For a long time, people thought zebras evolved stripes as a sort of communal camouflage. (A lion sees a big swath of stripes and gets a bad headache trying to isolate a target).
Then, a research group came out with a new theory: the stripes help repel bloodsucking flies.
And now, an even newer theory! The stripes are part of an air conditioning system. Researchers looked for a relationship between stripe patterns throughout Africa (turns out it varies a lot) and 26 environmental variables. What did they find?
We found no evidence that striping may have evolved to escape predators or avoid biting flies. Instead, we found that temperature successfully predicts a substantial amount of the stripe pattern variation observed in plains zebra.
Zebras in hotter regions have more defined stripes. Here’s a bit of logic that might explain the phenomenon: dark stripes heat up faster, white stripes heat up slower —> that creates areas of different temperature —> that creates little convection currents (remember how wind happens?) —> that helps the animals cool.
Of course, this is just one study - new data to help zero in on the answer of an old question. And it doesn’t provide a simple conclusion. The authors say that just as temperature has lots of effects on environment “the selective agents driving zebra striping are probably multifarious and complex.” I’m looking forward to more research into the camouflage and biting fly theories, too.
Photo: Kow Loon
Figure: Brenda Larison, et al.
Maybe they just find them slimming?
Figure yourself out, zebras! We’re certainly having no luck deciphering your camo.