There are 38 subspecies of Canis lupus listed in the taxonomic authority Mammal Species of the World. These subspecies were named over the past 250 years, and since their naming, a number of them have gone extinct. The nominate subspecies is the Eurasian wolf.
The red wolf is a canine native to the southeastern United States. Its size is intermediate between the coyote and gray wolf.
The eastern wolf also known as the timber wolf, Algonquin wolf or eastern timber wolf, is a canine of debated taxonomy native to the Great Lakes region and southeastern Canada. It is considered to be either a unique subspecies of gray wolf or red wolf or a separate species from both. Many studies have found the eastern wolf to be the product of ancient and recent genetic admixture between the gray wolf and the coyote, while other studies have found some or all populations of the eastern wolf, as well as coyotes, originally separated from a common ancestor with the wolf over 1 million years ago and that these populations of the eastern wolf may be the same species as or a closely related species to the red wolf of the Southeastern United States. Regardless of its status, it is regarded as unique and therefore worthy of conservation with Canada citing the population in eastern Canada as being the eastern wolf population subject to protection.
The Arctic wolf, also known as the white wolf, polar wolf, and the Arctic grey wolf, is a subspecies of grey wolf native to the High Arctic tundra of Canada's Queen Elizabeth Islands, from Melville Island to Ellesmere Island. Unlike some populations that move between tundra and forest regions, Arctic wolves spend their entire lives north of the northern treeline. Their distribution to south is limited to the northern fringes of the Middle Arctic tundra on the southern half of Prince of Wales and Somerset Islands. It is a medium-sized subspecies, distinguished from the northwestern wolf by its smaller size, its whiter colouration, its narrower braincase, and larger carnassials. Since 1930, there has been a progressive reduction in size in Arctic wolf skulls, which is likely the result of wolf-dog hybridization.
The Hokkaido wolf, also known as the Ezo wolf and in Russia as the Sakhalin wolf, is an extinct subspecies of gray wolf that once inhabited coastal northeast Asia. Its nearest relatives were the wolves of North America rather than Asia. It was exterminated in Hokkaido during the Meiji Restoration period, when American-style agricultural reforms incorporated the use of strychnine-laced baits to kill livestock predators. Some taxonomists believe that it survived up until 1945 on the island of Sakhalin. It was one of two subspecies that were once found in the Japanese archipelago, the other being the Japanese wolf.
A coywolf is a canid hybrid descended from coyotes, eastern wolves, gray wolves, and dogs. All of these species are members of the genus Canis with 78 chromosomes and therefore can interbreed. One genetic study indicates that these two species genetically diverged relatively recently. Genomic studies indicate that nearly all North American gray wolf populations possess some degree of admixture with coyotes following a geographic cline, with the lowest levels occurring in Alaska, and the highest in Ontario and Quebec, as well as Atlantic Canada. Another term for these hybrids is sometimes wolfote.
The Italian wolf, also known as the Apennine wolf, is a subspecies of the grey wolf native to the Italian Peninsula. It inhabits the Apennine Mountains and the Western Alps, though it is undergoing expansion towards the north and east. As of 2022 the wolf population within Italy is estimated to be 3,307 individuals. Although not universally recognised as a distinct subspecies, it nonetheless possesses a unique mtDNA haplotype and a distinct skull morphology.
The northwestern wolf, also known as the Mackenzie Valley wolf, Alaskan timber wolf, or Canadian timber wolf, is a subspecies of gray wolf in western North America. Arguably the largest gray wolf subspecies in the world, it ranges from Alaska, the upper Mackenzie River Valley; southward throughout the western Canadian provinces, aside from prairie landscapes in its southern portions, as well as the Northwestern United States.
The Great Plains wolf, also known as the buffalo wolf or loafer, is a subspecies of gray wolf that once extended throughout the Great Plains, from southern Manitoba and Saskatchewan in Canada southward to northern Texas in the United States. The subspecies was thought to be extinct in 1926, until studies declared that its descendants were found in Minnesota, Wisconsin and Michigan. They were described as a large, light-colored wolf but with black and white varying between individual wolves, with some all white or all black. The Native Americans of North Dakota told of how only three Great Plains wolves could bring down any sized bison.
The Indian wolf is a subspecies of gray wolf that ranges from Southwest Asia to the Indian subcontinent. It is intermediate in size between the Himalayan wolf and the Arabian wolf, and lacks the former's luxuriant winter coat due to it living in warmer conditions. Within this subspecies, the "Indian plains wolf" is genetically basal to all other extant Canis lupus apart from the older-lineage Himalayan wolf, with both proposed as separate species. The Indian wolf travels in smaller packs and is less vocal than other variants of the gray wolf, and has a reputation for being cunning. The Indian wolf is one of the most endangered populations of gray wolf in the world.
The Himalayan wolf is a canine of debated taxonomy. It is distinguished by its genetic markers, with mitochondrial DNA indicating that it is genetically basal to the Holarctic grey wolf, genetically the same wolf as the Tibetan and Mongolian wolf, and has an association with the African wolf. No striking morphological differences are seen between the wolves from the Himalayas and those from Tibet. The Himalayan wolf lineage can be found living in Ladakh in the Himalayas, the Tibetan Plateau, and the mountains of Central Asia predominantly above 4,000 m (13,000 ft) in elevation because it has adapted to a low-oxygen environment, compared with other wolves that are found only at lower elevations.
The Vancouver Island wolf, also known as the coastal wolf or sea wolf is a subspecies of grey wolf, endemic to the coast of the Pacific Northwest. They are unique amongst other wolves for their semi-aquatic lifestyle, which includes a diet that is almost entirely marine-based.
The Kenai Peninsula wolf, also known as the Kenai Peninsula grey wolf, is an extinct subspecies of the gray wolf that lived on the Kenai Peninsula in southern Alaska.
The Cascade mountain wolf is an extinct subspecies of the gray wolf that was once found in the Pacific Northwest, but became extinct in 1940.
The Alexander Archipelago wolf, also known as the Islands wolf, is a subspecies of the gray wolf. The coastal wolves of southeast Alaska inhabit the area that includes the Alexander Archipelago, its islands, and a narrow strip of rugged coastline that is biologically isolated from the rest of North America by the Coast Mountains.
The Greenland wolf is a subspecies of gray wolf that is native to Greenland. Historically, it was heavily persecuted, but today it is fully protected and about 90% of the wolf's range falls within the boundaries of the Northeast Greenland National Park.
The southern Rocky Mountain wolf is an extinct subspecies of gray wolf which was once distributed over southeastern Idaho, southwestern Wyoming, northeastern Nevada, Utah, western and central Colorado, northwestern Arizona, and northwestern New Mexico. It was a light-colored, medium-sized subspecies closely resembling the Great Plains wolf, though larger, with more blackish-buff hairs on the back. This wolf went extinct by 1935. Wolves of the subspecies Canis lupus occidentalis have now been reestablished in Idaho and Wyoming.
The Beringian wolf is an extinct population of wolf that lived during the Ice Age. It inhabited what is now modern-day Alaska, Yukon, and northern British Columbia. Some of these wolves survived well into the Holocene. The Beringian wolf is an ecomorph of the gray wolf and has been comprehensively studied using a range of scientific techniques, yielding new information on their prey species and feeding behaviors. It has been determined that these wolves are morphologically distinct from modern North American wolves and genetically basal to most modern and extinct wolves. The Beringian wolf has not been assigned a subspecies classification and its relationship with the extinct European cave wolf is not clear.
The Pleistocene wolf, also referred to as the Late Pleistocene wolf, is an extinct lineage or ecomorph of the grey wolf. It was a Late Pleistocene 129 Ka – early Holocene 11 Ka hypercarnivore. While comparable in size to a big modern grey wolf, it possessed a shorter, broader palate with large carnassial teeth relative to its overall skull size, allowing it to prey and scavenge on Pleistocene megafauna. Such an adaptation is an example of phenotypic plasticity. It was once distributed across the northern Holarctic. Phylogenetic evidence indicates that despite being much smaller than the prehistoric wolf, the Japanese wolf, which went extinct in the early 20th century, was of a Pleistocene wolf lineage, thus extending its survival to several millennia after its previous estimated extinction around 7,500 years ago.
The evolution of the wolf occurred over a geologic time scale of at least 300 thousand years. The grey wolf Canis lupus is a highly adaptable species that is able to exist in a range of environments and which possesses a wide distribution across the Holarctic. Studies of modern grey wolves have identified distinct sub-populations that live in close proximity to each other. This variation in sub-populations is closely linked to differences in habitat – precipitation, temperature, vegetation, and prey specialization – which affect cranio-dental plasticity.
