Predator Relocation Working
McGRATH: More moose calves are surviving with fewer bears around, but wolves could erase the gains
An effort to remove predatory bears from moose-calving grounds around McGrath earlier this summer appears to have achieved its aim of increasing the calves' chance of survival.
An Alaska Department of Fish and Game study of radio-collared calves shows that nearly three-fourths of this year's newborn moose survived their first six weeks of life. In previous study years, the survival rate was less than half.
The difference this year was fewer bears.
State biologists in May removed more than 90 black and grizzly bears from an area around McGrath as part of a plan to boost moose stocks for local hunters.
Through last week, bears had killed 19 percent of this year's moose crop, half as many as in 2001 and 2002.
"That's really as good as we had hoped for," said Fish and Game research biologist Mark Keech. "We thought if we could decrease calf mortality by 50 percent (by removing the bears), that would be a reasonable and realistic number to shoot for."
The young moose aren't home free, Keech said. Bears and wolves could kill several more calves between now and the end of August. But he doesn't expect the numbers will change significantly, he said.
The bear-removal was part of a Fish and Game experiment aimed at increasing the number of adult moose in a 520-square-mile area around McGrath. Previous studies have suggested that moose numbers could rise if predation by bears and wolves were eliminated for several years.
In May, Fish and Game biologists used a helicopter to chase down and tranquilize bears. After weighing and tagging them, the bears were loaded into airplanes and flown as far as 250 miles away.
The biologists had initially expected to find only about 30 bears but eventually removed more than 80 black bears plus nine grizzlies. The helicopter time, tranquilizer drugs and other costs totaled more than $50,000, department officials said.
The other part of the predator-reduction effort -- removing the wolves -- has yet to be tackled. Fish and Game had proposed shooting the animals from helicopters last winter, but Gov. Frank Murkowski nixed the plan. Hunters and trappers killed a portion of the wolves, but some 35 wolves are believed to remain in what biologists call the "experimental micromanagement area," or EMMA.
The summer portion of the predator-removal experiment seems to be working, Keech said. This appeared to be an average year for calving, with about 350 newborns. Through July 10, bears had killed some 65. Wolves took another dozen or so, according to Fish and Game estimates, while nearly 20 died from other causes, such as starvation.
Newborn moose weigh about 45 pounds and are an easy target for bears, Keech said. Black and grizzly bears often linger near calving grounds in the spring and summer and can kill several calves in a few days. By the end of August, however, the calves have grown to 250 to 300 pounds and can outrun a bear.
Wolves also kill moose calves during the summer but become a greater danger to moose after the snow flies. Keech said he'll be watching closely to see how this bumper crop of moose calves fares in the experiment area.
"If we can enter this winter with a higher proportion of calves (than usual), it will be interesting to see if the EMMA wolves kill the same number they always do or if, because there are more calves around, they kill more calves," he said. "The wolves may just clean up all these calves we saved. We may not end up with any more (adults)."
The fate of the McGrath predator-removal program is uncertain, said David James, Fish and Game's regional game manager in Fairbanks. If it looks like the bear-removal effort had a positive effect, it might be continued again next year. If the wolves next winter erase any gains made by removing the bears, it probably would be dropped.
"Right now I'd say it's about 50-50," James said Monday. "There's just a whole lot hanging out there right now we can't predict," such as whether wolf control is undertaken next winter.
In the meantime, about 15 of the removed bears have walked back to McGrath, according to Keech. Four radio-collared black bears returned within a month, but no others have joined them, he said. About one-fourth of the bears were outfitted with radio collars.
"It seems like the ones that wanted to come back, they came right back. The others either couldn't or didn't want to," Keech said.
Daily News reporter Joel Gay can be reached at email@example.com or at 257-4310.
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