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Helicopter wolf-kills help caribou calves

SURVEYS: Survival rate soars after shooters thin a herd's predators.

By CRAIG MEDRED
cmedred@adn.com

Published: November 11th, 2008 10:53 PM
Last Modified: November 11th, 2008 07:41 AM

Slaughtering wolves on the Alaska Peninsula appears to have had the desired effect -- more caribou got a chance to live, according to biologists with the Alaska Department of Fish and Game.

As ugly and as politically incorrect as the wolf killing might seem to some, they said, the helicopter gunning that took place earlier this year saved caribou, especially young caribou, from being eaten alive.

Fall surveys of the Southern Alaska Peninsula caribou herd completed in October found an average of 39 calves per 100 cows. That's a dramatic improvement from fall counts of only 1 calf per 100 cows in 2006 and 2007.

The success of past wolf-control programs, and of some of those still under way elsewhere in the state, has varied significantly, depending on what predators were involved. In some cases, bears, eagles and climate have proved to have more influence on calf survival than wolves.

In this case, however, even some groups staunchly opposed to Alaska wolf-control efforts are conceding the removal of 28 wolves appears to have played a major role in caribou calf survival.

"I think that certainly is good news," said John Toppenberg of the Alaska Wildlife Alliance. "I am supportive of that goal. How they arrived at that I might have an issue with."

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The southern peninsula caribou has been in a free fall for several years.

Numbering almost 5,000 animals at the start of this decade, the southern herd had shrunk to about 600 caribou by last year. A joint state-federal management plans calls for maintaining a herd of 3,000 to 3,500 animals to provide for local subsistence needs and the general productivity of the ecosystem.

Researchers studying the caribou decline concluded that the range the caribou use in and around the Izembek National Wildlife Refuge has plenty of food, and the few bull caribou shot by hunters prior to a prohibition on all hunting last year weren't an issue.

What was fueling the decline, researchers said, was the high ratio of predators -- bears and wolves -- to prey in the area. The predators were killing and eating caribou faster than the animals could reproduce, leaving the population nowhere to go but down.

THE 'PREDATOR PIT'

Caribou populations need 20 to 25 percent of calves to survive each year just to sustain herd size, given significant annual losses to accidents, starvation and predation even in the best of times.

If calf survival falls below that, the herd begins to shrink, and the shrinkage accelerates as the population becomes increasingly dominated by older animals nearing the natural ends of their lives.

In some cases, research indicates, the only way to keep the population from falling to very low numbers and getting trapped in what biologists call a "predator pit" is to reduce the number of predators.

"I don't have the benefit of independent, scientific consultation here," Toppenberg said, but all the available evidence indicates that something like that appears to have been the case with the southern peninsula herd.

"It does look like the science was there," said Toppenberg, who had earlier this year been angered by the killing of wolf pups on the range of the herd.

ORPHANED WOLVES

After biologists in helicopters gunned down 14 wolves in three packs in May and June, they discovered they had orphaned 14 wolf pups. A decision was subsequently made to euthanize those pups rather than leave them to starve.

That did not sit well with environmental and animal-rights groups.

"They should have tried to place them," Toppenberg said, "so they could live out a life that might not be all that bad."

Though not a fan of zoos, Toppenberg said he thought sending the young wolves to the Alaska Zoo or to a wolf park Outside would have been better than just killing them.

Doug Larsen, the state director of Wildlife Conservation, told the Board of Game last week that Fish and Game will try to make that the policy from now on, though he refused to prohibit biologists from killing wolf pups if there are no zoos or other facilities willing to take them.

"We didn't make that extra effort. We'll make that extra effort next year," said Bruce Bartley, spokesman for the Division of Wildlife Conservation.

Larsen hopes to avoid future problems altogether by scheduling wolf control efforts in non-pupping seasons.

"I do think ADF&G simply made a mistake regarding when they implemented wolf control," Toppenberg said.

Toppenberg added that he was also pleased to see that the state Board of Game on Monday also voted down two proposals to allow denning of wolves. Denning is the age-old practice of killing of pups in dens to control wolf numbers. Board members said they did not think restoration of denning as a wolf-control measure in Alaska would be worth all the bad publicity that would come with such an action.

Find Craig Medred online at adn.com/contact/cmedred or call 257-4588.