Researchers have analysed hundreds of videos and images to better understand a rare phenomenon: “play” between dolphins and whales.
The study, published in the journal Discover Animals, sought to find out if the marine mammals were playing with each other, or if the behaviour is more one-sided.
Whales responded more positively to the dolphins’ play than expected.
They analysed photographs and video taken by the public, tourism operators and scientists. The hundreds of images involved 19 species in 199 separate interactions in 17 locations around the world.
Images of whale and dolphin interactions used in the study. Credits: a) Roving media b) Wildlive media c) Dan Abbott d) Jaimen Hudson.
About 1,570 dolphins appeared in the images. Among these, 51% were bottlenose dolphins, 17% common dolphins and 15% were pacific wide-sided dolphins. A total of 425 whales from 6 baleen species were also involved. More than two-thirds were humpback whales, while 16% were grey whales and a further 7% fin whales.
Video analysis suggests that humpback whales responded positively to the interaction with dolphins about a third of the time.
“The humpback whales were rolling from side to side, undertaking belly presentation and other behaviours that are associated with courtship or friendly socialising,” says study lead Olaf Meynecke, lead of the Whales & Climate Program at Australia’s Griffith University, in a university media release.
“Whales also strategically moved slowly in the direction of the dolphins with their head and rostrum. The vast majority of the observed interactions did not show avoidance behaviour,” Meynecke explains.
“We were in particular interested to document the whales’ reactions and responses toward the dolphins’ as commonly dolphins are described to harass and annoy the whales.”
“When you’re out on the water, you often see whales and dolphins interacting and as a scientist, you can’t help but wonder why,” adds co-author Olivia Crawley, a master’s graduate at Griffith. “Having the opportunity to document these observations and observe some of the behavioural patterns like bow riding by dolphins and close touches was intriguing.”
“I hope that this study can serve as a foundation for future studies.”
Not all of the interactions showed the whales were on board with the dolphins’ playfulness. Some of the whales were observed slapping their heads or tails on the water surface – indicating aggressive responses – though these were very rare and almost non-existent in humpback whales in particular.
Credit: Supplied.
“While social play is cooperative and reciprocal, there is also one-sided play or interaction, with only one participant perceiving the interaction as playful, as seen in cases of teasing or harassment by dolphins during feeding events,” Meynecke adds.
“Behavioural studies of marine mammals such as these provide insight into their complex social structures, play a crucial role in enhancing our understanding of marine ecosystems and the interactions among marine species.”
In an email to Cosmos, Meynecke says the research is a glimpse into a little-studied world.
“Surprisingly there is not much research out there looking at whale and dolphin interactions,” he says. “Likely because information and data is not easy to obtain. It is not really possible to plan to document this type of behaviour as it can occur for short times and at different places.”
Dolphins and whales aren’t the only animals known to engage in interspecies play.
“We know interspecies social play (ISP) from chimpanzees playing with baboons, dogs playing with donkeys, and giraffes interacting with ostriches, for example,” Meynecke says. “But at sea documenting ISP is difficult due to the remoteness and inaccessibility.”
Meynecke theorises that the ISP between whales and dolphins may be down-time for these large, intelligent and social marine creatures.
“The dolphins usually instigate the interaction but, as we have learned, it is not always a one-sided meet up in the ocean. Whales also responded positively, as we have documented. Similar to humans, dolphins and whales also need creative times when their brain can relax and they don’t have to engage in a purpose-driven activity such as hunting food or reproduction. In that sense, there are times when whales and dolphins can have positive effects for their well-being.
“However, it all depends on the situation. Often the whales don’t show any direct visible response, but this does not mean they are not responding – e.g. they might be vocalising and communicating about the presence of dolphins.
“Either way the different behaviour categories that we were able to extract from the data shows the complexity of whale and dolphin interaction. Much to learn and study in the future.”