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+----- Thread: Bears as Predators ~ (/topic-bears-as-predators)
RE: Bears as Predators ~ - Wolverine - 03-10-2019
Here we can see that brown bear from Carphatian mountains in Romania (Transylvania) is actually equal in size with Ussuri brown bear from RFE:
https://www.bearbiology.org/fileadmin/tpl/Downloads/URSUS/Vol_9/Kalabar_Negrutiu_et_al_Vol_9.pdf
*This image is copyright of its original author
Average weight for adult males in Romania is 268 kg, for RFE - 264 kg, body length for males in Romania is 217,7 cm , for RFE - 196 cm.
*This image is copyright of its original author
*This image is copyright of its original author
RE: Bears as Predators ~ - brobear - 03-10-2019
Perhaps also, there was more game such as deer and boar. Perhaps also wolves. Just guessing. Edit and add: Thomas did some searching. Too much time has passed and he cannot relocate the Old Roman Games recorded and translated. I was also interested. But we do know they exist.
*Another edit and add: https://www.linkedin.com/pulse/short-history-scotlands-bears-david-hetherington
A short history of Scotland's bears
Published on May 16, 2016
Following on from my previous post about Scotland's extinct elks, I thought I'd follow it up with another, this time on our long-lost brown bears.
We know from a variety of sources that Scotland once had brown bears. Firstly, their bones have been discovered at a variety of sites, from Dumfriesshire in the extreme south to Caithness in the far north. This includes a near complete skeleton found in the bone caves near Inchnadamph in the north west corner of the Highlands (where my profile photo was taken). The youngest carbon-date so far from these bones was around 2700 years old. As with the elks, this shouldn't be interpreted as being the date of their extinction in Scotland. The cultural evidence suggests a much more recent occurrence here.
We know from the surviving works of Roman writers that bears from Caledonia were revered and prized in the arena for their large size and ferocity. Indeed during the opening festivities of the Coliseum in AD80, a Caledonian bear was unleashed on a bound and defenceless criminal for the entertainment of 50,000 people!
Bears were also depicted on several Pictish stone carvings dating from around the 8th and 9th centuries AD, including from Shetland, Easter Ross, Angus and Perthshire. The Gaelic word for bear is mathan. This has given us the modern Scottish surname of Mathieson, which is an anglicisation of MacMathan, literally 'Son of Bear'.
We don't know exactly when bears became extinct in Scotland, but it's likely they fell victim, perhaps in the later Middle Ages, to a mixture of deforestation, over-hunting and persecution arising from their likely attacks on livestock. The Cairngorms area may have been the last part of Britain to retain landscape-scale woodland cover, and could well have been the last stronghold of the Scottish, and indeed British, bear.
However, the most recent example of a free-ranging member of this species to wander the wilds of Scotland (just as with the elk curiously enough) was an escaped male named Hercules. While being filmed for a TV advert on Benbecula in the Outer Hebrides in 1980, Hercules the tame bear gave his handler, Andy Robin, the slip and went missing for over 3 weeks. He was eventually spotted swimming in the sea, tranquilised and then reunited with Andy, very hungry but otherwise unharmed.
RE: Bears as Predators ~ - GreenGrolar - 04-12-2019
Regarding bears as predators, only the polar bear today is almost a pure predator, however,the plasticene grizzly which has 85% of its diet as meat is a second close. Somebody posted an account of a barren ground grizzly hunting seals, therefore a polar bear should be able to learn how to hunt bovids. Black bears can be fearsome predators occasionally especially the big males according to Big Bons.
RE: Bears as Predators ~ - Shadow - 04-12-2019
(04-12-2019, 01:57 PM)GreenGrolar Wrote: Regarding bears as predators, only the polar bear today is almost a pure predator, however,the plasticene grizzly which has 85% of its diet as meat is a second close. Somebody posted an account of a barren ground grizzly hunting seals, therefore a polar bear should be able to learn how to hunt bovids. Black bears can be fearsome predators occasionally especially the big males according to Big Bons.
Most bears are very capable predators, when needed. In that way there is no significant difference between for instance polar bears and brown bears. But of course brown bears have evolved in different environment and have many other food choices than polar bears, so they hunt mostly after hibernation when too early to find so much other food sources. So it is not so much about capability to do something, but about it, that what is needed in different times of the year.
RE: Bears as Predators ~ - Sully - 06-06-2019
Bear predation on muskox
*This image is copyright of its original author
*This image is copyright of its original author
https://www.adfg.alaska.gov/static/home/library/pdfs/wildlife/propubs/reynolds.pdf
RE: Bears as Predators ~ - epaiva - 06-06-2019
(03-10-2019, 10:49 AM)Wolverine Wrote: Here we can see that brown bear from Carphatian mountains in Romania (Transylvania) is actually equal in size with Ussuri brown bear from RFE:@Wolverine
https://www.bearbiology.org/fileadmin/tpl/Downloads/URSUS/Vol_9/Kalabar_Negrutiu_et_al_Vol_9.pdf
*This image is copyright of its original author
Average weight for adult males in Romania is 268 kg, for RFE - 264 kg, body length for males in Romania is 217,7 cm , for RFE - 196 cm.
*This image is copyright of its original author
*This image is copyright of its original author
Thanks for your valuable information
RE: Bears as Predators ~ - Sully - 06-10-2019
More on 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."
References:
Clarkson, P. L. and I. Sarma Liepins. 1993. Grizzly bear, Ursus arctos, predation on muskox, Ovibos moschatus, calves near the Horton River, Northwest Territories. Canadian Field Nat.107:100-102.
Gunn, A. and F. L. Miller. 1982. Muskox bull killed by a barren-ground grizzly bear, Thelon Game Sanctuary, N.W.T. Arctic 35:545-546.
Reynolds, P. E., H. V. Reynolds and R. T. Shideler. 2002. Predation and multiple kills of muskoxen by grizzly bears. Ursus 13:79-84.
RE: Bears as Predators ~ - Sully - 06-11-2019
Bear grapples with caribou and prevails
RE: Bears as Predators ~ - BorneanTiger - 06-11-2019
(03-10-2019, 10:49 AM)Wolverine Wrote: Here we can see that brown bear from Carphatian mountains in Romania (Transylvania) is actually equal in size with Ussuri brown bear from RFE:
https://www.bearbiology.org/fileadmin/tpl/Downloads/URSUS/Vol_9/Kalabar_Negrutiu_et_al_Vol_9.pdf
*This image is copyright of its original author
Average weight for adult males in Romania is 268 kg, for RFE - 264 kg, body length for males in Romania is 217,7 cm , for RFE - 196 cm.
*This image is copyright of its original author
*This image is copyright of its original author
Speaking of the Carpathian Mountains,
a German guy who was hiking with his English girlfriend in the Carpathian mountains of southern Romania, even though they were warned by priests not to scale the mountains, got attacked by a 6-foot tall mother bear, getting his leg ripped in the process, before heeding his girlfriend's advise to punch it in the eye, which made the mother bear flee: http://www.ladbible.com/community/inspirational-man-survives-bear-attack-by-punching-it-in-the-face-20190609
*This image is copyright of its original author
In another case, a Russian guy who was illegally trying to collect deer antlers in Siberia, so that he could sell them in the black market, almost got killed by a brown bear, before biting its tongue off, and thus scaring him, but now, he's injured and there's a police case against him: https://www.news18.com/news/buzz/man-vs-wild-russian-man-bites-off-bears-tongue-to-escape-jaws-of-death-in-siberia-2182055.html
RE: Bears as Predators ~ - Shadow - 11-23-2019
Grizzly hunting elks, catching a calf.
RE: Bears as Predators ~ - Shadow - 12-07-2019
I´m not sure if this has been shared here before so I put this here just in case. People can make some calculations if knowing how many bears there are in the forests of Alaska.
Quote: "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."
Quote: "Adult grizzly bears consumed adult moose in 7- 14 days. Accurate estimates of days required for grizzly bears to consume adult moose carcasses were obtained in four instances in which single bears or family groups were observed on or immediately adjacent to carcasses (< 100 m) during consecutive daily flights; the bears completely consumed the carcasses before departing. The handling times were as follows: (i) an 11-year-old male grizzly spent 14 days on an adult bull during October, (ii) an 11-year-old male spent 8 days on an adult cow during September, (iii) an adult female and one 2-year-old cub spent 7 days on an adult cow during June, and (iv) an adult female and two 2-year-old cubs spent 7 days on an adult bull during June."
https://www.researchgate.net/publication/238015031_Predation_on_moose_and_caribou_by_radio-collared_grizzly_bears_in_east_central_Alaska
RE: Bears as Predators ~ - Shadow - 12-08-2019
One thing about brown bear diet, I´ve seen many times people saying that bears eat mostly other things and only 10-20 % meat. For instance in Finland estimation is, that approximately 70% is other food sources. That means, that almost 1/3 of bear diet is meat and with some bears it can be slightly more.
Quote:
"The bear is omnivorous. Its diet consists of berries, grain, fish, insects, birds and mammals. The bear will hunt deer and moose and also feed on carcasses. However, a majority of the bear's diet, around 70%, consists of something other than meat. A bear may leave behind a broken anthill or tree stump as it looks for insects to eat and it will also check under the bark of fallen trees for larvae."
That is quite a lot actually. I wonder how much cartoons etc. have modified thoughts of people to that direction that bears wouldn´t be very capable predators. People who have met bears in the woods in close range tell often how surprised they have been about it, that so big animal can move so silently and quickly. It´s not "Winnie the Pooh" :)
RE: Bears as Predators ~ - Spalea - 12-08-2019
@Shadow :
"The only one thing that a bear doesn't eat is the stone"... I heard this "sentence" a long time ago and I remembered it. That seems very true.
And despite a bad sight, his lone weakness, one never has to underestimate his capacities of predator. Hearing and sense of smell quite perfect, very silent walk if he has to. And of course his capacities of running at full speed.
Tamers of circus often say that bears are much more dangerous to train than lions and tigers. Especially because they know perfectly well how to conceal their intent.
RE: Bears as Predators ~ - Shadow - 12-08-2019
(12-08-2019, 01:38 PM)Spalea Wrote: @Shadow :
"The only one thing that a bear doesn't eat is the stone"... I heard this "sentence" a long time ago and I remembered it. That seems very true.
And despite a bad sight, his lone weakness, one never has to underestimate his capacities of predator. Hearing and sense of smell quite perfect, very silent walk if he has to. And of course his capacities of running at full speed.
Tamers of circus often say that bears are much more dangerous to train than lions and tigers. Especially because they know perfectly well how to conceal their intent.
What comes to it, that sight isn´t the best sense of the bear, that is good for people with weapons hunting them. What comes to other animals, they don´t have such advantage. And when closer, the bear will see good enough
RE: Bears as Predators ~ - Spalea - 12-09-2019
" Unimaginable Strength. Grizzly bear drags and finishes off a moose. "