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Copy cats don't harm their models


Mimicry is a common survival strategy seen throughout the animal kingdom. The harmless ash-borer moth, for instance, has evolved the yellow-and-black guise of the stinging common wasp to trick predators into thinking it's dangerous, too. Because the moth is poorly defended and the wasp is well defended, Hannah Rowland of the University of Liverpool in the United Kingdom and her colleagues wondered whether this form of mimicry comes at the expense of the creature being copied. The researchers offered a species of bird called the wild great tit (Parus major) "prey" in the form of almonds wrapped in paper marked with symbols that either made them look alike or look different. Some were flavored with an unpleasant solution to make them less tasty, like a stinging wasp. In the end, the birds did not pick up their attacks on almonds -- regardless of flavor -- suggesting that less tasty prey, like wasps, are not adversely affected by the copy cat behavior of other species.

BOTTOM LINE: Weakly defended animals can gain benefit by copying stronger animals without an apparent harm to the copied organism.

CAUTIONS: This study was using artificial prey: almonds of different tastes may not accurately represent real prey, such as butterflies.

WHAT'S NEXT: Researchers hope to test their theory using real prey.

WHERE TO FIND IT: Nature, July 5