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Zebra stripes have fascinated people for millennia, and there are a number of different theories to explain why these wild horses should be so brightly marked. A handful of laboratories around the world – including one lead by UC Davis wildlife biologist Tim Caro – have been putting these theories to the test. A new paper from Caro’s group, led by Ken Britten at the UC Davis Center for Neuroscience, puts a hole in one idea: that the stripes confuse biting flies by breaking up polarized light.
Many mammals, including zebras, pandas, racoons, anteaters and some monkeys are are partly or entirely covered with black and white markings. Many reasons have been suggested, from camouflage to communication. Charles Darwin and Alfred Russell Wallace themselves argued over whether a zebra’s stripes made it less conspicuous or more so.
UC Davis wildlife biologist Tim Caro has an extensive review published on the conundrum of black and white animals, and reviews some of the competing ideas, concluding that while some patterns may be for communicating within species or warning off potential predators, there is little evidence that, say, zebra-stripes act as camouflage.