Fish Are Surprisingly Smart
Fish lack many of our mental abilities but may use social learning strategies similar to those used by humans, according to new research.
Scientists have found that a certain fish species — called the nine-spined stickleback — can use information from its personal experience as well as observations of other fish to make the best decision about how to forage for food.
The work suggests that these fish may be capable of using social learning strategies that increase their overall fitness — strategies that so far have only been seen in humans, the researchers say.
In the experiment, the fish were placed in a tank with two feeders; let's call them A and B. The fish were taught that one feeder (A) was better than the other (B), meaning that feeder A gave more food. But then, the fish were shown contrary information: they observed a situation in which feeder B was the better feeder for a group of fish. After viewing this set-up, the majority of the fish (75 percent) preferred to eat from feeder B, even though a past experience had told them that this was a poor feeder.
But if the fish observed a situation in which a feeder gave about the same amount of food or less than the same amount of food that it had given during their personal experience, the fish did not have a preference for a particular feeder, the feeding was split 50:50.
The results showed that the fish were not simply copying other fish in their feeding habits. Rather, they were comparing two different pieces of information, personal and observed, and then using this information to select a feeder. If a feeder did not give a bigger "payoff" than another feeder they had eaten from, they did not overwhelmingly choose a different feeder.
"Lots of animals observe more experienced peers and that way gain foraging skills, develop food preferences, and learn how to evade predators," said Jeremy Kendal, a research fellow at Durham University, UK, and a study author. "But it is not always a recipe for success to simply copy someone. Animals are often better off being selective about when and who they copy."
