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Post by Gorilla king on Jul 8, 2021 10:32:30 GMT -5
Accepted scientific name: Ursus americanus kermodei (William Temple Hornaday, 1905)
Description: Both black and white colour phases, around 10% being white. Adult bears are around 180 cm to 2 metres in length and males weigh from around 125 kg to 365 kg and average around 200 to 230 kg. Females weigh between around 110 and 180 kg and average around 135 kg. White Kermode bears, also known as Spirit bears are the result of a recessive gene. Bears carrying this gene can be black or white but for white offspring to be born both parents must carry it.
Range: The Great Bear Rainforest of the central and north coast of British Columbia, Canada, specifically the coastal mainland from Burke Channel to Nass River and some adjacent coastal islands (including Princess Royal) and inland towards Hazleton.
Distribution area of Spirit bear in British Columbia (Creative Commons Licence)
Habitat: Mixed coastal rainforest and shoreline. Typical trees of this area are the sitka spruce, western hemlock and yellow cedar.
Status: Estimates of the current population vary between around 400 and 1,200 individuals. Inter-breeding with other subspecies of American black bear suggest that, in time, the Kermode subspecies will cease to exist. The bear is not specifically protected although some parts of its habitat are.
Life span: Normally between 20 and 25 years in the wild,
Food: Omnivorous, eating grasses, forbs, bulbs, nuts, berries, fruits, insects, small mammals, deer fawns, moose calves, carrion and salmon during spawning from late summer onwards.
Behaviour:. The bears hibernate in winter dens, usually in cavities in old-growth trees. Hibernation can last for up to seven months. Females are sexually mature at three or four years of age and mating takes place during the summer. Cubs are born in the winter den in January or February, are weaned at around eight months, but remain with the mother usually for seventeen months during which time she will not become pregnant again. Litters are usually of two cubs but single cubs and triplets have been recorded.
Threats: Oil development (tar sands pipeline; see “Action” below). Habitat loss due to logging operations. Climate change threatens the Great Bear Rainforest ecosystem.
www.bearconservation.org.uk/kermode-bear-or-spirit-bear/
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Post by Gorilla king on Jul 8, 2021 10:36:43 GMT -5
Spirit Bears of the Great Bear Rainforest This vast, pristine wilderness is home to a rare subspecies of black bear.
On the central and northern coast of British Columbia is a vast and pristine wilderness. Prowling within this wooded swath of earth is the rare Kermode Bear.
Often referred to as spirit bears, the Kermode is not a Polar Bear or an albino, it’s a rare subspecies of American Black bear with a recessive gene that causes its fur to be white. Between 10 to 20 percent of bears in this region are born with this recessive gene.
The spirit bears are the main attraction to the forest, as this is the only place in the world you can find them. Fewer than 400 are estimated to exist, with the majority living on Princess Royal Island, Gribble Island, and Roderick Island.
The chance of spotting one of these amazing bears isn’t the only reason to visit Great Bear Rainforest. While there, you can explore forests, glacial fjords, and soak in hot springs. You can enjoy hiking, fishing, kayaking, and wildlife safari. The rainforest is home to wolves, moose, otter, eagles, and dolphins. The Khutzeymateen region is home to the world’s largest population of Grizzly Bears, while Johnstone Strait and Broughton Archipelago are some of the best places in the world to spot orcas.
In 2016, the British Columbia government officially recognized the ecological and cultural importance of the region and thus passed the Great Bear Rainforest Act which protects 85 percent of the forest from habitat destruction. Know Before You Go There are few roads into Great Bear Rainforest. The area is mostly accessible by boat or floatplane with several operators providing fights and sailing tours. The warmest times to visit the forest are June to August and bear viewing seasons is June to October. The best time to see bears is late August to September during the annual salmon run when the bears are hunting the fish. Great Bear Rainforest is a pristine and protected environment so please practice responsible tourism by not leaving trash or chemicals in the forest, rivers, or ocean. Remember you are a visitor in the bear's home. Bears are majestic, wild animals capable of inflicting serious harm so please practice bear etiquette.
www.atlasobscura.com/places/great-bear-rainforest
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Post by Gorilla king on Jul 8, 2021 15:26:36 GMT -5
Why evolution is true
The Spirit bear
National geographic has a short but informative article on an unusual animal: the Kermode or “spirit” bear. This is a subspecies of the regular black bear (Ursus americanus kermodei) that occurs on the coast of British Columbia. The subspecies has about 400 individuals, and about 10% of these are homozygous for a mutation that turns their coats whitish. (Populations that contain two or more genetic variants like this are called “polymorphic,” meaning “many forms” in Greek.) Here are the two morphs:
These bears are not albinos, for their eyes and noses are pigmented. Nor are they hybrids with polar bears, although polar bears have been known to hybridize with a different species, the grizzly bear. The mutation that turns normally black bears white occurs at the MC1R locus (short for “melanocortin receptor”), a gene involved in the synthesis of the pigment eumelanin. A mutation at the same gene is what gives humans red hair. The white color gene is recessive; that is, it takes two copies of that gene to make the bear white. A bear carrying one copy of a black and one copy of a white gene is black.
Curiously, a similar MC1R polymorphism has been found in woolly mammoths using DNA sequences extracted from their bones. This has led to speculation that mammoths were polymorphic like these bears, with both light and dark-colored individuals.
What’s the evolutionary significance of this polymorphism (if any)? It’s been known for a while that white bears are better at catching fish than black ones:
Researchers have recently proved that the spirit bear’s white coat gives it an advantage when fishing. Although white and black bears tend to have the same success rate after dark—when bears do a lot of their fishing—scientists Reimchen and Dan Klinka from the University of Victoria noticed a difference during the daytime. White bears catch salmon in one-third of their attempts. Black individuals are successful only one-quarter of the time. “The salmon are less concerned about a white object as seen from below the surface,” Reimchen speculates. That may answer part of the question about why the white-fur trait continues to flourish today. If salmon are a coastal bear’s primary fat and protein source, a successful female can feast on salmon to store more fat for winter, potentially increasing the number of cubs she can produce.
Carriers that have two copies of the white gene have an additional advantage: according to the Geographic article, the local people, the Tsimshian, consider the white morph sacred and do not hunt white bears.
So, if the color gives an advantage at fishing and protection from being hunted, why aren’t all the bears in the area white? Even if black bears have an unknown countervailing advantage (like camouflage in the forest), that wouldn’t necessarily keep both color variants in the population: you’d expect the color conferring the highest net fitness to sweep through the population.
If the polymorphism is maintained by natural selection rather than being “neutral” (i.e. considering all factors, black and white bears have equal lifetime reproductive fitness), then it would have to be a special kind of natural selection, involving either one color being better in one area of the habitat and the other color in a different area (unlikely, since both forms live in the same place), or perhaps a reproductive advantage of the heterozygote: the black-colored bear that carries one copy of the white gene).
Paul Nicklen’s other photos of the spirit bear are here.
Mother and cub. What you can say with certainty here is that mother carries one copy of the white gene, and one copy of the black:
whyevolutionistrue.com/2011/07/19/the-spirit-bear/
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Post by Gorilla king on Jul 8, 2021 16:04:08 GMT -5
Genetic diversity and differentiation of Kermode bear populations
Abstract
The Kermode bear is a white phase of the North American black bear that occurs in low to moderate frequency on British Columbia's mid-coast. To investigate the genetic uniqueness of populations containing the white phase, and to ascertain levels of gene flow among populations, we surveyed 10 highly polymorphic microsatellite loci, assayed from trapped bear hairs. A total of 216 unique bear genotypes, 18 of which were white, was sampled among 12 localities. Island populations, where Kermodes are most frequent, show approximately 4% less diversity than mainland populations, and the island richest in white bears (Gribbell) exhibited substantial genetic isolation, with a mean pairwise FST of 0.14 with other localities. Among all localities, FST for the molecular variant underlying the coat-colour difference (A893G) was 0.223, which falls into the 95th percentile of the distribution of FST values among microsatellite alleles, suggestive of greater differentiation for coat colour than expected under neutrality. Control-region sequences confirm that Kermode bears are part of a coastal or western lineage of black bears whose existence predates the Wisconsin glaciation, but microsatellite variation gave no evidence of past population expansion. We conclude that Kermodism was established and is maintained in populations by a combination of genetic isolation and somewhat reduced population sizes in insular habitat, with the possible contribution of selective pressure and/or nonrandom mating.
www.researchgate.net/publication/11395336_Genetic_diversity_and_differentiation_of_Kermode_bear_populations
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Post by Gorilla king on Jul 8, 2021 16:06:26 GMT -5
Man Captures Photo of Rare Spirit Bear in Canada Where Only 400 of Its Kind Exist
This photographer recently had a bear-y lucky encounter while fishing in British Columbia, Canada.
Last October, Steven Rose came across a spirit bear — a rare white bear with an estimated 400 or less of its kind left in the wild — while exploring the Great Bear Rainforest, according to Discover Wildlife.
Rose was able to capture several shots of the animal in its habitat as the bear caught hold of fish and moved through a shallow river.
The bears can be seen cleverly digging up the eggs laid by the salmon by clawing away the sand on the riverbed to expose the eggs, then gulping them up,” Rose told the Daily Mailabout his stunning photos.
According to Discover Wildlife, a spirit bear — or a Kermode bear — is a subspecies of the North American black bear. This uncommon animal is not albino, rather the species has a rare gene variation that causes them to be white or cream in color.
Spirit bears are often found on the Canadian islands of Gribbell, Princess Royal and Roderick, where one in ten bears are part of this infrequent species.
The species is considered sacred to the indigenous Tsimshian people, who called the spirit bear “moskgm’ol” meaning “white bear.”
Since the spirit bear is so rare, the government of British Columbia outlawed the hunting of the species. However, as hunting of grizzly and black bears in the Great Bear Rainforest is still allowed, a hunter might kill a black bear that carries the infrequent recessive gene to create the white animal.
people.com/pets/rare-white-spirit-bear-photos-canada/
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Post by Gorilla king on Jun 8, 2022 20:22:33 GMT -5
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Post by Gorilla king on Sept 17, 2022 7:41:46 GMT -5
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