The feathers on the big red-tailed hawks had been scorched. Over the last several years, other large raptors with burn injuries also showed up, including two great horned owls. Moller nursed them back to health, a long and involved process because of the extent of the injuries.

"It's painful for the birds," Moller noted. "And probably more so psychologically. They don't understand they can't fly; they just keep trying."

But why the strange burns? Moller over a period of time solved the mystery — and found a way to halt the burns. Her efforts are now making a difference nationwide because, as it turns out, other burned birds were showing up elsewhere and the source of their injuries proved to be the same culprit Moller discovered in Rock County.

All of the burned birds cared for by Moller had been found near the Janesville municipal landfill on Highway 51 at the edge of the city. After the first birds turned up, Moller started contacting other bird rehabilitators to ask about similar experiences. One of them, from Horicon, asked if there were any landfills nearby and said she had also been taking in burned birds.

While her suspicions centered on the landfill, Moller remained unsure about what exactly was happening. For a while, she thought the birds were somehow being electrocuted. But the injuries didn't seem to match. Then she heard from another rehabilitator who turned her attention toward pipes used to burn off the methane gas that collects beneath landfills.

Moller found two tall pipes at the landfill. The pipes ignite intermittently to burn off the gas. Working with other rehabilitators around the country who have treated birds with similar burns, Moller figured out that the raptors were perching on the tall, 30-foot pipes to scan the landfill for prey. When the pipes flared with no warning, the birds were caught in the flames.

Among those Moller communicated with was Gary Siftar, with the Oklahoma Raptor Center in Broken Arrow, Okla. Siftar knew of the problem and wrote about it for the Audubon Society chapter in Tulsa.

"Active landfills have an abundance of rats and mice, which are an excellent food source for various raptors," Siftar wrote. "The nature of a landfill produces a treeless landscape. The height of the burner stack makes an attractive perch for raptors waiting for rodents and other prey.

"The burners have an igniter that causes a sudden flare, which can scorch or even kill anything perched on top, flying overhead or actually inside."

Moller and Siftar both believe the toll on raptors at landfills is much greater than most realize.

"A lot of the birds are not found," said Moller. "They wander away and die of starvation."

Doug Fendry, a wildlife specialist with the state Department of Natural Resources, worked with Moller to find a solution. He agreed the problem is probably more widespread than most realize.

Not all landfills have the methane burners because many, including the Dane County landfill, capture the methane and use it for energy. But Fendry said reports of burned birds are prevalent enough that increased awareness of the burners and their threat to raptors is important.

"At first I think the landfill thought this was like a one-time thing," Fendry said. "But I think they realize now that this is occurring more often. The birds can't fly and they hop off and are picked off by other predators. I wouldn't be surprised if it's more common than we know."

Moller, for example, has received two burned red-tailed hawks in the last month, found within two weeks of each other. Treatment of the birds involves keeping them long enough, up to a year, to allow them to molt and lose the damaged feathers, which are then replaced by new feathers.

Working with the landfill operators, Moller and others came up with a solution that is likely to be used at other landfills — stainless-steel spikes attached to the pipe that prevent the birds from perching. Mandy Bonneville, the assistant operations manager of the landfill, said the solution was welcome.

"We want the hawks," Bonneville said. "They help control the rodent populations."

Moller in the meantime, has continued her efforts to raise awareness of the problem. She's working with the U.S. Fish and Wildlife Service and is writing articles about the problem. She praised everyone involved, from landfill officials to the DNR, for working together to solve the mystery.

"I believe people do care," said Moller.