The way 8-year-old Katie Trojak grilled bird trainer Phung Luu today at The Philadelphia Zoo, you began to fear a bit for the man's job.

As Luu the trainer made Bella the red-fronted macaw do tricks for the crowd outside the zoo's new $17.5 million bird exhibit, Katie the second-grader fired off questions like a Senate inquisitor.

"The question is," Luu told a crowd outside the zoo's new, $17.5 million bird exhibit, "Is it true the heavier the bird the slower it flies?"

Luu's answer: It depends. Sometimes a big bird is more powerful in the air. Sometimes it's not.

Luu, 35, a bird man with a whisperer's touch, is used to questions and has a lot of answers. But Katie? She was no slouch. "She seemed especially interested."

If Katie's wide-eyed enthusiasm catches on, if the new avian center that opened yesterday inspires similar wonder among the world-weary or oblivious, it might make the world gentler to the soul.

If only for a moment, noticing a bird may turn hardened grown-ups into kids and kids into carefree critters, happy to marvel at the winged creatures soaring above.

"Flight is freedom," said Michael Trojak, 45, a systems analyst, aiming a camcorder toward his three children running circles around Luu: Katie, 6-year-old Michael Jr., and sister Kristi - "I'm four and a half!"

The opening of the zoo's McNeil Avian Center caps an effort begun in 1998 to reinvent the birdhouse, which first opened in 1918.

"When it was built, it was probably the leading bird facility in the country," said biologist Andrew J. Baker, the zoo's chief operating officer who himself has had a lifelong fascination with birds.

The local man who helped introduce the world to Tylenol - Robert J. McNeil Jr. - was the single largest private donor, giving a bit less than a third of the $17.5 million, said Sara Hertz, zoo vice president of development.

His daughter, Jody McNeil Lewis, board member and bird enthusiast, was central in securing the gift.

"She loves birds," Hertz said of McNeil Lewis. "They had parrots growing up."

The McNeil family's Philadelphia roots were planted in 1879, when Robert McNeil Jr.'s grandfather opened a pharmacy in the city's Kensington section. In the 1950s, McNeil Laboratories, under Mr. McNeil's leadership, unveiled Tylenol. He has channeled much of his philanthropy through The Barra Foundation.

McNeil's donation was among about $10 million raised from private donors, large and small, all in hand by about the end of 2007.

The Commonwealth of Pennsylvania kicked in most of the rest. Budget appropriations approved by lawmakers and Gov. Rendell in 2001 and 2002 steered $7.25 million to the zoo for the center, while former Mayor Street kicked in $300,000, said Kenneth Woodson, the zoo's vice president of community and government affairs.

The 11,000 square-foot exhibit hall is home to 120 birds - paradise for birdwatchers.

Although birdwatching is a popular hobby, many people remain oblivious to these animals that Baker calls "our most frequent link with the wild animal world."

Take the Trojak family. Yes, they have a pet bird. But it wasn't until two years ago, when they hung a finch feeder in their yard, that Lori Trojak, mother of the bird-loving brood, really began to appreciate them.

Trojak, a certified public accountant, is a stay-at-home mom who also cares for her live-in mother, who has been profoundly ill for years. To say her life is hectic would be putting it mildly.

Enter: The finch feeder.

When beautiful yellow finches make pit stops in her yard, Lori emerges from a haze.

"Life is so crazy and busy these days that it gives you a moment to stop and breathe," she said. "To remember there's more to life than the craziness."

The avian center has loads of colorful, whimsical birds. But no where in the rain forest wing today were the colorful headliners whose glossies are on aviary center tour placards: Two curl-crested Aracari's hand-raised at Dallas World Aquarium. (The bird is pronounced ah-ruh-SAR-ee).

The "little boys" made their debut during members-only tours but were a tad too friendly for their own good.

"They were landing on people's hands and arms and heads," birdkeeper Catherine Vine said. "We didn't want them walking out of here with anybody." They may return for special events or on quiet days when a birdkeeper can be on hand.

A less charming bird trait on display yesterday: the poo drop. With tree branches dangling over pathways, it proved a hazard.

A crimson-rumped toucanette - a bird so restless you wondered if it had downed a pound of sugar a few minutes earlier - darted onto a branch and took a bathroom break, just barely missing a male patron and, well, this reporter.

"Did it get me? Did it get me?" the man said with a tinge of panic, before scurrying away with a laugh.

Zoo folks say they are ready for such unwanted bird baths. A stash of wet wipes is but a few feet away, said aviary center attendant Daniel Harrison.

And for children on the receiving end of such a potty moment, there's even a treat:

"If you're lucky to get poo'd on," Harrison said, "you get a zoo tattoo."

And if you're an adult?

"You get good luck for the rest of your life," he said.

Contact Maria Panaritis at 215-854-2431 or mpanaritis@phillynews.com.