Too many kangaroos, too few Tasmanian devils. Two of the country's beloved icons are challenging Australians' thinking on wildlife management.

Researchers are trying to battle a cancer epidemic among Tasmanian devils, and on Wednesday they were listed as endangered.

At the same time, an abundance of kangaroos has prompted the government to begin administering lethal injections to 400 of the animals.

Protesters have vowed to seek a court injunction to stop the slaughter of the eastern gray kangaroos, which are viewed as sacred symbols by Australia's indigenous people.

Scientists say the kangaroos' rapidly growing population threatens their survival, as well as that of some reptiles and insects that share their grassy habitat.

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Police on Wednesday charged eight Aboriginal activists with trespassing on the Canberra site where the kangaroos are being killed. The activists hope to persuade officials to relocate the animals; the Defense Department says that would be too costly.

Canberra's local government leader, Jon Stanhope, said he understands that the killings distress many people. But he said more than 3.5 million kangaroos are commercially shot in the Outback each year. The meat is served in restaurants and is also used in pet food.

Pat O'Brien — president of the Wildlife Protection Association of Australia, whose patrons are the family of the late "Crocodile Hunter" Steve Irwin — said government leaders miss the point.

"Shooting millions of kangaroos doesn't make it right," he said. "The national capital has a chance to lead by example and show that Australia has moved beyond solving all our wildlife management problems with a gun."

While the kangaroo population is growing, another Australian favorite — the Tasmanian devil — is threatened by a contagious cancer that has cut its population by up to 60 percent in a decade.

The disease, which causes disfiguring facial tumors, has spread so quickly that scientists last year estimated there might be no disease-free animals in the southern island state of Tasmania within five years.

The government of Tasmania, the only place where the devils exist in the wild, on Wednesday reclassified the animal from vulnerable to endangered status.

The change qualifies Tasmanian devils for greater government conservation aid and adds pressure on the federal government to revise its threatened species list.

"We are committed to finding an answer and saving the Tasmanian devil for Tasmanians and the world," state Primary Industries Minister David Llewellyn said in a statement.

Early European settlers named the devil for its spine-chilling screeches and reputed bad temper, and it gained fame as the Looney Tunes cartoon character Taz.

Its larger cousin, the Tasmanian tiger, which like all marsupials carried its young in a pouch, was hunted to extinction in the 20th century.

Veterinarian Hugh Wirth, former president of the World Society for the Protection of Animals, said Australians have become more concerned about wildlife in the past 20 years.

He accused Defense Department officials of ignoring the growing kangaroo population until the animals were at risk of starvation.

"Impossibly high numbers have been allowed to develop, and then you have a mass slaughter. That's not close management and it's intolerable," Wirth said. "In a decade's time, we'll have another slaughter."