EVERY DAY IS APRIL FOOL'S FOR SOME SPECIES
by Whit Gibbons
April 1, 2012
A fish spies a wiggling worm under the river bank. Free meal? Yes, but not for the fish. April Fool's. The would-be worm was actually the tongue of an alligator snapping turtle, and the giant jaws slammed shut when the fish went after the bait. For almost any identifiable human behavior, including playing jokes on April 1, an equivalent or near-equivalent can be found somewhere in the plant and animal kingdoms. For many species playing tricks is a daily routine. But doing so is definitely no joke; it's a matter of life or death.
Successful predators that rely on capturing living prey must have effective strategies for doing so, and subterfuge is one such technique. A strategy as basic as a bobcat's use of camouflage while stalking a rabbit in a field of brown vegetation is clearly meant to deceive and catch the unwitting prey off guard. Likewise, a tiny deer fawn's response to potential danger is to lie motionless on the forest floor, where the white spots on its brown coat blend with the ground speckling of sunlight through the leaves. Perfect camouflage to trick a would-be predator.Luring prey to its death is a scam used by many predators. Baby copperheads and pigmy rattlesnakes wiggle their bright yellow tails to attract small frogs. Some tropical lightning bugs flash the mating signal of other species to attract males that think they are headed toward a romantic encounter only to become a meal for the deceiver. Lights are also used as lures by deep-sea angler fish. These big-mouthed creatures, which live in total darkness at ocean depths greater than a mile, have a fleshy structure that functions like a fishing pole with bait at the end. The lure is a luminous bulb containing bacteria that emit a greenish light to attract other fish, which are fooled into thinking they will be getting a meal instead of becoming one.
Some plants rival animals in their use of chicanery to capture prey. Well-known carnivorous plants include the pitcher plants with their sweet-smelling but deadly pitfall traps. Plants that eat animals typically live in highly acidic wetland habitats that are low in soil nutrients. Their captured prey, mostly insects and spiders, provide some needed nutrients. Among carnivorous plants, the showy Venus flytrap has an impressive April Fool's surprise for visiting insects. The two halves of an open flytrap leaf look innocuous enough but have long spinelike structures extending out from the edges. Nectar glands on the inside of the leaf signal a tasty meal for flies and other insects. When a bug alights and its legs begin to hit hair triggers, the trap slams shut so fast even a fly cannot escape. Over the next several hours the flytrap secretes digestive juices that absorb the prey as a nutrient meal.
To eat or and to avoid being eaten are not the only reasons to engage in trickery. Strategies used to acquire mates involve some of the highest forms of duplicity found in nature. A predaceous insect known as the scorpionfly definitely ranks high on the deceit-o-meter for its mate-luring behavior. Male scorpionflies impress females by presenting them with a blowfly acquired at great personal risk from a spider's web. The female's acceptance of the blowfly dinner assures the male of a mating opportunity. But some male scorpionflies do not capture their own blowflies. Instead they pose as females in order to fool another male scorpionfly into handing over its hard-earned blowfly. Once the male with a blowfly offers his tasty treat to the male poseur, the deceiver accepts the gift and flies quickly away to use the pilfered blowfly to attract a female for mating.
From simple to complex, the diverse tactics used by wildlife to get food, protect themselves, or acquire a mate provide endless reasons to marvel at the natural world. For these deceivers, life or death matters hang in the balance and they do not wait for the first day of April to play their tricks.
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