Wednesday, July 26, 2006

Isle Royale is a study in moose, wolves

BY BOB DOWNING - McClatchy-Tribune Services

ISLE ROYALE NATIONAL PARK, Mich. - It was a chance to meet a hero, even if it was only for 15 minutes. I had joined a tour to the 1855 Rock Harbor Lighthouse and the Edisen Fishery at America's least-visited national park, an island in northwest Lake Superior 55 miles off the Michigan coast. The old-time Lake Superior fisherman Les Mattson told visitors to the old fishing camp that the island's famed wolf-moose researchers, Rolf and Carolyn "Candy" Peterson, lived just down the shore.

Rolf Peterson has spent 35 years studying the dynamics between Isle Royale's most famous residents: moose and wolves. He appears frequently in National Geographic and on television news reports. He is to moose and wolves what Jane Goodall is to chimps and Dian Fossey is to mountain gorillas: the iconic scientist.

I checked with the crew of the cruise boat and was told the Peterson's encampment was a quarter mile down a trail through the woods and that we'd be departing in a half-hour. I hustled down the trail and arrived at the encampment just as the Petersons were coming ashore in a skiff. I called out, asking whether visitors were welcome. I was assured that they were. That's because the research is supported by public funds from the National Park Service and the National Science Foundation.

Candy even gave me a brief tour of the compound, which doubles as an eye-opening moose graveyard. Bones are everywhere in the yard: skulls, femurs, jaws and other body parts. Bones on planks in the sunlight in one area are this year's bones, and Candy said the researchers probably find and collect only one-third of the available bones. In another shaded grove sit 400 moose skulls, complete with antlers, which the researchers have collected on Isle Royale since 1958. It was an impressive and spooky sight: a shrine to the island's moose. Studying the bones allows scientists to determine the size and the health of the moose.

In 2005, Isle Royale had about 540 moose and 30 eastern timber wolves. That represented an increase of one wolf over the previous year and it was the third year in a row that moose numbers have declined. Isle Royale's isolation and the minimal human impact have made it a great place to study the dynamics between moose and wolves for the last 47 years.

The Norwegian flag was flying over the Petersons' cabins, once a Lake Superior fishing camp. The camp with its wood plank walls and tin roofs looks like something out of "Lord of the Rings." Candy gave Rolf, a professor at Michigan Technological University in Houghton, a front-yard haircut as I tromped through their camp, following the hand-lettered signs they had posted to guide visitors when they're not around. Their only request: Please sign the guest book.

Their encampment includes a small fenced-off grave where up to 20 miners may be buried in the wake of a drunken brawl between mining camps in the 1850s. At least that's what the handwritten sign on the picket fence reads. Another sign tells visitors that calves account for one-third of moose that are killed annually by the wolves. It also noted that the typical wolf-killed moose is 12 years old and suffering from osteoporosis, arthritis and periodontal disease.

The Petersons' research is done in the summer and again when the park is shut down in the winter. There are winter flyovers to locate wolf-killed moose. Then researchers snowshoe in to retrieve up to 70 pounds of moose remains, including bones, teeth and fat. In the summer, the research includes trapping and fitting wolves with radio collarings and tracking them from the ground and the air.

Rolf Peterson said the changing wolf-moose numbers on Isle Royale may be linked to global warming. The moose decline appears to be linked to increasing stress from hot summers and a tick infestation that weakens the moose and is triggered by milder winters, he said. One moose may have up to 30,000 of the biting insects. The more ticks, the more blood and hair loss and the weaker the moose get. It is a worldwide problem, according to Peterson.

Moose on Isle Royale have also had trouble finding food the last two winters because of snow and that has hurt their numbers, he said. The first moose arrived on Isle Royale about 1900. It is believed that hunger on the Canadian mainland drove the moose to swim to Isle Royale. They found plenty to eat and no predators, and their numbers soared to 3,000 by 1930. Moose numbers went up, then crashed after they ate up the available food.

Typically, there are between 800 and 1,200 moose on the island now. About 15 percent of the population dies annually from wolves and starvation. Moose numbers grow in years with mild winters, early spring greening, abundant winter forage, low wolf numbers and low levels of tick infestation.

Moose also have a big impact on Isle Royale's forest cover. They are most likely to be found at the eastern and western ends of the islands and around campgrounds where they know they are safe from wolves.

The first wolves crossed Lake Superior on the ice in 1948-49. Other darker wolves arrived in 1967. Typically, the island has 15 to 25 wolves in three packs and several loners. Wolves lose 20 to 25 percent of their population each year. Wolves are rarely seen on Isle Royale, not with its thick vegetation. You might hear their howls at night and you are likely to see droppings along the trails. Wolf packs kill moose every four to 10 days.

The Petersons get a boost in the summer from Earthwatch volunteers. The nonprofit group offers the public a chance to backpack with Rolf Peterson on Isle Royale to look for moose. Volunteers pay $800-a-person tax-deductible donations. For information, call 800-776-0188 or check out the Internet at

You can learn about Peterson's research at

The park itself has a limited season. It is open from mid-April through October. You can get there via four ferries from cities in Michigan and Minnesota. Isle Royale -- it is 45 miles long and up to 9 miles wide -- is a wilderness island with no roads, no bikes, no vehicles and few signs of man. Backpackers love the park with its 165 miles of trails.

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