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Post by brobear on Jul 21, 2021 6:58:26 GMT -5
I am moving this conversation over to: Amur Tiger vs Ussuri Brown Bear.
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Post by brobear on Aug 28, 2021 6:18:33 GMT -5
www.sciencedaily.com/releases/2021/08/210826095038.htm Carnivore interactions are a game of risk and reward. Coyotes can eat by scavenging cougars' prey but it's a risky proposition as coyotes often end up killed by cougars too, a new study of predator interactions by Oregon State University shows. Researchers in the OSU College of Agricultural Sciences also looked at black bears and bobcats and found the interplay within the four-species "guild" of predators defied simplistic description. Findings, published today in the Proceedings of the National Academy of Sciences, challenge the traditional model for carnivore interactions among species: that dominant predators suppress the other ones. The study, one of the first to quantify rates of both scavenging and intraguild predation, is important because understanding the influence of dominant predators is necessary for anticipating the ecological effects of changes in carnivore populations. Factoring in the study area's cougar and coyote density, the findings suggest nearly one-quarter of the area's coyote population is killed by cougars each year, although in many cases, coyotes did not appear to be killed while scavenging. "That kill percentage estimate implies a strong suppressive effect counteracting the benefit to coyotes provided by the cougars," said Oregon State Ph.D. student Joel Ruprecht. "Overall, the issue of whether subordinate species incur a net fitness cost or benefit from dominant predators is far from resolved." Coyotes seem to readily accept the risk of being near a cougar if a food reward is available, possibly because they can manage the risk by being extra vigilant, he added. Also, if a dominant predator becomes satiated after feeding on a kill, it may not be motivated to kill other carnivores. "Learning whether dominant carnivores kill subordinate carnivores for food or for the long-term benefit of removing a competitor needs to be the focus of further research," said OSU associate professor Taal Levi. Ruprecht, Levi and Ph.D. student Charlotte Eriksson led the study, which also involved scientists from the Oregon Department of Fish and Wildlife, the U.S. Forest Service and the University of California, Santa Cruz. Between 2016 and 2020 in the Blue Mountains of northeastern Oregon, researchers tagged a "guild" of predators -- 17 cougars, 17 coyotes, 11 black bears and six bobcats -- with GPS collars that recorded their location every few hours. Scientists also tested the animals' scat to see what they were eating. "How often elk turns up in the scats of the subordinate predators is a proxy for how much scavenging they're doing because it's unlikely any of them are killing adult elk," Levi said. "That means if they're eating elk it's probably either via scavenging or preying on calves, but in the Blue Mountains coyotes and bobcats rarely kill elk calves; black bears are somewhat more likely to." To further zero in on what the predators were eating, the scientists did ground searches based on clusters of cougar GPS locations -- indicating potential kills -- and set up cameras at 28 of the 128 confirmed kill sites. The cameras allowed for a daily tally of site visits by bears, bobcats and coyotes and thus enabled an estimate of scavenging rates. "The traditional paradigm for species interactions among carnivores has stressed hierarchies: Dominant predators curb the efforts of the next level, the mesopredators," Levi said. "We found evidence of that but also evidence of facilitation. The coyotes we studied had a strong attraction to kill sites, frequent carrion in their diet and high scavenging rates, compared to two indicators of suppression: They avoided cougars and also were preyed on by them." There was no evidence to suggest coyotes' attraction to kill sites was lessened if a cougar was around, he added, indicating coyotes' willingness to disregard cougar risk if a food reward was present. Bears had moderate scavenging rates and ate moderate levels of carrion but showed a statistically significant aversion to being around cougars. Nothing suggested bears were particularly attracted to kill sites or suffered predation at the hands of cougars, or that cougars had any effect at all on bobcats. "Bobcats were indifferent to both cougars and their kill sites," Ruprecht said. "And bobcats weren't avoiding coyotes in general, meaning coyote presence was probably not a primary reason bobcats didn't feed on cougar kills." There were coyotes on the scene at 89% of carcasses, bears at 50% of carcasses outside the hibernation period and bobcats at none of them. Scat analyses showed elk in 58% of coyote scats and deer in 12%, comparable to the percentages for cougar scats (61% and 22%). Bear scats contained elk 29% of the time and deer 8% of the time. No bobcat scats provided evidence they had eaten elk, and 8% of bobcat scats contained deer. "Investigations of the cougar kill sites showed that elk represented 64% and deer 16% of the prey items killed by cougars," Levi said. "Investigations also showed that coyotes represented 7% of cougar kills. In eight cases coyotes were the only prey item found, and in one case a dead coyote was found along with another prey item." The bobcat findings were particularly surprising, he noted, because bobcats are known to scavenge from and be eaten by cougars in other locations, and also because it's usually more likely for a wild cat like a cougar to kill another species of cat than a predator from outside their taxonomic family. "By foregoing the energy benefits they could gain from eating on cougar kills, and in doing so reducing mortality risk, bobcats in our study area approached the risk-reward tradeoff quite differently than the coyotes," he said. "But scavenging is only optimal under a specific set of conditions that also includes the probability of finding other food sources, and the energy required to search for them. The coyotes we studied faced little risk except from cougars and scavenged profusely; they're probably less likely to scavenge when there are lots of competitors for each carcass." Oregon State, the ODFW, the Forest Service's Pacific Northwest Research Station and the Wildlife Restoration Act supported this research.
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Post by brobear on Aug 28, 2021 6:22:04 GMT -5
From #339 - Between 2016 and 2020 in the Blue Mountains of northeastern Oregon, researchers tagged a "guild" of predators -- 17 cougars, 17 coyotes, 11 black bears and six bobcats -- with GPS collars that recorded their location every few hours. Scientists also tested the animals' scat to see what they were eating. Bears had moderate scavenging rates and ate moderate levels of carrion but showed a statistically significant aversion to being around cougars. Nothing suggested bears were particularly attracted to kill sites or suffered predation at the hands of cougars, or that cougars had any effect at all on bobcats.
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Post by OldGreenGrolar on Sept 12, 2021 10:11:17 GMT -5
Carnivore interactions are a game of risk and reward
Date: August 26, 2021 Source: Oregon State University Coyotes can eat by scavenging cougars' prey but it's a risky proposition as coyotes often end up killed by cougars too, a new study of predator interactions by Oregon State University shows. Researchers in the OSU College of Agricultural Sciences also looked at black bears and bobcats and found the interplay within the four-species "guild" of predators defied simplistic description. Findings, published today in the Proceedings of the National Academy of Sciences, challenge the traditional model for carnivore interactions among species: that dominant predators suppress the other ones. The study, one of the first to quantify rates of both scavenging and intraguild predation, is important because understanding the influence of dominant predators is necessary for anticipating the ecological effects of changes in carnivore populations. Factoring in the study area's cougar and coyote density, the findings suggest nearly one-quarter of the area's coyote population is killed by cougars each year, although in many cases, coyotes did not appear to be killed while scavenging. "That kill percentage estimate implies a strong suppressive effect counteracting the benefit to coyotes provided by the cougars," said Oregon State Ph.D. student Joel Ruprecht. "Overall, the issue of whether subordinate species incur a net fitness cost or benefit from dominant predators is far from resolved." Coyotes seem to readily accept the risk of being near a cougar if a food reward is available, possibly because they can manage the risk by being extra vigilant, he added. Also, if a dominant predator becomes satiated after feeding on a kill, it may not be motivated to kill other carnivores. "Learning whether dominant carnivores kill subordinate carnivores for food or for the long-term benefit of removing a competitor needs to be the focus of further research," said OSU associate professor Taal Levi. Ruprecht, Levi and Ph.D. student Charlotte Eriksson led the study, which also involved scientists from the Oregon Department of Fish and Wildlife, the U.S. Forest Service and the University of California, Santa Cruz. Between 2016 and 2020 in the Blue Mountains of northeastern Oregon, researchers tagged a "guild" of predators -- 17 cougars, 17 coyotes, 11 black bears and six bobcats -- with GPS collars that recorded their location every few hours. Scientists also tested the animals' scat to see what they were eating. "How often elk turns up in the scats of the subordinate predators is a proxy for how much scavenging they're doing because it's unlikely any of them are killing adult elk," Levi said. "That means if they're eating elk it's probably either via scavenging or preying on calves, but in the Blue Mountains coyotes and bobcats rarely kill elk calves; black bears are somewhat more likely to." To further zero in on what the predators were eating, the scientists did ground searches based on clusters of cougar GPS locations -- indicating potential kills -- and set up cameras at 28 of the 128 confirmed kill sites. The cameras allowed for a daily tally of site visits by bears, bobcats and coyotes and thus enabled an estimate of scavenging rates. "The traditional paradigm for species interactions among carnivores has stressed hierarchies: Dominant predators curb the efforts of the next level, the mesopredators," Levi said. "We found evidence of that but also evidence of facilitation. The coyotes we studied had a strong attraction to kill sites, frequent carrion in their diet and high scavenging rates, compared to two indicators of suppression: They avoided cougars and also were preyed on by them." There was no evidence to suggest coyotes' attraction to kill sites was lessened if a cougar was around, he added, indicating coyotes' willingness to disregard cougar risk if a food reward was present. Bears had moderate scavenging rates and ate moderate levels of carrion but showed a statistically significant aversion to being around cougars. Nothing suggested bears were particularly attracted to kill sites or suffered predation at the hands of cougars, or that cougars had any effect at all on bobcats. "Bobcats were indifferent to both cougars and their kill sites," Ruprecht said. "And bobcats weren't avoiding coyotes in general, meaning coyote presence was probably not a primary reason bobcats didn't feed on cougar kills." There were coyotes on the scene at 89% of carcasses, bears at 50% of carcasses outside the hibernation period and bobcats at none of them.
Scat analyses showed elk in 58% of coyote scats and deer in 12%, comparable to the percentages for cougar scats (61% and 22%). Bear scats contained elk 29% of the time and deer 8% of the time. No bobcat scats provided evidence they had eaten elk, and 8% of bobcat scats contained deer. "Investigations of the cougar kill sites showed that elk represented 64% and deer 16% of the prey items killed by cougars," Levi said. "Investigations also showed that coyotes represented 7% of cougar kills. In eight cases coyotes were the only prey item found, and in one case a dead coyote was found along with another prey item." The bobcat findings were particularly surprising, he noted, because bobcats are known to scavenge from and be eaten by cougars in other locations, and also because it's usually more likely for a wild cat like a cougar to kill another species of cat than a predator from outside their taxonomic family. "By foregoing the energy benefits they could gain from eating on cougar kills, and in doing so reducing mortality risk, bobcats in our study area approached the risk-reward tradeoff quite differently than the coyotes," he said. "But scavenging is only optimal under a specific set of conditions that also includes the probability of finding other food sources, and the energy required to search for them. The coyotes we studied faced little risk except from cougars and scavenged profusely; they're probably less likely to scavenge when there are lots of competitors for each carcass." Oregon State, the ODFW, the Forest Service's Pacific Northwest Research Station and the Wildlife Restoration Act supported this research. Video: Story Source: Oregon State University. "Carnivore interactions are a game of risk and reward." ScienceDaily. www.sciencedaily.com/releases/2021/08/210826095038.htm (accessed August 31, 2021). Journal Reference:Joel Ruprecht, Charlotte E. Eriksson, Tavis D. Forrester, Derek B. Spitz, Darren A. Clark, Michael J. Wisdom, Marcus Bianco, Mary M. Rowland, Joshua B. Smith, Bruce K. Johnson, Taal Levi. Variable strategies to solve risk–reward tradeoffs in carnivore communities. Proceedings of the National Academy of Sciences, 2021; 118 (35): e2101614118 DOI: 10.1073/pnas.2101614118 Abstract Mesopredator release theory suggests that dominant predators suppress subordinate carnivores and ultimately shape community dynamics, but the assumption that subordinate species are only negatively affected ignores the possibility of facilitation through scavenging. We examined the interplay within a carnivore community consisting of cougars, coyotes, black bears, and bobcats using contemporaneous Global Positioning System telemetry data from 51 individuals; diet analysis from 972 DNA-metabarcoded scats; and data from 128 physical investigations of cougar kill sites, 28 of which were monitored with remote cameras. Resource provisioning from competitively dominant cougars to coyotes through scavenging was so prolific as to be an overwhelming determinant of coyote behavior, space use, and resource acquisition. This was evident via the strong attraction of coyotes to cougar kill sites, frequent scavenging of cougar-killed prey, and coyote diets that nearly matched cougars in the magnitude of ungulate consumption. Yet coyotes were often killed by cougars and used space to minimize encounters, complicating the fitness benefits gained from scavenging. We estimated that 23% (95% CI: 8 to 55%) of the coyote population in our study area was killed by cougars annually, suggesting that coyote interactions with cougars are a complex behavioral game of risk and reward. In contrast, we found no indication that bobcat space use or diet was influenced by cougars. Black bears avoided cougars, but there was no evidence of attraction to cougar kill sites and much lower levels of ungulate consumption and carcass visitation than for coyotes. Interspecific interactions among carnivores are multifaceted, encompassing both suppression and facilitation. www.pnas.org/content/118/35/e2101614118
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Post by brobear on Sept 15, 2021 5:50:29 GMT -5
Quote: Black bears avoided cougars, but there was no evidence of attraction to cougar kill sites and much lower levels of ungulate consumption and carcass visitation than for coyotes. *Quite often, one science study will contradict another. This study was made in Oregon. Black bears avoid cougars. Certainly; why look for trouble. I'm sure that the cougars avoid the adult bears as well. Coyotes eat more red meat that black bears. Of course they do; no surprise. In Oregon, black bears are not attracted to cougar kill sites, while in Montana, black bears regularly visit cougar kill sites. Probably due to completely different foods available. ( IMO ).
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Post by OldGreenGrolar on Sept 15, 2021 6:23:35 GMT -5
Coyotes will eat more red meat than black bears as the former are full time predators.
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Post by brobear on Nov 29, 2021 2:31:39 GMT -5
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Post by OldGreenGrolar on Nov 29, 2021 2:39:50 GMT -5
Cougar vs black bear in a face-to-face confrontation is a mismatch. The black bear is just too big.
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Post by brobear on Nov 29, 2021 7:36:15 GMT -5
Cougar vs black bear in a face-to-face confrontation is a mismatch. The black bear is just too big. Even against a sun bear ( if that were possible ), I would wager on the bear.
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Post by brobear on Dec 15, 2021 17:52:45 GMT -5
Courtesy of King Kodiak: Book, The Works of Theodore Roosevelt: Outdoor pastimes of an American hunter
Author: Theodore Roosevelt, President, Hunter, Naturalist.
"In support of his position Mr Hudson alludes to the stories of cougars attacking the grizzly bear. Here i am on ground that i do know. It is true that an occasional old hunter asserts that the cougar does this, but the old hunter who makes such an assertion also invariable insists that the cougar is a ferocious and habitual man-killer, and the two statements rest upon equally slender foundations of fact. I have never yet heard of a single authentic instance of a cougar interfering with a full-grown big bear. It will kill bear cubs if it gets a chance, but then so will the fox and the fisher, not to speak of the wolf. In 1894, a cougar killed a colt on a brushy river bottom a dozen miles below my ranch on the Little Missouri. I went down to visit the carcass and found that it had been taken possession of by a large grizzly. Both i and the hunter who was with me were very much interested in whar had occured, and after a careful examination of the tracks we concuded that the bear had arrived on the second night after the kill. He had feasted heartily on the remains, while the cougar, whose tracks were evident here and there at a little distance from the carcass, had seemingly circled around it, and had certainly not interfered with the bear, or even ventuted to approach him. Now if a cougar would had ever meddled with a large bear it would surely have been on such an occasion as this."
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Post by kesagake on Dec 16, 2021 3:07:35 GMT -5
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Post by kesagake on Dec 18, 2021 11:54:20 GMT -5
Book, Bears in the Yellowstone Author, Milton Philo Skinner, scientist and educator, who worked for Yellowstone National Park, its concessioners, and its government partners in a variety of positions over more than thirty years. "Some of the Indians and our own pioneer hunters used to tell us that the cougar or mountain lion could kill a full-grown grizzly. But, while i have searched through much literature, i can find no authenticated instance. Personally, i doubt these stories very much. It does not seem likely that the big cat could spring upon him and bite through his heavy hair and thick hide quick enough and far enough to cripple him before the big bear could get into action. In a fair and square set-to the mountain lion would have no chance against the grizzly, superior in every way except the peculiar lithe swiftness of the cat. That might carry its possessor out of danger of the grizzly's rush, but it could not avail before the bear's vastly greater weight and strength in actual battle." books.google.com/books?id=_JQ_AAAAYAAJ&pg=PA123&dq=A+lion+lacks+strength+compared+to+bears&hl=en&newbks=1&newbks_redir=0&source=gb_mobile_search&sa=X&ved=2ahUKEwjCldrRtOf0AhW5TDABHdXVCw8Q6AF6BAgDEAM credits to Pablo
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Post by kesagake on Dec 18, 2021 11:58:39 GMT -5
The Works of Theodore Roosevelt: Outdoor pastimes of an American hunter Author: Theodore Roosevelt, President, Hunter, Naturalist. "In support of his position Mr Hudson alludes to the stories of cougars attacking the grizzly bear. Here i am on ground that i do know. It is true that an occasional old hunter asserts that the cougar does this, but the old hunter who makes such an assertion also invariable insists that the cougar is a ferocious and habitual man-killer, and the two statements rest upon equally slender foundations of fact. I have never yet heard of a single authentic instance of a cougar interfering with a full-grown big bear. It will kill bear cubs if it gets a chance, but then so will the fox and the fisher, not to speak of the wolf. In 1894, a cougar killed a colt on a brushy river bottom a dozen miles below my ranch on the Little Missouri. I went down to visit the carcass and found that it had been taken possession of by a large grizzly. Both i and the hunter who was with me were very much interested in whar had occured, and after a careful examination of the tracks we concuded that the bear had arrived on the second night after the kill. He had feasted heartily on the remains, while the cougar, whose tracks were evident here and there at a little distance from the carcass, had seemingly circled around it, and had certainly not interfered with the bear, or even ventuted to approach him. Now if a cougar would had ever meddled with a large bear it would surely have been on such an occasion as this." books.google.com/books?id=8qVJAQAAMAAJ&pg=PA21&dq=Cougar+killer+by+bear&hl=en&newbks=1&newbks_redir=0&source=gb_mobile_search&sa=X&ved=2ahUKEwj8947qveb0AhWQoXIEHVW1BeA4FBDoAXoECAEQAw credits to Pablo
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Post by kesagake on Dec 18, 2021 12:04:18 GMT -5
The two quotes posted above prove again that "there is no single confirmed account of a cougar killing a full grown grizzly".
In real life biologist proven that cougars are in truth subordinate to bears.
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Post by brobear on Dec 19, 2021 10:21:28 GMT -5
Reply #219... Quote: "The usurpation of puma kills was not without risk, as in one instance a puma killed a subadult black bear that had been feeding on its kill." *So much ( accidentally? ) left out of this statement: 1- The author fails to say that the subadult black bear ( female ) had no problem in displacing the cougar ( also female ) from her kill. 2- The author fails to say that the cougar returned only when hunger desperation drove her to, evidently after failing to make another kill. 3- The author fails to say that the cougar retuned 24 hours from the time she was displaced from her kill and then ambushed and killed the she-bear. 4- The author fails to tell that after owning the deer carcass for 24 hours, the well-fed bear was most likely sleeping when the cougar ambushed her.
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Post by kesagake on Dec 19, 2021 10:45:41 GMT -5
Reply #354 it's the same account of the female cougar killing a female bear in California, this study is from a year after the incident and Elbroch, the one who reported the case, is one of the biologists writing the study. So they are describing this case. This bear was a subadult.
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Post by kesagake on Dec 19, 2021 10:59:23 GMT -5
Verdict: no single confirmed account of a cougar killing a full grown bear. Only 2 confirmed cases are recorded, one of a cougar killing a bear cub in Arizona and the other a large female cougar killing a subadult female black bear in California. In all these confirmed cases the bears were young individuals.
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Post by brobear on Dec 24, 2021 11:41:40 GMT -5
In South America the cougar fares no better. There is not one single case of a cougar ever killing an adult Andean bear. Not by ambush nor by any other method. In a face-off, I would estimate - Andean bear defeats cougar 19 out of every 20 fights.
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Post by kesagake on Dec 24, 2021 12:08:57 GMT -5
Reply #358 yeah, that's my point. Even an Andean bear would beat the Crap out of a puma let alone a baribal and a grizzly.
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Post by brobear on Jan 19, 2022 2:34:31 GMT -5
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