ANCHORAGE (AP) -- Researchers made no mistakes in darting three Denali National Park and Preserve wolves who later died, according to a panel of experts who reviewed the deaths.
The seven-member panel was appointed by the Park Service and made up of state and federal wildlife biologists, Park Service officials and a senior scientist from the Audubon Society.
They looked at what drugs the wolves were given, in what dose, and how they were darted. They also reviewed necropsy reports on two wolves and Park Service interviews with researchers.
In their findings, released Wednesday, they accepted the conclusion of the biologist who performed the necropsies that a likely factor in the wolves' deaths was a pre-existing heart valve defect. But they said there was no way biologists could have known about the condition.
The three wolves were among a group of 10 darted in March and fitted with radio collars as part of ongoing research of the packs and their interaction with other wildlife.
''I'm very satisfied there was no negligence whatsoever on that project, and that's an emphatic no,'' said John Schoen, a senior scientist with the Alaska chapter of the Audubon Society who served on the panel.
The panel members, however, did urge Park Service officials to investigate whether Denali wolves are predisposed to heart defects.
The defect -- a slight thickening of a heart valve -- could indicate an infection, said John Blake, a University of Alaska Fairbanks biologist who conducted the necropsies.
Coupled with the effects of the drug used to sedate and immobilize the animals, the defect could have restricted the flow of oxygen to the brain, he said. Still, Blake admitted the heart valve problem is just a best guess. He ruled out other possible causes, such as a dart hitting a vital organ, an overdose, and a bad batch of drugs.
The wolves that died in March included two adults and a yearling who turned up dead shortly after they were darted. One had been eaten by other wolves and could not be necropsied.
On average, about 2 percent of captured wolves die nationwide, according to wildlife biologists. In Denali, the average has been about 1.5 percent -- five animals -- in the past 15 years out of nearly 320 wolf dartings. That figure does not include the four latest deaths.
The deaths triggered criticism from groups such as the Anchorage-based Alaska Wildlife Alliance, which has argued the Park Service should take more care with Denali wolves, among the most viewed and studied in the country.
Paul Joslin, who heads the group, said he had yet to see the panels' findings, but said the Park Service should have a veterinarian on hand when it darts wolves and should consider not darting certain animals key to the pack. Among the wolves killed was the alpha male of the Toklat, also known as the East Fork pack.
Park Service spokesman John Quinley said the agency had no immediate plans to change how they dart wolves. No more darting will be done until this fall, he said.
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