Male guppies exposed to predators in the wild or in captivity have heavier brains than those living in relatively predator-free conditions, according to new research published in the journal Functional Ecology.
Behavioural ecologists at ±«ÓãÖ±²¥ in Montreal sampled guppies from two rivers in northern Trinidad. In each river, guppies live both above a waterfall, a location that only guppies and a few other small species of fish have managed to colonize, and below the fall, where many predators including pike cichlids live.
