Butterflies Use Optical Illusions to Make Predators Miss
Butterflies use optical illusions to dodge predators
New research from the University of Exeter and the University of Essex, published in Nature, shows that butterfly wing patterns create optical illusions that confuse predators' motion perception. High-speed footage, a study of 400 European species, touchscreen experiments with 100 volunteers, and simulations evolving 50,000 wing patterns all point to the same conclusion: the markings mimic the barber-pole effect, scrambling a bird's sense of speed and direction so it strikes thin air or a less vital wing part. The finding may extend to zebras, snakes, and other animals.
The first slow-motion video of a butterfly I put through our bird-vision computer model was glowing with downwards motion even though the butterfly was moving up. First I checked this wasn’t a coding error, that I’d swapped up and down somehow, but then it dawned on me that this would be a perfect way to confuse attacking predators.
- isolay
Well, what the kids don’t learn in biology class, they can still learn on HN.
- yathern
> The team combined multiple lines of evidence. They used a high-speed camera to film real butterflies taking off at over 1,000 frames per second to capture how their patterns behave in flight, as seen through the eyes of a bird.
> To test how patterns affected real attacks, 100 volunteers acted as “predators”, trying to catch virtual butterflies on a touchscreen.
This sounds fascinating, and I'd love to see footage demonstrating the barber-pole effect. If that's not available, I'd alternatively love to see footage of volunteers trying to tap butterflies on an iPad.
- scun
Sounds like the ol' razzle dazzle