Wednesday, January 19, 2011

Decoding secrets in the snow

Winter hieroglyphs tell animalsí activities


By KATHERINE WUTZ
Express Staff Writer

The tracks of a small mammal snake across a hill just off the Valley View Trail near Galena Lodge. Ann Christensen, a winter tracker and environmental scientist, said Galena is a great place for interested trackers to see the signs of snowshoe hares and other small mammals. Express photo by Katherine Wutz

Winter in the Rocky Mountains can seem like a barren, blank season, with nothing but snow in sight for miles in any direction. Idaho's abundant wildlife almost seem to go into hiding, with the exception of the elk feeding by the side of state Highway 75.

But even if the animals are in hiding, a look at the snowpack can reveal hieroglyphic-like signs of life, signs the initiated say can be fairly easy to read.

"No matter where you are, if you're paying attention to the snow, you'll see animal tracks," said Lisa Huttinger, education director for the Ketchum-based Environmental Resource Center.

Environmental scientist Ann Christensen said she took up winter animal tracking out of curiosity.

"We wanted to know what these animals were doing," Christensen said, so she began taking workshops, learning how to follow tracks to find where animals were hibernating, storing food and scurrying about in the winter. Soon, she was running workshops of her own.

Making sense of the signs left behind can seem daunting at first, with the large variety of animals that inhabit the valley. Huttinger said there are a few tips that can help novice trackers tell a weasel from a wolf.

"Start with the toes! Count the toes!" she said.

Wolverines and weasels have five toes on each foot, while coyotes and foxes have four each. Ungulates such as moose, elk and deer, though, leave hoof tracks, limiting the usefulness of the toe trick.

Christensen said she recommends getting an animal-tracking book such as James C. Halfpenny's "Scats and Tracks of the Rocky Mountains" and studying the track patterns included in it.

"You need to get the patterns in your brain," she said. "Size is really important, and pattern is really important."

For example, the tracks of a fox and the tracks of a coyote can be identified by counting four toes on each paw, but from there it can be difficult. Both leave tracks about 2 inches long.

"It can be hard to tell the difference between a large male fox and a small female coyote," she said, "[But] foxes are quite dainty," with a narrower, more delicate stride and furrier feet.

Huttinger said one of her most useful tools was to use her hand as a point of reference for track size. A person's fist, roughly 3 inches long, is about the same size as the track of a German shepherd or a bobcat, while wolf and mountain lion tracks are the size of a full human hand, roughly 4.5 inches long.

"It's just a rule of thumb, but it's a good one," she said.

The same rule holds true when trying to determine which ungulate left a certain track, as deer, elk and moose tracks correspond roughly with finger, fist and hand size.

Christensen also recommends studying tracks for signs of a tail, which will be indicated by a slight line in the snow between the paw prints.

This is especially useful, she said, when attempting to determine the difference between the tracks of a vole, which has a short tail, and a deer mouse, which has a much longer tail.

"I think of them as looking like a necklace," she said, with the feet as beads on the string-like line created by the tail drag.

Her favorite tracks, Christensen said, are those of the short-tailed weasel.

"He's my favorite winter character! Their tracks are beautiful," she said, because of the weasel's tendency to zigzag through the snow, diving below the snowpack and popping back up in unlikely places. Following a weasel trail could also lead to a food cache, Christensen said, as weasels store food for the season.

Martens have a similar track, Christensen said, except they tend to be found around lodgepole pine trees. Martens leap from the trees and then scamper off, leaving a distinct trail.

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"You'll see a plop and a big weasel track," she said.

However, she said, it's often impossible to definitively identify a track, even once the patterns are memorized and the size rule is applied.

"Unless you see the animal, you never know absolutely for sure," she said.

Part of the reason for that is because warm weather and sunshine, along with wind and other weather factors, can destroy or distort tracks.

Huttinger said tracks expand over time, especially in sunny weather, which can make it difficult to tell a deer track from an elk track, or a dog from a wolf.

Christensen said the quality of tracking decreases substantially in February and March, months when the weather warms up.

"That messes the tracks up terribly," she said.

Christensen said the best time to track is after several days and nights with no snow, as fresh snow can hide interesting trails.

"Everything's covered up." she said. "You want the stories to still be there."

Huttinger said she likes to track through about an inch of soft snow on top of a harder crust. The powder captures the track while the crust prevents the animals from sinking too deep.

"You end up with a little more detail," she said.

But too much crust can reduce the number of tracks, Christensen said. The January thaw forms a hard crust in the snowpack that prevents smaller rodents such as voles and mice from tunneling under the snow. Once the animals are unable to tunnel, she said, they become more vulnerable to larger predators.

"That's the beginning of the end of the food chain," she said, and the number of tracks is reduced substantially after that.

But good tracking can always be found around fresh carcasses, she said. Dead elk out in Greenhorn or Elkhorn, or even fresh kills by the highway are gathering places for scavengers, from weasels and foxes to birds such as ravens and magpies.

"I've even seen the mark of wings in the snow," Christensen said, which is rare.

Huttinger said the best place to look for tracks is anywhere where different habitats mesh, such as where hills with confers run down into sagebrush or riparian habitat.

"You've got a lot more animals around and moving," she said.

Christensen and Huttinger said Greenhorn Gulch is a great place for elk and wolf tracks, and Christensen added that moose can often be found near Trail Creek and on other riparian corridors. She said the trails near Galena Lodge, as well as those near Warm Springs and Billy's Bridge north of Ketchum, are also prime track territory.

Christensen said she takes the students in her winter tracking workshops, run by the Environmental Resource Center, north to Prairie Creek to hunt down interesting trails. One workshop is scheduled for Saturday, Jan. 22, from 10 a.m. to 2 p.m.

Students in the workshops track on showshoes, which Christensen said is often the best method, as it allows trackers to get farther into the backcountry.

Christensen said that though it's nearly impossible to skate-ski and track, classic Nordic skiing is well suited to hunting down trails. She said that's her preferred method, as on trails such as Harriman north of Ketchum, trackers can move fast between areas.

Christensen said she's seen tracks from all the ungulates as well as rodents such as squirrels, snowshoe hares and weasels on her cross-country skiing trips, and has even encountered the "slide" tracks left by otters slipping into the river. But while she's encountered tracks from almost all of the animals that inhabit the valley, she said she's still hunting one more down.

"I'd die to see a cougar track," she said.

For more information on winter tracking, see the Environmental Resource Center's website at www.ercsv.org.

Katherine Wutz: kwutz@mtexpress.com




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