Gray Wolves
Symbol of wilderness or symbol of treachery, spirit guide or the embodiment of evil, few animals connote such different responses from people at the same time as the wolf. Throughout its history, the gray wolf has been both revered for its beauty, strength and hunting abilities by some, and persecuted to extirpation for almost the very same reasons. Gray wolves were once common throughout all of North America but were reduced to a fraction of their former range through a campaign of extermination by both government agencies and private individuals that, to this day, has no equal.
Perceived both as a threat to livestock and general safety of citizens, wolves were hunted, trapped and poisoned whenever they could be located. By 1960, they were essentially extirpated from the lower 48 states, save for a population in remote northern Minnesota, though sustainable populations have always been present in both Canada and Alaska. By 1965, Minnesota repealed its wolf bounty, though unregulated hunting continued for nearly ten more years. Despite this, the wolf population was able to increase from an estimated 300 to 500 animals in 1965 to around one thousand animals in 1975.
Advances in the understanding of wildlife populations by researchers and a general trend towards a more conservation oriented society in the 1970’s led to the protection of wolves in the continental united states under the newly drafted endangered species act. Through the provisions listed in the endangered species act, wolves have been able to recolonize former ranges naturally and through translocation efforts by the US Fish and Wildlife Service. In addition, the Minnesota population has reached a level at which delisting and state management is soon to be a reality.
The Basics
The gray wolf (Canis lupus) is a medium sized canid, ranging from 55-90 pounds for females and 70-120 pounds for males. Though they are commonly called ‘gray wolves’, coloration can range from all black to all white, with a range of brown, tan and gray. Wolves may change color over time, with some wolves ‘going gray’ as they age, similar to humans. Wolves are born brown or black, with blue eyes. The eyes change color as they grow – adult wolves do not have blue eyes, but can be brown, gold, gray or green. Coloration is generally darker on their backs and sides, white on the undersides, chin, and underside of tail. The white highlights are important in communication in social situations, while the darker body may lend a degree of camouflage to the animal.
Compared to the domestic dog, a wolf’s legs are long, with large paws that help in travel over snow. Their tail is one-third body length, not curled, but carried down or straight behind the body. Ears are upright, rounded, and heavily furred. Though wolves have strong claws on each foot, their purpose is for locomotion and digging, not prey acquisition. The method by which they catch their prey is by using their teeth - canines are strong and adapted to tearing and ripping. Studies of their jaws have suggested they are capable of producing up to eighteen hundred pounds per square inch of pressure (though more work needs to be done to accurately determine this), compared to 6-800 in a German shepherd, enough to bite through the femur of an elk. Wolves do not kill like big cats, which deliver crushing neck bites. Instead, they utilize the strength of multiple pack members to bring down and immobilize their prey. Though a wolf is a formidable predator, a healthy white tailed deer can seriously injure or kill an adult wolf.
In the wild, a wolf will generally live six to eight years, although in captivity wolves have lived to be as old as twenty. Wolves consume all parts of their prey, including fur, muscle, bones and viscera. Though they will eat some plant material, fruits and berries, the majority of plant matter is consumed from the digestive systems of the animals they kill.
The main diet of the gray wolf is large herbivores. For this reason, wolves tend to hunt and live in ‘packs’ – groups of anywhere from two to twenty, with average being six. Packs generally consist of a mated male and female pair – the alphas – as well as various offspring of previous years. Packs are not static, and numbers may change seasonally or during times of low prey availability. Breeding occurs anywhere from late January to early march, depending upon location, and puppies are born 63-65 days later (the same as all canids) in late March to early June. A litter may contain from one to thirteen puppies, with 4-6 being an average litter size. Dens are usually constructed by the mother, and consist of a tunnel with a larger dug out chamber within. In places where the ground prevents digging natural structures will be utilized. Den sites tend to be historical, with many generations of wolves utilizing the same area or dens.
Packs will inhabit and defend a territory from 10-100 square miles in areas of high prey density, up to 1000 square miles in low prey density areas such as the arctic. Boundaries are set between packs with territorial scent marking and howling as methods to decrease contact and aggression between neighboring packs.
Habitat
Though they are often portrayed as animals of the pristine, unbroken wilderness, the only real requirements of wolf habitat are available prey in areas outside of other wolf pack’s territories sufficiently isolated from high human activity. Historically wolves have had to fear little from other animals, except for encounters with humans. Therefore, wolves avoid humans as much as possible. Human encounters historically have often been negative, so human avoidance seems to have become a survival strategy for wolves. Currently, there is no evidence to suggest that a healthy, wild wolf has killed a human recently in North America. In contrast, there have been over 133 deaths caused by grizzly bears and black bears in the last hundred years in North America. There have already been several instances of attacks from wolves habituated to human presence, and as wolves move further into populated areas the chances for such encounters will increase. As wolf recovery continues and human tolerance increases, further conflict between wolves and humans may be the inevitable result.
Subspecies
Originally described to contain as many as twenty-four subspecies in North America alone, recent analysis using substantial data on morphometric variation has reduced that number to five recognized subspecies of gray wolves in North America. The North American subspecies include: C. l. arctos, the arctic wolf of the mainland and islands of the Canadian high arctic; C. l. occidentalis, tundra wolf of Alaska and western Canada; C. l. nubilus, great plains wolf of northeastern Canada, central and western United states and the west coast of Canada; C. l. lycaon, eastern timber wolf of the eastern united states and southeastern Canada; and C. l. baileyi, Mexican gray wolf of the southwestern United States. Original classification into so many different subspecies may have been the result of using poor data sets, including lack of differentiation between male and female skulls, inclusion of hybridized animals with both coyotes and dogs and arbitrary designation according to author bias and historical associations of locations. This reclassification has been slow to become adopted in general discussion of the gray wolf, but has generally become accepted among the scientific community as valid (The Minnesota professional basketball team still goes by the name ‘Timberwolves’. Technically they should be reclassified ‘Great Plains Wolves’). Because of this, some questions were raised about the validity of translocating the occidentalis subspecies to western recovery areas such as Yellowstone National Park. This new classification should warrant the reintroduction of the Great Plains (nubilus) wolf, but recolonization of areas only slightly north of the park by wolves of the tundra subspecies suggests this change in subspecies would have occurred naturally.
Diet, prey selection
The meat and potatoes of the wolf diet, as it were, consists of herbivorous animals larger than themselves, though they will often take smaller animals. Larger prey includes whitetail deer, mule deer, moose, antelope, caribou, elk and musk oxen. Small mammals make up a much smaller portion of the diet, and may include beaver, muskrat, rodents etc. It is generally accepted that prey is selected according to its overall fitness, with the old, young and sick individuals in a herd being preyed upon preferentially. This is advantageous not only to the herd from which these animals are taken, but also to the wolves hunting the individuals in question, since healthy ungulates generally have no problem fending off attacks from a wolf pack and are very capable of killing a wolf during an attack.
Weather can play an important role in hunting success as well. During the deep snow months of February and March, repeated freeze/thaw events can create a crust of ice capable of holding a wolf’s weight with it’s wide paws, giving the wolf an advantage over the smaller hoofed deer who ends up to it’s chest in snow. In extreme cases, deer movement can be so dramatically hindered that surplus killing by wolves may occur. Wolves may in such instances kill well beyond their immediate needs, and leave much of a carcass behind for possible later consumption, akin to stocking up one’s freezer for unknown tough times.
It is often thought that since wolves take big game animals, their presence essentially translates into fewer opportunities for hunters to harvest an animal. In Minnesota, counties with wolf populations have not only had higher hunter success rates than the state as a whole, but also slightly higher success rates than adjacent counties with similar habitat, but free of wolves. Overall, the presence of wolves in an area should not directly mean that there are fewer trophy bucks and does in an area, since the selection process of hunting wolves will not impact that portion of the herd.
This does not mean, however, that local populations cannot be influenced by the presence of wolves. Often, the presence of wolves in a given area will influence the movement of local deer. This can be easily misinterpreted when, in a given area one hears wolves howl one night, and finds the next night that all the deer in the area have disappeared. Instead, it is simply the response of a prey population moving to reduce its chance of encountering a predator. The loss of land open to hunting is a much greater threat to hunter success than any predator will ever be.
