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Post by brobear on May 1, 2021 3:03:25 GMT -5
www.sciencedaily.com/releases/2021/04/210412084554.htm Shift in diet allowed gray wolves to survive ice-age mass extinction. Gray wolves are among the largest predators to have survived the extinction at the end of the last ice age. A new study analysing teeth and bones shows that the wolves may have survived by adapting their diet over thousands of years --- from a primary reliance on horses during the Pleistocene, to caribou and moose today. Gray wolves are among the largest predators to have survived the extinction at the end of the last ice age around11,700 years ago. Today, they can be found roaming Yukon's boreal forest and tundra, with caribou and moose as their main sources of food. A new study led by the Canadian Museum of Nature shows that wolves may have survived by adapting their diet over thousands of years -- from a primary reliance on horses during the Pleistocene, to caribou and moose today. The results are published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology. The research team, led by museum palaeontologist Dr. Danielle Fraser and student Zoe Landry, analysed evidence preserved in teeth and bones from skulls of both ancient (50,000 to 26,000 years ago) and modern gray wolves. All the specimens were collected in Yukon, a region that once supported the Beringia mammoth-steppe ecosystem, and are curated in the museum's national collections as well as those of the Yukon government. "We can study the change in diet by examining wear patterns on the teeth and chemical traces in the wolf bones," says Landry, the lead author who completed the work as a Carleton University student under Fraser's supervision. "These can tell us a lot about how the animal ate, and what the animal was eating throughout its life, up until about a few weeks before it died." Landry and Fraser relied on established models that can determine an animal's eating behaviour by examining microscopic wear patterns on its teeth. Scratch marks indicate the wolf would have been consuming flesh, while the presence of pits would suggest chewing and gnawing on bones, likely as a scavenger. Analysis showed that scratch marks prevailed in both the ancient and modern wolf teeth, meaning that the wolves continued to survive as primary predators, hunting their prey. What then were the gray wolves eating? The modern diet -- caribou and moose -- is well established. The diet of the ancient wolves was assessed by looking at the ratios of carbon and nitrogen isotopes extracted from collagen in the bones. Relative levels of the isotopes can be compared with established indicators for specific species. "The axiom, you are what you eat comes into play here," says Landry. Results showed that horses, which went extinct during the Pleistocene, accounted for about half of the gray wolf diet. About 15% came from caribou and Dall's sheep, with some mammoth mixed in. All this at a time when the ancient wolves would have co-existed with other large predators such as scimitar cats and short-faced bears. The eventual extinction of these predators could have created more opportunity for the wolves to transition to new prey species. "This is really a story of ice age survival and adaptation, and the building up of a species towards the modern form in terms of ecological adaptation," notes Dr. Grant Zazula, study co-author, and Government of Yukon paleontologist who is an expert on the ice-age animals that populated Beringia. The findings have implications for conservation today. "The gray wolves showed flexibility in adapting to a changing climate and a shift in habitat from a steppe ecosystem to boreal forest," explains Fraser. "And their survival is closely linked to the survival of prey species that they are able to eat." Given the reliance of modern gray wolves on caribou, the study's authors suggest that the preservation of caribou populations will be an important factor in maintaining a healthy wolf population.
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smedz
Ursus abstrusus
Recent Graduate
Posts: 410
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Post by smedz on May 30, 2021 10:25:12 GMT -5
www.yellowstonepark.com/things-to-do/wildlife/grizzly-bear-vs-wolves/ Yellowstone Grizzly Bears vs. Wolves For decades, the sole rulers of Yellowstone were grizzly bears. Today, they are learning how to cope with the rise of an equal competitor - the reintroduced gray wolf. Some of the most fascinating things observed during the Yellowstone wolf reintroduction program, which began in 1995, involve the interaction between wolves and grizzly bears, says Doug Smith, the Yellowstone Wolf Project’s leader. More grizzly bears are showing up near wolf dens, and grizzly bears are taking away more wolf kills. Smith says grizzlies are often attracted to wolf dens because of the “stank aroma” existing from the leg bones and other food items the alphas bring back to feed to their young. The grizzlies are more powerful, but the wolves are quicker and out-number the bear, says Smith. “It’s almost like the wolves are the mosquitoes buzzing around the bear’s head,” Smith says. “Although individual mosquitoes can’t overpower you, if there are enough of them, they’ll win. That’s sometimes what happens with grizzlies and wolves. The bear gets near the den, and wolves just annoy the heck out of him.” “The wolves in Yellowstone won’t give up. They just constantly orbit around the bear. I’ve actually seen one wolf bite a bear in the butt when he turned around,” says Smith. But around wolf kills, it’s another story. In these cases, the grizzly is almost always the victor. One time Smith watched as one bear held 24 wolves at bay at a carcass. The wolves had taken down a bull elk, but the bear took over the meal. Another time, he says there were 10 wolves and four bears on a wolf kill. The biggest bear controlled the situation. All of the wolves and the three other bears “sat around and waited for their turn.” Without a doubt, Smith says Yellowstone’s grizzlies are benefiting from the wolves’ presence due to their ability to successfully usurp the large canid’s meals. There has been opposition to the wolf reintroduction program by some ranchers and other groups, but for the most part, the program has been successful without bothering the bears.
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smedz
Ursus abstrusus
Recent Graduate
Posts: 410
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Post by smedz on May 30, 2021 11:41:54 GMT -5
domainofthebears.proboards.com/post/new/518 Gray wolves create balance between predator and prey in Yellowstone Contrary to what some wolf opponents claim, ecology expert says gray wolves in Yellowstone will not wipe out prey, such as elk and deer Scott Creel, an ecology professor at Montana State University, does not think that Yellowstone wolves will wipe out their prey, as some critics of wolf reintroduction fear. Some critics have claimed that wolves will kill all the deer and elk, sterilizing the landscape. That doesn’t make sense to Creel or wildlife biologist Doug Smith. “I studied predators for 10 years in Africa, where there is no control on predators, yet there is an abundant prey base on the Serengeti plains,” Creel said. Predators and prey balance out, he said, and Smith agreed. “What I see is an evolutionary arms race between elk and wolf,” Smith said. Wolves are not super-predators and healthy elk are tough to kill, he said. Neither side is so formidable as to wipe out the balance between the two species, he said. “They’re pretty evenly matched,” Smith said. Wolves can and do get injured or even killed when fang is countered by muscle, mass, horn and hoof. “Wolves are having a harder time,” Smith said, because there are both fewer elk in the Yellowstone National Park and the herd has fewer individuals with problems – the old, sick or injured. A decade ago, elk population density was as high as 13-15 per square kilometer, Smith said. Today, it is down to 6-7 per square kilometer. “Wolves are capable predators, but they’re not super-predators,” Smith said. Population plateaus Creel and Smith agree that as the prey base gets smaller, so do predator numbers. Indeed, in 2011, for the first time since wolves were reintroduced to the park, wolf numbers appear to have hit a population plateau. Smith estimates about 169 wolves in 15 packs in the park in 2011, down from 174 the year before, indicating wolves could be approaching the carrying capacity of the park. In 2014 the wolf count was 104. Competition between packs has intensified, Smith said, while packs are beginning to run up against food limits. That means that wolves will kill members of rival packs. Even when a pack has a larger than expected number of pups, their survival rate is not as great as it was even a few years ago, Smith said, because there is less food. Surprises About Wolf Packs Smith and other biologists characterize the past decade as a series of surprising discoveries about wolves and wolf behavior. The classic pattern of a pack limiting breeding to an alpha male and an alpha female didn’t always hold true. “We had one pack the winter of 2010-2011 that had four breeding pairs,” Smith said. “That’s pretty rare, because most packs hold to the classic norm of a single breeding pair.” Some packs had multiple breeding pairs and large numbers of pups, leading some wolf critics to predict that wolves would breed and eat until there was no prey base left. That’s the most persistent wolf myth Smith encounters as he speaks to groups. The myth hasn’t happened, as a predator-prey balance continually reasserts itself, said Smith. In the past few years, packs that have had large numbers of pups have also had pup survival rates more in line with average packs, he said.
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Post by King Kodiak on Jun 4, 2021 9:23:12 GMT -5
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Post by kesagake on Jun 6, 2021 14:41:35 GMT -5
Can I just ask a question: Is that true? Tigers almost caused Wolves extinction in Russia? I saw Tiger Fanboys saying that.
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Post by King Kodiak on Jun 6, 2021 15:51:57 GMT -5
Can I just ask a question: Is that true? Tigers almost caused Wolves extinction in Russia? I saw Tiger Fanboys saying that. That's what it looks like, there is several reports on that. Maybe its because wolves are direct competitors with tigers, and tigers eliminate them. Anyways, it would be great to know the opinion of our wolf expert, thenormalguy.
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Post by brobear on Jun 6, 2021 17:47:56 GMT -5
Big cats will eliminate as much predator competition as they possibly can. Brown bears are better off with other predators living within their domains. Big difference.
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Post by brobear on Jun 7, 2021 0:54:48 GMT -5
( IMO ) A full-grown male Ussuri brown bear is roughly 98% immune to a tiger attack. It is possible ( in theory ) for a bigger than average male tiger to ambush and kill a smaller than average full-grown male brown bear which weighs less than himself. Of course, this possibility does not remove the full-grown male brown bear from his spot at the top of the food chain in the RFE. Edit and add - RFE ( Russian Far East )- Carnivores and Omnivores listed as top of the food chain ( IMO ): 1- adult male brown bear. 2- adult male tiger. 3- adult female brown bear. 4- adult male black bear. 5- adult tigress. 6- adult female black bear. 7- wolf pack. 8- wild boar. 9- leopard.
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Post by OldGreenGrolar on Jun 8, 2021 15:28:09 GMT -5
Big cats will eliminate as much predator competition as they possibly can. Brown bears are better off with other predators living within their domains. Big difference. Other predators in a brown bear’s Domain, easy access to meat. Big cats also usurp from predators weaker than them but having other predators in their territory also means less meat for them.
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Post by King Kodiak on Jun 9, 2021 18:42:01 GMT -5
I would put a wolf pack above adult tigress and adult female black bear, IMO.
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Post by brobear on Jun 10, 2021 2:24:50 GMT -5
I would put a wolf pack above adult tigress and adult female black bear, IMO. It's not what they can do, but what they do. I haven't seen any recorded events of wolves killing adult female bears or female tigers, even though a wolf pack is clearly capable. If we place the wolf pack according to what they are capable of doing, then they would take the number #1 spot. But; I see clearly that the proper placement of a large healthy wolf pack is highly debatable.
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Post by kesagake on Jun 10, 2021 3:58:32 GMT -5
( IMO ) A full-grown male Ussuri brown bear is roughly 98% immune to a tiger attack. It is possible ( in theory ) for a bigger than average male tiger to ambush and kill a smaller than average full-grown male brown bear which weighs less than himself. Of course, this possibility does not remove the full-grown male brown bear from his spot at the top of the food chain in the RFE. Edit and add - RFE ( Russian Far East )- Carnivores and Omnivores listed as top of the food chain ( IMO ): 1- adult male brown bear. 2- adult male tiger. 3- adult female brown bear. 4- adult male black bear. 5- adult tigress. 6- adult female black bear. 7- wolf pack. 8- wild boar. 9- leopard. Wild Boars and Black Bears are mainly herbivores and pack of wolves have killed American black bears.
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Post by brobear on Jun 10, 2021 4:12:42 GMT -5
Quote: Wild Boars and Black Bears are mainly herbivores and pack of wolves have killed American black bears. *Wolves probably have killed adult black bears, although I have not come across any confirmed accounts of this - although I have not searched. We are talking here about the Asiatic, but what's true for one is generally true for the other. As for tigress and wolves... ? But I see your point... maybe a change is in order. RFE ( Russian Far East )- Carnivores and Omnivores listed as top of the food chain ( IMO ): 1- adult male brown bear. 2- adult male tiger. 3- adult female brown bear. 4- adult male black bear. 5- wolf pack. 6- adult tigress. 7- adult female black bear. 8- wild boar. 9- leopard.
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Post by King Kodiak on Jun 10, 2021 10:47:42 GMT -5
Because i really dont see an adult tigress or a an adult female black bear ever being dominant or getting the better of an interaction with a pack of wolves. And to be honest, thinking about it good, i dont see an adult male black bear winning either. Like Kesagake said, American black bears are subordinate to wolf packs. They are dominant over lone wolfs, but lose to wolf packs most times.
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Post by brobear on Jun 10, 2021 11:40:53 GMT -5
Because i really dont see an adult tigress or a an adult female black bear ever being dominant or getting the better of an interaction with a pack of wolves. And to be honest, thinking about it good, i dont see an adult male black bear winning either. Like Kesagake said, American black bears are subordinate to wolf packs. They are dominant over lone wolfs, but lose to wolf packs most times. According to what source? I have watched documentaries ( more than one ) of a large pack of wolves attempting to harass a mother grizzly to separate her from her cubs. Those wolves probably succeed from time-to-time, but not on any documentary that I have watched. A male Ussuri black bear is as big or bigger than a grizzly she-bear ( on average ). We are talking about inland grizzly. The wolves are after the cubs, and do not even attempt an actual attack on the adult she-bear. Notice that I did place the wolf pack above the tigress and the she-bear; even though I have read no reports of either being killed by wolves.
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Post by King Kodiak on Jun 10, 2021 12:39:41 GMT -5
I said pack of wolves are dominant over American black bears, not female grizzly bears. And here is the source:
Reply #159:
domainofthebears.proboards.com/post/24372/thread
Lone Wolf, Canis lupus, Displaced from a Kill by an Adult Black Bear, Ursus americanus, in Northeastern Alberta
Wolf (Canis lupus) packs are generally competitively dominant over Black Bears (Ursus americanus); however, less is known about lone Wolf-Black Bear interactions. We report an observation of a lone Wolf and an adult Black Bear at a kill made by the Wolf in northeastern Alberta. In this instance, the bear chased the Wolf from the kill site. Our observation supports the hypothesis that Wolf-Black Bear interactions may fit the pattern of asymmetrical interference competition when the interaction involves a lone Wolf rather than a pack.
There is extensive literature documenting gray wolves as the dominant competitor to black bears and cougars, through both interference competition (demonstrated by usurping prey carcasses and direct mortality; Ballard et al. 2003;Kortello et al. 2007;Hebblewhite and Smith 2010;Elbroch et al. 2015b) and exploitation competition (demonstrated by prey switching and spatiotemporal shifts by the subordinate competitors; Kortello et al. 2007;Ruth and Murphy 2010;Bartnick et al. 2013;Elbroch et al. 2015b). Wolves achieve this competitive domi- nance through their social nature, as cougars and black bears are able to overpower and even kill lone wolves (Rogers and Mech 1981;Ballard et al. 2003;Jimenez et al. 2008;Fremmerlid and Latham 2009). Through their capacity to effectively kleptoparisitize cougar kills, black bears have also demonstrated their ranking as a dominant competitor to cougars and can pose significant constraints on cougar fitness ( Murphy et al. 1998;Ruth and Murphy 2010;Elbroch et al. 2015a). ...
First, a sympatric predator such as an American Black Bear, a Coyote, or a Red Fox could have found the den site, destroyed it as it attempted to gain access to one or more pups that were hiding, and killed and eaten the pup that we found (i.e., interspecific predation). However, while there have been a few accounts of mature American Black Bears chasing off (or in one instance killing) lone wolves (Joslin 1966;Rogers and Mech 1981;Fremmerlid and Latham 2009), we are unaware of any instances where these species have attacked a Gray Wolf den or killed Gray Wolf pups. Furthermore, although these opportunistic predators may be capable of attacking and killing Gray Wolf pups, they have been shown to be the loser in competitive interactions with Gray Wolves, particularly in a pack (e.g., Carbyn 1982;Peterson 1995;Ballard et al. 2003). ...
www.researchgate.net/publication/233398670_Lone_Wolf_Canis_lupus_Displaced_from_a_Kill_by_an_Adult_Black_Bear_Ursus_americanus_in_Northeastern_Alberta
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Post by brobear on Jun 10, 2021 12:59:15 GMT -5
OK; a wolf pack can displace an American black bear from a carcass. A few things to note; ( 1 ) the black bear is even less dependent on meat as a brown bear; ( 2 ) the wolves use harassment to cause the bear too much confusion to enjoy a meal. They are probably ( for a male bear ) more of an annoyance than a threat. Nevertheless, the wolves take dominance over the black bear if they take the carcass. However, the Ussuri black bear is bigger and more aggressive that the American black bears west of the Mississippi - 400 pounds and up. I would like to see video ewvidence or a biological report. *Edit and add: I seriously doubt that a wolf pack will risk a fight against a 400+ pound Asiatic black bear.
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Post by King Kodiak on Jun 10, 2021 13:13:40 GMT -5
Well, i have never seen a scientific study on the weights of the Ussuri black bear, all we have is the Bear conservation site which has them up to 200 kg (440 lbs) at their max weight.
Reply #2:
domainofthebears.proboards.com/post/21450/thread
This source from Shaggygod has them up to 550 lbs:
Reply #12:
domainofthebears.proboards.com/post/26496/thread
Anyhow, i have never seen the Ussuri black bear best anything, not a wolf, not an Amur leopard, and certainly not an Amur tiger. And never seen any predation feats either. At least for the ABB we have seen predation feats and displacement of lone wolves and cougars.
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Post by brobear on Jun 10, 2021 13:34:17 GMT -5
The Ussuri black bear is the biggest and strongest of the Asiatic black bears. shaggygod.proboards.com/thread/726/ursus-thibetanus-ussuricusThe Asiatic black bear inhabiting the south of the Russian Far East (RFE) belongs to Ussury subspecies (Ursus thibetanus G. Cuvier 1823). This is the northeastern edge of the species' range. These animals are characterized by black color, a prominent crescent-shaped marking on the chest, and large rounded ears. Mature males are up to 2m in height, and in autumn, after accumulating fat, weigh up to 250 kg. Females are smaller. ( 250 kg = 551.16 pounds ). en.wikipedia.org/wiki/Eurasian_wolf#Conflicts Many Eurasian wolf populations are forced to subsist largely on livestock and garbage in areas with dense human activity, though wild ungulates such as moose, red deer, roe deer and wild boar are still the most important food sources in Russia and the more mountainous regions of Eastern Europe. Other prey species include reindeer, argali, mouflon, wisent, saiga, ibex, chamois, wild goats, fallow deer, and musk deer. *Note: bears are not listed on the wolf's menu.
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Post by brobear on Jun 10, 2021 14:29:19 GMT -5
Here, once again, we run into a brick wall. I can find no information on the Ussuri black bear and the Eurasian grey wolf interactions in the wild.
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