credit: Association Tursiops.
In the first known footage of its kind, it’s been confirmed ‘ship sinking’ sperm whales headbutt one another, as well as ships.
New research from the University of St Andrews reports sperm whales headbutting one another.
The behaviour was captured on film and described scientifically for the first time, confirming accounts by 19th Century mariners of sperm whales using their heads to deliberately push and strike objects, occasionally even sinking ships, thereby inspiring Herman Melville’s classic tale Moby Dick.
Using drone technology, researchers were able to film sperm whales headbutting each other, as well as the surrounding behavioural and social context.
The images were filmed during fieldwork in the Azores and Balearic Islands between 2020 and 2022.
The paper also shows how sub-adult whales engaged in this headbutting activity, rather than between large males as was previously hypothesised.
This new discovery raises intriguing questions about the function and consequences of such behaviour on group cohesion and social dynamics.
Lead author Dr Alec Burslem, who carried out the research whilst at the University of St Andrews in collaboration with researchers at the University of the Azores and Asociación Tursiops (an NGO based in the Balearic islands), said: “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.”
Unseen behaviours
More observations will be needed to understand the function of this behaviour but the widespread use of drones in the field will offer increased opportunities for observations of this as well as other, as yet unseen, near-surface behaviours.
There is speculation as to whether sperm whale headbutting may have originated from physical contests between sperm whales.
Some hypothesised that this behaviour may be a widespread part of male-male competition but occurs under the surface and is therefore difficult to observe from boats.
Others argued that habitually using the head as a weapon was unlikely to have been favoured by evolution, as it would endanger structures in the head which are vital for producing sounds used for echolocation and social communication.
Moby Dick
The use of the head by sperm whales to push and strike objects has been reported anecdotally since the open-boat whaling of the 19th Century.
The most famous example is that of Essex, a 27m sail-powered whaleship which was reported to have been sunk by two head-on strikes from a large bull sperm whale off the Galapagos in 1820 and which inspired Herman Melville’s novel Moby Dick.
Owen Chase, First mate upon the Essex described the force of the whale’s headbutt in a contemporaneous report quote: “I turned around and saw him about one hundred rods [~500m] directly ahead of us, coming down with twice his ordinary speed of around 24 knots, and it appeared with tenfold fury and vengeance in his aspect.
“The surf flew in all directions about him with the continual violent thrashing of his tail.
“His head about half out of the water, and in that way he came upon us, and again struck the ship.”
Other similar accounts of whaling ships being sunk by sperm whales include the sinkings of Ann Alexander and Kathleen in the 19th Century.
Burslem, who is now based at the University of Hawaii, added: “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.
“It’s exciting to think about what as-yet unseen behaviours we may soon uncover, as well 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.”
The paper is published in Marine Mammal Science.
