This is the one page you should only read after you have been convinced that sperm whales might be our equals. If not, all that will be detailed to you below is one more anomaly which does not fit the current paradigm as well as scientists would wish it to…
Long ago, in my student days, I recall the story of a post graduate quitting his research team because of their failure to follow through on a certain problem. Though it happened in distant Brazil, the reason was sufficiently interesting as to warrant a brief comment in an article published here. His group had been studying a ‘fishing cooperative’. In these, dolphins and humans work together to catch more than they could separately. The most common species involved in these cooperatives are the Irrawaddy dolphins that live in the brackish waters and rivers of Southeast Asia. Something very similar was happening off the Brazilian coast with bottlenose dolphins, but the more they studied it the less sense it made. No matter what parameters they tweaked, their models still gave the same result: this association was advantageous only to the humans. It made even less sense given its history.
All accounts have this partnership beginning abruptly in 1847. One day, a pod of bottlenose dolphins approached a group fishing by the shore then demonstrated how they could herd fish into their nets. No fisherman today shares any of their catch with their dolphin helpers. When questioned over their behaviour their common stated answer is that the hungrier their dolphins are the harder they will work (by the way, none of them are subsistence fishermen, they are all commercial).
Such selfish behaviour by the human partners didn’t help the analysis and, in the end, all but one of the research team gave up on the point. They might not have been able to demonstrate any gain for the bottlenoses involved, but it must exist! Convention has it that you don’t publish negatives except in exceptional circumstances, thus the dissent.
To this day research continues, but a carefully reading of published papers shows no progress on this matter. When they come to discuss how the dolphins might benefit, statements get vague. They might point out that engaging in this cooperative behaviour was easier for them than chasing tuna through the open ocean, but they never make the comparison of herding mullet into a vacant section of the beach, compared to one that contains take-everything fishermen.
Other recent work has shown all dolphins involved are closely related to each other, and far more docile than the ‘wild’ bottlenoses that surround them (it may surprise some readers to learn that dolphins often show much aggression to each other – but not these ones). Docility is characteristic of domesticated animals, so all evidence points to them being domesticated before 1847, yet that conclusion seems precluded by the impossibility of our domestication of an open ocean species. Below I describe a way to answer the mystery.
If we knew sperm whales to be sapient, the conclusion that these dolphins had been domesticated, and that they were responsible for it would be almost trivial for the following reasons. Forget their intelligence, sperm whales are the only species I know with the means to corral dolphins in open ocean. Between a third and one half of a sperm whale’s body is devoted to a biological sound gun. It is so effective that they can project a ray of sound for miles, a beam that no animal with sensitive hearing would ever want to swim towards the intense centre of. Nimble, fast swimming dolphins are built to chase schools of fish so, once kept long enough to train, they could bring fish to their whale masters just as they now do towards fishermen’s nets. If they can drive the fish close enough, the sperm whales can stun them, then both dolphin and whale can feast. Interestingly enough, sperm whales have been observed stunning fish with their sound gun, yet tests indicate it to be ineffectual against their main prey of today (squid). Also of interest is that data collected from the first sperm whaling era, shows more fish-filled whale stomachs than squids filled ones. 1847 (or as close as I can tell it) was the year when close-to-shore sperm whale populations collapsed, and whalers had to move much further out to continue their operations. Any domesticated animals they had would have suddenly found themselves abandoned and in need of finding new masters.
Could it even be possible that sperm whale populations have recovered sufficiently to try again? Very recently, a pod of sperm whales off the Azores began looking after a deformed dolphin of that very same species. It represents the only know association in modern times between Sperm whales and another cetacean.
Sadly, I never wrote down the name of the student whose dissidence began this page. I can’t even remember whether it was a man or a woman. Even all these years later, I would love to hear from them. And another thing… To those of you reading this with interest and time on your hands, there is something you could do if you could find diaries of whalers operating in that region before 1847. I would be grateful if you hunt through them looking associations between sperm whales and pods of bottlenose dolphins.