Branches snap. We push apart webs with the force of our faces, hands and shoulders; the spiders scramble. A few birds sing from the tops of red cedars and pines, as we crush fallen, dead trees with the weight of our shoes.
It’s a few hours into the afternoon and deep in the forest we cut our own paths through thicket, bog, and high grass. We listen for crunching–the promise of footsteps in a wilderness less frequented by humans. We pause at every rocky area or uprooted tree to search for dens; we scan the ground for scat; and look for bare patches on bark with rolled out sides…all signs of the creature we just can’t seem to find. The forest is so vast, our eyes get lost searching the canopy.
Porcupines are generally not elusive, but today they remain undercover. Dr. Linda Ilse, a part time professor at the University of Maine in Orono, doesn’t seem discouraged; for more than twelve years she’s studied the North American Porcupine, Erethizon dorsatum, and is comfortable with the unpredictability of fieldwork. And anyway, variation holds its own significance. It helps Dr. Ilse answer her central question: what habitat do porcupines prefer? Since the 1930s and 1940s, the porcupine’s range has shifted. So far, data from recent studies shows that wet, marshy areas are uninhabited by porcupines. A number of reasons are possible–perhaps the creatures don’t like walking on the springy moss.
Dr. Ilse carries a GPS which she refers to as a virtual Hansel and Gretel bread crumb track. Every move we make is recorded and by the end of the day, she hopes to cover an area of ground graphically similar to a soft-cornered “M”. She’s already covered other land around Schoodic and marked points for return trips, when she’ll come back to gather more precise data (like tree measurements) on the areas with evidence of porcupine activity.
“It’s tough. It’s a thankless job–but somebody’s gotta do it,” she says, crawling under a fallen tree branch.
She pauses to analyze the pile of animal droppings on the ground–scat. But whose? Deer, rabbits, moose, bobcats, and porcupines coexist in these forests. Dr. Ilse informs us that porcupine scat is similar to deer’s, but slightly more curved on the end and lighter in color. Furthermore, porcupine scat is usually spread out over an area, instead of piled up. She picks a piece up, and crumbles it between her fingers–if it’s very fibrous, it could be porcupine.
Porcupines are strictly herbivores, and a large portion of their diet consists of tree bark. They may remain in one tree for a couple days at a time, stripping away the inner bark with their teeth. Where patches of bark have been stripped away, new growth curls inwards around the perimeter of the damaged spot.
We stand looking at some tree damage when we hear loud rustling behind us…could it be? Lauren looks in the distance and YES! Porcupine of the day spotted high in a tree. We walk over and Dr. Isle marks a point on the GPS. This is a place to return to.
Generally, porcupines do not kill trees, although bark stripping does weaken the trees vascular system (which is in charge of transporting nutrients and water from the roots to the leaves). Girdling–the process of completely removing a strip of bark around a tree’s circumference–can kill the tree, but porcupines often move up and down branches, not around them. In response to porcupine gnawing, a damaged tree will seep a protective layer of sap (sort of like the human bodies response to send blood platelets to plug a cut in the skin), which remains on the tree for years and looks like as a frozen, translucent stream.
Under a damaged tree you’ll usually find a scattering of droppings, similar to the ground layer of a porcupine den. Porcupines don’t build their own dens, but seek out sheltered places like uprooted trees or rocky areas. A female porcupine remains pregnant for seven months until giving birth to a single baby, and outside of its den will often stash the baby under fallen trees or in thicket to protect it while she feeds. Although a baby’s quills are soft and wet at birth, they harden within only a couple hours!
After hours of walking through thick brush, my legs lose coordination. I begin making less precise movements, practically flailing my body in the forward direction. I try to save energy by using roots as steps and branches as hand holds. Porcupines also consider energy conservation when seeking out a tree to climb. No sense in trying to climb a tree without a built-in ladder… Many of the trees in the forest begin their leafy layers way at the top, but they at least have branch stubs the wind around the lower trunk like a spiral staircase. Porcupines prefer to scale these than trees with bare trunks.
After seven hours, we break through the boundary leading to the road. We smell of dirt and cedar. Dr. Ilse checks the GPS and tells us we walked only under 3 miles….We all agree to tell the other stat: we covered an area of 77 acres.
I think back to something Dr. Ilse said earlier when I asked her why she got involved in studying porcupines. Out in the field doing other research, she said she felt some sort of presence, that there was something in the forest watching her, and she wanted to study whatever it was. The forest does have eyes–hundreds of thousands of them; total, we only had eight. As we squinted and scanned, searching for the brown, needled bodies, perhaps the porcupines were there, looking down on us…sitting quietly, munching on tree bark, watching the evening sun illuminate the forest floor.