Survival of the Fittest: Defense Mechanisms in Nature

The intricacy and detail, the structure of every living thing is astounding. Each new personal discovery produces a broader appreciation and respect for nature, such as learning the number of species equipped with specialized defense mechanisms. This innate ability develops over time through adaptation. Adaptations are changes in an organism's physiological structure, function, or habits that allow it to survive in new surroundings. Animals utilize numerous weapons to escape harm. These include camouflage, trickery in the form of mimicry, chemical combat, and appearing injured or playing dead.

I had heard of birds feigning a broken wing in order to lure intruders away from their nest. After what seemed like eons of waiting, this behavior finally manifested itself in a neglected pasture littered with tansy, bull thistles, and piles of ancient, petrified horse manure. The killdeer had been crying out its shrill warning for sometime when, suddenly, it appeared with its wing askew, looking quite broken. Mesmerized, I watched as the fearless mother valiantly attempted to lead me away from her nearby nest.

While numerous species have defensive weapons at their ready, others, such as the monarch butterfly, go to great lengths to survive predation. The adult butterfly lays its eggs on milkweed leaves. After hatching, the caterpillars feed on the milkweed, which contains a poison called cardenolides, or cardiac glycosides that is toxic to nearly all vertebrates. The monarch stores this bitter tasting chemical throughout the changes from larva to pupa to adult. One attempt at a monarch lunch is all it takes to teach a hungry predator to avoid the bright colors of monarch caterpillars and butterflies. No wonder several other ...

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...nisms are trickier to locate which means predators often become frustrated and give up.

As environments and conditions change, the organisms living there must also change. Developing defensive mechanisms such as mimicry, camouflage, and chemical combat increases the chance for survival. Adaptation is necessary for organisms to survive predation.

"Adaptation is not limitation. It means power of resistance and assimilation."

-Mahatma Gandhi

Come read about adaptation

Made to eat the vegetation;

Or still more gruesome is the tale,

Of those who chewed another's tail.

Look at your hand, and then your thumb;

A dinosaur was not so dumb;

Just like your hand its claw worked well

To grasp, or push, or climb, or kill.

-Author Unknown