ANIMALS KNOW THE MEANING OF VALENTINE'S DAY
February 13, 2011
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
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
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.
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.
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.
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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