Butterfly Self-Defense
Caterpillars have many predators, including ants, spiders, wasps, flies, birds, rats, toads, and lizards. Consequently they have evolved elaborate defenses, such as prickly spines. Some caterpillars eat poisonous plants, which makes their tissue toxic to predators. The bright coloration of the adult butterflies of these species is like a warning sign. Other species mimic the coloration of those bad-tasting species, and birds and lizards avoid these imitators too.
Another strategy is camouflage. The underside of many species' wings is relatively drab, and when these butterflies fold up their wings, only the underside shows, enabling them to blend in with their surroundings. "How that change can occur so rapidly, just by opening or closing their wings, is something that fascinates people," observes Bruning.
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