Saturday, January 28, 2012

Part 2 of a Great New Series--Wolf Winter Study

January 27, 2012

Wolves, Snow and the Red Dragon

Flying low over Isle Royale National Park, looking for a radio-collared wolf the researchers have named Romeo.John VucetichFlying low over Isle Royale National Park, looking for a radio-collared wolf the researchers have named Romeo.
John Vucetich, a wildlife ecologist from Michigan Technological University, leads the wolf-moose Winter Study at Isle Royale National Park.

Monday, Jan. 23

Shortly before midnight, our pilot Don Glazer shakes my sleeping bag. The sky has dumped something halfway between snow and rain, and it is freezing to the wings of the Flagship.
We all head to the harbor, wrestling with a northeast wind as we try to stretch nylon covers over the wings. Slush has also begun to bubble up through a nearby crack in the ice. We fear the Flagship’s skis will freeze into the slush, so we prop them up on 4x4s. Then it’s back to bed.
It snows all day. So we occupy ourselves with chores around the cabin: hauling water and setting up a sauna. We also prepare the Red Dragon — a 25-pound propane tank, 12-volt battery, spark-ignited torch and blower, and a hose, all strapped to a toboggan. As soon as the wet snow stops falling, we’ll need that.

John Vucetich
Tuesday, Jan. 24

By early morning, the snow has stopped. The temperature drops, and the northeast wind comes up again. After a bowl of oatmeal by the light of our headlamps, we slog to the harbor. Removing the wing covers, we can see that we put them on too late. Every flying surface of the Flagship is coated with ice. Planes fly because their wings are shaped like a foil. Ice distorts that shape and compromises lift. All the ice will have to be removed.

Luckily, that’s what the Red Dragon does best. We haul the contraption onto the icy harbor next to the plane. Firing up the Red Dragon, we heat the flying surfaces, then brush the ice off as it melts. Ice removal is a delicate affair. The Flagship’s wings are wood covered with fabric. Brush at the ice too hard, and the fabric will tear. Heat it too much, and it will catch fire. For three hours, we gently melt, rub and flake off ice.

Using the Red Dragon to remove ice from the Flagship. 
John VucetichUsing the Red Dragon to remove ice from the Flagship.
 
Our work, observing wolves and moose, depends on the weather. Waiting for snow or wind to stop is routine. Fixing cold-stricken equipment is standard. Wishing it had been just a few degrees colder, so that wet snow hadn’t frozen to the wings: we make lots of “if only” weather wishes. But the weather is part of what makes a place, any place, special. And as the weather changes, the wolves and moose have much more at stake than we do. Fighting the weather is futile. Appreciating it, even when it’s not pleasant, is as good as it gets.

By noon, the plane is ready for flight, and by 3 p.m., the wind has lightened up. Rolf Peterson, a co-researcher, and Don depart to look for wolves. They find Chippewa Harbor Pack near the site where we’d seen them a couple days ago. It is clear what kept them there: the carcass of a moose they’d killed. The few remaining bones suggest they’d killed it about five days ago, perhaps the day we arrived. Rolf and Don also find fresh tracks of a lone wolf near Halloran Lake, leaving and then returning to a cedar swamp filled with tracks of the snowshoe hares that probably became the wolf’s dinner.

Wolves eating a moose. 
John VucetichWolves eating a moose.
 
Rolf and Don spend most of the flight searching for Romeo, a radio-collared male from Chippewa Harbor Pack. Flying at 4,000 feet over the island they should pick up any signal. Static is all they hear.

Wednesday, Jan. 25

I get up at 4 a.m. to fire up the portable generator we use to heat the plane’s engine. I might as well have stayed in my sleeping bag. By 6:30 a.m., the clouds had lowered until they touched the island. Freezing drizzle was threatening, so we put the wing covers on again. Why does the weather keep frustrating our desire to collect information?

The researchers have to chop holes in the ice of the harbor to get their drinking water. 
John VucetichThe researchers have to chop holes in the ice of the harbor to get their drinking water.
 
In the five days that we’ve been here, we’ve made just two research flights. Actually, that’s a pretty typical rate of being grounded. And on each flight, we’ve gained only fragments of insight. But multiply each observation by the 30 to 40 flights we make each winter, then multiply that by more than five decades. It adds up to a significant bank of data.

I spend each day searching for something significant. During each flight, we record the locations of wolves or their tracks. I have condensed several decades of wolf travel routes onto a single map. We are working to quantify what we’ve long intuited: that the predation risk for moose is greatest near the island’s shoreline. It is easier for wolves to walk along shorelines, where the snow is windswept, and moose are attracted to shoreline habitats because they tend to find better forage there.

Knowing that predation risk decreases with distance from the shoreline is also just a tiny insight. Add this to several other long-term observations and some sophisticated analysis from Robert Montgomery, a habitat expert from Michigan State University, put it all together, and, well, our insight is not in perfect focus yet, but it’s looking as though younger, healthier moose spend more time in these risky shoreline habitats during severe winters than do the aging moose who would be more vulnerable to predation.

It feels good to pour through old maps, recalling individual wolves, many of which are now dead, their travels and lives, and the adventures we had making those observations.

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