SOME ANIMALS KNOW THE MEANING OF VALENTINE'S DAY

by Whit Gibbons

February 13, 2011


"In the spring a young man's fancy lightly turns to thoughts of love." So said Alfred, Lord Tennyson. And though he may not have realized it, as spring approaches, courtship behaviors are prevalent throughout the animal kingdom. For example, male goldfinches are beginning to show a hint of the stunning yellow plumage soon to come, and male indigo buntings are turning bright blue. The females of these and many other species of birds remain comparatively drab, while the males use their plumage to attract females. Male displays of breeding colors in some species might be considered the equivalent of brightly colored Valentine cards intended to appeal to a member of the opposite sex.

One of the most vivid displays of Valentine red is that of the blue-tailed skinks of the eastern United States. The largest is the broad-headed skink. The commonly seen juveniles have a metallic blue tail and bright yellow stripes, a color pattern that remains in a more subdued fashion in the adult females. The males, which become enormous by typical southeastern lizard standards, develop shiny, coppery brown bodies. In the springtime, not too long after Valentine's Day in the southern parts of their range, the male broad-headed skinks begin their courtship. At this time their head and neck turn brilliant red, making them look rather like a Valentine heart moving through the forest.

As with humans, gift giving is not an uncommon courtship practice among many animal species. A male common tern does not change color in an effort to attract females. Instead, he brings the largest fish he can catch as an offering to the female he is courting, presumably to show off his fitness as a mate.

Even some insects, such as scorpionflies, enter into the spirit of Valentine gift giving. These harmless-to-us insects have four transparent wings like a dragonfly, six long legs, and a long tail reminiscent of a scorpion's. Scorpionflies are found throughout most of the world. One U.S. species eats other insects, sometimes raiding the webs of spiders and removing captured blowflies, which apparently are quite a delicacy, considering the risk the scorpionfly takes of becoming spider food itself. During the courtship period, a blowfly in the clutches of a male scorpionfly acts as a Valentine treat, a lure to the opposite sex.

Hanging from a twig, the male scorpionfly emanates a pheromone (a chemical signal that probably smells like a top-flight cologne to a female scorpionfly). Females as far as 40 feet away can sense the airborne pheromone and come to investigate what the male has to offer. A big, fat blowfly is the best Valentine gift of all, and few females can resist. After a bit of back and forth in which the female inspects the wares, she makes her decision. If the gift is a large, savory blowfly, she ends up taking the offering from the male. The male then mates with the female while she dines. Not your usual courtship procedure, but it apparently works for scorpionflies.

Some wily male scorpionflies add another twist to an already complex gift-giving phenomenon by posing as females. How does mimicking female behavior in order to fool another male scorpionfly work to his advantage? In this case, being a transvestite has a direct reproductive benefit because the poseur ends up with the first male's blowfly. The first male, who has risked his life to get the blowfly from the spider's web, is deceived into thinking the second male is actually a female scorpionfly. He offers his tasty treat to the second male, who accepts the gift. The deceiver then flies quickly away and uses the pilfered blowfly to attract a female for mating. Pretty sneaky behavior and a lot less risky than extricating a blowfly from a spider's web.

For almost any form of human behavior that can be identified, an equivalent or near-equivalent can be found somewhere in the animal kingdom. The assertion that in spring a young man's fancy turns to thoughts of love is no exception.


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