Measured Against Reality

Wednesday, September 13, 2006

Amazing Dolphins

There have been a few stories circulating about dolphins lately. First they say that they’re about as smart as goldfish, then a couple that say that they’re actually quite intelligent, as we’d always thought. I fall in with those who think that they’re intelligent animals; that’s certainly the conclusion their behavior leads me to.

Today I saw an amazing example of this. In certain coastal, warm areas, dolphins and local fisherman cooperate. The dolphins drive schools of fish into the shore, and the men cast their nets into the schools. The men get nets full of fish, and in the chaos the dolphins pick off stragglers from the school.

Continue reading...This is pretty remarkable. My guess about how it started is that the dolphins were using their normal tactics to break up a school near the shore, noticed that humans threw nets when the fish were in close, noticed how the school dispersed without much work on their part, and put two and two together. But what’s pretty significant is that this is a culturally transferred behavior, meaning that dolphins are capable of passing learned knowledge through generations. That’s quite extraordinary.

Another great example of undeniable dolphin intelligence comes from this Guardian article:

At the Institute for Marine Mammal Studies in Mississippi, Kelly the dolphin has built up quite a reputation. All the dolphins at the institute are trained to hold onto any litter that falls into their pools until they see a trainer, when they can trade the litter for fish. In this way, the dolphins help to keep their pools clean.

Kelly has taken this task one step further. When people drop paper into the water she hides it under a rock at the bottom of the pool. The next time a trainer passes, she goes down to the rock and tears off a piece of paper to give to the trainer. After a fish reward, she goes back down, tears off another piece of paper, gets another fish, and so on. This behaviour is interesting because it shows that Kelly has a sense of the future and delays gratification. She has realised that a big piece of paper gets the same reward as a small piece and so delivers only small pieces to keep the extra food coming. She has, in effect, trained the humans.

Her cunning has not stopped there. One day, when a gull flew into her pool, she grabbed it, waited for the trainers and then gave it to them. It was a large bird and so the trainers gave her lots of fish. This seemed to give Kelly a new idea. The next time she was fed, instead of eating the last fish, she took it to the bottom of the pool and hid it under the rock where she had been hiding the paper. When no trainers were present, she brought the fish to the surface and used it to lure the gulls, which she would catch to get even more fish. After mastering this lucrative strategy, she taught her calf, who taught other calves, and so gull-baiting has become a hot game among the dolphins.


This is truly spectacular behavior, corroborating the conclusions of transferability of knowledge down generational lines. It also shows a level of intelligence that I had never suspected dolphins to be capable of.

Dolphins have even been observed doing the gold standard of animal intelligence: using tools. They’ve been observed using a scorpion fish they recently killed to cajole an eel out of rocks. They will also place sponges on their noses to protect from stinging animals as they hunt for food along the bottom.

Dolphins even test similarly to us, at least when what’s being tested for is new behaviors.

A dolphin's ability to invent novel behaviours was put to the test in a famous experiment by the renowned dolphin expert Karen Pryor. Two rough-toothed dolphins were rewarded whenever they came up with a new behaviour. It took just a few trials for both dolphins to realise what was required. A similar trial was set up with humans. The humans took about as long to realise what they were being trained to do as did the dolphins. For both the dolphins and the humans, there was a period of frustration (even anger, in the humans) before they "caught on". Once they figured it out, the humans expressed great relief, whereas the dolphins raced around the tank excitedly, displaying more and more novel behaviours.


There are even indications that they’re capable of understanding language and are self-aware, putting them on par with humans and great apes.

I’m sure we’ve barely scratched the surface of what dolphins can do. Maybe one day, millennia from now, after our society has collapsed, they’ll rise up and inherit the earth, and marvel at the wondrous ruins left behind by humanity. Nah.

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