Why a zebra’s stripes may confuse horseflies

“Since the debate between Francis Galton, Alfred Russel Wallace and Charles Darwin between the 1850s and 1870s, many ideas have been proposed for the possible functions of a zebra’s stripes. The main hypotheses are the following:

• Apparent size increase

The stripes could induce a visual illusion, increasing the apparent size of zebras and ensuring an advantage over their predators.

• Decreased visibility in twilight

At dusk and dawn, or in moonlight, stripes might be difficult to discern.

• Dazzling the eyes of predators through motion

The moving stripes of escaping zebras may dazzle and confuse predators, making it difficult for them to select an individual zebra from the herd.