THE hippopotamus, floating serenely among the water hyacinths, knows he must tolerate the attentions of the oxpecker birds who pluck their sustenance from his hide. The celebrity, wading through an atrium full of orchids and furs sent by known and unknown admirers, grudgingly acknowledges that she must submit, often if not always, to the incursions of paparazzi. But New Yorkers, who are used to exploiting each other without competition from outsiders, lately have found themselves flummoxed by the arrival in Manhattan of several species of predatory newcomer, who have come to these newly wealth-spangled parts intending to make like the oxpecker. One of these newcomers is the gypsy, common to Russia, Germany, Italy and much of Europe, but not seen here until last fall, when New York cleaned up, paid up and grew up. In Rome, when gypsy children drop on to one's shoulders like leopards from a tree and lunge for the moneybelt, one steps out of the belt and moves on, accepting the loss as the price to be paid for the pleasure of sipping an espresso in the shadow of the Coliseum. But in New York, while espresso has long since arrived, resignation to the depredations of projectile barefoot children has not. The unenlightened New Yorker can't help thinking, "Hang on, that's mine"; but, accustomed to the native brand of children, who, when they are projectile, are also armed, he surrenders the booty anyway. But he resents it.

Unlike other higher-ups in the food chain, New Yorkers are resistant to the live-and-let-sponge attitudes that prevail on the Zambezi, in the Hollywood Hills and on the way to the Forum. One reason may be that they doubt they will remain top dogs for long: hippopotami have wallowed around for millennia, and thanks to video, even B-actors glimmer on beyond the grave; but the fortunes of this city have the life- span of a souffle. That souffle, at the moment, is up and full of steam, which begs the question of when it will fall, and makes people uninterested in sharing. Unused to having anything that could be construed as an enviable quality-of-life, now that they do have it, New Yorkers are not complacent; they hoard it jealously. That may be why they do not feel like treating the gypsies, and it also may be why, when the other entrepreneurial scene-sharers arrived - the squeegee-men - so many New Yorkers in the black saw red.

To a foreigner, a squeegee-man is an irritation; a fellow who impolitely leaps on to one's car at a traffic light, and with a rag, a squeegee, and a pail of soapy, dirty water, mucks up one's windscreen and asks for money. But to New Yorkers, a squeegee-man is also a competitor, and not only that, a reminder of who they might end up being if they and too many others unload their capital on too many squeegee-men. Mayor Giuliani does not like squeegee-men any more than the next guy, especially since vowing to squelch the squeegees (who'd hung on after the last well-heeled era, the Gordon Gekko Eighties) had helped him win his first election. And so when a scattering of squeegees spritzed the city during a recent spate of unseasonably mild weather, and the front page of a local paper screamed "Squeegee Pests Return to the Streets!" the mayor promptly called a squeegee- zero-tolerance press conference. He urged New Yorkers to phone a quality- of-life emergency line if they spotted one plying his sudsy trade - 888- 677-LIFE. Anyway, between the gypsies and the squeegees, the mood in town during what should be a happy time has been roughly on par with the mood at a Missouri picnic where a mad dog has just been spotted loping past the barbecue pit. Which doesn't leave people much appetite for souffle.