Fish, chimpanzees know how to pick best partner for task

A new study has revealed that when it comes to choosing the right partner for some task, fish are just as good as chimpanzees.

For the first time, researchers at the University of Cambridge have cross-examined the collaborative capacities of the Coral trout with the highly-intelligent chimpanzee using comparably similar experiments, and found that the fish perform as well, if not better, than humankind's closest evolutionary relative when it comes to successful collaboration.

The trout even matched the chimpanzees in the ability to learn at speed which possible collaborator is the best candidate for the job.

The researchers caught wild coral trout and recreated hunting scenarios in set-ups that mirrored their natural environment, with the aim of creating experiments analogous to those previously conducted using chimpanzees, known as the rope-pull experiments, except relevant to the trout's habitat.

The trout undertook the same number of trials as the chimps over a similar time frame. When conditions required collaboration, the trout were at least as proficient as chimps at determining when they needed to recruit a collaborator, doing so in 83 percent of cases, and learned more effectively than chimps when the collaborator was not necessary.

For both trout and chimps, six subjects participated in six trials per day for two days. On the first day, while they were learning about the collaborators' effectiveness, the trout choose each collaborator and equal number of times. But by day two they were over three times more likely to choose the effective hunting partner over the infective partner, a significant increase that matches the selection prowess of the chimps in the rope/pull experiment and appears to demonstrate rapid learning in the fish.

The results showed that, like chimpanzees, trout could determine when a situation required a collaborator and quickly learned to choose the most effective one, said Alexander Vail from the University, who led the study.

However, the researchers added that the increased effectiveness of the trout's ability to judge when to employ an eel collaborator would suggest that the accessibility of each prey was being assessed.

The study is published today in the journal Current Biology.