Fish as good as chimpanzees at choosing the best partner for a task
Latest research shows that coral trout can now join chimpanzees as the only non-human species that can choose the right situation and the right partner to get the best result when collaboratively working.
Coral trout are fast when chasing prey above the reefs of their habitat, but can’t pursue their quarry if it buries itself into a hard-to-reach reef crevice. When this happens, the trout will team up with a snake-like moray eel to flush out the unfortunate fish in a remarkable piece of interspecies collaboration: either the eel takes the prey in the reef, or scares it back into the open so the trout can pounce. Coral trout – along with close relative the roving coral grouper – will use gestures and signals to flag the location of prey to an eel, including head shakes and headstands that actually point the eel in the right direction. Field observations also suggested that they have a startling ability to assess when a situation needs a collaborator and to pick the right partner in the vicinity to get the best hunting results.
Now, for the first time, researchers at the University of Cambridge have cross-examined the collaborative capacities of these 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 match chimpanzees in the ability to learn at speed which possible collaborator is the best candidate for the job.
The trout undertook the same number of trials as the chimps over a similar time frame. When conditions required collaboration, i.e. when the food was out of reach, the trout were at least as proficient as chimps at determining when they needed to recruit a collaborator, doing so in 83% of cases, and learned more effectively than chimps when the collaborator was not necessary.
“Our results show that, like chimpanzees, trout can determine when a situation requires a collaborator and quickly learn to choose the most effective one…This study strengthens the case that a relatively small brain – compared to warm-blooded species – does not stop at least some fish species from possessing cognitive abilities that compare to or even surpass those of apes.”
…complex behaviour doesn’t always reflect a complex mind.
“Perhaps the biggest question is whether the processes underlying collaborative partner choice in humans, chimpanzees and trout are the result of common ancestry or an evolutionary convergence…Convergence – where species of different lineages evolve similar features – has been suggested as the reason for other superficially similar ape and human abilities, and is the most likely reason why trout would seem to share this one too.”