Butterflies

Camouflage and Mimicry

Camouflage for butterflies consists of efforts to change external appearance or behavior to help them blend into or match their surroundings. Different environmental settings present myriad conditions that butterflies attempt to match. Through the use of different colors, patterns, and shapes, butterflies can attempt to look like the things around them. For example, the cassia (Senna spp.) is one of the host plants for the larva of the cloudless sulphur (Phoebis sennae) butterfly. When the cassia blooms, the larvae eat the flowers and turn yellow. The chrysalis of the cloudless sulphur butterfly is shaped and colored like a cassia leaf. When the adult butterfly emerges, it is yellow, like the large flowers of the cassia.

Mimicry is a strategy that butterflies use to appear similar to another butterfly species that predators avoid. During the 19th century, Henry Walter Bates, a British naturalist who studied butterflies in the Amazon, first described this type of mimicry, which is now known as Batesian mimicry. For example, many birds find the Viceroy (Limenitis archippus) butterfly very tasty, but some Viceroy butterflies have evolved to protect themselves by mimicking the appearance of the Monarch (Danaus spp.) butterfly, a species that birds generally find very foul-tasting. Another type of mimicry consists of using a body part to imitate another type of body part of another animal.

This type of mimicry is known as Muellerian mimicry, which is named after Fritz Mueller, a German zoologist who worked in the Amazon region three decades after Bates. Many butterfly species, for instance, have developed what appear to be large eye spots (ocelli) on their wings, and these can be rapidly flashed by the flapping of their wings, which frequently startles a predator, allowing the butterfly to escape. For example, the owl (Caligo spp.) butterfly has eye spots that appear similar to those of an owl, which is a common predator of many birds that might, in turn, prey on the butterflies. The gatekeeper (Pyroni tithonus) and the grayling (Hipparchia semele) butterflies have eye spots that are used as decoys to divert bird attacks away from their vulnerable bodies and toward the outer parts of their wings.

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