COME into my parlor, beckons the male bowerbird to females that stop to appraise the mating courtyard he has constructed. See my fine bower, he suggests, a perfect avenue and platform of sticks, and see all the decorations I've gathered: bright blue feathers so rare, blue straws and bottle caps and clothespins I stole from someone's line, along with lovely leaves and snail shells, all carefully arranged on my parlor floor.

And, he might add, aside from humans, no other creature in the animal world rivals my ability to assemble such a structure simply to please my mates. In the bird world in particular, nearly all males rely on inherent qualities like coloration, song, feathery displays and aerial antics to woo females, although a few offer fruits, feathers or flowers to prospective mates.

The architectural and decorative skills of bowerbirds have intrigued naturalists since Charles Darwin's day. The structures they build are striking edifices, some as high as nine feet, and decorated with collections of natural objects arranged in distinctive patterns and colors. Indeed, some 19th century explorers mistook the bowers as man-made, and many others assumed they were merely nests.

"The bowerbird fascinates people because it exhibits behaviors reminiscent of what we do to advertise ourselves and attract mates," said Melinda Pruett-Jones, a biologist who has spent thousands of hours studying bowerbirds. "The bowerbird can extend what nature gave it by using secondary sex characteristics the way young men wear special clothing and drive fancy cars to attract girls."

To learn more about these "Picassos of the bird world," as Dr. Jared Diamond of the University of California describes them, a handful of researchers have sacrificed physical comfort and sometimes risked life and limb, trekking through dense mountainous jungle in a remote part of the world once populated by head-hunters.

After decades of casual observations and speculation, recent scientifically designed studies are yielding a deeper understanding of bowers, especially their evolutionary significance and and the role they play in sexual selection. At the same time, the bowerbird has become an important case study in theories of how females choose males.

"Currently, there is a resurgence of interest in the function of bowers," said Dr. Diamond, a physiologist at the University of California Medical School in Los Angeles, who has trudged into the jungles of the Indonesian part of New Guinea year after year to explore the biological meaning of these edifices.

For example, Dr. Gerald Borgia, an evolutionary biologist at the University of Maryland, has enlisted 75 volunteer assistants to monitor activity in bowers. They have observed thousands of bowerbird courtships and copulations.

To consummate the relationship, the male must move behind the female. Dr. Borgia found that the walls of bowers actually reduce the male's ability to capture uninterested females since they offer the females a means to escape should the male try to jump them. Why then would the male bother to build these walls of sticks? he wondered.

"The stick bower seems to increase recruitment of females, who are more willing come to visit the bower, see the male's show and decide if they want to mate," he said in an interview. "So while the male may get to mate with a smaller percentage of females who come to check him out, many more females visit the bower and the total number of matings is higher.

"It's like a loss leader in the grocery store," Dr. Borgia said. "It gets the traffic in and you end up doing better business."

To spy on bower activity, Dr. Borgia and his assistants set up cameras at 30 bowers, with the cameras designed to roll whenever a bird crossed an infrared beam.

Until studies like Dr. Borgia's, much that was known about bowerbirds was anecdotal, and a lot of those "facts" turned out to be wrong.

Of the 18 species of bowerbirds, all denizens of Australia and New Guinea, 15 are known to build bowers. There are several types. The satin, Australian regent and great bowerbirds build a simple avenue as their bower. The yellow-breasted bowerbird consructs a double avenue. Macgregor's bowerbird of New Guinea weaves a maypole-style bower of sticks around a sapling or fern and surrounds it with a raised circular courtyard. Architecture For Mating Game

Some bowerbirds elaborate on the maypole style by constructing huts nearly five feet high around it. And the golden bowerbird decorates adjacent saplings with sticks, sometimes piling them to a height of nine feet, and uses a crossbar between them as a display perch.

The least elaborate structures are the wall-less mat bowers of the tooth-billed bowerbird. This bird decorates a clearing with leaves more than a foot long, all carefully turned upside down to create a contrasting stage for the male's brief courtship dance.

Dr. Borgia, who spent three years studying tooth-billed bowerbirds, was the first to observe their copulatory behavior, which is tantamount to rape. When females come into the bower, the male doesn't bother with courtship: he simply jumps them. Cameras positioned this year by Dr. Borgia at 21 bowers showed that about 70 percent of female visits resulted in copulation.

Most other bowerbirds, he noted, "are much more polite; they wait for the female to show she's interested." Less than 8 percent of such visitations result in mating. Yet many more females visit the avenue style of bower, which means that the courteous architects of these edifices do not lose out in the mating game.

Another mat-builder is Archbold's bowerbird, which constructs a courtyard of lichens and decorates it with piles of snail shells. However, Archbold's, a little known New Guinean species, has an added attraction. Dr. Dawn Frith and Dr. Clifford Frith, two Australian naturalists who discovered the Arhbold's bowers, found them decorated with "borrowed" head plumes from the male King of Saxony bird of paradise. The Friths note that this is no small feat: the bird of paradise is rare, lives in nearly impenetrable jungle and molts its two magnificent head feathers only once a year.

Archbold's bowerbirds also drape trails of orchids over their bowers, daily replacing fading flowers with fresh ones. Some bowerbirds gather huge leaves several times their length. Others adorn their bowers with lichens and mosses; butterfly wings and beetle skeletons; brightly colored fruits and stark black fungi; red, white or blue flowers; berries; insect frass; seed husks, and yellow leaves.

And those that dwell near human habitats selectively scavenge artifacts, from ball-point pen tops and "lost" bracelets to toothbrushes and red shotgun cartridges, that match the bird's color scheme. One particularly brazen individual even untied and struggled to remove a researcher's blue shoelaces as loot for its bower. The Message Of the Bower

To the outside observer, "the bower decorations often look like a pile of junk," said Glen Threlfo, an Australian nature photographer who has chronicled the life cycle of Australian bowerbirds from courtship through nestlings. But naturalists correctly inferred that the bower trinkets must mean something to potential mates. Along with the bower structure itself, they presumably convey to females that the owner is a desirable male.

More than 30 years ago, E. Thomas Gilliard of the American Museum of Natural History noted that the less colorful the male bowerbird, the more fanciful his bower. Bowerbirds seemed to have evolved a system of sexual selection that transferred the female's attention from personal appeal of the male himself to the attractiveness of his proverbial etchings.

But careful studies made recently by American researchers indicate artistic talent alone is hardly enough to seduce the female bowerbird. Rather, it is the finesse of the bower's construction, its state of repair and the desirability, rarity and quantity of its accouterments that together inform the discriminating female whether she should let herself be beguiled by its owner.

As Dr. Borgia pointed out, the female bowerbird gets nothing from the polygamous male except his genes. He does not protect the nest, procure food for the young or even visit his family after mating. Thus the female's goal, in Dr. Borgia's view, must be to assure that her chosen Don Juan will bestow upon her offspring genes with top-notch survival value. In other words, females would naturally be drawn to dominant males.

Mrs. Pruett-Jones of Chicago's Field Museum and her husband, Dr. Stephen Pruett-Jones, an evolutionist at the University of Chicago, discovered wide variations in the bowers of a single species. Since 1980, they have spent thousands of hours in eastern Papua New Guinea observing Macgregor's bowerbird, an olive-brown bird the size of a robin. The maypole-building male has a bright orange crest to enhance his allure.

"No two bowers are alike," Mrs. Pruett-Jones said in an interview. The maypole can range from 1 to 10 feet in height, and the decorations, which vary widely, may include bits of charcoal, fungi, seeds, fruit, insect frass, pandanus leaves, lichens and the parts of iridescent insects.

"We have counted as many as 500 decorations at a single bower," they reported in Natural History magazine. Dr. Diamond has noted that the combined weight of the towers and ornaments of the Vogelkop gardener bowerbird can reach 70 pounds.

Researchers have found that birds of various ages build bowers, but those of young males are crude "practice" bowers. Only fully mature males among these long-lived birds build bowers likely to attract females. Young males seem to learn from their elders by observing the construction techniques of master builders. Survival Of the Fiercest

The effort to enhance his bower's attractiveness and to diminish competition for mates keeps the male bowerbird fully occupied. He must divide his time between trying to loot and destroy the bowers of nearby males and protecting his own bower from the competition.

Whenever a bower is attacked, its owner must scurry to repair it and replace any stolen decorations. The more time he must spend repairing his bower, the less time is available for courtship and mating.

Given the rigors of this competition, it is no surprise that a well-constructed and heavily decorated bower sends a powerful message to females that the owner is a mature, clever, dominant, aggressive male that is likely to contribute genes with high survival value.

The bower of the gardener bowerbird, Dr. Diamond said, is the most elaborate structure erected by any animal other than humans. To construct a good bower, he wrote in The American Naturalist, "a male must be endowed with physical strength, dexterity and endurance, plus searching skills and memory -- as if women were to choose husbands on the basis of a triathlon contest extended to include a chess game and sewing exercise."

Not all bowerbirds rely on thievery and bower attacks to prove their mettle. Dr. Borgia has found that spotted bowerbirds space their avenue bowers too far apart for there to be much interaction between neighboring males. Instead of wooing females with the quality of bowers, he said, "the male puts on a very energetic display -- running three meters from the bower, charging back in, throwing decorations and using its aggressive call for courting."

Since other bowerbird species that engage in stealing and bower destruction have much more sedate displays, Dr. Borgia concluded that "the athleticism of the spotted bowerbird compensates for the fact that his bower doesn't reveal much about his quality to potential mates."

According to several studies, the birds experiment, like professional decorators, with the choice and placement of bower art. Dr. Diamond offered bowerbirds poker chips of seven different colors. He found that the birds has definite color preferences. They moved the chips around, placing certain colors inside their bowers and others in the courtyard outside. Some threw all the colors out. The Search For Bowers

Three bowerbirds are known to be bowerless. Unlike the polygamous bower builders that assume no parental responsibilities, the bowerless species help defend the nest and find food for the nestlings.

Other species thought to be bowerless turn out to be adroit concealers. The fire-maned bowerbird hides its bowers in a remote jungle high in the Adelbert Mountains in Papua New Guinea, according to Roy Mackay, an Australian naturalist whose studies have been supported by the New York Zoological Society.

Mr. Mackay said his quest for the bower took four visits to the Adelberts, during which he had to endure false leads from the local villagers, hundreds of mosquito bites, unseasonably heavy rains and devastating attacks of dysentery. Eventually a woman who had stumbled upon a bower while hunting the previous week led him to it. He found an avenue bower simply decorated with seven Prussian-blue berries and one large blue and white berry. A few days later, he said, a spotted catbird dove in and swallowed all the berries.

On a later visit he finally saw the bird in full display. It fanned its fiery nape and mantle feathers into a sort of platform above its eyes. Then it hopped near the female trying to impress her with its finery. After many hours of patient endurance in the steamy jungle, it was for Mr. Mackay an ample reward.

Diagrams: 'Trysting, Not Housekeeping' So elaborate are the male bowerbirds' dens that some early explorers thought they were manmade. They serve only as courtship sites, however, and the male does not stay around after mating. Each species builds its own style of bower. A well-constructed bower signals to females that the owner is a mature, clever, dominant and aggressive male likely to contribute valuable genes. The satin bower bird, shown here, first erects two walls of sticks, then lays down a layer of yellow twigs on which he places piles of orange flowers, blue objects like parrot feathers and small yellow leaves. He arranges small snail shells near the wall of sticks and large shells at the periphery. The avenue is oriented north to south. (Sources: Dr. Gerald Borgia; International Wildlife; "Sharing a Dream," Glen Threlfo (Anzea Publishers). (pgs. C1 & C8)