But even the island’s moosiest hollows seem sparsely populated these days. Rolf Peterson, a Michigan Technological University ecologist who has worked on the Isle Royale research project since the 1970s, has tracked an 80-percent decline in the moose population since the late 1990s.
“We need to figure this out,” he says. “We would expect the moose population to be spiking right now. There is plenty of food and the fewest wolves since we started keeping track, so we expect the number of calves counted each spring to go up. But that doesn’t appear to be happening very quickly, though there have been signs of increase this year.”
He postulates the stalled growth could be due to a warming climate. By collecting fecal pellets in winter and analyzing hormones, he has identified low pregnancy rates as a top factor in the flagging population. And since ovulation rates are directly related to fat reserves, perhaps female moose aren’t feeding enough during warmer summers and autumns, spending their time cooling off instead.
To be sure, there are still lots of moose on Isle Royale—the 2012 count is up to 750, or more than 1.5 per square mile (a density nearly equal to that in Maine). And during the rut, the terrain in hot spots like Feldtmann may well be an ungulate red light district.
The route to the lake starts with a level stroll through mixed spruce–birch forest, then we take a hard left turn, climbing switchbacks 200 feet to a grassy ridge-top terrace. Dark red maples and yellow birches carpet the forest below, interrupted by ribbons of evergreen stands and a tangle of lazy creeks flowing through muskeg. From here, the trail rides the spine southeast through meadow after meadow. Alongside the trail in one of the clearings lays a moose-antler cairn—two antlers stacked atop each other. In the next meadow, another antler hangs in a tree. Since it’s illegal to take antlers off the island, backpackers decorate the trail with moose sheds. At Feldtmann Lake, a stack three antlers high towers at our lakeside campsite.
The howl electrifies the still evening air. Mike and I freeze like scared rabbits. Our private lakeside campsite is tightly hemmed in by dark forest. We haven’t seen another living thing all day, but obviously we aren’t alone.
Another howl, this one closer. I peer into the veil of thick balsam firs, but all I can see are branches and needles. A third howl. Now all three in unison!
“They’re just a few yards away!” Mike whispers. My heart pounds so hard I can barely hear Mike. I start to sweat, mostly with excitement, partly with fear.