Ursid hybrid

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Possible hybridisation between different species of bear Ursidae hybridisation.svg
Possible hybridisation between different species of bear

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.

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Note all of the confirmed hybrids listed here have been in captivity (except grizzly × polar bear), but suspected hybrids have been found in the wild.[ citation needed ]

A recent study found genetic evidence of multiple instances and species combinations where genetic material has passed the species boundary in bears (a process called introgression by geneticists). [1] Specifically, species with evidence of past intermingling were (1) brown bear and American black bear, (2) brown bear and polar bear, [2] (3) American black bear and Asian black bear. Overall, this study shows that evolution in the bear family ( Ursidae ) has not been strictly bifurcating, but instead showed complex evolutionary relationships.

All the Ursinae species (i.e., all bears except the giant panda and the spectacled bear) appear able to crossbreed.[ citation needed ]

Brown × black bear hybrids

Possible grizzly-black bear hybrid in Yukon Territory, Canada To replace picture in 'Ursid hybrid'.jpg
Possible grizzly-black bear hybrid in Yukon Territory, Canada

In 1859, a black bear and a European brown bear were bred together in the London Zoological Gardens, but the three cubs did not reach maturity. In The Variation of Animals and Plants Under Domestication Darwin noted:

In the nine-year Report it is stated that the bears had been seen in the Zoological Gardens to couple freely, but previously to 1848 most had rarely conceived. In the Reports published since this date three species have produced young (hybrids in one case), ... [3]

A bear shot in autumn 1986 in Alaska was thought by some to be a grizzly × black bear hybrid, due to its unusually large size and its proportionately larger braincase and skull. DNA testing was unable to determine whether it was a large American black bear or a grizzly bear. [4]

Intercontinental brown bear hybrids

Although Eurasian brown bears and North American Brown bears are isolated, they are listed as a single species, so technically mating between the two sub-species is not hybridization, even though it cannot possibly occur in the wild. However, cross-breeding between the European brown bear and the North American grizzly bear has occurred in Cologne, Germany.[ citation needed ]

Brown × polar bear hybrids

Polar/brown bear hybrid, Rothschild Museum, Tring Polarbrown-2.jpg
Polar/brown bear hybrid, Rothschild Museum, Tring

Kodiak × polar bear hybrids

"Kodiak" or "Kodiak brown" is a term now applied to brown bears found in coastal regions of North America. In the far north, these bears feed on salmon and often attain especially large size. "Alaskan brown" is sometimes used for Alaskan bears, but the main distinction is how far the bear is found from the coast. "Grizzly bear" is the term used for the brown bear of the North American interior.

Grizzly × polar bear hybrids

The grizzly bear is now regarded by most taxonomists as a variety of brown bear, Ursus arctos horribilis. Clinton Hart Merriam, taxonomist of grizzly bears, described an animal killed in 1864 at Rendezvous Lake, Barren Grounds, Canada as "buffy whitish" with a golden brown muzzle. This is considered to be a natural hybrid between a grizzly bear and polar bear. On 16 April 2006, a polar bear of unusual appearance was shot by a sports hunter on Banks Island in the Northwest Territories. DNA testing released 11 May 2006, proved the kill was a grizzly×polar bear hybrid. This is thought to be the first recorded case of interbreeding in the wild. [7] The bear was proven to have a polar mother and a grizzly father. The DNA testing also spared the hunter the C$1000 fine for killing a grizzly bear, as well as the risk of being imprisoned for up to a year. The hunter had bought a license to hunt polar bears; he did not have a license to hunt grizzly at that time. [8]

The animal had dark rings around its eyes, similar to a panda's, but not as wide. It also had remarkably long claws, a slight hump on its back, brown spots in its white coat, and a slightly indented face — the nasal "stop" between the eyes which polar bears lack. The guide leading the hunt, Roger Kuptana of Sachs Harbour in the Northwest Territories, was the first to note the oddities.

Several names were suggested for this specimen. The Idaho hunter who killed it, Jim Martell, suggested "polargrizz". The biologists of the Canadian Wildlife Service suggested "grolar" or "pizzly", as well as "nanulak", an elision of the Inuit nanuk (polar bear) and aklak (grizzly or brown bear). Both "grolar" and "pizzly" were used by the Canadian Broadcasting Corporation in widely distributed stories. Presently, though the mating seasons overlap, the polar bears' season begins slightly earlier than the grizzly bears'. A blog columnist for the Seattle Post-Intelligencer suggested that more hybrids may be seen as global warming progresses and alters normal mating periods. The Canadian Wildlife Service noted that grizzly-polar hybrids born of zoo matings have proven fertile.[ citation needed ]

Grizzly bears have been sighted in what is usually polar bear territory in the Western Arctic near the Beaufort Sea, Banks Island, Victoria Island, and Melville Island. A "light chocolate colored" bear, possibly a hybrid, is reported to have been seen with polar bears near Kugluktuk in western Nunavut.[ citation needed ]

Asian black bear known or suspected hybrids

Sloth bear hybrids

Related Research Articles

<span class="mw-page-title-main">Bear</span> Family of carnivoran mammals

Bears are carnivoran mammals of the family Ursidae. They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout most of the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, and Eurasia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails.

<span class="mw-page-title-main">Brown bear</span> Large bear native to Eurasia and North America

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.

<span class="mw-page-title-main">Polar bear</span> Species of bear native largely to the Arctic Circle

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.

<span class="mw-page-title-main">American black bear</span> Species of bear

The American black bear, also known as the black bear, is a species of medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. It is an omnivore, with a diet varying greatly depending on season and location. It typically lives in largely forested areas but will leave forests in search of food and is sometimes attracted to human communities due to the immediate availability of food.

<span class="mw-page-title-main">Ursinae</span> Subfamily of bears

Ursinae is a subfamily of Ursidae (bears) named by Swainson (1835). It was assigned to Ursidae by Bjork (1970), Hunt (1998), and Jin et al. (2007).

<span class="mw-page-title-main">Sloth bear</span> Species of bear

The sloth bear, also known as the Indian bear, is a myrmecophagous bear species native to the Indian subcontinent. It feeds on fruits, ants and termites. It is listed as vulnerable on the IUCN Red List, mainly because of habitat loss and degradation. It is the only species in the genus Melursus.

<i>Ursus</i> (mammal) Genus of bears

Ursus is a genus in the family Ursidae (bears) that includes the widely distributed brown bear, the polar bear, the American black bear, and the Asian black bear. The name is derived from the Latin ursus, meaning bear.

<span class="mw-page-title-main">Asian black bear</span> Bear species native to Asia

The Asian black bear, also known as the Indian black bear, Asiatic black bear, moon bear and white-chested bear, is a medium-sized bear species native to Asia that is largely adapted to an arboreal lifestyle. It lives in the Himalayas, southeastern Iran, the northern parts of the Indian subcontinent, Mainland Southeast Asia, the Korean Peninsula, China, the Russian Far East, the islands of Honshū and Shikoku in Japan, and Taiwan. It is listed as vulnerable on the IUCN Red List, and is threatened by deforestation and poaching for its body parts, which are used in traditional medicine.

<span class="mw-page-title-main">Kodiak bear</span> Largest subspecies of brown bears/grizzly bears

The Kodiak bear, also known as the Kodiak brown bear, 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.

<span class="mw-page-title-main">Spectacled bear</span> Species of mammal

The spectacled bear, also known as the South American bear, Andean bear, Andean short-faced bear or mountain bear and locally as jukumari, ukumari (Quechua) or ukuku, is a species of bear native to the Andes Mountains in northern and western South America. It is the only living species of bear native to South America, and the last remaining short-faced bear. Its closest relatives are the extinct Tremarctos floridanus, and the giant short-faced bears, which became extinct at the end of the Pleistocene around 12,000 years ago. Unlike other omnivorous bears, the diet of the spectacled bear is mostly herbivorous. The species is classified as Vulnerable by the IUCN because of habitat loss.

<span class="mw-page-title-main">Grizzly–polar bear hybrid</span> Cross between grizzly and polar bear

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.

Endangered mammals of India are the mammal species in India that are listed as threatened in the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Animals

<span class="mw-page-title-main">Bear conservation</span>

Bear conservation refers to the management of bears and their habitat with a view to preventing their extinction.

<span class="mw-page-title-main">Bear hunting</span> Practices in Europe and North America

Bears have been hunted since prehistoric times for their meat and fur. In addition to being a source of food, in modern times they have been favored by big game hunters due to their size and ferocity. Bear hunting has a vast history throughout Europe and North America, and hunting practices have varied based on location and type of bear.

<span class="mw-page-title-main">Grizzly bear</span> Subspecies of brown bear

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.

<span class="mw-page-title-main">Alaska Peninsula brown bear</span> Subspecies of carnivore

The Alaska Peninsula brown bear or "peninsular grizzly" is a colloquial nomenclature for a possible brown bear subspecies that lives in the coastal regions of southern Alaska. It may be a population of the mainland grizzly bear subspecies.

<span class="mw-page-title-main">ABC Islands bear</span> Subspecies of brown bear found in Southeast Alaska

The ABC Islands bear or Sitka brown bear is a subspecies or population of brown bear that resides in Southeast Alaska and is found on Admiralty Island, Baranof Island, and Chichagof Island in Alaska, and a part of the Alexander Archipelago. It has a unique genetic structure that relates them not only to brown bears, but also to polar bears. Its habitat exists within the Tongass National Forest, which is part of the perhumid rainforest zone.

Formerly or currently considered subspecies or populations of brown bears have been listed as follows:

<span class="mw-page-title-main">Dietary biology of the brown bear</span> Diet of brown bear

The brown bear is one of the most omnivorous animals in the world and has been recorded to consume the greatest variety of foods of any bear. Throughout life, this species is regularly curious about the potential of eating virtually any organism or object that they encounter. Certainly no other animal in their given ecosystems, short perhaps of other bear species and humans, can claim to feed on as broad a range of dietary opportunities. Food that is both abundant and easily obtained is preferred. Their jaw structure has evolved to fit their dietary habits. Their diet varies enormously throughout their differing areas based on opportunity. In spring, winter-provided carrion, grasses, shoots, sedges and forbs are the dietary mainstays for brown bears from almost every part of their distribution. Fruits, including berries, become increasingly important during summer and early autumn. Roots and bulbs become critical in autumn for some inland bear populations if fruit crops are poor. The dietary variability is illustrated in the western United States, as meat made up 51% of the average year-around diet for grizzly bears from Yellowstone National Park, while it made up only 11% of the year-around diet for grizzlies from Glacier National Park a few hundred miles to the north.

References

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Further reading