As many as half of Minnesota's bird species — including the loon, the beloved state bird — could disappear because of accelerated climate change.

It's not the birds themselves that are endangered, it's the places that they live — the lakes, the forests, the grasslands — that are at risk. As those areas disappear, so will the birds that nest there.

"In real estate, it's 'location, location, location,' " said Bob Janssen, the author of several books about birds in Minnesota. "The bird equivalent is habitat, habitat, habitat. And it's declining, declining, declining."

If overall temperatures in the state continue to climb at the current rate for 65 years, it will drive many species that live in Minnesota farther north in search of suitable environments, according to a study by the National Audubon Society. It would mean that by 2080, the nearest loon might be in Canada.

Currently, the area in the state populated by loons runs roughly along Interstate 94, said Carrol Henderson, nongame wildlife program supervisor for the Minnesota Department of Natural Resources.

"South of that line, there are few loons," he said. "North of that line are the lakes with the clear, cool water that loons need. If those lakes warm up, the loons will move farther north as the lakes they're living in now will become unusable or, at least, marginalized."

In addition to loons, which are known for their haunting calls and piercing red eyes, Minnesota birds said to be at risk include the American white pelican, sharp-tailed grouse and mallard duck. The study also warned that the trumpeter swan could disappear entirely.

"We've been talking about birds being killed by flying into glass," Jim Williams, a bird expert who writes the Wingnut blog for the Star Tribune, said in referring to a recent controversy over the design of the new Minnesota Vikings stadium. "That's going to be nothing compared to this."

The report looked at 297 of the 323 bird species commonly found in Minnesota. Of the 297, it said, 76 are at risk of severe declines in 35 years and another 90 face the same fate in 65 years.

"Everyone — not just birders and hunters — stands to lose out," Audubon Minnesota's executive director, Matthew Anderson, said in a statement. "We have new urgency for tackling climate change."

Most species of birds can't adapt to changes in their habitat.

"Birds are habitat-specific," Williams said. As their habitats change, they must either find another place with suitable conditions — or die.

"This problem is very, very serious," Janssen said. "As long as birds have a place to feed, rest and raise their young, they're OK. But without that, they're not."

Habitats do evolve, but that can take centuries.

"Vegetation can't keep up with weather change," said Williams. "A new spruce forest can't grow in time for the birds who live there to survive."

As alarming as the Audubon study is, Henderson said that other issues may pose even bigger — and much more immediate — problems for the state's bird population. He's particularly concerned about contaminants in lakes, especially lead used in fishing gear, that's poisoning the loons. He also pointed to the loss of grasslands and an increasing use of pesticides.

"If people want to do something to help the loons, they can start requesting nontoxic, loon-safe fishing tackle," he said. "It exists, and it works just as well. But retailers won't carry it if people don't ask for it."

The number of birds has been steadily declining for a long time, said Janssen, 82, who has been monitoring bird populations for decades.

"I don't see half the birds now that I saw in the '70s and '80s, and the drop is even more so compared to the '50s and '60s," he said.

Similar predictions about dramatic bird losses have been made before, Williams said.

Jeff Price, a professor with the American Bird Conservancy, "warned us about this more than 10 years ago," he said. "But nobody listened. Hopefully, with the Audubon Society confirming this, with all their scientific data, it will have an impact."