Don’t tell the zebras... stripes make you easier to catch
DULL, featureless camouflage may provide better protection from predators than zebra stripes, new research from Exeter scientists suggests.
A study by researchers at the University of Exeter indicates that lowcontrast, featureless targets were hardest to catch when in motion.
Biologists explaining the existence of such stripes have proposed the motion dazzle hypothesis, which suggests high-contrast patterns can make it difficult for predators to track a moving target.
University of Exeter scientists tested this using a touch-screen game called Dazzle Bug in which visitors to Cornwall’s Eden Project had to catch a moving rectangular ‘bug’. Bug patterns were programmed to evolve to find the best camouflage strategy.
Senior author Dr Laura Kelley, of the Centre for Ecology and Conservation at Exeter’s Penryn Campus in Cornwall, said: “Surprisingly, targets evolved to lose patterns and instead match their backgrounds.
“Our results indicate that low-contrast, featureless targets were hardest to catch when in motion.”
Lead author Dr Anna Hughes, now at the University of Essex, added: “The presence of highly visible and striking patterns on many animals such as zebras has puzzled biologists for over a century, as these markings are conspicuous to predators.
“Early naturalists suggested that these patterns might create ‘motion dazzle’, making it hard for predators to estimate the speed or direction of their prey.
“Dazzle patterning was used on ships in the First World War and has been tested in numerous studies, but its protective effects remain unclear – largely due to experiments being small-scale tests of a limited range of patterns.”
More than 77,000 people played Dazzle Bug at the Eden Project, tracking more than 1.5 million bugs in total.
The study was published in the journal Proceedings of the Royal Society B.