This might be hard to believe if you've ever paused to admire a hawk's or eagle's majestic swooping, but not so long ago people despised these birds. Raptors were hunted, trapped, even deliberately poisoned.

"They were considered varmints, basically," said Julia Ponder, executive director of the Raptor Center at the University of Minnesota.

Raptors were thought to prey on farm animals. That's simply untrue in the case of bald eagles; they eat fish. Golden eagles have been known to go after medium-sized mammals such as sheep and calves, but that's not their primary food source, Ponder said.

Thank the Raptor Center, celebrating its 40th anniversary this year, for helping change public attitudes. In addition to treating injured birds in its clinic (914 last year, 22,000 throughout the center's history) and conducting research, it also offers community education, reaching 150,000 to 200,000 people a year.

"At this point, there is much more appreciation, an understanding of the magnificence of the birds and the role they play in the world," Ponder said. "We hope we've been a part of that."

People don't attack raptors like they used to (though the clinic still sees birds that have been shot), but the birds are still being harmed by human activity: cars, buildings, power lines, toxins — "the wide variety of problems they get into when living in an urban or suburban landscape," said Ponder. Even when a bird doesn't die after consuming something toxic, it can damage its reproductive and immune systems, jeopardizing whole populations.

People can help in lots of ways, Ponder said. Don't throw food out of car windows — yes, it's biodegradable, but it lures rodents, which in turn draw hawks to roadsides, where they get hit by cars. When hunting with lead bullets, bury or dispose of the gut pile after field dressing your game — it may harbor lead fragments that can poison scavengers. Don't leave soccer nets up after the kids' game; rodents scour the field for discarded snacks, attracting owls that can't see the nets. Use mousetraps instead of rodenticides that can turn mice into "little poison pills for the owls and predators that eat them."

Raptor populations have stabilized with the center's help. Peregrine falcons, having once vanished east of the Rockies, are back in the Upper Midwest and adapting well, even to urban living. No longer endangered, the bald eagle population is increasing.

"But it's still only at 10 percent of historical norms," Ponder said. "It will never be up to historic levels. There's not enough habitat."

Katy Read • 612-673-4583