Any ornithologist worth the salt on his tailfeathers could spot the dramatic change in the pecking order in the bird kingdom that took place tonight in Memorial Stadium before 47,387 surprised fans.

The Toronto Blue Jays, heretofore the scuffiest flock of fowl to be found in the major leagues, especially when they had the misfortune to migrate to this city, were preening after a 9-3 victory of enormous symbolic importance to them.

Baltimore's Orioles, proud almost as peacocks for a generation, were taken down a notch in the big-league aviary after a slapstick four-error infield performance full of amateurish mental blunders.

Throughout their six seasons of existence, the Blue Jays have been perfect--perfectly awful--finishing dead last five times, then tying for the cellar last year. Three symbols of Toronto frustration stood above all others: the Baltimore Orioles, Memorial Stadium and Mike Flanagan.

Before tonight, the Blue Jays had a 25-59 record against Baltimore. Even worse, since August 1978 that mark was 13-46 (.220). Here on 33rd Street, they had eight victories in six years, an 8-34 mark. They once lost 19 games in a row in Memorial Stadium.

Flanagan's 15-4 record against them didn't begin to express the pain he'd brought to Ontario. In his last six starts against Toronto, he was 6-0 with a 0.88 ERA. In Memorial Stadium, he was 10-0 in 10 starts with a 1.11 ERA and nine complete games. There was no surer bet in baseball than the whammy Flanagan, the Orioles and Memorial Stadium had on Toronto.

This evening, those yokes of bondage were thrown off. And 'twas done with panache by the young and plucky Blue Jays, who now stand in third place in the AL East, just one game behind the Orioles. Baltimore, thanks to Milwaukee's loss, remains alone in second place, one-half game out of the lead.

"In the past, they played a tune on us here," said catcher Buck Martinez. "Now, we can play with any team in any park on any day."

Toronto could have folded easily this evening. The scene was so familiar. Flanagan, who eventually allowed seven runs in three innings, got three feeble outs in the first inning. Al Bumbry opened the Orioles' first with a single through the legs of Luis Leal, a right-hander with a typical Toronto record against Baltimore: 1-6. Next, Eddie Murray launched a 420-foot homer to right for a 2-0 lead. Who'd guess Leal would go on to win a 121-pitch seven-hitter--his first victory in five weeks?

The old Blue Jays would have called it a night, but not the new Jays. This was "Buddy Night" at the ballpark, but they refused to be the Orioles' familiar pennant-race pals. In the next three innings, they pounded out nine runs, aided by four errors and three walks. Toronto's hits were honest, but Baltimore's sins led to at least five of the runs.

Lenn Sakata, who hadn't made an error in 144 previous chances this season, was eaten alive by two grounders, both of which were right at him and made to order for vital double plays. "I just stunk," he said. Flanagan, whose knee still bothers him, tried to nonchalant his grab of a sacrifice bunt and left the ball in the grass for an error.

Todd Cruz, who made two excellent defensive plays this evening, but who constantly shows his lack of experience at third base, got his feet tangled and turned a routine chop into a no-throw infield hit in the three-run third. On an awful sacrifice bunt attempt in Toronto's five-run fourth, he could have fielded the ball with two hands, checked the spelling of Lee MacPhail's signature on the ball and lobbed to first in time to nail the bunter by 10 feet.

Instead, he barreled in, barehanded the ball and made a spectacularly graceful throw. Unfortunately, the throw sailed 10 majestic feet over the first baseman's head and hit the box seat railing far down the right-field line. The batter still hadn't reached first base. One run scored and runners, who both scored, ended up at second and third.

That error sent Flanagan to the showers, where he probably felt safer.

Of the spate of three errors within four batters, and four in one turn through the Blue Jays' order, Oriole wit John Lowenstein offered, "It's better to be incongruous all at once." The Orioles, who made six errors in a game earlier this year, began the game leading the AL in fielding.

Reliever Sammy Stewart entered with the score only 5-2, but by the time he'd finished sloshing gasoline on the blaze it was 9-2 and the evening done. Dennis Martinez, the man against whom the league has hit .340 this year, hurled five glorious shutout innings of completely meaningless long relief, adding to the mystery of how this proven winner in the prime of life can be 6-14.

In victory, the Blue Jays were forgivably bumptious, irritating the Orioles with some of their postgame comments. Moseby, after his three RBI, said of Flanagan's previous streak, "I wasn't here in '77 and '78, but that's when he got his wins, obviously."

Actually, Flanagan has beaten Toronto six for six in 1981-'83, in Moseby's presence. "Obviously," retorted Orioles Coach Ray Miller, "the reason Moseby didn't hit much the last two years is that he didn't know who was pitching.

"They don't even know what pressure's about yet."

Peck, peck, peck.