What was going on when I was born?

For a third successive day, Lebanese Army units battled today with Moslem militiamen opposing their takeover of positions abandoned by the French around Shatila, a Palestinian refugee camp on the southern edge of the capital. Mortars, rockets and tank fire shook the southern suburbs, and buildings were set ablaze. Estimates of the death toll over the last three days ranged from 20 to over 50. A cease-fire was supposed to have been arranged this afternoon, but the firing did not ease until dusk. It was not clear how long the truce would hold.

-shouldered hawk, perched on a limb of a giant oak, lifts off from the branch and maneuvers swiftly and silently on its four-foot-wide wings through the air to a squirrel on the ground below. It grasps the rodent in its talons and makes off with it. The encounter, a classic snapshot of America's wilderness in action, occurs in the Bronx, one of the most thickly settled human populations in the world. The hawk, a recently arrived visitor, is an example of how some species of wild animals are coping with the interaction between humans and feral creatures as man spreads in ever-widening circles his housing and industrial complexes, encroaching on areas wild animals used to call their own. Other such examples include the peregrine falcons that now nest on two New York City bridges and roost atop casinos in Atlantic City. In California, coyotes and great horned owls now roam the suburbs, and tracks of mountain lions appear alongside construction projects. Flocks of Canada geese infest city parks around the country. Skunks and opossums are seen more and more often in both city and village back yards. Woodchucks are taking up residence on the grounds of the Bronx Zoo or the Botanical Garden, now, like the red- shouldered hawk, deciding freely to live in an area where other, captive animals have been brought in from the wild against their will.

Yuri V. Andropov, who has not been seen in public for more than four months, failed to attend a meeting today of the Communist Party's Central Committee. The occasion is normally obligatory for a Soviet leader, but Mr. Andropov is widely thought to be seriously ill. Despite the Soviet leader's absence, officials at the session approved the promotion of four of Mr. Andropov's loyalists to key positions in the party hierarchy. ''I deeply regret that because of temporary causes I will not be able to attend the session of the plenum,'' Mr. Andropov said in a speech read to delegates for him. Second Absence Foreign diplomats here said it was the first time in recent memory that the party had acknowledged the absence of its leader from a meeting of the Central Committee, a body of slightly more than 300 members that is theoretically the party's sovereign body between congresses, which convene every five years.

-expected and much-discussed decline in college and university enrollment once again failed to materialize this fall, according to higher education organizations. Early enrollment figures show that more Americans enrolled in colleges in September than ever before. The increases, though only about 1 percent, ranged across the spectrum of public and private institutions and included both full-time and part-time students. ''It's remarkable,'' said Elaine El-Khawas, vice president for policy analysis and research of the American Council on Education, ''especially since the increases were not confined to certain types of students.'' Dr. El-Khawas and others suggested that the continuing strength of college enrollment was related to the current economic recovery but that other factors were also involved, including more effective recruiting and marketing by the admissions offices of private institutions.

Education Secretary T. H. Bell arrived in Washington in January 1981 with as much furniture as he could cram into a drive-yourself trailer and a firm expectation that within a year he would have worked himself out of a job and be back in Utah. ''I figured that it would take about that long to fulfill the President's promise to abolish the Department of Education,'' he recalled in a recent interview. This month Mr. Bell sat on the dais at the National Forum on Excellence in Education and, with 2,300 Congressmen, governors and educational leaders, heard President Reagan outline his ideas on how to improve the nation's schools. There was no mention of abolishing the Federal department. The stance is typical of the changes and paradoxes of the Reagan Administration's education policy.

The New York Times today publishes an interview with Senator John Glenn, Democrat of Ohio, the second in a series of interviews with candidates for the Presidency. In the interview Senator Glenn made these major points: Arms Control - He has prepared a detailed proposal that involves the participation of other nations with nuclear weapons.

Nothing troubled the silence in the dun-colored woods framing a hawk's-eye view of the Hudson River and the Palisades beyond. But there were tracks to be seen in the light dusting of snow. Surely, the birders were not far away. There, a familiar cry: ''I hear a jay. I hear a jay.'' Another familiar one: ''Chickadee on the fence. Chickadee.'' Then the more unusual: ''Oooh, here's a nuthatch, nuthatch.''

The Economy The Fed is under pressure to relax its grip on inflation and give the economy easier credit. Many economists suspect that recent jawboning by the White House may mark the start of new attacks on the Fed and its chairman, Paul A. Volcker. The Fed may have unequaled influence on the economy next year. (Page D1.)

that ancient and formidable malady that bedeviled Caesar, Darwin and Freud - seems almost as agonizing to medical researchers as the suffering it has inflicted on its millions upon millions of victims. Modern migraine sufferers have been heartened on several occasions by reports of promising new treatments, only to be frustrated because the medical realities have not met expectations. One drug after another has failed to live up to its billing, sending scientists back to the laboratories. Now a new class of drug, called a calcium channel blocker, has led to some cautious optimism after experimental use. But these calcium channel blockers, under study by the Food and and Drug Administration, are at least a year away from approval for migraine. Part of the reason for the delay is that Federal officials see a need for extra precaution because the recent record of drugs developed for migraine has been scarred by side effects, in some cases more serious than the ailment they were meant to cure.

For 70 years, the Audit Bureau of Circulations has worked at one job: verifying circulation claims of newspapers and magazines. The task is important to advertisers, who decide how to spend more than $20 billion of advertising, and to publishers, who peg their ad rates to circulation. Over the years, A.B.C. built up an impeccable reputation, its image that of an old, but sharp-eyed, watchdog. Lately, however, the nonprofit organization has been assailed from several sides, and its carefully nurtured credibility has been questioned. These challenges have thrust A.B.C. into a struggle to redefine itself, and to change to meet the needs of today's sophisticated publications and marketing techniques.

''People out here don't know they're in New York. They think they live in the rural Midwest.''

They don't want to be a part of it, New York, New York. ''Never have,'' said George Vaiana, a deckhand on the Staten Island ferry. He said that to grow up on Staten Island was to hear about secession at your daddy's knee. ''You talk about it at the dinner table,'' he said. ''Everybody has always felt that we could govern our island better than a bunch of outsiders.''