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 49 another aposematic mammal DHJanzen100213.jpg high resolution
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This unfortunate Michigan porcupine had a lethal encounter with a large car. But, it gives us the opportunity to see that the porcupine with its very personal close-encounter defenses uses the same black and white aposematic colors to advertise its defense as does the skunk. Again, porcupines the world over have repeatedly independently evolved, and they have repeatedly evolved the same black and white colors as advertising for their defenses (along with behavioral traits such as stamping their feet, making false rushes and growling - all of which some species of skunks do as well). Like skunks, some tropical terrestrial porcupines have harmless Batesian (black and white) mimics. And now you know why when field biologists see pure black birds - crows, vultures, anis, grackles, etc. - they suspect that these birds may have chemical defenses in addition to their other defenses. On the other hand it is important to note that there are places in the world where black and white may indeed be cryptic. |
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