The brown bear is a large bear native to Eurasia and North America. Of the carnivorans, it is rivaled in size only by its closest relative, the polar bear, which is much less variable in size and slightly bigger on average. The brown bear is a sexually dimorphic species, as adult males are larger and more compactly built than females. The fur ranges in color from cream to reddish to dark brown. It has evolved large hump muscles, unique among bears, and paws up to 21 cm (8.3 in) wide and 36 cm (14 in) long, to effectively dig through dirt. Its teeth are similar to those of other bears and reflect its dietary plasticity.
The polar bear is a large bear native to the Arctic and nearby areas. It is closely related to the brown bear, and the two species can interbreed. The polar bear is the largest extant species of bear and land carnivore, with adult males weighing 300–800 kg (660–1,760 lb). The species is sexually dimorphic, as adult females are much smaller. The polar bear is white- or yellowish-furred with black skin and a thick layer of fat. It is more slender than the brown bear, with a narrower skull, longer neck and lower shoulder hump. Its teeth are sharper and more adapted to cutting meat. The paws are large and allow the bear to walk on ice and paddle in the water.
The walrus is a large pinniped marine mammal with discontinuous distribution about the North Pole in the Arctic Ocean and subarctic seas of the Northern Hemisphere. It is the only extant species in the family Odobenidae and genus Odobenus. This species is subdivided into two subspecies: the Atlantic walrus, which lives in the Atlantic Ocean, and the Pacific walrus, which lives in the Pacific Ocean.
The reindeer or caribou is a species of deer with circumpolar distribution, native to Arctic, subarctic, tundra, boreal, and mountainous regions of Northern Europe, Siberia, and North America. It is the only representative of the genus Rangifer. More recent studies suggest the splitting of reindeer and caribou into six distinct species over their range.
The ringed seal is an earless seal inhabiting the Arctic and sub-Arctic regions. The ringed seal is a relatively small seal, rarely greater than 1.5 metres (5 ft) in length, with a distinctive patterning of dark spots surrounded by light gray rings, hence its common name. It is the most abundant and wide-ranging ice seal in the Northern Hemisphere, ranging throughout the Arctic Ocean, into the Bering Sea and Okhotsk Sea as far south as the northern coast of Japan in the Pacific and throughout the North Atlantic coasts of Greenland and Scandinavia as far south as Newfoundland, and including two freshwater subspecies in northern Europe. Ringed seals are one of the primary prey of polar bears and killer whales, and have long been a component of the diet of indigenous people of the Arctic.
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 Kodiak bear, also known as the Kodiak brown bear and sometimes the Alaskan brown bear, inhabits the islands of the Kodiak Archipelago in southwest Alaska. It is one of the largest recognized subspecies or population of the brown bear, and one of the two largest bears alive today, the other being the polar bear. They are also considered by some to be a population of grizzly bears.
The Eurasian brown bear is one of the most common subspecies of the brown bear, and is found in much of Eurasia. It is also called the European brown bear, common brown bear, common bear, and colloquially by many other names. The genetic diversity of present-day brown bears has been extensively studied over the years and appears to be geographically structured into five main clades based upon analysis of the mtDNA.
The mammoth steppe, also known as steppe-tundra, was once the Earth's most extensive biome. During glacial periods in the later Pleistocene it stretched east-to-west, from the Iberian Peninsula in the west of Europe, across Eurasia to North America, through Beringia and northwest Canada; from north-to-south, the steppe reached from the Arctic southward to southern Europe, Central Asia and northern China. The mammoth steppe was cold and dry, and relatively featureless, though climate, topography, and geography varied considerably throughout. Certain areas of the biome—such as coastal areas—had wetter and milder climates than others. Some areas featured rivers which, through erosion, naturally created gorges, gulleys, or small glens. The continual glacial recession and advancement over millennia contributed more to the formation of larger valleys and different geographical features. Overall, however, the steppe is known to be flat and expansive grassland. The vegetation was dominated by palatable, high-productivity grasses, herbs and willow shrubs.
An ursid hybrid is an animal with parents from two different species or subspecies of the bear family (Ursidae). Species and subspecies of bear known to have produced offspring with another bear species or subspecies include American black bears, grizzly bears, and polar bears, all of which are members of the genus Ursus. Bears not included in Ursus, such as the giant panda, are expected to be unable to produce hybrids with other bears. The giant panda bear belongs to the genus Ailuropoda.
A grizzly-polar-bear-hybrid is a rare ursid hybrid that has occurred both in captivity and in the wild. In 2006, the occurrence of this hybrid in nature was confirmed by testing the DNA of a unique-looking bear who had been shot near Sachs Harbour, Northwest Territories, on Banks Island in the Canadian Arctic. The number of confirmed hybrids has since risen to eight, all of them descending from the same female polar bear.
The barren-ground caribou is a subspecies of the reindeer that is found in the Canadian territories of Nunavut and the Northwest Territories, in northern Alaska and in south-western Greenland. It includes the Porcupine caribou of Yukon and Alaska. The barren-ground caribou is a medium-sized caribou, smaller and lighter-colored than the boreal woodland caribou, with the females weighing around 90 kg (200 lb) and the males around 150 kg (330 lb). However, on some of the smaller islands, the average weight may be less. The large migratory herds of barren-ground caribou take their names from the traditional calving grounds, such as the Ahiak herd, the Baffin Island herds, the Bathurst herd, the Beverly herd, the Bluenose East herd, the Bluenose West herd, the Porcupine herd and the Qamanirjuaq herd.
Hybrid speciation is a form of speciation where hybridization between two different species leads to a new species, reproductively isolated from the parent species. Previously, reproductive isolation between two species and their parents was thought to be particularly difficult to achieve, and thus hybrid species were thought to be very rare. With DNA analysis becoming more accessible in the 1990s, hybrid speciation has been shown to be a somewhat common phenomenon, particularly in plants. In botanical nomenclature, a hybrid species is also called a nothospecies. Hybrid species are by their nature polyphyletic.
The wildlife of Alaska is both diverse and abundant. The Alaskan Peninsula provides an important habitat for fish, mammals, reptiles, and birds. At the top of the food chain are the bears. Alaska contains about 70% of the total North American brown bear population and the majority of the grizzly bears, as well as black bears and Kodiak bears. In winter, polar bears can be found in the Kuskokwim Delta, St. Matthew Island, and at the southernmost portion of St. Lawrence Island. Other major mammals include moose and caribou, bison, wolves and wolverines, foxes, otters and beavers. Fish species are extensive, including: salmon, graylings, char, rainbow and lake trout, northern pike, halibut, pollock, and burbot. The bird population consists of hundreds of species, including: bald eagles, owls, falcons, ravens, ducks, geese, swans, and the passerines. Sea lions, seals, sea otters, and migratory whales are often found close to shore and in offshore waters. The Alaskan waters are home to two species of turtles, the leatherback sea turtle and the green sea turtle. Alaska has two species of frogs, the Columbia spotted frog and wood frog, plus two introduced species, the Pacific tree frog and the red-legged frog. The only species of toad in Alaska is the western toad. There are over 3,000 recorded species of marine macroinvertebrates inhabiting the marine waters, the most common being the various species of shrimp, crab, lobster, and sponge.
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.
On Your Knees Cave (49-PET-408) is an archaeological site located in southeastern Alaska. Human remains were found at the site in 1996 that dated between 9,730 ±60 and 9,880±50 radiocarbon YBP or a calendrical date of 10,300 YBP. In addition to human skeletal remains, stone tools and animal bones were discovered. DNA analyses performed on the human skeletal remains document the presence of mitochondrial haplogroup D which occurs widely in the Americas. Isotopic analysis indicated that the individual had a primarily marine based diet.
The grizzly bear, also known as the North American brown bear or simply grizzly, is a population or subspecies of the brown bear inhabiting North America.
The northern and southern hemispheres of the earth have a dynamic history of advancing and retreating ice sheets. The glacial and interglacial periods are linked to regular eccentricities in the Earth's orbit and correspond to approximately 100 kyr cycles. The advancing, or glacial periods can cause a massive displacement of flora and fauna as it drives them away from the poles, with the most recent glacial maximum having occurred about 20,000 years ago.,
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 Haida ermine is a mustelid species endemic to a few islands off the Pacific Northwest of North America, namely Haida Gwaii in Canada and the southern Alexander Archipelago in the U.S. state of Alaska.
