CRYPTIC COLORS

Mimicry, blending into their natural surroundings, helps creatures to survive

The American bittern, often heard but difficult to see, has developed colors that help it blend well into the wetlands in which it hunts. When alarmed it lifts its bill straight up, giving the bird the look of a cattail leaf.

IN THE OUTDOORS • Story and photos by Scot Stewart
“There are two ways to be fooled. One is to believe what isn’t true; the other is to refuse to believe what is true.”
– Søren Kierkegaard

Imagine having to spend your whole life looking over your shoulder and wondering who was eyeing you up as their next meal. Most creatures go through their lives with the belief they could be eaten at any moment. Not only do they need to find food, find a mate and often care for their young, they have to outrun, outfly or outswim everything larger than them who is interested in a meal.
Nevertheless, the world is full of magic. Acts of trickery abound as animals try to stretch out their days as best they can. Animals that are unable to be quick, squeeze into small places, or adequately fight back must seek out other strategies to avoid being something else’s nourishment. The bag of tricks they use is amazingly varied, including cryptic coloration (blending into their environment and attempting to become invisible) and mimicry (appearing to be something they are not). Some rely on protective coloration: colors that warn of poisons or stingers to proudly advertise as a way to warn away possible danger.
For animals in the air or active swimmers, cryptic coloration may simply involve dark dorsal, or top (back) sides and lighter ventral or belly sides. This coloration allows birds, fish, frogs and even swimming garter snakes to blend in with vegetation and the muddy or sandy bottoms of ponds and lakes when seen from above. When viewed from below – in the water looking up or on land or trees looking up at the sky, the light bellies blend in with the light above or the brighter sky.
For large flocks of birds moving in across the sky or over water or schools of fish darting back and forth, turns can help a flock or school match either the dorsal or ventral sides to match the background on either bright or cloudy days, literally causing the entire group to temporarily disappear. This momentary disappearance can give the group the crucial seconds needed to escape a predator in chase.
Some birds take the light top, dark underside strategy to a whole different level. Birds like vireos and some warblers spend most of their time in the treetops feeding on insects where their shading works very well. However, their wings and back are not only darker, but also come in a variety of green shades, helping them blend into the leaves even more efficiently. During the summer months one of the most commonly heard songs across the U.P. is the loud, clear, fluid, “Here I am here, where are you,” of the red-eyed vireo heard endlessly in the tops of poplar, maple and oak trees. As loud and ubiquitous as they are, the red-eyed vireo is rarely seen, because of its ability to blend in. They can continue to seek out mates and defend their nesting territories, often very loudly, with little fear of being caught…

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