Alexander Wilson was swimming in the Atlantic Ocean, filming a group of sperm whales, when he noticed something odd: a strange-looking dolphin was interacting with the whales.
“Immediately it struck us as strange, but it appeared that the sperm whales were being rather friendly with the dolphin,” he says. “The first time we saw this mixed-species group, we thought it might just be a transient encounter – the dolphin happened to be swimming by. When we saw this a second time, we realized we might be witnessing something important.” Ultimately, they saw the dolphin with the sperm whales several times over an eight-day period.
The sighting was unusual enough that Wilson wrote a “note” about the encounter for the journal Aquatic Mammals, and the story quickly caught the attention of the public. “It was kind of the perfect storm of cuteness,” he says. “People love whales and dolphins, but the two together even more so. We thought there might be some coverage but ended up with far more than we expected. For a little while, everybody was talking about it, including National Geographic and the Discovery Channel.”
Wilson’s video of one sighting is linked at the bottom of this page. In it, you can see the interaction among the whales and the dolphin, which has an abnormally curved spine. “Cetaceans (whales) will touch each other with their flukes, or rub their tails against each other’s bodies, and sperm whales often roll around over each other to show affection,” Wilson says. “Dolphins do this as well as more poking or nuzzling. We saw lots of rubbing and rolling and touching each other. The dolphin was being friendly, and that friendliness was reciprocated.”
At the time of this discovery, Wilson was working with colleagues from the Leibniz Institute of Freshwater Ecology and Inland Fisheries based in Berlin, Germany. They were on an exploratory trip to see how feasible it was to collect information about sperm whale behaviour by, yes, hanging out in the water watching them.
Wilson’s interest in marine life started when he was growing up in Toronto. “We went fishing a lot when I was a kid, and I was always interested in what might come out when I threw my hook in the water.” That curiosity stuck, and he studied marine and freshwater biology, earning undergraduate and master’s degrees in zoology at U of G and a PhD at Carleton University. He’s an Alexander von Humboldt Postdoctoral Research Fellow at Leibniz.
His research focuses on animal personality and social networks, and he’s studied guppies, frogs and sailfish as well as sperm whales. “To observe the whales, we would take a small Zodiac boat out about 15 to 20 kilometres from the shore and look for surfacing whales. Sperm whales have a very distinctive plume – the misty vapour that spouts up when the whales surface. Once we saw that, we’d jump in the water with our cameras.”
Wilson and his colleagues had a special permit to be in the water near the whales – it’s usually not allowed – but did not chase or harass the animals in any way.
“They could swim past or away from us if they wanted. They are as big as boxcars and sometimes they would swim towards us and flip upside down so they could get a better look at us. That’s a bit unnerving but also very exciting.”
Their research goals were accomplished: Wilson and his colleagues were able to determine what kind of more in-depth observations would be possible. The encounter with the dolphin was an amazing bonus.
“Originally, we had no idea how long this mixed-species group had been together; we were only there for 10 days. After the story came out, though, we talked to some other naturalists in the area, and people told us they had seen that dolphin with the sperm whales for a couple of years. We still need to confirm this. Interactions over the course of a week were very significant, but this made it potentially even more interesting.”
Dolphins do have a history of forming groups with other species, Wilson says, and recalls a report of humpbacked whales playing with dolphins near Hawaii. He speculates that a possible reason for the dolphin to want to stay with the whales is that sperm whales are very messy eaters. To feed, they dive into deep water – often more than 800 metres down – and come up with bits of squid on them. One theory is that the dolphin, which may have been less successful at hunting because of his deformity, ate some of these extra bits of squid. “We never saw the dolphin feeding, so we don’t know,” says Wilson.
“Lots of people have seen whales on whale-watching trips,” he adds, “but it’s like an iceberg: 90 per cent of what happens with whales happens below the water. When we can get into the water with them, we learn so much more. We didn’t know sperm whales were capable of this kind of interaction with other species. Now we know.”