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Revealed: How playful whales and dolphins socialise with each other
Rolling from side to side, presenting their bellies, and even lifting their dolphin playmate into the air are some of the ways that whales socialise with their smaller cousins, a new study finds.
The Australian research looking at images and video from 17 locations around the world challenges previous scientific assumptions that dolphins “harassed” whales, finding instead that the play was often mutual.
Griffith University whales and climate program lead Dr Olaf Meynecke and co-author Olivia Crawley analysed nearly 200 separate and unrelated interactions between 425 baleen whales and 1570 dolphins. Their findings were published in the journal, Discover Animals, on Tuesday.
“When we go out and do our whale surveys or tagging whales, we always joke that we can find the whales by looking for the dolphins,” Meynecke said. “Whales that show a lot of active behaviours seem to get the most interest from the dolphins.”
A group of bottlenose dolphins swimming alongside a southern right whale that is moving its fluke towards the dolphins in Esperance, Western Australia.Credit: Jaimen Hudson
Meynecke said the dolphins, being faster swimmers, usually initiated the encounters, but the whales responded either positively or neutrally most of the time. Across all whale species, at least a quarter of the interactions were mutual, and for humpback whales it was at least a third. It was rare that the whale would try to avoid the dolphin or become aggressive.
Most of the documented interactions were between adult animals, but a whale calf was present in 44 events and a dolphin calf in 53 events. Both whale and dolphin calves were present on 21 occasions.
A bottlenose dolphin close to a humpback whale rostrum (front area) bow-riding near Queensland’s Gold Coast.Credit: Roving Media
There were six different whale species in the dataset – more than two-thirds were humpbacks, followed by grey whales (16 per cent) and fin whales (7 per cent). More than half the dolphins were bottlenose, followed by common dolphins (17 per cent) and Pacific wide-sided dolphins (15 per cent).
The dolphins favoured slow and gentle behaviours such as bow-riding (where they surf the wave in front of the whale as it swims), meandering (where they make slow movements with a slight change in direction), touring (where they swim steadily alongside the other animal), and belly rolls.
In at least eight instances, there was rubbing or petting, when dolphins purposely touched the whales around the head area.
A surface rush by a bottlenose dolphin close to a pectoral fin of a humpback whale at Bermagui on the NSW South Coast.Credit: WildLive.Media
The whale species each responded differently to the dolphin behaviour. Humpback whales most often moved their pectoral fins towards the dolphins and also presented their bellies, rolled and moved upside down. Grey whales most often rolled, and southern right whales displayed pectoral slaps.
The interactions were defined as positive because whales used the same behaviours for courtship and friendly socialising within their own species, Meynecke said.
In one case, a whale slowly lifted a dolphin into the air, which Meynecke said could either be inter-species social play or maternal caregiving behaviour by the whale.
The research looked at 197 unique posts on Facebook, Instagram, Flickr, TikTok, X and YouTube between 2004 and September 2024, with an increasing number from within the past five years.
“A lot of it is basically drone footage and that is giving us this aerial view so we see much better where the whales are in position to the dolphins,” Meynecke said.
The study also included two underwater videos from suction camera tags on humpback whales, which showed bottlenose dolphins following the whales not only on the surface but also to the ocean floor where they continued engaging in close approaches including possible touching and social play.
Baleen whales have previously been observed playing with logs, jellyfish, rope and sea turtles, while wild dolphins have been seen playing with seaweed, pufferfish and plastic.
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