By ELIZABETH LEE, Living With Wilderness
During the cold spells at this time of year, animals in the forest balance their need to stay warm with their need for groceries just like people.
So despite the recent bitter temperatures, there's a lot going on outside in the way of animal activity. If you are inclined to enhance your snowshoeing or skiing adventures with some animal tracking, the woods are full of sign. This weekend, the porcupine traffic got my attention.
You have to respect porcupines — they're undaunted by freezing temperatures and deep snows. Sign of them in the woods is something to be thankful for since it means they are less apt to be gnawing at my barn siding or my car tires (as they have been known to do). They are able to survive in the forest without resorting to the bird feeders relied on by birds and squirrels or landscape shrubs relied on by deer and mice.
Recently, a friend and I skied into the Split Rock Wild Forest along Lake Champlain to conduct the Department of Environmental Conservation Eagle Survey mentioned in my last column. Although 6 to 8 more inches of snow would have made the going easier for us on skis, light snow cover allows animals to find food without expending all of their energy negotiating the snow pack.
As we passed through a section of the forest with a significant stand of hemlock, we saw sign of porcupines all around us. Many trees were missing sections of bark where they had been chewed. Some bare spots were up quite high, indicating that the chewer in question was a good climber.
The snow beneath several young hemlocks was littered with small twigs showing teeth marks where the porcupines had eaten through. These small branches, called nip twigs, are characteristic of porcupine foraging. In some stands of hemlock, porcupines will completely deform trees by their repeated assaults on the young growth. And although deer also browse among the low hemlock branches, you can tell the difference between deer and porcupine foraging by the cuts made. A deer will rip a twig off, leaving a rough break, whereas a porcupine will efficiently nip through the wood with its sharp incisors, leaving a clean line.
Another characteristic sign of porcupines is the deep troughs they make in the snow. When snow cover is more than a few inches, the porcupines waddle their way through it, making a sort of half-pipe trail between their hillside shelters and the trees that supply their food. These "porcupine highways" wind over and around obstacles and are often dotted with the neon yellow of their urine. They aren't known for good housekeeping or fastidious hygiene, especially when it might interfere with eating and staying warm.
Where there is prey there are usually predators, and the predator most successful at hunting porcupines is the fisher, whose vicious nature can overcome porcupines' otherwise efficient defense systems. Apparently this weekend the fishers had had their fill of mice or other prey — we saw no track or sign of them in the porcupine neighborhood. As the winter progresses, it's likely that they'll turn up, using their own set of adaptations for winter survival.
Elizabeth Lee is a licensed guide who lives in Westport. She leads recreational and educational programs focused in the Champlain Valley throughout the year. Contact her at lakeside5047@gmail.com.
