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Carnivorous and Omnivores Animals, Excluding Felids
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Bears
Bear Species and Subspecies
Bear Species and Subspecies
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Bear Species and Subspecies
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https://www.nps.gov/yell/learn/nature/gbearinfo.htm
Grizzly ( Ursus arctos horribilis ). Grizzly Bear Ecology - Population The estimated Greater Yellowstone Ecosystem grizzly bear population increased from 136 in 1975 to an estimated 717 in 2015, and the bears have gradually expanded their occupied habitat by more than 50%. As monitored by the Interagency Grizzly Bear Study Team, the criteria used to determine whether the population within the Greater Yellowstone Ecosystem has recovered include estimated population size, distribution of females with cubs, and mortality rates. An estimated 150 grizzly bears occupy ranges that lie partly or entirely within Yellowstone. The number of females producing cubs in the park has remained relatively stable since 1996, suggesting that the park may be at or near ecological carrying capacity for grizzly bears. There were 59 known and probable grizzly bear mortalities in the Greater Yellowstone Ecosystem in 2015. Thirty-four were attributed to human causes. Four were of undetermined cause, 2 were natural deaths, and 19 were still under investigation at the time of this printing. Three human conflicts with grizzly bears occurred inside the park in 2015, and resulted in a human fatality and the removal of a female grizzly and two cubs from the park. (Learn More: Your Safety in Bear Country) Description The grizzly bear’s color varies from blond to black, often with pale-tipped guard hairs. In the Greater Yellowstone Ecosystem, many grizzly bears have a light brown girth band. However, the coloration of black and grizzly bears is so variable that it is not a reliable means of distinguishing the two species. Bears are generally solitary, although they may tolerate other bears when food is plentiful. Grizzlies have a social hierarchy in which adult male bears dominate the best habitats and food sources, generally followed by mature females with cubs, then by other single adult bears. Subadult bears, who are just learning to live on their own away from mother’s protection, are most likely to be living in poor-quality habitat or in areas nearer roads and developments. Thus, young adult bears are most vulnerable to danger from humans and other bears, and to being conditioned to human foods. Food-conditioned bears are removed from the wild population. Diet Bears are generalist omnivores that can only poorly digest parts of plants. They typically forage for plants when they have the highest nutrient availability and digestibility. Although grizzly bears make substantial use of forested areas, they make more use of large, non- forested meadows and valleys than black bears. The longer, less curved claws and larger shoulder muscle mass of the grizzly bear makes it better suited to dig plants from the soil, and rodents from their caches. Grizzly bear food consumption is influenced by annual and seasonal variations in available foods. Over the course of a year, army cutworm moths, whitebark pine nuts, ungulates, and cutthroat trout are the highest-quality food items available. In total, grizzly bears in the Greater Yellowstone Ecosystem are known to consume at least 266 species of plant (67%), invertebrate (15%), mammal (11%), fish, and fungi. They will eat human food and garbage where they can get it. This is why managers emphasize that keeping human foods secure from bears increases the likelihood that humans and bears can peacefully coexist in greater Yellowstone. Bears spend most of their time feeding, especially during “hyperphagia,” the period in autumn when they may gain more than three pounds per day until they enter their dens to hibernate. In years and locations when whitebark pine nuts are available, they are the most important bear food from September through October. However, not all bears have access to whitebark pine nuts, and in the absence of this high-quality food, the bear’s omnivory lets them turn to different food sources. Fall foods also include pondweed root, sweet cicely root, grasses and sedges, bistort, yampa, strawberry, globe huckleberry, grouse whortleberry, buffaloberry, clover, horsetail, dandelion, ungulates (including carcasses), ants, false truffles, and army cutworm moths. From late March to early May, when they come out of hibernation, until mid May, a grizzly bear’s diet primarily consists of elk, bison, and other ungulates. These ungulates are primarily winter-killed carrion (already dead and decaying animals), and elk calves killed by predation. Grizzly bears dig up caches made by pocket gophers. Other items consumed during spring include grasses and sedges, dandelion, clover, spring-beauty, horsetail, and ants. When there is an abundance of whitebark seeds left from the previous fall, grizzly bears will feed on seeds that red squirrels have stored in middens. From June through August, grizzly bears consume thistle, biscuitroot, fireweed, and army cutworm moths in addition to grasses and sedges, dandelion, clover, spring-beauty, whitebark pine nuts, horsetail, and ants. Grizzly bears are rarely able to catch elk calves after mid-July. Starting around mid-summer, grizzly bears begin feeding on strawberry, globe huckleberry, grouse whortleberry, and buffaloberry. By late summer, false truffles, bistort, and yampa are included in the diet as grasses and others become less prominent. Hibernation Bears’ annual denning behavior probably evolved in response to seasonal food shortages and cold weather. Bears hibernate during the winter months in most of the world. The length of denning depends on latitude, and varies from a few days or weeks in Mexico to six months or more in Alaska. Pregnant females tend to den earlier and longer than other bears. Grizzly bear females without cubs in Greater Yellowstone den on average for about five months. Grizzly bears will occasionally re-use a den in greater Yellowstone, especially those located in natural cavities like rock shelters. Dens created by digging, as opposed to natural cavities, usually cannot be reused because runoff causes them to collapse in the spring. Greater Yellowstone dens are typically dug in sandy soils and located on the mid to upper one-third of mildly steep slopes (30–60°) at 6,562–10,000 feet (2,000–3,048 m) in elevation. Grizzly bears often excavate dens at the base of a large tree on densely vegetated, north-facing slopes. This is desirable in greater Yellowstone because prevailing southwest winds accumulate snow on the northerly slopes and insulate dens from sub-zero temperatures. The excavation of a den is typically completed in 3–7 days, during which a bear may move up to one ton of material. The den includes an entrance, a short tunnel, and a chamber. To minimize heat loss, the den entrance and chamber is usually just large enough for the bear to squeeze through and settle; a smaller opening will be covered with snow more quickly than a large opening. After excavation is complete, the bear covers the chamber floor with bedding material such as spruce boughs or duff, depending on what is available at the den site. The bedding material has many air pockets that trap body heat. The body temperature of a hibernating bear, remains within 12°F (22°C) of their normal body temperature. This enables bears to react more quickly to danger than hibernators who have to warm up first. Because of their well-insulated pelts and their lower surface area-to-mass ratio compared to smaller hibernators, bears lose body heat more slowly, which enables them to cut their metabolic rate by 50–60%. Respiration in bears, normally 6–10 breaths per minute, decreases to 1 breath every 45 seconds during hibernation, and their heart rate drops from 40–50 beats per minute during the summer to 8–19 beats per minute during hibernation. Bears sometimes awaken and leave their dens during the winter, but they generally do not eat, drink, defecate, or urinate during hibernation. They live off of a layer of fat built up prior to hibernation. The urea produced from fat metabolism (which is fatal at high levels) is broken down, and the resulting nitrogen is used by the bear to build protein that allows it to maintain muscle mass and organ tissues. Bears may lose 15–30% of their body weight but increase lean body mass during hibernation. Bears sometimes awaken and leave their dens during the winter, but they generally do not eat, drink, defecate, or urinate during hibernation. They live off of a layer of fat built up prior to hibernation. The urea produced from fat metabolism (which is fatal at high levels) is broken down, and the resulting nitrogen is used by the bear to build protein that allows it to maintain muscle mass and organ tissues. Bears may lose 15–30% of their body weight but increase lean body mass during hibernation. Bears emerge from their dens when temperatures warm up and food is available in the form of winter-killed ungulates or early spring vegetation. Greater Yellowstone grizzly bears begin to emerge from their den in early February, and most bears have left their dens by early May. Males are likely to emerge before females. Most bears usually leave the vicinity of their dens within a week of emergence, while females with cubs typically remain within 1.86 miles (3 km) of their dens until late May. Life Cycle Grizzly bears reproduce slowly compared to other land mammals. Females rarely breed before age four, and typically become pregnant once every three years. Grizzly and black bears breed from May through July, and bears may mate with multiple partners during a single season. Because implantation of a fertilized egg in the uterus is delayed, the embryo does not begin to develop until late November or December, about one month after the mother has denned. This appears to allow her to conserve energy until she enters her den, where in late January or early February she gives birth to one or two cubs, sometimes three, rarely four. At birth the cubs are hairless and blind, are about eight inches (20 cm) long, and weigh from 8 to 12 ounces (224–336 g). The cubs do not hibernate. They sleep next to the sow, nurse, and grow rapidly. At ten weeks, grizzly bear cubs weigh about 10–20 pounds (4.5–9.0 kg). Male bears take no part in raising cubs, and may actually pose a threat to younger bears. Grizzly bear cubs usually spend 2½, and sometimes 3½ years with their mother before she or a prospective suitor chases them away so that she can mate again. Females frequently establish their home range in the vicinity of their mother, but male cubs disperse farther. Grizzly Bears, Black Bears, and Wolves Grizzly bears are more aggressive than black bears, and more likely to rely on their size and aggressiveness to protect themselves and their cubs from predators and other perceived threats. Their evolution diverged from a common ancestor more than 3.5 million years ago, but their habitats only began to overlap about 13,000 years ago. Grizzly bears, black bears, and gray wolves have historically coexisted throughout a large portion of North America. The behavior of bears and wolves during interactions with each other are dependent upon many variables such as age, sex, reproductive status, prey availability, hunger, aggressiveness, numbers of animals, and previous experience in interacting with the other species. Most interactions between the species involve food, and they usually avoid each other. Few instances of bears and wolves killing each other have been documented. Wolves sometimes kill bears, but usually only cubs. Wolves prey on ungulates year-round. Bears feed on ungulates primarily as winter-killed carcasses, ungulate calves in spring, wolf-killed carcasses in spring through fall, and weakened or injured male ungulates during the fall rut. Bears may benefit from the presence of wolves by taking carcasses that wolves have killed, making carcasses more available to bears throughout the year. If a bear wants a wolf- killed animal, the wolves will try to defend it; wolves usually fail to chase the bear away, although female grizzlies with cubs are seldom successful in taking a wolf-kill.  *This image is copyright of its original author
Grizzly of the Yukon ( Ursus arctos horribilis )... http://www.yesnet.yk.ca/projects/bears/facts/e/grizzly.html
Grizzly Bear (Ursus arctos)... of the Yukon: The grizzly bear is one of the most powerful animals in North America, but it should be feared no more than any other type of bear. Like all bears, it should be treated with respect. • An estimated 6,300 grizzlies inhabit the Yukon from the B.C. border to the Arctic coast. • Ninety per cent of the grizzly’s diet is made up of vegetation such as roots, grasses and berries. It also eats small rodents, salmon, moose and caribou when available. • The average adult male weighs about 175 kg when it emerges from its den in the spring; the average female weighs about 100 kg. Yukon grizzlies are about two-thirds the size of grizzlies in more productive southern or coastal regions. • The grizzly reaches its adult size of about one metre at the shoulder in 7 to 10 years. • It has a lifespan of about 20 years. • The grizzly bear’s fur ranges in colour from dark brown to almost blonde. The longer hairs are often yellow-tipped, giving the bear its “grizzled” appearance. Some bears have dark brown fur on their back and blond fur on their legs. • Distinguishing characteristics of the grizzly include a concave face, a prominent hump over the shoulders and long claws about the length of a human’s fingers. The claws are better suited to digging rather than tree climbing. • The grizzly can move at speeds of up to 60 km/h over short distances. Like all bears, it is a good swimmer. • The female produces its first litter at 6 to 10 years of age and every 3 to 5 years afterwards. A litter usually consists of two cubs. The reproductive rate of this species is so low that the loss of even a few bears can have a major impact on the population.  *This image is copyright of its original author
Barren Ground Grizzly ( Ursus arctos horribilis )... http://www.nwf.org/news-and-magazines/national-wildlife/animals/archives/2006/grizzly-bears-on-ice.aspx
ABOUT 50 MILES NORTH of tree line in Canada's western Arctic, Andrew Derocher picked up the tracks of four grizzly bears following a herd of caribou across hard snow and ice toward the coast. Derocher, a University of Alberta biologist, wasn't sure whether the tracks had been left by a family or by a male following a female with two cubs. If it turned out to be the latter, he said, the mother and offspring could be in trouble. Contrary to what may appear in popular movies and books, a lone male grizzly is more likely to kill and eat bear cubs than befriend them. By the time Derocher caught up with the bears, it looked like his fears were justified. With two cubs following close behind, the mother was loping off as fast as she could. Suddenly, she whirled around to confront her pursuer. But instead of beginning a bloody brawl, the bears stopped inches short of one another with no sign of aggression. "These four animals are together," concluded Derocher. "The female just turned around to check on her largest cub." Known as "barren ground grizzlies," the bears Derocher observed are the same species of grizzly that inhabits the Rockies in southern Canada, the interior and coastal regions of British Columbia and Alaska and, in the Lower 48, Montana, Wyoming, northern Idaho and the North Cascades of Washington. Here, at the northern edge of the species' range--where the bears roam from the North Slope of Alaska to the coast of Canada's Hudson Bay--grizzlies look almost identical to their southern kin, but are only about two-thirds their size. Barren ground grizzlies are among the most enigmatic of Arctic mammals. Few in number and rarely seen, they are as much myth as reality. Discovering how the bears manage to make a living in a treeless landscape that is covered in snow and ice for as long as nine months a year is one of the objects of Derocher's studies. But what really intrigues him are reports of more and more grizzlies showing up on sea ice, territory traditionally dominated by polar bears. Researchers know that barren ground grizzlies feed on alpine hedysarum in spring, horsetail and bearflower in summer and berries in fall. They also dig up Arctic ground squirrels and other small mammals. Caribou, however, may be the most important compensation for the constraints these animals face. Biologists have found that the more a bear population feeds on caribou or other meat, the higher its densities are likely to be and the more successful an individual bear will be at reproducing. It's not surprising, then, that in the absence of caribou in early springtime--when the animals emerge from their dens to find only snow and cold--barren ground grizzlies will occasionally venture onto the sea ice. The scent of a seal, dead or alive, or the tracks of a caribou herd that has crossed to an Arctic island may be all that's required for them to take that first step away from land. But sightings of grizzlies on ice have increased since 1991, the year that Northwest Territories polar bear biologist Mitch Taylor first spotted one of the bears during a flight across Melville Sound, 600 miles north of mainland Canada. Researchers also have observed more than a dozen bears on Banks and Victoria Islands, 100 or more miles north of the mainland, and at least one has been spotted on Hudson Bay, where it appeared to be searching for seals. The most startling discovery so far came in 2003, when Canadian glaciologist John England spied a grizzly along a river valley on uninhabited Melville Island. Not only was the bear more than 700 miles north of where scientists would have expected it to be, it was roly-poly and in as good a shape as a healthy grizzly could be. England, who had worked 40 years in the Arctic, was flabbergasted by what he saw that day. The following year, researchers found fresh tracks and hair in the same area. DNA analysis of the hair samples showed that the bear had come from a population along the central Arctic coast of Canada more than 600 miles away. "The clear implication was that this grizzly had denned somewhere up around Melville, far from where grizzly bears are normally found," says England. "Presumably, it was feeding on muskoxen because apart from the occasional caribou you see high up on the Arctic islands there isn't much else for them to eat." What grizzlies are actually doing up there in the kingdom of their great white cousins is not clearly understood. Biologists have long considered the differences between the two bears significant enough to warrant separate species status. Physical distinctions are obvious: Polar bears are white rather than brown, which helps camouflage the predators from their prey on the sea ice. They are also generally larger, and have heads and bodies that are much more elongated, and therefore better adapted to penetrate seal lairs. Their larger, sharper teeth allow them to tear up seals efficiently, and shorter claws and larger feet make it easier for polar bears to travel on sea ice and swim across great expanses of water. Many Eskimos believe that rising temperatures in the Arctic explain why grizzly bears--as well as marten, wolverines and several other species of birds and mammals--are showing up in extreme northern places where they were rarely, if ever, seen before. Global warming, they say, is creating conditions that are more favorable for these animals, at least in the short term. While most scientists see that idea as a genuine possibility, experts like Canadian Wildlife Service biologist Ian Stirling, who has studied polar bears for more than 30 years, suspects that some grizzlies have always been venturing onto the ice. Perhaps, Stirling says, "what we're witnessing today is behavior similar to the evolutionary process that resulted in polar bears filling a rich but vacant niche as supreme predator of the sea ice." Like all creatures, barren ground grizzlies will continue to adapt and evolve. But just how successful they will be is unclear. Warmer temperatures that are already melting Arctic sea ice are also hitting caribou hard in places like the northern Yukon and Alaska, where the Porcupine caribou herd has dropped from an estimated 178,000 in 1989 to 123,000 today. The theory is that warmer spring days followed by cold snaps are making it harder for caribou to crater through the hard snow. Desperate for food, the animals are driven into windswept hills where they are more vulnerable to wolves, bears and the debilitating effects of malnutrition. If caribou populations shrink dramatically, Derocher doesn't see much of a future for grizzlies in the Arctic. Nor does he see the bears moving north if a warming climate is going to melt sea ice. Another predicted consequence of climate change--northern migration of the tree line--may also hurt grizzlies; research has shown that the bears survive better in the barrens than they do in boreal forest. What worries Derocher even more, though, are massive oil, gas and pipeline developments planned for Alaska and northern Canada. While the United States considers development in Alaska's Arctic National Wildlife Refuge, the Canadian government is fast-tracking a $5-billion natural gas pipeline down the Mackenzie Valley from the Beaufort Sea. "This is a population at the edge," says Derocher. "They're at the edge of their northern range. They're smaller and they're resource poor. They have to work a lot harder to make a living up here." Add a pipeline, oil and gas wells and a road to their habitat, he says, "and it becomes pretty apparent that these animals are going to be challenged." For now, though, the Arctic remains one of the last strongholds for grizzlies in North America. Farther south, many populations are struggling with industrial development and other human activity. During last year's field season, Derocher was heartened by the sight of the four grizzlies he had observed the year before. Somehow, in a wilderness that is frozen over for three-quarters of the year, this large family had found a way to make it through another winter. Ed Struzik is a Canadian freelance writer and photographer based in Edmonton, Alberta. Aklak vs. Nanook: A Tale of Two Bears Like most scientists, the Inuit view Aklak, the grizzly bear, and Nanook, the polar bear, as two very different creatures. Their traditional tales of polar bears almost always portray these animals as powerful, keen-witted and worthy of great esteem. The grizzly, on the other hand, is seen as a more sinister beast, one that is likely to charge unexpectedly in an explosive manner. Some biologists might agree with that assessment, citing evidence that barren ground grizzlies appear to be more aggressive than grizzlies living farther south. One explanation, they say, could be that northern grizzlies evolved in a treeless world where there's no place to hide, so threatening one's opponent may make far more sense than fleeing. Whatever the reason, bear biologist Andrew Derocher says he is "a lot more comfortable capturing a big polar bear on the sea ice than a small grizzly on land. Grizzlies tend to react much more aggressively. It can be very unnerving." NWF Priority: Guarding Grizzlies For several years, NWF and its affiliates have been working to bring back the grizzly bear to areas in Western states where the species' populations plummeted beginning in the 1800s. In the Yellowstone Ecosystem, such actions--which include habitat restoration and reducing conflicts with ranchers--have been so successful that the species may soon be removed from the federal Endangered Species List. More recently, NWF has been combating global warming, which poses a special threat to Arctic ecosystems and their inhabitants, including the barren ground grizzly. To learn more, go to www.nwf.org/globalwarming. Polar Bear Meltdown As global warming causes Arctic sea ice to melt earlier each year, barren ground grizzlies and polar bears may come in contact more often if the great white bears are unable to reach their traditional prey--seals, which they hunt from ice floes--and are forced to go after land animals like caribou, a favorite fare of grizzly bears. If the two species must compete for prey, grizzlies are likely to prevail because they are the more aggressive of the two bears. Already, there is evidence that polar bears are suffering as a result of global warming: Along the western shore of Canada's Hudson Bay, biologists have found that the bears weigh less and give birth to fewer cubs than they did two decades ago, when the ice was melting two weeks later than it does today. The most recent, and dramatic, bad news about the bears emerged last December, when researchers discovered some 40 polar bears swimming as far as 60 miles off the northern coast of Alaska. At least 4 of the animals drowned. While polar bears can swim short distances between ice floes, disappearing ice may increasingly force them to swim longer distances, making it more likely that the bears will tire and drown.--Laura Tangley  *This image is copyright of its original author
Alaskan Peninsula Grizzly ( Ursus arctos horribilis )... http://www.atlasomega.com/2010/09/photog...of-katmai/
I love the fact that I can say I’ve been 6 feet away from a 1000+ pound wild grizzly bear with nothing separating us but a two foot stream bank. This, to state the obvious, focuses one’s mind (and distresses ones parents when they hear about it after the fact). I had this, and many other close encounters with grizzly bears in the 8 days I spent photographing them in Kukak Bay, part of Alaska’s Katmai National Park and Preserve. Kukak Bay See the area on a map. For a few months each summer the coast of Katmai is home to one of the densest populations of bears on the planet. Backed by the volcanoes of the Kejuik Range to the north and the Shelikof Strait and Kodiak Island to the south, Kukak Bay is one of the many bays punctuating the Katmai coast, and it abounds with the resources that make supporting such a high number of bears possible: clams, sedge grass, and, most importantly, numerous salmon streams. This superabundance of food is also what makes it (relatively) safe to be in such close proximity to these large bears. With so much food available there is little reason to wonder what the tall skinny animals that move around in groups taste like. That’s not to say there is no danger. The next bay to the south of Kukak Bay is Kaflia Bay, the “Grizzly Maze” where Timothy Treadwell and his girlfriend were killed and eaten by a grizzly bear in 2003 (as described in the 2005 documentary Grizzly Man). In addition to the bears, Kukak bay is also home to hundreds of sea otters and harbor seals plus breeding colonies of horned puffins and black-legged kittiwakes. There seemed to be a bald eagle nest on every seastack as well. There is confusion on whether to call these bears grizzly bears or brown bears. Some sources define a grizzly as any brown bear in North America that lives more than a hundred miles from the coast, others conflate the label grizzly as any brown bear in North America (as opposed to the brown bear in Eurasia). I’ve decided to use the term grizzly for this article because when talking to people about my trip, no one ever asked me what a grizzly bear was, while I had a few people ask me if a brown bear was the same as a grizzly when I used that term in conversations. Regardless of which label you prefer to use the bears of Katmai are giants of their kind. Males can reach a weight of 1500 pounds and stand 8 feet tall when rearing on their hind legs. The females average 35% smaller but are still quite imposing. Even with this bulk grizzlies can sprint at up to 35mph. The ecology of Kukak Bay and the feeding habits of the bears are dictated by the tides, which are the second most extreme in North America. At low tide extensive tidal flats are exposed allowing the bears to dig for clams. Low tide can also strand salmon and other fish in shallow pools that the bears are quick to notice. As the tide comes in the bears move back into a large area of sedges that fringe the area between the ocean and the brush-covered hills that mark the beginning of the Kejuik Mountains. These sedges are high in protein and provide the bulk of the bears diet early in the summer before the salmon runs begin. At high tide the streams become too deep for fishing and the bears retire into the bush and are not as active. It is also more difficult for humans to get around as most of the bear trails (which are what we use to get around) are underwater, and those that remain are being used by the bears. High tide is better spent out on the bay looking for otters, eagles and the other wildlife that calls the Kukak Bay home. Cutting through the coastal plains are numerous small streams. These streams are not very long but their upper reaches are used by numerous species of salmon as spawning grounds. As the tide drops bears return to the sedge flats and the banks of these streams to hunt for salmon. Consequently, both the highest density of bears, and the most action is found along these streams, and this is where you will be spending most of your time while photographing. The most bears I counted at once was 12. One important difference between photographing grizzly bears versus most other wildlife photography is that you want the bears to see you. Surprising them or hiding is a bad idea. Another difference, again for safety reasons, is that you’ll be in a group of 5-7 people. A group is much more intimidating than a single human alone. This means that you’ll need to cooperate when setting up tripods so that fields of view are not compromised. Remember that the bears movements are dictated by the tide. Don’t setup your camera for where the bears are when you arrive, set up so that you’re ready to shoot in the place where the action will be once the salmon start to run up the streams. In general you’ll want your tripod setup without the legs extended as you’ll most likely be a few feet above the level of the river, and you’ll want to be shooting on the same level as the bears, not looking down on them. Even better is if you flatten the legs completely so that you’re lying on the ground, but this may not be possible if there is vegetation between you and the bears. Being low will also have a positive effect on the backgrounds in your shot, especially when using wide apertures. But always be ready to stand up and shoot if something happens in the distance. Your tripod is adjustable for a reason, make the most of it. One last piece of advice is not to get sucked into just using your telephoto lens. Don’t forget to use wider lenses to capture the bears in their environment. Don’t let the majestic glacier-clad peaks in the background go to waste. Getting The Shot | Bear Behaviors Fishing – this is iconic behavior everyone one wants to see. It’s explosive, violent and can last for five seconds or five minutes over which time the bear may sprint back and forth across hundreds of yards of ground. The bears can go from lying in the grass to running flat out in a couple heartbeats and you need to be ready for this change. The bears keyed on the splashes the salmon made on the water’s surface as they made their way upstream, you should listen for this cue as well. The strategy I evolved after a couple days shooting was to have aperture priority mode on my camera always set to my widest aperture (f/4 in my case) to maximize my shutter speed. This allowed me to use shutter priority and manual modes for shots of bears while they were resting or grazing and then instantly switch over to the fastest shutter speed possible in the available light if any fishing began. I could then switch back to manual or shutter priority mode during a lull in the action if I wanted a specific shutter speed. I found 1/1000 to be the absolute minimum shutter speed necessary to freeze both the movement of the bear and the water spraying around it, with 1/1600 or 1/2000 even better options. Shutter speeds faster than this were rarely possible on the mostly overcast days, but go for it if the light allows. The same rules apply for fights between the bears – fast shutter speads and wide apertures, but unlike fishing you’ll be able to predict when a fight may occur. It’s simple really, any time two bears are in close proximity there are only two possible outcomes: one will give way to the more dominant bear, or a fight will break out. Adjust your tripod and shooting mode any time you see that two bears will cross paths. While most of the time nothing will happen, you’ll regret it if you get lazy and consequently miss a brawl.Another great time a fight is likely to occur is after a bear successfully catches a salmon. Others bears come running at the sound of bear charging through the water after a fish, and it is quite common for larger, more dominant bears to attempt to steal a kill. Just because the fish has been caught doesn’t mean the action is over. Another great time for photography is when a mother and her cubs are on the scene. I’ve always read that being near a bear cub is a really, really, bad idea, but there were numerous times when a mother bear brought her cubs quite close to us. It seemed to me that the mother would use our group as a buffer or shield from the other bears. While I don’t have any evidence to back this up besides my own observations, there is good reason to think this may be the case, as male grizzlies routinely kill cubs to bring the mother back into estrus. The most memorable example of this occurred when a female caught a salmon, and then ran straight at us with her clubs close behind. She stopped about 60 feet away to bolt down the fish. As soon as she finished eating her three cubs joined her and began nursing. This was the only time I can recall a smaller bear not having to fight for it’s catch when there were other larger bears in the area. As soon as she finished eating her catch her three cubs joined her and began braying, a sound that increased in both volume and frequency until mom rolled on her back and began nursing them. Mothers and cubs will be your only chance to capture the more intimate moments in a bears life. They are always in close proximity to each other so be on the lookout for those small special moments of interaction. You’re biggest problem in getting these shots will not be lack of opportunity, but rather that they never all seem to want to “pose” at the same time. I have many, many shots of a mother and cub looking at the camera with the second cub with it’s head buried in the grass, or two cubs playing in the foreground with the mother’s ass providing a not-so-appealing background. Be patient and be quick with the shutter during the fleeting moments when all involved are at their photogenic best.  *This image is copyright of its original author
ABC Bears of Alaska ( Ursus arctos sitkensis )... DNA study clarifies relationship between polar bears and brown bears
Unusual population of brown bears on Alaskan islands turns out to have a remarkable and revealing history March 14, 2013 By Tim Stephens At the end of the last ice age, a population of polar bears was stranded by the receding ice on a few islands in southeastern Alaska. Male brown bears swam across to the islands from the Alaskan mainland and mated with female polar bears, eventually transforming the polar bear population into brown bears. Evidence for this surprising scenario emerged from a new genetic study of polar bears and brown bears led by researchers at the University of California, Santa Cruz. The findings, published March 14 in PLOS Genetics, upend prevailing ideas about the evolutionary history of the two species, which are closely related and known to produce fertile hybrids. Previous studies suggested that past hybridization had resulted in all polar bears having genes that came from brown bears. But the new study indicates that episodes of gene flow between the two species occurred only in isolated populations and did not affect the larger polar bear population, which remains free of brown bear genes. At the center of the confusion is a population of brown bears that live on Alaska's Admiralty, Baranof, and Chicagof Islands, known as the ABC Islands. These bears--clearly brown bears in appearance and behavior--have striking genetic similarities to polar bears. "This population of brown bears stood out as being really weird genetically, and there's been a long controversy about their relationship to polar bears. We can now explain it, and instead of the convoluted history some have proposed, it's a very simple story," said coauthor Beth Shapiro, associate professor of ecology and evolutionary biology at UC Santa Cruz. Shapiro and her colleagues analyzed genome-wide DNA sequence data from seven polar bears, an ABC Islands brown bear, a mainland Alaskan brown bear, and a black bear. The study also included genetic data from other bears that was recently published by other researchers. Shapiro's team found that polar bears are a remarkably homogeneous species with no evidence of brown bear ancestry, whereas the ABC Islands brown bears show clear evidence of polar bear ancestry. A key finding is that the polar bear ancestry of ABC Islands brown bears is conspicuously enriched in the maternally inherited X chromosome. About 6.5 percent of the X chromosomes of the ABC Islands bears came recently from polar bears, compared to about 1 percent of the rest of their genome. This means that the ABC Islands brown bears share more DNA with polar bear females than they do with polar bear males, Shapiro said. To understand how hybridization could lead to this unexpected result, the team ran simulations of various demographic scenarios. "Of all the models we tested, the best supported was the scenario in which male brown bears wandered onto the islands and gradually transformed the population from polar bears into brown bears," said first author James Cahill, a graduate student in ecology and evolutionary biology at UC Santa Cruz. This scenario is consistent with the known behavior of brown bears and polar bears, according to coauthor Ian Stirling, a biologist at the University of Alberta in Edmonton, Canada. Mixing of polar bears and brown bears is seen today in the Canadian Beaufort Sea, where adult male brown bears wander onto the remaining sea ice in late spring and sometimes mate with female polar bears, he said. In areas such as western Hudson Bay and the Russian coast, polar bears are spending more time on land in response to climate warming and loss of sea ice, a behavior that could have left polar bears stranded on the ABC Islands at the end of the last ice age. Young male brown bears tend to leave the area where they were born in search of new territory. They may well have dispersed across the water from the Alaskan mainland to the ABC Islands and hybridized with polar bears stranded there when the sea ice disappeared. "The combination of genetics and the known behavior of brown and polar bears hybridizing in the wild today tells us how the ABC Islands bears came to be: they are the descendants of many male brown bear immigrants and some female polar bears from long ago," Stirling said. The findings suggest that continued climate warming and loss of arctic sea ice may lead to the same thing happening more broadly, said coauthor Richard E. (Ed) Green, an assistant professor of biomolecular engineering in UCSC's Baskin School of Engineering. "As the ice melts in the Arctic, what is going to happen to the polar bears? In the ABC Islands, the polar bears are gone. They're brown bears now, but with polar bear genes still present in their genomes," he said. The first genetic studies of ABC Islands brown bears looked at their mitochondrial DNA, which is separate from the chromosomes and is inherited only through the female lineage. The mitochondrial DNA of ABC Islands brown bears matches that of polar bears more closely than that of other brown bears, which led some scientists to think that the ABC Islands brown bears gave rise to modern polar bears. The new study looks at the "nuclear DNA" carried on the chromosomes in the cell nucleus. It is the latest in a series of genetic studies of polar bears published in recent years, each of which has prompted new ideas about the relationship between polar bears and brown bears. A 2010 study of fossils and mitochondrial DNA supported the idea that polar bears evolved from the ABC Islands brown bears. But a 2011 study of mitochondrial DNA from extinct Irish brown bears showed an even closer match to polar bears and suggested that polar bears got their mitochondrial DNA from hybridization with Irish bears. Shapiro, a coauthor of that study, said she now thinks the Irish brown bears may be another example of what happened in the ABC Islands, but she can't say for sure until she studies their nuclear DNA. "In retrospect, I think we were wrong about the directionality of the gene flow between polar bears and Irish brown bears," she said. Two studies published in 2012 sought to determine when the polar bear lineage diverged from the brown bear lineage using nuclear DNA data. The first, published in April in Science, put the split at 600,000 years ago and concluded that polar bears carry brown bear mitochondrial DNA due to past hybridizations. The second, published in July in Proceedings of the National Academy of Sciences, suggested that brown bears, black bears, and polar bears diverged around 4 to 5 million years ago, followed by repeated episodes of hybridization between polar bears and brown bears. The new study does not address the question of how long ago polar bears diverged from brown bears, but it may help sort out the conflicting results of recent studies. "It's a good step in the right direction of understanding what really happened," Shapiro said. The study does indicate that the divergence of polar bears from brown bears was only half as long ago as the split between the brown bear and black bear lineages, said Cahill. "We can tell how long brown bears and polar bears have been separate species as a proportion of how long ago they separated from more distantly related species, but putting a year on it is very difficult," he said. Green noted that efforts to understand the relationship between polar bears and brown bears has been complicated by the unusual case of the ABC Islands brown bears. "It's as if you were studying the relationship between humans and chimpanzees and your analysis included DNA from some weird population of humans that had hybridized with chimps. You would get very strange results until you figured that out," he said. In addition to Cahill, Green, Shapiro, and Stirling, the coauthors of the new paper include postdoctoral researchers Tara Fulton and Mathias Stiller, undergraduate Rauf Salamzade, and graduate student John St. John at UC Santa Cruz; Flora Jay and Montgomery Slatkin at UC Berkeley; and Nikita Ovsyanikov at the Wrangel Island State Nature Reserve in Russia. Green and Shapiro direct the UCSC Paleogenomics Lab. This research was funded by the Searle Scholars Program. http://news.ucsc.edu/2013/03/polar-bear-genomics.html  *This image is copyright of its original author
I'm glad that Vinay and I had that disagreement about the sloth bear's climbing ability. I was proven wrong. A great many sources claim that sloth bears are slow and clumsy tree-climbers. This is a mere assumption due to the fact that they are primarily ground dwellers and do not retreat up a tree at the first hint of danger. Fact is, they are probably as good at tree-climbing as the black bears.
Great Bear Almanac by Gary Brown. Climbing Abilities. Polar Bear: Does not climb trees; agile climber of ice ridges; climbs to travel and pursue prey. Can jump/scale a thirty-five foot ice wall. Brown Bear: Poor climber due to claw structure and body weight. Climbs to feed ( pursue prey, seek human food ) and travel, even steep rock ridges; capable of laddering up only trees with low branches. Cubs climb trees. American Black Bear: Outstanding climber. Climbs regularly and easily to feed, escape enemies, or to hibernate in some areas. Climbing ability declines with age, with large adults climbing infrequently for food. Climbing is also the principal means of defense. Asiatic Black Bear: Good climber. Climbs to feed, rest, sun, escape from enemies, and hibernate. Excellent climber in rocks and cliffs; frequently climbs trees. Climbing important in feeding habits; some older bears become too heavy to climb. Giant Panda: Poor climber. Climbing is uncommon and less efficient than that of other bears; climbs slowly and clumsily, appearing inept; embraces tree, ascending with caterpillar movements. Climbs for defense - to escape dogs, humans, and other giant pandas - and to rest and sun. Females climb to escape courting males. Spectacled Bear: Excellent climber. Climbs quite high. Climbs to feed, rest, sleep, escape; able to climb vines and small trees ( less than four inches in diameter ); spends more time in trees than other bears. Sun Bear: Expert climber, nimble, skillful. Climbs to feed, rest. Cubs climb better than they run. Can nearly hang upside down with claws. Sloth Bear: Excellent climber despite appearing slow and clumsy. Climbs to feed, rest; does not climb to escape enemies - runs or fights probably because its major predator is the leopard, an excellent climber. Can jump down ten feet, climb a smooth-bore tree or pole, and hangs upside down like a sloth.
It is rather easy to find pictured a "family tree" of bears in general. However, I have never found a family tree pictured of just the grizzly - Ursus arctos. I know that the American grizzly is closely related to the Amur brown bear. I know that the Kodiak bear is closely related to the Kamchatka brown bear. I believe that the Gobi bear, Himalayan brown bear, Syrian brown bear, and Tibetan brown bear are all closely related. A family tree would be awesome! If its ever been done, I can't locate a copy. One thing for sure. If the polar bear is not present, then the family tree would be incomplete.
https://evolution.berkeley.edu/evolibrar...polarbears
What is a polar bear? Evolutionarily speaking, polar bears (Ursus maritimus) are brown bears (Ursus arctos). That might seem counterintuitive, but modern biologists classify species according to their evolutionary history. Organisms that are more closely related are grouped together. In this system, only clades — groups of organisms that contain all the descendents of an ancestor — are named. When we look at the family tree of bears, we can see that not only are polar bears most closely related to brown bears, but they actually fall within the brown bear clade. There is no clade that includes all the brown bears and excludes the polar bears. From an evolutionary perspective, polar bears are simply a unique and highly specialized sort of brown bear! 
Chuang Chuang, a 19-year-old giant panda at Chiang Mai which was popular across Thailand, and refused to mate with any female companion, died suddenly, causing upset not just in Thailand, but also for China, which loaned the panda to Thailand in 2003: https://www.bbc.com/news/world-asia-49737215
 *This image is copyright of its original author
 *This image is copyright of its original author This picture seems to be an unconfirm hybrid according to the wikipedia which could likely be true. However, grizzly bears usually treat American black bears as prey. There are more accounts of barren ground grizzlies mating with female polar bears because unlike the black bears, the yellowish white bears of the north are viewed as competitors not prey. (11-29-2019, 04:23 PM)GreenGrolar Wrote: ... Check my post above.  (11-29-2019, 04:23 PM)GreenGrolar Wrote: Somewhat odd coloration, but otherwise looks like a black bear. |
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