WHEN A CHILD is used to seeing the wonders of wildlife just by turning on the television, how do you introduce her or him to the real thing? Few kids will willingly sit still long enough to earn even a fleeting glimpse of animals living wild and free.

At the 300-acre Wildfowl Discovery Center in Grasonville, Md., youngsters get up close and personal with wild creatures the same way nature photographers and hunters do: by hiding in blinds.

"There's a green heron, he's a regular," said Benedict J. Hren, executive director of the Wildfowl Trust of North America, on a recent visit to the center. While we spied on the heron from a blind overlooking a pine-fringed pond, the sleek, fierce-looking bird watched a muskrat swimming nearby, apparently in hopes the animal would startle a fish into exposing itself.

The pond buzzed and bubbled with birds and beasts. "This is a particularly rich spot because you've got everything from grass to a tidal pond to forest," Hren said. "Transition zones, what we call 'edge,' serve more species than any pure habitat type."

For its size, the center contains more variety than perhaps any other place in the Chesapeake region. There are six distinct marshland habitats on the property, which is almost an island in Eastern Bay, connected to the mainland only by a narrow neck of land. The nonprofit Wildfowl Trust, established in 1979, has increased the diversity by adding several freshwater ponds. Short, intermediate and "all afternoon" self-guiding trails wind throughout the grounds. Bald eagles and otters are among the species commonly seen.

Blinds have been established at strategic spots, with shield approaches that allow observers to come and go with minimal disturbance of foraging foxes and browsing deer. Signboards point out habitat types and identify most of the animals that are likely to be present.

Hren led my son and me to an enclosure containing two pairs of Florida cranes -- a threatened species -- and four half-grown chicks they hatched this spring.

"The conventional wisdom is that you can bring off only one chick per pair in captivity," he said. "We've found that the critical thing is for them to have enough room so that the less aggressive chick can retreat. That doubles the propagation rate, of course."

The graceful cranes moved through the brushy enclosure with the air of royalty taking a turn through their palace gardens, maintaining a discreet distance from the visitors.

Although the Wildfowl Trust focuses on education and habitat preservation, it undertakes considerable captive breeding of birds. Pure-strain wood ducks, black ducks, gadwalls and blue-winged teal are raised and released to join the local wild breeding populations. Wild birds come and go freely on the breeding ponds.

Last year the center became home to a flock of dusky Canada geese, an Alaskan subspecies that has been in decline since a 1964 earthquake raised the level of its breeding area by five feet, creating instant uplands.

Now brush and trees cover the former marshes of Alaska's Copper River delta, making it easy for brown bears and coyotes to ambush the nesting dusky geese, which are smaller, darker and tend to cluster together much more tightly than other Canadas. Breeding success in the wild has fallen below 10 percent, and as the core breeding population ages, the 12,000 remaining duskys are headed for a crash.

As of last week the 38 duskys at Grasonville had hatched 10 goslings. Eventually the captive flock may become the nucleus of a "rewilded" flock introduced into a more suitable Alaskan breeding area. Although most of the center's duskys were born in captivity -- the flock had been maintained for some years by a Montana bird lover -- they're tolerant rather than tame, and demonstrate vigorously if anyone approaches a nest.

The grounds of the center are landscaped to maximize edge and variety, as well as to create subtle patterns that invite rather than direct visitors toward the various trails. The discovery center provides tours and lectures for school, scout and other groups, but families probably get the most out of the center.

Take it easy on the long dirt road that connects the center to the mainland. On the way in we stopped to move a turtle out of the track, and on the way out we followed a bold-as-brass red fox for nearly half a mile.

WILDFOWL DISCOVERY CENTER -- Grasonville, Md. Follow U.S. 50 across the Bay Bridge to Maryland Route 18 east. Follow 18 into Grasonville and turn right onto Perry Corner Road. The center entrance is a half-mile on the right. 301/827-6694. Open 9 to 5 Wednesday through Sunday. Admission $3 adults, $2 seniors, $1 children.