As New York City gets back on its feet after the staggering events of the autumn, a Fordham University scientist and his students are returning a different type of life to the city's parks.

So far, biologist Bill Giuliano and his team of students have released 18 screech owls into Central Park, a species that hadn't been seen in the park for 50 years. They are also studying a tern population at Far Rockaway Beach in Queens and are considering other species for future reintroduction into the park system.

"The parks project is bringing new life to the city," Giuliano said. "People in the parks are really excited."

Giuliano's work with the Urban Park Service of the city's Department of Parks and Recreation began last fall, but his interest in wildlife conservation began when he was a child in Boston.

"I grew up in the city, and even though I spent a lot of time in rural areas, I developed an interest in urban wildlife and in why some species do so well in urban settings and others don't," he said.

Giuliano earned his doctorate at Texas Tech University in 1995 and took a faculty position in Pennsylvania's state university system. He enjoyed his work, but he wasn't well placed geographically to do the urban studies he sought. A heavy teaching load also limited the time he could give to research. Then, nearly 2 years ago, the Fordham position came along, offering a better mix of teaching and research.

"Fordham was a good fit," he said. As an assistant professor, Giuliano teaches undergraduate and graduate students in the field and in his lab at the Louis Calder Center, the university's biological field station in Westchester County.

"I enjoy being out in the field, and this allows me to do that more than most jobs would," he said.

Giuliano's current work with the city resulted from a series of fortunate encounters. Fordham's faculty has a cooperative relationship with the scientists of the Wildlife Conservation Society, based at the Bronx Zoo. Coincidentally, the city had approached the zoo with plans for reintroducing native species into city parks. Giuliano attended a meeting of zoo and city officials that resulted in his receiving a grant from the city to survey wildlife and habitat in six parks.

That survey identified 112 species of wildlife, including 83 birds, 15 mammals, five amphibians, and nine reptiles. Giuliano and his students also assessed the parks for their potential as habitat for the screech owl and other species. The screech owls were good candidates for this first round of reintroductions because they are neither migratory nor high-flying birds; the tall buildings surrounding Central Park would provide sufficient containment barriers. The park also offered a good food supply, and there was no sign of the screech owl's principal predator. The study also found a good supply of the tree cavities preferred by screech owls as well as a suitably diverse and dense forest. "It all checked out," Giuliano said.

The release of the owls was just the beginning of the reintroduction project. The owls wear leg bands and radio transmitters, allowing Giuliano and his students to monitor mortality, nesting patterns, foraging habits, and the impact of human and other park activities on the owls.

Not surprisingly, a number of the owls have escaped their radio transmitters, requiring Giuliano and his team to capture the recalcitrant owls for retagging. Because the owls prefer densely wooded areas in the park, Giuliano and his team go to those places to listen for the owls' calls or to attract owls with calls. Bal-chatri traps, each consisting of a wire mesh box with dozens of fine and small nooses on top, are used to humanely trap the owls. After the owl is lured into the box by a live mouse, its feet become ensnared in the nooses. Both the owl and the mouse are unharmed.

"We've caught a few that way," Giuliano said. "But some of [the screech owls] seem to sit on top of the box and laugh at us."

For obvious reasons, the monitoring involves a lot of late nights. Fortunately, the students working with Giuliano are night people.

"Rule one is safety. No one goes out at night alone," Giuliano said. He himself monitors the owls at least one night a week, sometimes working as late as 4:00 a.m. Urban Park Service rangers accompany the students on other nights.

The reintroduction of the screech owls is the first in what Giuliano hopes will be a series of experiments designed to enhance and restore biodiversity in the city's parks. And the parks project is not the only wildlife conservation work keeping Giuliano busy. He is one of four principle project leaders in the Appalachian Cooperative Grouse Research Project, a 6-year study of ruffed grouse that involves 12 sites, eight states, five universities, and thousands of birds. The study is monitoring habitat loss and other reasons for the grouse's decreasing population in the Appalachian region. Giuliano is also working with the Maritime Aquarium in Norwalk, Connecticut, on a research and education project involving eight high schools that is studying the return of harbor seals to areas in western Long Island Sound.

As he pursues his longtime interests, Giuliano is also passing on these interests to a new generation of scientists. Five undergraduates and a graduate student are working with him on the screech owl project, a doctoral student is working on the tern project, a master's student is doing his thesis on the screech owls, and two undergraduates are studying the parks' flying squirrel and chipmunk populations.

Giuliano and E. J. McAdams, coordinator of the city's Urban Park Rangers Biodiversity Program, work on other public education programs related to the project. They have brought Columbia University students into Central Park to demonstrate the radio telemetry used in the study. And they bring school groups on weekly visits to their park site and, when time permits, brief citizen advisory groups on the screech owls' progress.

New Yorkers have a rather proprietary attitude toward their green spaces, with Central Park holding a special place in people's hearts. Bird watchers pursue their avocation with a particular passion. The team regularly encounters members of the Audubon Society and other bird watchers who frequent the park. "Several owls have a favorite haunt, and the local birders now know where those are," Giuliano said. As a result, Giuliano, McAdams, and the others have a lot of people to pacify. Giuliano maintains an admirable equanimity in the face of 8 million potential commentators. "As long as my boss is happy, I'm safe," he says.

One species that Giuliano and his students have found to be in good supply in Central Park is the night owl. They often encounter the park's bipedal nightlife during their late-night surveys. "Strange people will just appear out of the bushes," he said. One night, when they needed to recapture an owl, they set up a cage in what they believed was a quiet spot. As they waited, they discovered that the area they had chosen was a prime spot for, well, trysts. Seeing no screech owls, they left discreetly.

"We'll try again," Giuliano said.