Forest Journal - Prickly Questions
By Dave Anderson
New Hampshire Sunday News
Publication date: September 30, 2007
“Nature is not cruel, pitilessly, indifferent. This is one of the hardest lessons for humans to learn. We cannot admit that things might be neither good nor evil, neither cruel nor kind, but simply callous - indifferent to all suffering, lacking all purpose.” - Richard Dawkins
Among the more common wild mammals found road-killed are slow-moving skunks and porcupines which have unique natural defenses against predators. Scent glands and sharp quills make it unnecessary to run. They need only turn tail to deploy formidable defenses. Yet that strategy fails regularly in the glare of oncoming headlights. You’ve no doubt seen the result.
The prey mammals are ever-wary and quick. Mice, squirrels, chipmunks, rabbits and deer are well-adapted to dash, dart and dodge hungry predators which can include the weasels, foxes, coyotes, bobcats, hawks and owls. While more agile and unpredictable in traffic, these prey species are also far more numerous resulting in relatively frequent road kills.
More rarely are stealthy predators killed along rural back roads. Thus, when I recently spotted a mostly nocturnal, seldom-seen long-tailed weasel dead at the edge of the road, I stopped to investigate the woodland “who done it” mystery.
“CSI South Sutton” I deadpanned to neighbors out for a walk or stopping a car to see what I was doing. I snapped lurid photos lying prone at the edge of the road. If I’d had sidewalk chalk, I’d have outlined the handsome squirrel-size body on the pavement.
The soft brown and white pelage was not matted or wet but its beady black eyes had already begun to dim in death. Blood-tinged its nostrils and its open mouth was filled with rows of puppy-sharp teeth for tearing flesh. The weasel’s furred tail was nearly as long as its narrow body. It wasn’t squished or flattened because it hadn’t been struck by a vehicle. The cause of death was even more obvious: porcupine quills protruded from its neck, chest and front legs.
A large adult porcupine can have as many as 20,000 quills loosely attached to its skin. When cornered, special muscles erect an array of quills that dislodge easily and the porcupine tucks its head between its front legs or under protective cover while turning its rear to the threat and swinging its tail like a mace. Sharp, three to four inch long quills pierce its victim’s skin and absorb moisture, expanding as the needle-like tips covered with hundreds of tiny overlapping scales are drawn deeper into tissue by involuntary muscle contractions. Barbed quills can travel as much as one inch per day, slender slow-motion spears. Depending on the location of the wound and the size of the victim, quills can pass harmlessly out through a victim’s loose skin or may lodge painfully against bone or pierce muscles and vital organs - heart, lungs, brain - causing excruciating suffering and inevitable death.
Gray squirrel-size long-tailed weasels are ferocious little predators - sharp of tooth and claw. They are expert tree climbers and persistent hunters who prefer to dine on mice, chipmunks, squirrels, bats, hares, birds, frogs, snakes, earthworms, insects and even rotting carrion. A young weasel can consume almost half its body weight each day. They are renowned efficient predators who lunge at the base of the skull to bite the spinal cord and wrap their long bodies around a victim using claws to hang on in a quick kill style. Weasels cache uneaten meat and return to feed and defend a kill.
Yet porcupine quills are a problem; they just can’t tolerate quills the way their larger weasel family cousin, the famous fisher can.
A fisher is not a cat – that name belongs exclusively to Manchester baseball players. The fisher is a fierce, nearly housecat-sized weasel known for seeking-out and deliberately hunting-down porcupines, killing them by circling and attacking the face and head. Fishers feed on a porcupine beginning at its head and neck and proceed inside the skin along the underside where there are no quills. The skin is left inside out, flat and cleaned of flesh and bones. Speed and agility allow a fisher to minimize contact with quills. Researchers report finding quills embedded deep inside fishers, but the quills seem to cause no inflammation or infection. Porcupine quills are readily passed through a fisher’s digestive tract, passing out in droppings or becoming absorbed or encapsulated in glands and fat deposits.
While I was admiring the dead weasel, eventually moving it off the road and into some ferns, the local Road Agent – an occasionally prickly guy himself - stopped his official red municipal pickup truck. Noting a quizzical, amused smile, I showed him the roadside crime scene. I wondered aloud why such a handsome and elegant little predator would tangle with a large slow and heavily-armored opponent. Did that weasel pick the fight? Did it aspire to be a fisher? Did it intentionally stagger into the road to die?
With a classic New Hampshire accent, the Road Agent just shrugged and offered: “Why, he just messed ‘round with somethin’ he shouldn’tah.” He jumped in his truck and roared off.
Naturalist Dave Anderson is Director of Education for the Society for the Protection of New Hampshire Forests. He can be reached through the Forest Society website at www.forestsociety.org.
Forest Journal appears in the Lifestyles section of the New Hampshire Sunday News and online at NH.com