Grey Wolf
Canis lupus
Strip away a few thousand years of mixed connotations, and wolves are simply wild dogs, highly variable in appearance; those of us living in temperate climates likely picture a large animal with thick fur and glowing yellow eyes, while tropical residents may think of a smaller, somewhat more 'dog-like' creature. Wild wolves can be pure white, black, or any combination of mottled greys, reds, and browns; in temperate regions, there may often be a high degree of color variation between members of the same pack. Wolves range from as little as 50 pounds up to 175, usually growing larger the farther north they are found. Height at the shoulder ranges from around 24 to 36 inches. Females are generally somewhat smaller than males.
Despite the familiarity of wolves in almost every culture in the northern hemisphere, scientists don't always agree on exactly what a wolf is. Most believe that the domestic dog is a wolf subspecies, Canis lupus familiaris, but others feel the dog has changed too much and should be treated as its own species, simply Canis familiaris. A similar disagreement centers around the 'pariah dogs', those animals that live among human beings, but don't belong to anyone - are they feral animals descended from household pets, or are they wolves in an early stage of association with human beings, undergoing the same domestication process that eventually led to golden retrievers, English bulldogs, and Pomeranians? And what of the truly wild dogs? Australian dingos, New Guinea singing dogs, and others are known to have been the hunting companions of aboriginal tribesmen, but many feel that they are simply wolf subspecies with a history of symbiosis with human beings. Some scientists speculate that the Carolina dog, a feral breed in the southern United States, may have descended from the dogs that crossed the Bering land bridge with North America's first human residents, some 12,000 years ago.
Habitat: Wolves can live in a variety of habitats, from Arctic tundra and pack ice to tropical jungles. They are as at home in deserts and grasslands as in the temperate pine forests with which we typically associate them. In general, one will not find wolves in excessively wet, swampy areas, but their long-term adaptability has made them capable of surviving virtually anywhere that their prey can be found.
Distribution: The wolf is on of the world's most widespread land mammals, with a former range that encompassed most of the northern hemisphere. Its current range is significantly smaller, but wolves still inhabit three continents - four if you include Australian dingos. In North America, the grey wolf's range is slowly increasing, and may eventually come close to its former extent.
The dingo is an Australasian subspecies, but it has mixed with domestic dogs to a great extent, diluting its gene pool; the purest bloodlines are now found in Thailand, with a few, isolated populations of pure dingos still remaining in Australia.
Behavior: Wolves are highly social animals and live in packs that can exceed thirty members in areas where prey is abundant. Each pack is led by an alpha pair, a male and a female that govern its activities; the overall pack leader may be of either sex. While they often kill young prey or older animals weakened by disease, a pack of hungry wolves will take whatever food is available. Because of its small size, a single wolf would have a difficult time bringing down large prey, but thanks to pack hunting, wolves can kill animals many times their size, including American bison (Bison bison) weighing in excess of 2,000 pounds. Hunting methods vary; a few pack members might attempt to chase an animal toward the rest of the wolves hidden in ambush, or the whole pack might simply surround the animal. Deep snow works to the advantage of wolves in colder climates, as they are light enough to run over the top of it, while heavier, hoofed mammals sink through. A large kill may feed a pack for a few days, but wolves do not hesitate to take animals as small as insects; Arctic wolves have been observed to eat little other than voles (Microtus spp.) and lemmings (Lemmus, Synaptomys, and Dicrostonyx spp.) for perhaps half the year.
In temperate regions, wolves breed in winter or early spring; tropical wolves may breed at other times of the year. Gestation lasts around 60 days, and litters may number up to fourteen, but are usually six or fewer. Pups are born with closed eyes and ears; which open by two weeks of age. Usually the alpha pair are the only two to breed, but all the pack members take part in caring for the pups; a low-ranking pack member might stay behind as a babysitter while the rest of the animals leave the area to hunt. When the pack returns, the pups lick and bite at the adults' chins and throats, inducing them to regurgitate partially digested meat for them to eat. Weaning begins when the pups are around three weeks old, and is usually complete at seven weeks. Wolf pups begin to hunt with the pack at around ten months of age; they may stay with the pack for life, or leave to form their own packs as early as a year after they are born, depending on the availability of food.
A pack's territory can be as large as a few hundred square miles, and wolves move throughout their territories regularly. Boundaries are reinforced with scent marks in the form of urine and droppings, and for the most part, they are respected, as rival packs prefer to stay out of each other's way. Wolves communicate vocally by barking, growling, whining, and howling; a pack may come together for a group howling session prior to setting out for an evening hunt. They also communicate with each other through a system of exaggerated posturing; lower-ranking pack members communicate their submission to other members of the pack by nipping and licking their chins, mimicking the behavior of pups begging for food, or by walking low to the ground, holding their tails between their hind legs, and rolling over to expose their undersides when approached. A dominant wolf may arch its neck and hold its tail erect during social interactions; with every step down in the hierarchy, the head and tail drop a little more. Wolves engage each other in games by play-bowing, a posture in which the animal lowers the front half of its body to the ground, accompanied by shuffling side to side, leaping in the air, or turning in circles. Wagging tails indicate an excited state, but not always happiness as some believe; rigid tail-wagging may precede an attack, while more relaxed or circular wagging is generally associated with play.
While they are capable of killing massive prey and can be highly physical in their social interactions, wolves tend to be timid around people; stories of wolves attacking human beings are typically fabricated, although a few children have been killed by wolves in India in recent years. They have been known to occasionally take livestock and to kill domestic dogs, and wolves regularly eliminate competitors like coyotes (Canis latrans) when the opportunity to do so arises.
Human Impact: Wolves have been persecuted by human beings for thousands of years, but perhaps more damage has been done in the last two hundred than in all of human history. Viewed as a threat to livestock and mistaken as man-eaters, wolves have been deliberately hunted to extinction in parts of the world, and many populations remain under threat from hunting and poaching. The Canadian government issued a bounty on wolves in the 1800s that was not repealed until 1972; and some US states still offer wolf bounties. Poison, traps, and guns have taken a heavy toll - perhaps millions of wolves have been killed by hunters in North America in the last century. The Alaskan state government promotes aerial wolf hunting in some areas, claiming it is for management purposes, allowing hunters and pilots to circumvent fair chase regulations that would make the practice illegal. Ranchers remain the biggest proponents of wolf extirpation, despite the infrequency with which wolves hunt domestic livestock, and the existence of government reimbursement programs that pay for animals killed by wolves.
While some work to eradicate the wolf, others have taken steps to ensure its survival. The critically endangered Mexican wolf has been successfully reintroduced in Arizona and New Mexico, where biologists are tracking its movements and educating local ranchers about wolf conservation. An even greater success story is the one that has taken place in Yellowstone National Park; wolves introduced there in the 1990s have thrived and spread into Utah and Colorado. A growing number of ranchers have made the decision not to kill predators, and with their cooperation, the ranges of the Great Plains wolf and the Mexican wolf may once more overlap.
Other wolf populations are under threat from habitat loss; on the Indian subcontinent, the exploding human population has left little room for wildlife throughout much of the country, and wolves have suffered as a result. Interbreeding with pariah dogs may also be a factor leading to their decline.
Wolves may be the most common mammals in the captive wildlife trade; it is estimated that as many as 100,000 wolves and wolf-dog hybrids are born in captivity each year in the United States. The average person is wholly incapable of meeting the needs of wolves in captivity, and even the best breeding facilities contribute to a highly destructive trade. With so many wolves entering the wildlife trade each year and so few people capable of caring for them, many are euthanized, and many more die from starvation, dehydration, disease, and from fighting due to overcrowding and lack of food. Others are killed for sport and trophies on illegal hunting ranches, or raised for their skins on fur farms. Wolf sanctuaries have formed to address the problem, but many are unaccredited, under-funded, and become no better than the abysmal facilities from which the wolves were originally rescued. Those that are capable of caring for the animals properly are full to capacity; if the wolf trade is to be dealt with successfully, legislation must be created to illegalize ownership of wild animals, and more, qualified sanctuaries must be formed to care for rescued animals. (Read more about wildlife sanctuaries.)
Great Plains wolf; Canis lupus nubilis; Gerald and Buff Corsi © California Academy of Sciences
Great Plains wolf with mottled grey coloration; Gerald and Buff Corsi © California Academy of Sciences
Great Plains wolf with black coloration; Gerald and Buff Corsi © California Academy of Sciences
Arctic wolf; C. l. arctos; © Ralf Schmode, http://www.schmode.net
A critically endangered Mexican wolf; C. l. baileyi; © Smithsonian National Zoological Park; photo by Jessie Cohen
Dingo; C. l. dingo; this subspecies is believed to have traveled to Australia with sea-going traders and naturalized on the continent around 5,000 years ago. Gerald and Buff Corsi © California Academy of Sciences
Spencer is a pariah dog from the American Southwest; he is the dominant dog in his pack, as evidenced by his posture. Pariah dogs throughout the world look fairly similar.
Precious is a typical pariah dog from a tribal reservation in the Pacific Northwest; she has thicker fur than Spencer, who originally came from a warmer climate.
Rosie is a pit bull mix, but she exhibits a number of wild dog characteristics, both physical and behavioral.
Spencer demonstrates an expression of dominance over Rosie, who initiated the interaction by biting his cheek to show submission.
These wolves of mixed origin endure overcrowding, unsanitary conditions, and lack of food at a residence in Idaho. Perhaps several hundred thousand wolves and wolf-dog hybrids live in similar conditions in captivity throughout the United States and Canada. Photo courtesy of WOLF; Laporte, CO.
