Suppose you've written a book which it tells more about penquins than most people want to know. Or you could be fascinating at social gatherings with long stories about the albatross, but find it difficult to get a guest to stop and hear you out.

George Watson, the author of "Birds of the Antarctic and Sub-Antarctic," is a specialist on - among other feathered things - penguins and albatrosses. When he's at a party and someone inquires what he does, he says, "I'm an ornithologist."

And the person inevtitably replies, "Oh, I'll send my child to see you."

Watson is one of many Washingtonians in small, not obviously sovernmental fields who have trouble with that ubiquitous Washington question, "What do you do?"

Some find that their previously obscure areas have suddenly acquired chic, and they have besieged at parties. More are used to inspiring glassy stares whenever they venture out of their offices.

Facts which are only discovered which dust is blown from them, events which move at a dignified historical pace, species whom one does not need to know to make it socially - these are unnecessary luxury, if not a bore to people who are breathless just trying to keep up with daily events.

The experts on such things may have world-wide respect may even be remembered for longer than people who are busy with today. But who, is busy, gossipy Washington, is going to stop to listen to the latest news from the world of esoterica?

Watson, who works at the Smithsonian's Museum of Natural History where there are many specialists in odd academic fields, says he does attract bird-watchers socially. And he can have intelligent professional talk not only in the Smithsonian but with colleagues from the National Science Foundation or the Navy.

But Saul Riesenberg, who says he's the town's only specialists in Micronesian ethnology let alone in the island of Ponape in the Caroline chain, has to call long distance when he wants to chat about his work.

Socially, he's learned to tell people only that he's an anthropologist. "They always say, 'Oh, Do you know Margaret Mead?"'

"And then I gave them a glassy stare."

It isn't as though his stories of Ponape were devoid of adventure, excitement and romance. One of Riesenberg's books documents his discovery that a 19th-century Irish salor, ship wrecked on Ponape and later rescued and used as a scientific source on the island, was a big fat liar.

"An awful lot of what he said which was accepted as the first real information on Ponape - was fishy," said Riesenberg, who has repriated the stories of the sailor, James F. O'Connell with his own critique and commentary. "I think his name was false, and I'm convinced he was covering up a convict past."

Riesenberg's own interest in the 130 square mile island was accidental. When he was a graduate student at the University of California at Berkeley. "They used to give us $50 for our field work and tell us to go off and find some Indian tribe and interview the survivors about how their grandfathers used to hunt rabbits. But when I was there, the Navy had just taken those islands from the Japanese and wanted to know something about them, so there was Navy money to give me a chance to sit down and talk to some real live people."

The lifelong interest now can be only fully shared with a dozen or so people around the country whom he sees at professional meetings. "For years, I was pretty much alone, but now where are lots of younger people getting into it." By lots, he means more than a dozen.

Robert Van Nice has been working virtually alone, since 1937, on architectural drawings of Hagia Sophia, the great Turkish mosque dating from the 1940s which has been through so many changes and so much history. Some of the drawings may take 1,200 hours to make, he said, and that isn't counting the on-the-scene research.

"But people are always impressed by the wrong things," he said. "They are amazed and astonished at what I'm doing but for the wrong reason. What they're staggered by is that a guy like myself is silly enough to spend his life on this - actually, with money and manpower it could have been done more quickly."

What he has a harder time impressing upon people is the importance of his work, which is done in the Dumbarton Oaks basement and supported by Harvard University.

"I'm an architect," he said, "but surrounded by what the world thinks of as scholars, whose interest is in documenting what people have said or written about Hagia Sophia, not with the building itself. And that's a whole different riding academy. Mistakes come from believing what others write."

Charles Gunn, who may be the world's greatest identifier of seeds, has given up trying to explain to people what he does.

"I don't go to parties," he said. "My children accept me, my dog accepts me, my wife accepts me, and that's enough for me.

"Although my wife did ask me this morning what I was going to do today, and I said, 'Get the legumes straightened out to show the artist for the plates,' and she replied, "Oh, that's thrilling.'"

Gunn works at the Beltsville Research Center of the Deparment of Agriculture, but is called upon by other agencies - to identify the seed which has poisoned a child, or which someone wants to bring across the border, or which clings to the trousers of a suspected criminal and might provide information on his previous whereabouts.

His regular work is research and Classification; he estimates that he can identify more than 2,000, perhaps 3,000 seeds. There is only one peer with whom he can fully discuss his work - Elizabeth Wiseman, who is on the law enforcement side of seed identification.

Laetitia Kennedy-Skipton Yeandle is the Elizabethan handwriting expert at the Folger, where she is curator of manuscripts. Reading the "secretary hand," which was in common use before italic began to become popular, is, for her, "a tool," giving access to original sources. But it is beginning to attract the attention of lay people.

People newly interested in genealogy - the "Roots" crowd - may approach her and ask if they can bring her the old family deed or letter they have discovered.

And the new calligraphy buffs want to examine manuscripts for handwriting samples. They are surprised to find her "not a partitioner of beautiful handwriting. One of them gave me one of those special pens, but I'm afraid my handwriting merely serves I suppose this new interest is tied up with the interest in reviving crafts."

Simone Yaniv, a leading psycho-acoustician at the Department of Commerce's National Bureau of Standards, finds that she attracts the new environmentals.

The entire field of researching the psychological effects of noise - she blasts volunteers with tapes of screeching brakes, roaring garbage disposals of whatever a government agency wants studied - is under 15 years old, she said, with lay-person interest increasing along with the volume of airplane noise.

"People will come up to me at parties and ask, 'What can I do to make my house quiet?' or 'What can I do to prevent aircraft noise?'" She noticed this was stepped up with the arrival of the Concorde.

Edward Ayensu, a botanist at the Museum of Natural History, finds that the amateurs he attracts are always rich. One of Ayensu's specialties is the orchid family, which attracts him because it is the largest plant family in the world.

"There are quite a lot of orchid buffs in town - many of them very intelligent, and most of them very wealthy," he said. "The orchid plant is unique, but people are fascinated because of its beauty and because it is a status symbol."

However, Ayensu has other specialties, which do not attract such flattering attention. He is an expert in bats, and likes to take his Snooperscope or Owl Eye out at night to watch bats stick their heads into flower to cat pollen, thus inadvertently pollinating other flowers, an activity for which bees, who operate in daylight, often get the credit.

It might make a more exciting story than the ones Ayensu is coaxed to tell the Orchid Society.But there is no Bat Society in town.