Speedy Animals

Fast-moving animals - especially small ones, creatures that fly and top ocean predators - perceive time [blank] quickly than others. That is, they can process more frames per second than slow-moving animals lower [blank] the food chain, such as starfish, according to a comparison of more than 100 species. "We already know that different animals perceive time differently from us," says Kevin Healy at the University of Galway in Ireland, [blank] presented the results at a meeting of the British Ecological Society on 20 December. But he wanted to find out, "If you're a predator, do you have faster eyes than [blank] you're an herbivore?" He and his colleagues began by reviewing previously published research on the flicker fusion test, a common measure of the rate at [blank] animals perceive the passage of time. During the test, researchers increased the frequency of flashing light until an animal sees it as a continuous glow, indicated by the reaction of light receptors in the animal's retina.