EGG-STRA. EGG-STRA. Big Bird has flown the stoop and headed for the heartland. Muppets and "Sesame Street" people mount a tri-state search for the six-year-old runaway in "Follow That Bird."

This first film from "Sesame Street" is this summer's sweetest surprise, a wholly good-natured children's comedy with enough wit and whimsy left over to win parents' hearts, too. Like the TV series, it's not violent, not threatening and not to be missed.

The movie's lessons are familiar ones about self-reliance, tolerance, sharing, caring and, most especially, the brotherhood of man. Big Bird learns how much he values his varied friends when he leaves his multi-ethnic neighborhood for a xenophobic one in Oceanview, Illinois.

The story by Emmy-winners Tony Geiss and Judy Freudberg begins in the headquarters of the Feathered Friends Society, where a certain Miss Finch decides to find a foster home for the eight-foot fellow. "He needs to be with his own kind," says the dowager, who if she weren't a bird, would be in the DAR.

Imagining a family that looks rather like himself, Big Bird agrees to live with a foster flock. But they turn out to be four dumb clucks called the Dodos -- Mommy, Daddy, Donny and Marie -- stupid, exclusionary birds who look like members of the Spanish royalty who intermarried for too many years.

Big Bird digs worms, swims in the birdbath and does the "20-Minute Workout" to be like the Dodos, but he longs for his open, easy-going old neighborhood. And while he knows it's wrong, he runs away, back to Sesame Street, but gets lost in America.

Oscar the Grouch, Count Von Count, Bert and Ernie -- the whole shaggy gang, their fur tatty as a beloved stuffed animal's -- set out to find their friend, last seen singing a duet with Waylon Jennings in a truck full of turkeys. The several songs, achingly lovely and uplifting, are by Lennie Niehaus and Van Dyke Parks who also teamed for the movie "Popeye" and an Uncle Remus album.

Ken Kwapis, a 27-year-old maker of children's programs, adeptly directs the "Street" regulars, human and otherwise, along with Paul Bartel, Sandra Bernhard, Chevy Chase, John Candy, John Flaherty and Dave Thomas in cameos. Underneath the success of it all, however, is veteran puppeteer Carroll Spiney who has been the soul of Big Bird for some 16 years. It's a gracious performance in a comforting, playful, moral movie.

FOLLOW THAT BIRD (G) -- At area theaters.