Troutbeck Farm is a paradise for birds, and birders - and that's by design.

Bill Lucas, a stormwater engineer with a horticultural bent, and his wife, Sue, who's pure bird lady, share the Lucas family homestead in Willistown with Bill's mother and two siblings. But winged creatures rule this idyllic place, and every effort is made to attract, feed, and shelter them.

"A goldfinch sitting on a coneflower . . . how pretty is that?" says Sue Lucas, a well-known bird-habitat instructor in the Philadelphia region.

"I love that they can fly, that they're so elusive. They have a wonderful freedom, an ability to be invisible," she says, giving every indication that she could continue in this vein for some time.

Actually, it was a goldfinch that sparked Lucas' bird fascination more than a half-century ago in Yosemite National Park, where her family went camping every summer of her childhood.

A charming yellow bird landed on a picnic table beside Sue, who was 8 at the time, and she wondered aloud what it was. "A wild canary," her mother replied.

Using a bird book she got as a birthday present, Sue soon decided that the "canary" was a goldfinch, an American native that all these years later is one of more than 120 bird species that Lucas has identified on Troutbeck Farm's 80 acres.

The list includes owls and hawks, bald eagles and herons, woodpeckers (four kinds), warblers, cardinals, orioles and bluebirds, and on and on - and no wonder. This former cattle and horse farm, which dates to the 18th century and still devotes 20 acres to crops, hosts four family houses and an old stone barn, three ponds, seven natural springs, wetlands and trees, and a 50-by-80-foot meadow planted with birds in mind.

It's a splendid habitat with many native plants that produce the seeds and berries birds love: winterberry, serviceberry, chokeberry, butterfly weed, coneflower, partridge pea, and sunflowers, to name a few, along with native grasses and wildflowers that others - nonbirds, clearly - might consider weeds.

From Lucas' two decks, you can see a long row of bluebird houses and feeders of all sorts that she fills with the ever-popular black-oil sunflower seeds; nyjer, tiny seeds that finches favor; and cakes of suet, or rendered beef fat, considered a winter treat.

The menu's similar in the 19 feeders in George and Chris Fore's backyard in Merchantville. Owners of the Wild Birds Unlimited store in Cherry Hill, the Fores also put out safflower seeds, which grackles and squirrels don't like. Both can be pesky pigs at feeders, which, Chris Fore insists, are more often about human enjoyment than the needs of birds, except in winter.

"Birds are nature's creatures. They know how to find food," she says, "but when there's a lot of snow or ice on the ground, it's hard for them."

(Cornell Lab of Ornithology, however, advises that during spring and fall migration, feeders can be welcome, even lifesaving, for exhausted birds.)

The point Fore raises, about bird-feeding's having a strong entertainment component for people, is reinforced by David Mizejewski, a naturalist with the National Wildlife Federation in Reston, Va. And he sees it as a good thing.

"It gives people an easy wildlife-watching opportunity, which is really important, with people, kids in particular, spending so much time indoors nowadays," he says.

Beyond that, Mizejewski says, birds are an important player in the ecosystem, even in a small backyard. A few, like hummingbirds, perform pollinator duties. Chickadees, purple martins, robins, nuthatches, and others are major insect predators, capable of devouring hundreds (or more) in a single afternoon. Even birds that eat seeds in winter feed their young insects in summer.

But birds, too, are prey, for hawks and owls. In a joke only a naturalist could love, Mizejewski says, "When you put out a seed feeder, you're putting out a feeder for bird-eaters."

It's the ecosystem thing, endlessly interwoven and complex.

"If you do the right things in your yard - if you have great native plants that provide food and shelter, places to raise young, and a water source - you'll have great diversity of wildlife in relative balance," Mizejewski says.

Unless you're the type who screams at the sight of insects, you might wonder at the benefits of birds' eating so many. After all, despite their scary reputation, most insects, like the birds that dine on them, are good garden citizens, pollinating plants and eating other insects with nefarious intent.

"It's true that most insects are good, but a lot of insects would eat your whole garden if they weren't kept in check," says Doug Wechsler, ornithologist at Philadelphia's Academy of Natural Sciences, who, despite devoting his professional life to the study of birds, is not a big fan of feeders.

"I don't think feeding birds overall greatly adds to the diversity of birds or anything," Wechsler says. "My gut feeling is that if you want to see the birds up close, go ahead and feed them, but . . . the best thing for birds is to provide food in your garden in the way of native plants and fruits."

Nesting season is almost upon us, and Sue Lucas cannot wait. This is a woman who throws parties on her deck for birding friends, who watch the meadow action through telescopes while the BBQ gets hot. "We have better birding on the deck than on some of the walks I lead," she says.

Lucas' favorite field guides for birds are ones by Roger Tory Peterson, Sibley, and National Geographic. Her favorite fields? They're here at Troutbeck Farm, where the best seats in the house are outside.

Contact garden writer Virginia A. Smith at 215-854-5720 or Read her blog, "Kiss the Earth," at gardening.