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- REPRODUCTION: A-Courting to Nature! LIFE SCIENCES SIG
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- For some time she had watched his movements, appearing coyly in his
- haunts. And now, had it paid off? Doubtless, he was in love. His
- muscles were taut; he swooped through the air more like an eagle
- than a Greylag gander. The only problem was, it was not for her that
- he then landed in a flurry of quacks and wingbeats, or for her that he
- dashed off surprise attacks on his fellows. It was, rather, for
- another - for her preening rival across the Bavarian lake.
-
- Poor goose. Will she mate with the gander of her dreams? Or will
- she trail him for years, laying infertile egg clutches as proof of her
- faithfulness? Either outcome is possible in an animal world
- marked daily by scenes of courtship, spurning and love triumphant.
- And take note: these are not the imaginings of some Disney screen-16
- writer. Decades ago Konrad Lorenz, a famed Austrian naturalist,
- made detailed studies of Greylags and afterwards showed no
- hesitation in using words like love, grief and even embarrassment to
- describe the behavior of these large, social birds.
-
- At the same time he did not forget that all romance - animal and
- human - is tied intimately to natural selection. Natural selection
- brought on the evolution of males and females during prehistoric
- epochs when environmental change was making life difficult for
- single-sex species such as bacteria and algae. Generally, these
- reproduced by splitting into identical copies of themselves. New
- generations were thus no better than old ones at surviving in an
- altered world. With the emergence of the sexes, however,
- youngsters acquired the qualities of two parents. This meant that
- they were different from both - different and perhaps better at
- coping with tough problems of survival. At the same time, nature
- had to furnish a new set of instincts which would make "parents"
- out of such unreflective entities as mollusks and jellyfish..
-
- The peacock's splendid feathers, the firefly's flash, the humpback
- whale's resounding bellow - all are means these animals have
- evolved to obey nature's command: "Find a mate. Transmit your
- characteristics through time!" But while most males would accept
- indiscriminate mating, females generally have more on their minds.
-
- In most species, after all, they take on reproduction's hardest
- chores such as carrying young, incubating eggs and tending
- newborns. Often they can produce only a few young in a lifetime.
- (Given half a chance, most males would spawn thousands.) So it's no
- surprising that the ladies are choosy. They want to match their
- characteristics with those of a successful mate. He may flap his
- wings or join a hockey team, but somehow he must show that his
- offspring will not likely be last to eat or first in predatory jaws.
-
- Strolling through the Australian underbrush that morning, she had
- seen nothing that might catch a female bowerbird's eye. True,
- several males along the way had built avenue bowers - twin rows of
- twigs lined up north and south. True, they had decorated their
- constructions with plant juices and charcoal. Yet they displayed
- nothing out front! Not a beetle's wing. Not a piece of flower.
- Then she saw him. He stood before the largest bower and in his mouth
- held a most beautiful object. It was a powder blue cigarette
- package, and beneath it there glinted a pair of pilfered car keys.
- Without hesitation she hopped forward to watch his ritual dance.
-
- Males have found many ways to prove their worth. Some, like
- bowerbirds, flaunt possessions and territory, defending these
- aggressively against the intrusion of fellow males. Others, like
- many birds and meat-eating mammals, pantomime nest building or
- otherwise demonstrate their capacity as dads. Still others,
- however, do nothing. Gentlemen may bring flowers, but most male
- fish just fertilize an egg pile some unknown female has left in
- underwater sand. For a fish, survival itself is a romantic feat.
- For other species, though, love demands supreme sacrifices.
-
- Shortly after alighting on the back of his mate, the male praying
- mantis probably had no idea what was in store. This would have
- been a good thing too, because as he continued to fertilize his
- partner's eggs, she twisted slowly around and bit off his head. She
- continued to put away his body parts until well nourished and thus
- more able to sustain her developing young.
-
- Luckily for most species, the urge to mate come on only
- occasionally, usually in springtime. For love can hurt, particularly
- if you intended has difficulty telling a mate from a meal. Pity the
- poor male of the spider species, Xysticus Cristatus, for instance.
- His only hope of survival is to tie a much larger female to the
- ground with silk thread, and keep her there.
-
- Every time a moth releases its attracting scent, or a bullfrog sings
- out its mating call, these animals are risking a blind date with some
- predator. Such alluring traits have long puzzled scientists,
- particularly those which seem not only risky but useless as well.
- Why, after all, should a frigate bird mate more if he puffs out an
- extra large red throat sac? How does ownership of such a thing
- indicate a superior individual? Until recently, the question stymied
- biologists, but then researchers in the U.S. and Sweden announced a
- possible answer. While studying widowbirds, among whom
- extravagant tail feathers are hip, they discovered that the
- longest-tailed males also carried a lower number of blood parasites.
- Sexual ornamentation seemed to be a means by which males could
- show of superfluous health and energy.
-
- All of which may bring us to fast sports cars, flashy clothes and
- other accessories of the human suitor. After all, if he can afford
- dinner at the city's most expensive restaurant, chances are he could
- finance a baby too.
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