More than 1,000 people turned out yesterday at the Patuxent Research Refuge National Wildlife Visitor Center to celebrate the 100th anniversary of the national wildlife refuge system -- which they did by snapping pictures, pointing at turkey vultures and making noises at owls.

Not everyone came for the party, however. About a dozen protesters from the nonprofit Fund for Animals demonstrated outside against the policy of allowing sport hunting at 39 refuges across the country since 1997. The protesters stood silently at the gate of the Laurel facility for two hours, offering pamphlets to motorists.

"I believe wildlife should be able to live out its natural life with minimal interference," said Andrea Cimino, 23, of Gaithersburg. The nonprofit group challenged the hunting policy in court last week.

But there was little hint of any controversy inside the sprawling 12,750-acre complex. President Theodore Roosevelt established the first wildlife refuge off the coast of Florida a century ago; since then, 540 refuges have sprouted up across the nation. The Laurel complex was formerly limited to research but was opened to the public in the early 1990s.

In a short opening ceremony marking the centennial, Patuxent refuge manager Brad Knudsen rattled off a stream of wildlife facts:

The nation's refuges are home to more than 700 species of birds, 220 species of mammals, 250 reptile and amphibian species and more than 200 kinds of fish. More than 250 endangered plants and animals, such as bald eagles, also make homes in the refuges. At least one refuge is found in each state, and more than 10 million people visit one of the centers each year.

"A century-old idea is just as compelling today," Knudsen said.

The crowd included many youngsters, including Sabrina Marth, 9, and her sister Lorraine, 7, of Laurel, who said they were excited when they found out that the surprise their father had in store for them yesterday was a trip to the center.

"I like animals," Sabrina said, "birds, rabbits, anything furry."

The taciturn owls at an outdoor exhibit drew steady admirers and had an eager spokeswoman in Karen Sprague. A seasonal naturalist with the Maryland Department of Natural Resources, Sprague satisfied the curiosity of such visitors as Malika Howell, 11, of Baltimore.

"Can they eat whole fish?" Malika asked.

"They'll eat small mice," Sprague said.

"Good, I need him in the house," the sixth-grader said.

Malika hooted at the brown speckled owl with olive eyes. "Actually, these give off more of a purring sound," said Sprague, who offered up a pitch-perfect imitation.

Matthew Shafer, 6, of Sterling was most excited about the bat exhibit inside the hall. It wasn't live, just a model in a display case, but he had recently learned about bats in school. He likes the nocturnal creatures. "They have pointy ears," Matthew said.

Retirees Betty and Bob Miller of Springfield are avid birders but had never visited the Patuxent center before yesterday. They have traveled to more than 30 refuges throughout the country to peer through their binoculars. The joy of bird-watching is in the details, said Bob Miller, 87.

The birthday event was the perfect reason to visit the refuge closest to home, said Betty Miller, 78.

"We're so enthusiastic about the 100-year anniversary of the organization," she said. "We had to celebrate by coming out here today."

Mario Gonzalez, 4, and his sister Enya, 7, try apparently in vain to draw the attention of an owl at the refuge visitor center. During a brief opening ceremony, the center's director, Brad Knudsen, observed, "A century-old idea is just as compelling today." Volunteer Glenda Kamosa displays Canada goose artwork, done by visiting children, inside the Patuxent Research Refuge National Wildlife Visitor Center, while crowds gather outside, where birds are displayed by the center's staff members.