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Post by brobear on Apr 19, 2017 18:49:04 GMT -5
www.eurekalert.org/pub_releases/2005-03/nsae-gst030905.php PUBLIC RELEASE: 9-MAR-2005 Grizzlies set to invade high Arctic? NATURAL SCIENCES AND ENGINEERING RESEARCH COUNCIL The telltale paw prints with huge 10 centimetre-long nails spoke volumes. But now definitive corroborating DNA evidence seals the case of the most northerly sighting of a grizzly bear. The discovery fuels mounting evidence that Canada's High Arctic is no longer the sole preserve of the polar bear - Nanuk is having to make room for its southern cousin. The evidence of the barren ground grizzly bear (Ursus arctos) was discovered on Melville Island, an uninhabited part of the western Arctic archipelago 1,500 kilometres due north of Yellowknife, and 1,000 kilometres north of the Arctic Circle. "We know grizzlies go out on the sea ice to hunt seals, but no one has ever seen one that far north," says Dr. John England a geology professor and the NSERC Northern Chair at the University of Alberta. Dr. England got his first glimpse of the surprising Melville Island grizzly bear from the air during a helicopter ride to a geology research site in 2003. He photographed mid-distance shots of the large bear with characteristic grizzly features including a prominent shoulder hump, dark brown hair on and around the rear legs, and faded (grizzled) hair on the rest of the body. Then in the summer of 2004, Dr. England's research group found physical proof that a grizzly bear was indeed calling Melville Island home. Near a cabin used by researchers for temporary stop-overs, they found grizzly bear paw prints in the mud. And from the cabin's outside walls and a guy wire attached to the roof they collected two intriguing brown hairs. These were sent for analysis to Wildlife Genetics International Inc. in Nelson, British Columbia, one of the world's premier bear DNA labs. The result: the genetic analysis pointed to a male barren ground grizzly bear, rather than a Viscount Melville polar bear, the variety known to inhabit the Melville Island area. During the past 15 years there have been more and more sightings for barren-ground grizzlies on the sea ice in the Arctic from the Beaufort Sea to Hudson Bay. They're also known to be able to survive the winter and den on Victoria Island, the island separated from Melville to the north by Viscount Melville Sound. The geologists, now bitten with the grizzly bear research, emphasize that they are not wildlife biology experts. Nonetheless, they say the discovery of a grizzly bear on Melville Island raises numerous issues. Could grizzlies move east to one day take up home on Ellesmere Island, in the heart of polar bear country? Could polar bears in the wild interbreed with brown bears, their evolutionary close cousins, as has occurred at least once in captivity? What impact will grizzlies, already known to prey on polar bear cubs, have on these northern bears? For now, however, the greatest issue might be for the geologists themselves, says Dr. Jonathan Doupé, a postdoctoral researcher working with Dr. England. "We have bear safety courses when we go up there, and people would normally say you don't have to worry about grizzlies because it's really just polar bear country," he says. "But I think that's no longer the case." Dr. England notes that the grizzly bear find is a highly visible example of important changes occurring in the Arctic. "The Arctic is very large and diverse, and this complex but exciting environment is just coming into focus for Canadians in general. It's now a mainstream issue."
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Post by brobear on Apr 20, 2017 16:34:14 GMT -5
www.bearbiology.com/fileadmin/tpl/Downloads/URSUS/Vol_13/Wyman_13.pdf Based on the paucity of documentation in the literature, grizzly bear predation on adult bison is likely very rare. However, the incident I observed indicates that grizzly bears can opportunistically pursue and kill adult bison under conditions where the bear has an advantage. In this case, the bison was alone and lacked the group protection afforded by a herd; it was also young and likely lacking in experience. The bison attempted to flee rather than stand its ground. Large ungulates such as bison (Smith et al. 2000), moose (Mech 1966), and elk (D. Smith, YNP, personal communication, 2001), are often more successful at deterring predatory attacks by confronting predators rather than fleeing. Although human safety concerns required euthanizing the bison and moving its carcass, the extent of the injuries already inflicted on the bison lead me to conclude that given more time and less human interference, the grizzly would undoubtedly have killed the bull.
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Post by brobear on Apr 20, 2017 17:15:35 GMT -5
Muskox Bull Killed by a Barren-Ground Grizzly Bear. Thelon Game Sanctuary, INTRODUCTION Muskoxen and barren-ground grizzly bears are relatively common along the banks of the Thelon River in the Thelon Game Sanctuary. In June 1981 we were flying a helicopter search of the Thelon River area during a study of water crossings used by barren-ground caribou (Rangifer tarandus groenlandicus). In the early afternoon of 23 June we were flying eastward when we spotted a grizzly bear standing on its hind legs among willow (Sulix spp.) bushes in a clearing surrounded by black spruce (Picea mariana) on the north shore. As there were two gulls (Larus spp.) in attendance, indicating the possibility of a kill, we circled closer and could then see a dead muskox on the ground near the bear. The grizzly bear alternately reared up and dropped onto all fours as we came close and when the helicopter was about 100-150 m away, the bear galloped away. We landed near the carcass of an adult muskox bull lying on its left side. The carcass was intact except for some exposed flesh and head wounds. The nose was tom away and the nasal turbinal bones were crushed and the cartilage torn. The right ear was split and torn away at the base where there was a penetrating wound into the skull. Traumatized areas were hemorrhagic, indicating that the wounds were inflicted on a living animal. The hide and musculature had been removed in the lumbar and thoracic areas, exposing the vertebrae and the right scapula. The internal organs were still intact and warm to touch. Subsequent histological examination of the dental annuli of a first incisor indicated that the muskox bull was 9-10 years old. The greening sedges (Carex spp.) immediately around the carcass were trampled and we backtracked along a disturbed path to a heavily trampled area of 5 m in diameter about 15 m away. The willow bushes peripheral to that trampled area were flecked with blood clots and clumps of blood-stained muskox wool. The ground cover was beaten down and the ground surface disturbed in many places with footprints pushed 10-15 cm or more into wet soil. We suggest that the grizzly bear surprised the muskox bull while it was grazing on sedge (indicated by rumen contents). The bear most likely grabbed the bull above the muzzle. In response, the bull must have braced its front legs and tried to dislodge the bear, suggested by front-foot hoof prints driven deep (15 cm) into the churned-up ground. Either the bull collapsed or the bear swung him off balance. At that point, the bear probably transferred its bite to just below the back of the bull’s horn boss. After making the kill, the bear dragged the carcass to where we found it, and had begun feeding when we interrupted. We returned about 48 hours later and found a light grey wolf (Canis lupus) and a grizzly bear whose colouring suggested it was not the bear that had made the kill. The carcass was dismembered and had settled into the wet ground. Most of the muscle masses and the internal organs had been consumed and the limb bones were scattered around the hide. The rumen had been pulled from the carcass but had not been fed on. The destruction of the facial area was also the mode of attack of a barren-ground grizzly bear killing a caribou cow whose carcass we found on the Beverly caribou herd’s calving ground, northeast of the Thelon Game Sanctuary, in June 1981. Griffel and Basile (1981) described puncture wounds in the frontal or jugal bones of 109 of 332 bear- killed sheep (Ovis aires) in Idaho. The facial area is richly innervated, and Mystervd (1975) in Griffel and Basile (1981) suggested that unconsciousness and hypoxic asphyxiation would follow severe and sudden injury to that area. Also, the seizing of the muskox bull’s muzzle would reduce chances of the muskox using its horns to gore the bear and increase the bear’s chances of throwing the muskox off its feet. Solitary muskox bulls usually seem particularly alert, and their speed of response, size, strength, thick coat and horns must combine to make them a formidable quarry even for a grizzly bear. The location of this kill, at the edge of a small clearing where ambush by rushing from nearby cover was possible, suggests that the kill was opportunistic. The muskox bull was probably so intent on foraging on the new growth of sedges 10-20 cm high that he was not aware of his attacker until it was too late. The femoral marrow fat was pinkish-white and firm, suggesting good nutritional status, and we did not observe any obvious infirmities that would have made the bull particularly vulnerable. Tener (1965) summarized predation on muskoxen and noted that Pederson’s report of a possible kill by a polar bear (Ursus maritimus) may be the only reported instance of bear predation. He further commented that predation by barren-ground grizzly bears is rare, since up to 1965 only Hornby (1934, in Tener, 1965) had observed bears feeding on muskoxen on the banks of the Thelon River. In the late 1970s A.M. Hall (pers. comm.) observed grizzly bears feeding on muskox carcasses along the banks of the Thelon River (see photograph of grizzly bear sleeping near partially- eaten bull muskox in Hall, 1980). In 1978, on the banks of the Thelon, Hall observed three muskox carcasses on which grizzlies had fed, but he could not determine whether the bears had killed or were scavenging the muskoxen. Hall (pers. comm.) believes that grizzly bear predation on muskoxen is high, especially on solitary bulls along the Thelon River, probably because the dense willow stands favour surprise ambushes. In June and July 1981, we saw only solitary bull muskoxen feeding in the willow stands, which leads us to the same supposition. Within 40 km of the carcass described in this paper, during the same flight, we observed five other grizzlies on the north shore. Pegau (1973) briefly described an apparent kill of a 2- or 3-year- old muskox by a bear but the carcass was almost completely consumed, so scavenging could not be ruled out. The carcass was found on the Seward Peninsula, Alaska, where Grauvogel (1979) speculated that the slow rate of increase of the transplanted muskox herd might be partially attributed to grizzly bear predation on muskox calves, though no evidence was cited. Our account of an apparently healthy, prime adult muskox bull that was killed by a grizzly bear is the first documentation of such an event.
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Post by brobear on Apr 20, 2017 17:20:07 GMT -5
The ultimate scavenger upon the ultimate carcass.
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Post by brobear on Apr 20, 2017 18:30:53 GMT -5
In Russia, where the grizzly is their national animal, the two top prey animals of the grizzly are the red deer, which are slightly smaller than their American cousin, the elk or wapiti, and the Russian wild boar which is the largest wild hog on earth, sometimes weighing over 700 pounds ( 318 kg ).
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Post by brobear on Apr 24, 2017 2:30:13 GMT -5
Notorious Grizzly Bears by W.P. Hubbard - 1960 - Food and feeding. The grizzly bears are omnivorous. Being both herbivorous and carnivorous, they are fitted by nature and instinct to feed upon both vegetation and meat. This wide range is entirely the result of environment. With few exceptions their feeding habits in any given region are identical. Their chief foods are roots, bulbs, grasses, berries, fish, insects, carrion, fresh flesh in the form of gophers, marmots, and mice. They occasionally kill deer, elk, mountain sheep and goats, but it is seldom a deliberate hunt on their part for meat. Such animals usually fall prey to grizzlies upon sudden meetings at close quarters, where the victim is often in a position from which it has little or no chance to escape, for a grizzly can charge with terrific speed in short distances.
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Post by brobear on Apr 24, 2017 3:32:47 GMT -5
Continued.... In by-gone days grizzlies sometimes stalked the drag of a buffalo herd to obtain food. By following a herd, often a grizzly could bring down some aged, sick, or crippled animal, a straggler, or one that had been wounded by Indians or buffalo hunters. In their journals, Lewis and Clark stated that the bears were particularly numerous in the vicinity of the Great Falls of the Missouri, where well-worn buffalo trails led down through the cut banks of the river's edge. Great herds wound down the narrow trails to drink daily. The press of oncoming buffalo often forced the leaders out into the current. Many were swept over the falls. The dead drifted ashore, providing a banquet for the grizzly bears gathered there. In this instance, as was the general rule, the grizzly did not kill, but fed upon animals killed under other circumstances.
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Post by brobear on May 4, 2017 17:36:50 GMT -5
Displacing other more proficient predators from a kill is a common method for a grizzly to obtain meat. More common, in fact, that doing their own hunting. shaggygod.proboards.com/board/38/felidae "Cougars, however, generally give the bears a wide berth. Grizzlies have less competition with cougars than with other predators such as coyotes, wolves, and other bears. When a grizzly descends on a cougar feeding on its kill, the cougar usually gives way to the bear. When a cougar does stand its ground, the cougar will use its superior agility and its claws to harass the bear yet stay out of its reach until one of them gives up, usually the cat." Though grizzlies likely kill few cougars, they may see the cats as a feline gravy train. Between 1990 and 1995, wildlife biologist Kerry Murphy and other HWI researchers monitored 113 cougar kills (mostly deer and elk) in Glacier and Yellowstone and discovered that bears (grizzlies and blacks) were claiming a significant share of the spoils. Bruins visited about one of every four cougar kills, robbing the feline owner of as much as 26 percent of its food requirement, sometimes for several days running. "It appears," says Murphy, "that competition for kills creates significant gains for bears and significant losses for cougars." "Grizzly and Black bear visited 24% of cougar kills in GNP and YNP and displaced cougars from their kill 10% of carcasses. Bears gained up to 113% and cougars lost 26 % of their respective daily requirements from these encounters. Bear predation and incomplete consumption of carcasses (especially salmon) provide food for a variety of scavengers."
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Post by brobear on May 14, 2017 14:04:27 GMT -5
www.ncbi.nlm.nih.gov/pubmed/21174359 Food habits and hunting patterns of Tibetan brown bear during warm seasons in Kekexili region on Qinghai-Tibetan Plateau. Tibetan brown bear (Ursus arctos pruinosus) is an endemic subspecies of brown bear on the Qinghai-Tibetan plateau. We once reported a preliminary study on the summer food habit of Tibetan brown bear from July to August, 2005 in the Kekexili (Hoh Xil).. However, the hunting modes of the Tibetan brawn bear have not been reported. From July to August, 2009, we collected additional data on food habits and hunting patterns of Tibetan brown bear in the Kekexili region. We found Tibetan brown bears are more raptatorial than vegetarian, and their basal food was plateau pika (Ochotona curzoniae), relative frequency occurrence of pika in the fecal residual of brawn bear was 37.3%, dry weight of pika residuals was 44.7%, respectively, followed by wild yak (Bos grunniens) , 18.7% and 30.2%, and Tibetan antelope (Pantholops hodgsoni) 15.0% and 16.2%. Both prey actively mode and scavenge mode were used by Tibetan brown bears in Kekexili. Tibetan brawn bears actively dug and hunted for pika and scavenged bodies of wild yak, Tibetan antelope and Tibetan gazelle. We observed that Tibetan brawn bears spent about 10% of their time to dig and to hunt for pika but we had never seen Tibetan brawn bears actively hunted large mammals such as wild yak, Tibetan antelope and Tibetan gazelle. The total amount of Tibetan antelope, Tibetan gazelle and wild yak ingested by Tibetan brown bear through scavenge was about the same amount of Plateau pika and Himalayan marmot (Marmota himalayana) eaten by the bear.
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Post by brobear on Jan 13, 2018 6:27:25 GMT -5
The Yak - Info from: Aichun, X., Zhigang, J., Chunwang, L., Jixun, G., Guosheng, W., Ping, C., 2006. Summer food habits of brown bears in Kekexili Nature Reserve, Qinghai-Tibetan Plateau, China. Ursus 17, 132-137. Pikas in KNR appeared relatively stable and consis- tently available to bears, but wild yak and Tibetan wild ass were less predictable prey items. In the transect surveys we found 2 carcasses of wild yak. One had been consumed, with almost no meat remaining on the skeleton; the other was relatively fresh. Around the carcasses, we found fresh bear tracks and feces. We documented a similar instance involving a Tibetan wild ass carcass. Neither we nor the managers of KNR observed bears preying actively on ungulates in Kekexili. We believe that brown bears scavenged the carcasses of large ungulates.
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Post by brobear on Jan 14, 2018 6:20:54 GMT -5
Just a thought: Those early pioneers from about 1820 up until perhaps about 1840 discovered an American West far different than that which followed and is rather familiar to us today; the old cowboy days of about 1860 through to about 1890. In the early years, the prairie was referred to by some as the American Serengeti because of the rich abundance of wildlife. Prey was plentiful as well as a lush menu of other foodstuffs enjoyed by bears. Just as in the Pleistocene, the grizzly was a big well-fed bear. He was much more of a predator that those kept on reservations today. By GrizzlyClaws: The Brown bears were also hypercarnivores in the Pleistocene, but the radical climate change had forced them to switch their diet preference. After the horrific great bison slaughter, and the bison was replaced by domesticated cattle as prey for the bears. The grizzly became known as the "outlaw bear" and became the target of an undeclared war. Guns and dogs, steel traps, and ( worst of all ) strychnine were used to slaughter an estimated 100,000 grizzlies.
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Post by brobear on Jan 17, 2018 16:59:39 GMT -5
www.researchgate.net/publication/238015031_Predation_on_moose_and_caribou_by_radio-collared_grizzly_bears_in_east_central_Alaska www.researchgate.net/publication...ral_Alaska Radio-collared grizzly bears (Ursus arctos) were sighted daily for approximately 1-month periods during spring, summer, and fall to estimate predation rates. Predation rates on adult moose (Alces alces) were highest in spring, lowest in summer, and intermediate in fall. The highest kill rates were by male grizzlies killing cow moose during the calving period. We estimated that each adult male grizzly killed 3.3–3.9 adult moose annually, each female without cub(s) killed 0.6–0.8 adult moose and 0.9–1.0 adult caribou (Rangifer tarandus) annually, and each adult bear killed at least 5.4 moose calves annually. Grizzly predation rates on calves and grizzly density were independent of moose density and are probably more related to area-specific factors, e.g., availability of alternative foods. An important implication of our results is that managers should not allow moose densities to decline to low levels, because grizzlies can have a greater relative impact on low- than on high-density moose populations and because grizzly predation can be difficult to reduce. Grizzly bears were primarily predators, rather than scavengers, in this area of low prey availability (11 moose/grizzly bear); bears killed four times more animal biomass than they scavenged. Predation on moose and caribou by radio-collared grizzly bears in east central Alaska (PDF Download Available). Available from: www.researchgate.net/publication...ral_Alaska
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Post by brobear on Jan 17, 2018 17:04:45 GMT -5
www.researchgate.net/publication/290297996_Grizzly_bear_predation_on_a_bull_bison_in_Yellowstone_national_park ... Previous studies (Mattson 1997; Schwartz et al. 2014 ) identified ungulate meat as an alternative food for grizzly bears during years exhibiting poor whitebark pine cone production. The importance of ungulates [mule deer (Odocoileus hemionus), elk, moose, and bison] for grizzly bears in the GYE is well documented, both as prey and for scavenging opportunities (Schleyer 1983; Gunther and Renkin 1989; Mattson et al. 1991; Green et al. 1997; Mattson 1997; Wyman 2002). Bison experienced large fluctuations in abundance due to disease management, but overall increased during the study period (Cross et al. 2010; White et al. 2011 ). ... ... Grizzlies also hunt actively for wapiti calves (Cole, 1972). Grizzlies are capable of killing adult bison and have been observed killing a bison calf, although most wildlife experts point out that bison are much better defenders of their young than elk or caribou (Varley and Gunther, 2002; Wyman, 2002). However, we can be fairly sure that some bison calves would have fallen prey to grizzly bears. ... ... Most meat consumed by extant brown bears is from ungulates of various sizes (Clevenger & Purroy, 1991). Scavenging is the most common form of animal resource procurement (Mattson, 1997; Wyman, 2002). Because bears do not move carcasses to their dens, they are most likely to be found in archaeological contexts of hibernation, where several events can be identified, or even in the same areas occupied by other carnivores or hominids (Andrews & Fernández Jalvo, 1997; Stiner, 1998a Stiner, , 1998b Pinto & Andrews, 2002; ...
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Post by brobear on Jan 18, 2018 6:14:08 GMT -5
www.tolweb.org/treehouses/?treehouse_id=4728 Hunting Techniques. When searching for prey, grizzlies primarily rely on their acute sense of smell by bowing their heads low to the ground and sniffing while they walk. They also capitalize on their sight and hearing by periodically standing on their hind legs to gain a better view of their surroundings as well as hear further. While standing, they turn their head and ears in various directions to scan the area. Most of the time, a bear will not know where a herd of ungulates is located and can spend up to several hours conducting a search. Grizzlies are usually searching for calves that are lying down and sleeping, or bedding calves, as these are the easiest to catch. When a herd is located, the bear will pace around a 200 m radius where the herd was just previously standing in hopes of finding a bedding calf. While doing this, the bear will avoid being seen by the herd. Army cutworm moths, Euxoa auxiliaris, are an important food source for some grizzly populations. Image © Whitney Cranshaw When a bedding calf cannot be found, a grizzly can resort to a chase or an ambush to catch its prey. The bear will stalk a herd closely while remaining unseen, and suddenly attack with a burst of speed. They will focus on straggling calves that lag behind the herd and have little protection from adults. When the bear closes in on its prey it can knock it over with its muzzle or paw, and will usually begin eating the abdomen of the calf to quickly kill the victim. Grizzlies have been seen waiting on the edges of forests near fields and meadows for herds to enter where they can easily ambush their prey. Large numbers of grizzly bears on the Absaroca Mountains in Yellowstone National Park rely heavily on army cutworm moths (Euxoa auxiliaris) as a main source of nutrition during the months of late June to mid September (French et al, 1994). Large numbers of moths arrive here during flowering season, and during the day take shelter under large rocks covering the side of the mountain. After locating a cluster of moths by their scent, the bears move rocks, dig and excavate until they find the moths. Although bears are found in large groups here, there is little social tension as plenty of food reduces the need for competition. Moth eating Grizzlies have also been found on Talus slopes in the Mission Mountains of Montana and in Glacier National Park.
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Post by brobear on Mar 8, 2018 7:16:12 GMT -5
gobiestogrizzlies.blogspot.com/2008/07/muskox-on-menu-grizzly-predation-on.html The muskox (Ovibos moschatus) is a large ungulate (the average male weight is from 273 to 364 kg [600 to 800 pounds]) equipped with curved horns and a shaggy pelage which can be up to 10 cm (4 inches) thick. It is a close relative of the sheep or goats (subfamily Caprinae) and is able to withstand incredibly frigid, arctic conditions (down to at least – 70 ºF). Muskox tend to live in herds and are famous for their defensive posturing – they often form a defensive circle with their heads (i.e., armament) facing outward toward the potential threat. Youngsters often hide amongst the adults for protection. The barren-ground grizzly bears and muskox overlap in their distribution in northern Canada and Alaska. This shaggy beast would appear to be fairly impervious to grizzly attack. But, this is not the case. Grizzlies were originally reported feeding on muskox by early explorers and with recent reintroduction of these ungulates in parts of the Arctic, there have been a number of papers written on the predator-prey relationship of U. arctos and O. moschatus. Below I have reviewed what is known about the barren-ground grizzly predation on muskox. Multiple Hunting Strategy In the Thelon Game Sanctuary, grizzlies and muskox coexist, but the relationship is not always copasetic. Near the Thelon River, bears may use thick willow stands along the waterway to ambush muskox feeding on sedge in nearby clearings. Willows also attract muskox, as it is a preferred food of this beast. Gunn and Miller (1982) report finding a bear on a freshly killed, bull O. moschatus. They were able to scare the adult bear off and examine its kill and concluded that the bear had dispatched the big ungulate by first grasping its nose (crushing the nasal turbine bones and tearing off the nose in the process) and then inflicting a crippling bite to its skull. By grasping the nose, the bear may have prevented the muskox from bringing its horns to bear and also may have been more effective at throwing the animal to the ground. In another study carried out in the northeastern Arctic slopes of Alaska, 92 grizzly-muskox interactions were observed (Reynolds et al. 2002). Fifty percent of these were known kills, 40 % were possible kills or scavenging events, and 10 % were incidents where a grizzly was seen chasing muskox. It was estimated that 16-39 % of muskox mortality was the result of bear predation. During the study period (1982-2001) the number of muskox killed by grizzly bears was zero to two deaths per year before 1993, one to four musk ox per year from 1994-1997 and five to ten deaths per year from 1998-2001. This increase in kill numbers was a function of an increase in the size of musk ox herds. An increase in kills may also be indicative of the bears learning how to better attack and take down these big, formidable animals. While solitary adult bears were most often seen attacking muskox (69 occasions), pairs or trios of adult bears were seen chasing, killing or eating these animals (three episodes). Sows with cubs or yearlings were seen interacting with muskox on three occasions. Surplus Killing Grizzly bears sometimes engage in surplus killing of muskox. In the study carried out by Reynolds et al. (2002) there were ten episodes where one to three bears killed from two to four adult muskox. On several occasions even more muskox were dispatched during a single hunting bout. For example, in one case five individuals (two adult females, a yearling and unsexed adult musk ox) were incapacitated by a single bear. In another case, a grizzly killed four calves and in another incident the victims were one adult female, one two-year old male and one yearling. In most cases, solitary bears were involved in these killing sprees, but in one case three grizzlies instigated the melee. Clarkson et al. (1993) reported a fascinating case of surplus killing of muskox calves by a heterosexual pair of adult grizzlies. Within a distance of about two km, the two bears took down five young musk ox. By doing a little forensic work, the researchers were able to put together a likely picture of what had happened. Rather than form a defensive circle to try and parry the bear attacks, this herd of musk ox tried to out run the grizzlies. The researchers postulated that the calves trailed behind the adults and, therefore, were more vulnerable. The two bears chased the herd, which consisted of 40 to 50 muskox (with a minimum of eight calves). They killed the first calf and ate 90 % of the carcass. They then chased the herd down again and about 1.5-2.0 km from the first kill dispatched a second young musk ox. They ate 60 % of this second calve and began the hunt again. They killed the third calf about 300 m from the second. The third calf was about 30 % consumed by the bears and a wolverine (Gulo gulo) that was feeding on the carcass when the researchers arrived on the scene. The fourth calve was killed 400 m from the third. A golden eagle had just begun to feed on calf four when the researchers arrived. The final calf was killed about 200 m from the fourth – this last young muskox was not eaten either.
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Post by brobear on Mar 17, 2018 4:09:19 GMT -5
www.cbc.ca/news/canada/calgary/grizzly-bear-eats-black-bear-in-banff-1.1414994Grizzly bear eats black bear in Banff 'It may not be as rare as we think,' park official says. Banff's Sundance Canyon trail has reopened after a grizzly bear ate a black bear in the popular hiking area west of Calgary earlier this month. "We closed the trail immediately," said Steve Michel, a human-wildlife conflict specialist with Banff National Park. Michel said he knows of four other instances when a grizzly has hunted, killed and eaten a black bear in Banff. "It may not be as rare as we think it is," he said. "But it is rare that we actually are able to document it. We tend not to know about it all." 'Opportunistic hunters' Michel said he suspects the kill was opportunistic. "Grizzly bears are opportunistic hunters," he said. "They will take advantage of any food source that presents itself." The grizzly that ate the black bear on the Sundance Canyon trail is known to conservation officers. It has been handled and radio collared in the past. The bear is known as Grizzly Bear No. 122. Largest bear in area "Bear 122 is the largest, most dominant grizzly bear on the landscape," the park official said. "Last fall, I would estimate his weight at 650 to 700 pounds, which is enormous for the Rocky Mountains — about as big as grizzly bears get around here." Michel said the black bear was likely a fifth the size of the grizzly. "We know it's a dog-eat-dog world out there, but we're finding out it's a bear-eat-bear world as well," he joked. Right now, it is buffalo berry feeding season in the Rockies, which is the most important time of the year for grizzlies. "They need to put on weight before the fall," Michel said. Campground closure Michel also warned there is increased potential for surprise encounters between bears and humans around now because bears are feeding on buffalo berry patches near populated areas. Campsites at the Crandell Mountain Campground were closed to tents this week in Waterton Lakes National Park, in southern Alberta, because of bear activity in the area. Officials said the berry patches are drawing the animals in, but some bears have also wandered into campsites and tents looking for food. Parks Canada has been trying to deter the bears, including stripping nearby bushes of berries, but the the agency said that isn't working. People with hard-top campers and trailers are still allowed in the area. There was no word on when the restrictions will be lifted.
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Post by brobear on Mar 17, 2018 4:14:30 GMT -5
Above post. Grizzly No. 122 has an estimated weight of from 650 to 700 pounds Autumn weight. His Summer weight ( proper time to weigh bears ) would likely be roughly 500 pounds. I will add: Park rangers who must sometimes dart a bear with drugs must have a keen eye for a bear's weight. Too little drug is dangerous for the rangers. Too much is dangerous for the bear.
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Post by brobear on Mar 30, 2018 19:22:32 GMT -5
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Post by brobear on Sept 26, 2018 2:53:58 GMT -5
A kleptoparasite is an animal that routinely displaces accomplished predators from their kills. Some ( non-bear ) animals of the far distant past ( possibly ) includes Tyrannosaurus rex, Andrewsarchus, and Daeodon. The giant short-faced bears ( Arctodus and Arctotherium ) were probably kleptoparasites. Feeding on Carrion and Prey of Other Predators Brown bears are commonly consuming dead animals found by them (Zavatsky, 1979, Zyryanov, 1979, Kaletskaya, 1981, Zhiryakov, 1987 and Pazhetnov, 1990), including in Sikhote-Alin (Bromlei, 1965, Matyushkin, 1974, Darman, 1982, Yudin, 1993 and Zaitsev and Seryodkin, 2011). The results of the capture of bears conducted by us in the Sikhote-Alin Nature Reserve have shown that they are attracted to carrion (Seryodkin et al., 2005b). In 1992–2001 six brown bears were caught with the use of bait: three animals using meat bait and three — using fish bait. The rate of successful capture was much higher using these baits (560 days/individual), rather than using trails and marked trees (1196 days/individual). Meat baits are consumed by the animals in any season.
Besides dead and wounded animals bears eat the prey of other predators and the remnants of their meals in Sikhote-Alin. Most often, the bears consume prey of tigers and lynxes (Matyushkin, 1974, Kostoglod, 1976 and Seryodkin et al., 2005a). A case of using the prey of yellow-throated marten is known (Zaitsev, 1991). Large bears cannot only eat up remains after tigers, but also chase them off their prey or join the fight (Sysoev, 1966, Kucherenko, 1971, Kostoglod, 1976 and Seryodkin et al., 2005a). In the snow period some bears purposely track tigers and lynxes to find the remains or take away their prey (Kostoglod, 1976 and Seryodkin et al., 2012). According to observations of Kostoglod, the trail of a bear not settled in its lair tracking other predators in order to capture their prey was 22% of the total length of the bear trail (44 km out of 200 km) (Kostoglod, 1976). In the spring before snow melting bears look for animals which died during winter and prey of tigers buried in snow (Seryodkin et al., 2005a). For this purpose bears go along the floodplain of a river or a creek, often leaving the path to examine interesting places, winding, sometimes stopping to sniff. A bear is able to smell the odor of the remains of an animal at a distance of 250 m at a temperature below 0 °C. Bears also go in the footsteps of their relatives, picking uneaten remains of carrion. Snowtracking of three brown bears in the basin of a creek in the Sikhote-Alin Nature Reserve in April revealed that along the 17 km trail the bears have four times found the remains of red deer crushed by tigers during the winter, and once — a whole red deer that died of a broken limb. In three cases other bears have been on these tiger prey before them.
Behavior Near Prey or Carrion Covering the prey with soil, forest cover, branches and other forest products is typical, but not necessary for brown bears in Sikhote-Alin (Matyushkin, 1974). The burial of the prey may be complete when the whole animal is hidden, or partial. Apparently, the act of covering primarily provides saving the prey from spongers, as the bear's prey attracts corvid birds, and the predator guards it from them (Pazhetnov, 1990). On the Kola Peninsula, burying of the remnants allows to distinguish the bear's prey from accidental carrion (Semyonov-Tyan-Shansky, 1972). For the Sikhote-Alin this assumption is not true. Out of 28 known cases of brown bears feeding on dead bodies of animals in 8 cases (28.6%) the burial occurred. Four times out of five bears were burying their prey, twice — the prey of tigers (out of 20), in both cases the tigers were chased off by the bears, and twice the bears buried dead wounded animals found by them. It is clear from these data that the bears are more likely to bury whole carcasses of animals rather than their remains left after other predators. A brown bear may cover its prey after he had already started to eat it (Matyushkin, 1974), or after burying the carcass, may wait for some time without eating it. In the latter case, covering the prey with the forest cover by maintaining the temperature contributes to faster fermentation processes that make fresh meat “ripe” that is more attractive for animals (Korytin, 1998). We know of two cases when brown bears buried dead animals, but did not eat them at once. In the first case, a bear buried a dead wounded boar and returned to the place of burial on the third day. In another case, a brown bear that killed another brown bear covered it with forest cover and left the place without touching the food. For covering a red dear one of predators had to dig up and bring to the center the soil and forest cover from an area of 60 m2. The author also observed Kamchatka brown bears waiting for “ripening” of dead prey. A large male bear began to eat a buried female bear three days after procuring it at Kronotskaya River (Kronotsky Reserve) in September 2003.
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Post by brobear on Sept 26, 2018 3:05:20 GMT -5
www.redorbit.com/education/reference_library/animal_kingdom/mammalia/1112523651/ussuri-brown-bear-ursus-arctos-lasiotus/ Reports of Ussuri brown bears hunting Siberian tigers have been reported. These incidents occur because of disputes over prey or territory. Some bears will change their course if they smell a tiger has passed, while others will follow the tiger’s trail and even sleep in its den. It has even been reported that some Ussuri bears have followed tigers in order to eat the leftovers from its kills. Scientists have dubbed these bears “satellite bears” because of this frequent behavior.
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