What was going on when I was born?

A picture appeared erroneously yesterday with a report about whooping cranes in the Science Watch column of Science Times. The bird shown was a great blue heron.

Donald T. Regan, the loyal Treasury Secretary whom President Reagan made his chief of staff today, has been an enigma through the first four years of the Administration. It has never been clear, as his views on issues have shifted and changed over that period, where he really leans. The simple answer is that Donald Regan shifts where the President shifts and leans where the President leans. Rarely since he was first appointed to the Treasury has Mr. Regan stood apart from the President on the nation's major economic questions - the budget deficit, growth, taxes, budget cuts - that often produced open splits within the Administration and sometimes even within the White House staff.

New York City's Transit Authority won the right today to hire more than 1,000 supervisors outside the Civil Service process for jobs that will also be outside union jurisdiction. The authority said the ruling by the State Civil Service Commission would lead to improved bus and subway service. The authority would be free to hire better managers and to dismiss those new managers whose performance turned out to be unacceptable, the authority said. The unions representing transit supervisors said they planned to challenge today's ruling in court.

''We can't be sure where these negotiations will lead and, clearly, we have a long road ahead of us.

The Supreme Court ruled unanimously today that the police may act without a warrant to stop and briefly detain a person they know is wanted for investigation by a police department in another city. In another ruling, the Court held that Trans World Airlines violated the law by forcing 60-year-old pilots to retire, rather than take other jobs in the cockpit. But the ruling limited the damages the pilots could recover. (Page D7.)

Senate Republicans Wednesday will begin considering a proposal to reduce the Federal deficit by freezing spending across the board and eliminating all cost-of-living increases next year, Congressional sources said today. The freezes would affect both military spending and Social Security. President Reagan refused both choices in his budget proposal, which fell about $40 billion short of meeting the Administration goal of trimming the deficit to $100 billion by 1988. Last Friday, Senate Republicans began their own attempt to meet the target.

President Reagan unexpectedly announced today that the White House chief of staff, James A. Baker 3d, and the Treasury Secretary, Donald T. Regan, were to switch jobs. ''After four grueling years in their current positions, their desire for change is completely understandable,'' Mr. Reagan said in an announcement this morning. The President was flanked by a beaming Mr. Baker, a 54- year-old lawyer from Texas, and by Mr. Regan, 66, a former Wall Street broker who has emerged as Mr. Reagan's principal adviser on economic policy. It was Mr. Regan who suggested the job exchange, a proposal the President was said to have first heard on Monday. ''This particular change will allow them each to meet new challenges and will bring renewed vigor to their respective responsibilities while it gives me and the public the benefit of the continued service of two extraordinarily talented individuals,'' said Mr. Reagan, reading a statement in a packed White House press room.

Britain's oil pricing system is under intense pressure, with increasing amounts of its North Sea oil being sold at spot prices instead of at its official price. The weakness of the North Sea oil pricing structure threatens to undermine OPEC's effort to maintain its $29- a-barrel benchmark price for Saudi Arabian Light crude. Recent cold weather has pushed the spot market price of Brent crude, the North Sea's benchmark grade and its most commonly traded oil, up a bit, to $26.35 a barrel. But that price is still $2.30 below the official Brent price of $28.65.

SOME of the most remarkable mixings of food styles I have ever witnessed were demonstrated in my kitchen recently by 30-year-old John Sedlar, chef and part owner of the Saint Est ephe Restaurant in Manhattan Beach, Calif., about 15 miles south of Los Angeles. The ingredients he used were from the American Southwest, but his techniques were solidly anchored in the French tradition. One of the dishes he prepared was chiles rellenos - stuffed chilies - which are traditionally made by roasting or charring spicy green chilies, peeling them, and then filling them with either cheese or a ground meat mixture known as picadillo. They are then dipped in flour and egg, deep-fried and usually served with a tomato sauce.

THE contemporary New York City restaurant scene falls roughly into three categories that have nothing to do with food: the crowded and very noisy, the crowded and audibly bearable, and the roomy and tranquil. The young graduates of singles bars who want to be where the action is choose places like Mezzaluna, Amsterdam's Bar and Rotisserie, El Internacional or El Rio Grande, where diners sit cheek by jowl and those waiting for tables are packed as tightly as the subway at 5 P.M. The noise level in such establishments precludes conversation. Older diners prefer Le Cirque, La Grenouille, the ''21'' Club or Gino, where they can see and be seen - and be heard - by friends. These patrons are willing to sit elbow to elbow as long as conversations are not drowned out by the din and they know the people whose elbows they are rubbing. Those seeking privacy in public places generally prefer the spaciousness and clublike atmosphere of restaurants such as the Four Seasons or Woods Gramercy, which are conducive to striking business deals.

The General Motors Corporation, continuing the sweeping reorganization that began early last year, said today that it was establishing a subsidiary corporation to sell a new line of advanced-technology subcompacts under the Saturn name. It is the first time in 67 years that G.M. has established a new brand name and the first time it has tried to use a subsidiary, rather than a division, to make cars. G.M. said it would commit $5 billion to the new unit, to be called the Saturn Corporation, with an initial capitalization of $150 million. Separate Labor Contract The subsidiary will have its own labor contract with the United Automobile Workers union and its own network of dealers, G.M. said. The development of a separate corporaton, which was unexpected within the industry, is an outgrowth of Project Saturn, G.M.'s research effort to use advanced manufacturing technology and revised labor relations to produce small cars that are equal in cost and quality to those made in Japan.

The surviving Seabrook nuclear reactor is once again on the verge of cancellation, with three of the participating utilities under orders to find buyers for their 9.7 percent share of the project by Friday or to end their participation. Spokesmen for several of the participants indicate that such a sale would have to be at a deep discount, if it is possible at all, and likely buyers say that they are not interested. The latest Seabrook ultimatum was made on Dec. 13 by the Maine Public Utilities Commission. The Central Maine Power Company, which owns 6 percent, the Bangor Hydro-Electric Company, 2.2 percent, and the Maine Public Service Company, 1.5 percent, had asked for permission to borrow more money to pay for their share of construction costs.