Do optical illusions work on animals?

BBC Wildlife contributor Stuart Blackman answers your wild question. 

Close up of three zebras in Masai Mara Kenya

Animals and humans can be bamboozled by similar illusions. For example, hummingbirds cannot maintain a stationary hover at a flower presented against a rolling striped pattern, which gives the birds a false impression of movement.


There is evidence that zebras’ stripes have a similar effect on predators, causing them to mistime their final lunge for the target, while male great bowerbirds deploy an optical illusion to impress females. They decorate their bowers with bones, shells and stones in size order – smallest at the front, largest at the back – to give the impression that they are all the same size. It also makes the bower appear smaller than it actually is, which in turn makes the male look bigger.