Radio-collared Montana moose slow to give up secrets
For critters that hardly ever get seen, moose get around.
One 5-year-old female even took an ambitious wander through the Bob Marshall Wilderness that would make a good extreme trail race, if only there was a trail. She left her home range near Choteau, Montana, crossed the Continental Divide, spent the summer along the Clark Fork River around Deer Lodge and Anaconda, and then moseyed back north near Rogers Pass to Fairfield, past Choteau and was last seen near Conrad.
As Montana Fish, Wildlife and Parks Region 4 spokesman Bruce Auchly noted, “AAA couldn’t have come up with a more scenic trip.”
We know this because biologist Nick DeCesare of Montana Fish, Wildlife & Parks has completed four years of a 10-year study looking at Montana’s moose population across the Rocky Mountains. The study now includes 105 moose with radio collars. Most never travel outside a few square miles of home range. But a few demonstrate just how well those long legs ramble.
But anyone who’s encountered a moose moving through deep snow understands the value of those stilts. They can sprint through chest-deep powder while a pursuing wolf flounders.
DeCesare cited an Albertan study which found that moose breathing rates and metabolism improve as the temperature drops, even when the mercury reaches 40 below zero.
“When the temperatures got above 20 Farenheit in winter, they breathe harder and metabolize harder,” DeCesare said. “That speaks to how they really are adapted to cold, snowy places.”
Biologist and wildlife guidebook author Kerry Foresman noted a moose’s forelegs are so long, it must get down on its elbows to drink unless it’s standing in a lake. DeCesare added that while they show up everywhere from valley bottoms to high mountain plateaus, the spots they pick tend to be surprisingly wet.
All of which leads up to the fact we don’t know as many facts about moose as we do with deer or elk — their nearest relations in the wild ungulate family. DeCesare said the historical record indicates moose weren’t even a regular resident of Montana until around 200 years ago. Lewis and Clark reported seeing only two moose during their Voyage of Discovery through Montana in 1805-06.
The FWP study looks at moose in three major landscapes: the Rocky Mountain Front, the Cabinet Mountains and the Big Hole Valley. Each has important differences in forage, predator composition, agricultural use and weather patterns.
Each also shows different population dynamics. The Rocky Mountain Front moose appear healthiest, despite being most affected by a winter tick infestation that makes many scratch off significant amounts of fur. This problem has become widespread in New England moose populations. But both adult and calf survival rates are strong, which may explain why that 5-year-old took such a hike. DeCesare said the landscape may be nearing full occupancy, encouraging younger members to seek out new grazing grounds.
Adult moose in the Cabinets near Libby do well, but their calves lag. DeCesare suspects predation by wolves and black bears may be taking out the youngsters. Nevertheless, the population holds fairly stable there.
In the Big Hole of Montana’s southwestern edge, disease drives the numbers.
“Calf production is good, but the cows are dying at a higher rate than you’d like to see,” DeCesare said. “We think the mortality is health-related, particularly from some parasite, disease. They’re dying at times of the year when nutrition shouldn’t be a problem. We’re still trying to figure what’s going on.
“We’re at a population level that’s below what we were at 20 years ago,” DeCesare said. “There have been a few rises and falls in between. But we’re not looking at a crash like in Minnesota, where they’re disappearing from the landscape.”