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One of the fundamental flaws of humankind is that we just can’t help ourselves when it comes to seizing, gutting, and profiting from things we’ve stolen from the natural world. When humans first discovered whales and the precious goo inside their heads, whalers went to town hunting down these enormous marine mammals at sea. Oil from these animals could be used for fueling lamps as well as making soap, and we couldn’t get enough of the stuff. Whales were undoubtedly on the sour end of this profiteering business, but new research published in the journal Biology Letters suggests that they were far from sitting ducks.
Sperm whales aren't the only cetaceans with magic oil
Humans – and environmental change triggered by their activity – remain one of the leading threats for many species on Earth, but animals are sometimes able to mitigate how much they suffer from our existence by altering their behavior. When whale hunting really picked up as an industry, the whales were on the receiving end of harpoons for the first time, and as such, had little by the way of defense to keep them alive. This new research looked at digitized logbooks from whaling operations in the North Pacific, which revealed a surprising drop off in the success of harpooning as whalers were striking whales at less than half the rate they had been just a few years prior.
Based on the data in these logbooks, the researchers estimate that whaling success dipped by 58 percent. What’s even more interesting is that the reduction couldn’t be explained as a reduction in whaling skills (the earliest whalers would have to have been novices), nor that they’d simply been able to take out all the older or more infirm whales at the start. So why were fewer being harpooned?
The team on this new study suggests that the sudden drop off may have been caused by a behavioral change in the sperm whales as a means of tackling this newfound threat. Whales are very intelligent animals, with many species existing within large and highly social groups. It’s possible, then, that whales were rapidly developing and practicing effective defensive behavior which enabled them to evade the whalers’ harpoons.
Sperm whales live in families of related individuals and they can communicate with other groups across great distances. They are able to coordinate behavior to protect themselves from hunting orcas by forming a circle with their tails on the outside to act as a powerful deterrent. Such behavior would only make matters worse when evading whalers, but it demonstrates their capacity to communicate and coordinate a defense strategy.
Using social learning models to map the behavior of naive social units – those who hadn’t come across whalers before – the researchers were able to establish that such a drop off in harpooning success could’ve happened in tandem with experienced groups sharing information. This would lead to the rapid spread and adoption of a new set of defensive behaviors, successful enough to slash the whalers' yield by over half.
“Our models show that social learning, in which naive social units, when confronted by whalers, learned defensive measures from grouped social units with experience, could lead to the documented rapid decline in strike rate,” wrote the study authors. “This rapid, large-scale adoption of new behaviour enlarges our concept of the spatio-temporal dynamics of non-human culture.”
Love whales? Find out what it's like working as a whale entanglement response coordinator in our interview with Ed Lyman.
