Dave Anderson's Forest Journal: Fresh snowfall reveals habits of wildlife
Tracker's log: "Three days and nights after a recent heavy snowfall, fresh tracks beckon from backyard woods. Robert Frost was right, the woods are lovely dark and deep."
It took the gray squirrels three days to dig out and await a rain-crust on the snowpack before they hit the bird feeders hard just after sunrise. Their galloping track patterns on the snow made me wonder who else had begun moving since the storm. I headed out to explore a familiar, backyard circuit of roughly three quarters of a mile round-trip.
I left the border collie behind. I tried to explain: She spoils the tracks and struggles in belly-deep snow while breaking through crust. Border collies don't seem to much regard their own well-being.
I personally find snowshoes more trouble than they're worth until snow is at least knee deep. The sixteen inches we received last weekend had compressed to about a foot so boots alone would suffice for a quick backyard hike before heading to the Concord office.
Breaking trail beyond driveway snow banks, I sank only eight inches while stomping toward the woods behind the hen house. The first set of tracks encountered were those of a short-tailed weasel (also called an "ermine") that had bounded down an incline and disappeared into a stone wall. The ermine tracks re-emerged near a melt-well surrounding the trunk of an old sugar maple. Ermine utilize stone walls for hunting mice. Discovering fresh weasel tracks so near the hen house was no comfort.
I ascended a trail and soon crossed the hop pattern of two deer moving in tandem. I swung into their tracks to follow them. Deer instinctively travel beneath dense hemlocks where canopy branches intercept snow and reduces the depth on the ground. It's easier walking than beneath bare hardwood branches or on woods roads where snow is deeper. I assume this deer pair are the same resident doe and spring fawn we watched grazing amid fireflies in fields last summer.
Higher up the hill, I crossed the lone track of a large deer who crunched across the rain-crusted snowpack, again while sticking to hemlocks and avoiding the woods roads. I've consistently tracked three deer this winter. I assume the loner to be a buck. I've not seen it, but the hoof prints and gait suggest impressive size.
At the apex of my route, I pause and listen: tires whine on the pavement of Route 114 in the valley. I hear a blue jay, the first in many weeks. By late winter when snow buries acorns and cones, larger birds become scarce in the deep woods. Turkeys flee the oak forest of the hill and stay in the village at bird feeders or down along the river where dry fern stalks in wetlands provide sustenance. Following rowdy calls of jays and crows might lead to a deer carcass killed by coyotes.
An interesting story and accompanying photo came last week from wildlife photographer Kittie Wilson on Pleasant Lake in New London: "Eagles on the lake this week. A deer was brought down by coyotes. The carcass is a distance out on the lake... An adult eagle was spotted as well as two immature eagles and they have been stripping the carcass. Crows are participating as well. Soon all the meat will be gone and whatever is left will become fish food."
The story illustrates how coyote kills attract and sustain winter eagles, crows and other scavengers, including weasels ranging from ermine to fishers. The intricate food chain links oak acorns to deer flesh to feed coyotes which drive winter-weakened deer onto frozen snow-covered lakes where crows and eagles scavengers scatter remains.
As I loop downhill, I find a lone coyote track, arrow-straight and parallel to the travel lines taken by deer. Winter wildlife trails are re-established annually, crossing my woodlot diagonally from northeast to southwest. These trails connect landscape features and resources: a talus slope of jumbled boulders for den sites, open water at springs along a seasonal brook, and sapling witch hazel and striped maple stems that provide nutritious buds and bark for deer browse in clearings created by cutting trees for firewood.
On my return, I spy paired prints of a larger weasel: a fisher with five toes in each print. On a recent Forest Society tracking workshop, participants identified fresh fisher tracks accompanied by an uncharacteristic drag mark. Following these tracks produced small bright flecks of fresh blood where the fisher had dragged its prey across the snow only hours before our arrival. It was most likely a red squirrel based on the size of diagonal body drag marks and our location in a pine stand with ample red squirrel tracks nearby.
The fisher which crossed my trail had done so near three-inch-wide red squirrel tracks and six-inch-wide gray squirrel tracks. Both exhibit the galloping gait of rodents, rabbits and hares. The largest rodents - beavers - are not built for galloping. Squirrel tracks are easy to learn and are the most common tracks, particularly if you have birdfeeders. Squirrel tracks often dead-end at tree trunks where they ascend a vertical trail network to access the forest canopy.
Back at the house, I look back at my tracks - a clumsy walking gait stitched across the blank canvas of fresh snow. I wonder if passing animals might pause to study my tracks?
Each snowfall is like shaking an "Etch-a-Sketch" screen clean. Tracks in snow reveal who lives out the backdoor. In 30 minutes, I found tracks of six common species: two squirrels, two weasels, coyote and deer. You could spend years walking in the woods without actually seeing ermine, deer, coyote, fisher, fox or bobcat, but tracks in the snow are irrefutable evidence that perhaps they've seen you!
Naturalist Dave Anderson is Director of Education and Volunteers for The Society for the Protection of New Hampshire Forests. His column appears once a month in the New Hampshire Sunday News. E-mail him at firstname.lastname@example.org or through the Forest Society Web site: forestsociety.org.