Wolverine (Gulo gulo)

25. November 2007 by Ranger.

INTRODUCTION
The wolverine, Gulo gulo, (gluton) is the largest terrestrial member of the Mustelidae family which includes otter, mink, weasels, badgers, fisher and martens among many others. There are 56 species in this, the largest family of carnivora, or flesh eating mammals. Some common names for the wolverine are devil beast, skunk bear, devil bear and carcajou. The wolverine is medium brown or almost black and resembles a small bear as they are compact and strongly built with heavy musculature, a short stout neck and a bushy tail. They have white to tan fur on their throat. Their large feet are specially adapted for traveling over snow, climbing and digging. Their claws can be partially retracted, are sharply curved and range from three fourths to one and a quarter inches long. They have smaller hind feet, and during the winter the hair between their toes and around their pads becomes bristle like, which aids them as they travel over deep snow. Wolverines have a dense underfur and stiff guard hairs. Their ears are fully furred. Not counting the length of their tail, they can range in size from approximately 25 to over 40 inches long. Females can weigh over 30 pounds and the largest males might go over 60 pounds. Wolverines have a highly developed sense of smell, but poor eyesight. The animal is clever, courageous, and unusually powerful for its size. Determined wolverines have been known to run off a pack of wolves from a kill.

The strength of the animal is legendary. Their jaws and teeth are very much respected by other animals, because they can crush bones at least to the size of a moose. Wolverine fur is highly valued by those that live in the Arctic where it is used as ruffs on parkas. The guard hairs do not ice up, and rime ice or personal breath frost is easily brushed off wolverine fur. The coldest temperatures of Canada and Alaska do not seem to bother the wolverine in the slightest. Other than man, they have no natural enemies and no animal in their habitat is a serious threat other than a large grizzly. Wolverines prefer solitude and avoid humans. I have seen only two wolverines in the wild, and they completely ignored my presence. Wolverines exist in North Central Canada, the Northwest Territories to the Yukon, all of Alaska, and have been recorded as present in Colorado, Nevada, Idaho, Oregon, Utah, Washington, Wyoming and Montana. At this writing, it is uncertain if they are in Yellowstone, but the probability of their presence is likely. Wolverines are also found in the northern extremes of Eastern Europe, Russia, Siberia and Scandinavia.

March

The 37 pound three year old female fed cautiously on the young caribou she had stolen from the small female grizzly that made the kill earlier in the morning. No other animal, except a larger grizzly and the fierce wolverine, could have driven this sow away from her kill. The sow was respectful of the ferocity of the wolverine and her powerful jaws and strong teeth. She satisfied her hunger for the time being, and decided to cache the remains of the caribou for some other time. It was an easy task to drag what was left of the caribou several hundred yards to the base of a large Evergreen Spruce tree, the dominate tree species of the boreal forest. There her powerful legs dug a deep hole near the base of the tree. She placed the remnants in the hastily prepared plot and covered it with dirt. It would be easy for her to find the caribou at some future time. Wolverines have the ability to locate food in snow eight feet deep with their keen sense of smell. Satisfied with her work, the well fed female moved on. She would travel another six miles before resting. Her home range covered over 150 square miles.

Not far away, and on a collision course with the ambling trail of this young female was a 48 pound, five year old, husky male. He had spent his morning tearing through the door of an abandoned trapper’s cabin, and consuming what food was left behind when the trapper left his cabin a week ago. That happened to be a number 10 can of unopened blackberry jam, which he easily punctured and battered around the cabin floor until much of the sticky sweet contents spilled out. It was the breeding season, and this polygamous male had covered a large portion of his 355 square mile home range in the last week. Wolverines are constantly on the move and their travel is not inhibited by mountains, rivers or valleys. They do not hibernate in the winter. He had mated with two other females in the past few weeks. During the night, their paths crossed, and he mated with this female before moving on in search of others.

The female had mated with another male a week earlier and like some other mustelids, there was a delayed implantation of the blastocyst. After implantation, her active gestation would be from 30-40 days.

June

The female moved to a higher elevation near the base of a talus slope where she dug an elaborate den with several tunnels to give birth to her young. Here she gave birth to three blind kits. The kits would be weaned sometime in August, but stay with their mother until next March. During that time, the mother would educate her offspring in the art of hunting and the capture of pine marten, squirrels and larger mammals of the North Country. The mother would not breed again until next year.

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