NEW YORK On the street, Caroll Spinney is a 74-year-old of modest proportions. On the job, transformed into Big Bird, he stands 8-foot-2 and is 6 years old.

Being Big Bird is sweaty, physical work. But Spinney, who has worked on "Sesame Street" for nearly four decades playing Big Bird and Oscar the Grouch, has no wish to be anywhere else.

"I can't imagine willingly walking away from Big Bird and Oscar," he said.

To play Big Bird, "you have to not be claustrophobic," Spinney said. "You have to be willing to walk, not seeing anything in front of you."

Spinney got his start on "Sesame Street" during its first season in 1969, after Muppets founder Jim Henson saw him perform at a puppeteer's convention.

Henson chose him as Big Bird after Frank Oz, who helped develop Bert, Grover and Cookie Monster, swore off costume puppets after a stint in commercials as the La Choy Dragon, which was equipped with an in-costume flame-thrower.

Spinney met his wife, Debra, at Sesame Workshop, and has three grown children and four grandchildren. He's one of a handful of original cast members still on the show; the only other original puppeteer still working full time is Jerry Nelson, who plays The Count.

"One of the things I really enjoy about 'Sesame Street' is that years go by and I'm still the same age," Spinney said. "I'd love to be 70 again, 60 and 50 and 40."

While the show takes place in a magical mirror New York, the set is at the Kaufman Astoria Studios in Queens, where decidedly grittier fare such as "Fort Apache-The Bronx" was also filmed.

When Big Bird and Oscar appear in the same scene, Spinney prerecords Oscar's voice, then acts the scene as Big Bird while someone else puppeteers Oscar.

Spinney says he modeled Oscar on the Bronx taxi driver who drove him to the old Muppet Mansion the first day he played the character, greeting him with a gruff, "Where to, Mac?" In Spinney's mind, Oscar is 43.

On-the-job lessons
Caroll Spinney's book, "The Wisdom of Big Bird (and the Dark Genius of Oscar the Grouch): Lessons from a Life in Feathers," published in 2003, contains career advice even nonpuppeteers can put to work.

• Ask: Muppets founder Jim Henson saw Spinney perform at a convention and told him he should come to New York so they could talk about the Muppets. Spinney asked what he meant and Henson answered that he was offering Spinney a job.
• Stick it out: After his first year on Sesame Street, Spinney felt he couldn't live in New York on his salary. Puppet builder Kermit Love told him to give it a month; the next week, Big Bird was on the cover of Time magazine, and Spinney couldn't imagine leaving.
• Share: When the character Elmo became a star in the 1990s, "it was like having a new, younger brother in the family," Spinney wrote. "Elmo was now the cute young child on the street." His realization, though, was that Sesame Street is a big place, with room for everyone to contribute.