Biology Reference
In-Depth Information
settlers in North America applied the name
ficher
to the unfamiliar animal that bore a cousin's resemb-
lance to the familiar polecat. Incidentally, the Native American name of
pekan
or
pekane
is also used
for the fisher on occasion.
As is the case with many other wild animals, the size of the fisher is often grossly overestimated.
Far from being large, it is comparable in weight to a house cat, though longer. Like most others of the
weasel tribe, fishers exhibit sexual dimorphism, which is the scientist's fancy term for a major differ-
ence between the sexes. In this instance, it refers to the fact that males are much larger than females.
Thus a huge male can weigh up to twenty pounds, but that's unusual; adult males typically weigh ten
or twelve pounds, females only five to seven.
The fisher is very much an animal of the northern forests. Most of its range is in Canada, though it
is also found in the United States throughout most of northern New England, the northern Great Lakes
region, the far northern Rocky Mountains, and parts of the Pacific Northwest.
Although the fisher eats a wide variety of food, its major claim to fame is as the only truly effective
predator of the porcupine. How do fishers manage to kill porcupines with some degree of consistency
when this feat mostly eludes much larger predators, including coyotes, wolves, cougars, and bobcats?
It's widely believed that fishers kill porcupines by approaching them from the front, then flipping
them on their backs and attacking their quill-less bellies. But on close examination, this notion makes
little sense, because it requires fishers to perform the extremely difficult feat of overturning unwilling
victims as much as five times their own weight.
Research has shown that fishers use a different and much more effective method of attack. Extremely
quick and agile, they dart in and out, repeatedly biting the porcupine around its unprotected face while
dodging the potent slaps of its quilly tail. Eventually the porky succumbs to numerous bites or becomes
so disabled that the fisher actually can roll it over with impunity and attack the unprotected belly.
The fisher's excellent tree-climbing ability offers a second major advantage, for it enables the fisher
to attack porcupines when they're feeding or sunning themselves aloft. Despite these advantages, the
majority of fisher attacks on porcupines fail because the porky protects its face in a den or a tree hollow,
or between its paws.
The fisher's well-earned reputation as a porcupine killer has led some to the notion that fishers are
immune to harm from quills. This is decidedly untrue: fishers are very good at avoiding quills, but oc-
casionally one makes a mistake and gets a faceful. At best this is extremely painful, and at worst occa-
sionally fatal.
Despite their fondness for fresh porcupine, fishers dine on a wide variety of food. Mice, voles, squir-
rels, chipmunks, and similar small creatures make up a major part of their diet, supplemented by grouse,
hares, and the carrion of larger animals, such as deer. And despite being carnivores, fishers also con-
sume a surprising amount of apples, berries, other fruit, and nuts.
