American bison interactions with predators

[Gorilla king]

"I do not know, though, of any record of a puma actually killing a full-grown bison."







books.google.com.ar/books?id=pzlBAAAAYAAJ&q=do+not+know+

[brobear]

Quote: "I do not know, though, of any record of a puma actually killing a full-grown bison."

*I would have to see some really good evidence to believe that. I have humongous doubts.

[arctozilla]

There are 2 accounts of pumas attacking bisons but those are hunting accounts. Not reliable at all.

[Gorilla king]

Oct 4, 2022 2:46:41 GMT -5 arctozilla said:

There are 2 accounts of pumas attacking bisons but those are hunting accounts. Not reliable at all.

Adult male bisons?

[Gorilla king]

3 adult male pumas working together (which they dont) are needed to kill an adult male bison, and even that's doubtful. The historic bovid would wreck the kitty cat, even by ambush, simple as that.

[Gorilla king]

On two occasions, coyotes wandering into a herd of bison at the National Bison Range were horned and trampled to death (McHugh 1958).







books.google.com.ar/books?id=GabwAAAAMAAJ&q=On+two+occasions

[Gorilla king]

Bison are rarely killed by wolves on the Northern Range, typically only when individuals are weakened by starvation or injury (Smith et al. 2000).







books.google.com.ar/books?id=CLcsAQAAMAAJ&q=Bison+are+rarely+killed+by+wolves+on+the+Northern+Range+;+typically+only+when+individuals+are+weakened+by+starvation+or+injury+(+Smith+et+al+.+2000+)+.+Most+bison+killed+by+wolves+have+been+recorded+in+Central+YNP+where+elk+are+...&dq=Bison+are+rarely+killed+by+wolves+on+the+Northern+Range+;+typically+only+when+individuals+are+weakened+by+starvation+or+injury+(+Smith+et+al+.+2000+)+.+Most+bison+killed+by+wolves+have+been+recorded+in+Central+YNP+where+elk+are+...&hl=en&sa=X&ved=2ahUKEwiy9IPC8aT7AhURtJUCHQ3AARYQ6AF6BAgGEAM

[Gorilla king]

Bison between two and five years were relatively immune to wolf predation.







books.google.com.ar/books?id=EINFAQAAIAAJ&q=Predation+rates+were+highest+in+1979-1980+when+the+Hornaday+River+pack+was+largest+

[Gorilla king]

In Northern YNP, most of the bison eaten by wolves are from scavenged carcasses rather than kills (Metz et at. 2012). And in Yellowstone's Pelican Valley, wolves commonly scavenge bison remains when bison are invulnerable.







books.google.com.uy/books?id=BJbICQAAQBAJ&pg=PA114&dq=In+northern+YNP

[Jiren]

Kodiak bear vs wood bison, who wins? I’m going Kodiak. Since Grizzlies already kill adult American bison.

[Gorilla king]

Feb 9, 2023 20:24:51 GMT -5 Jiren said:

Kodiak bear vs wood bison, who wins? I’m going Kodiak. Since Grizzlies already kill adult American bison.

There are rarely any accounts of grizzlies killing adult bison, much less healthy males. Kodiak bears average around 1050 lbs, wood bison average around 2080 lbs, double the weight of the bear, wood bisons have shoulder and head adaptations that make them the best head butter of all bovids, it also has brain protection, and a very thick neck, the horns are placed straight forward. As much as i like the Kodiak bear, forget it, Wood bison would win 8/9 out of 10 times. The bear is getting rammed or gored to death.

[Jiren]

I disagree. I’d still favor the Kodiak bear. There’s a handful full of adult bisons killed by grizzlies.

I wonder, how much bigger is a wood bison than a American bison?

[Gorilla king]

Feb 10, 2023 17:50:52 GMT -5 Jiren said:

I disagree. I’d still favor the Kodiak bear. There’s a handful full of adult bisons killed by grizzlies.

I wonder, how much bigger is a wood bison than a American bison?

Plains bison average 832 kg (1834 lbs), that's 234 lbs less than the wood bison, but still a huge weight advantage over the Kodiak:

Reply #26:

beargorillarealm.proboards.com/post/1176/thread

There’s a handful full of adult bisons killed by grizzlies.

Most are adult females though, there are several of bull bison, but most of those could be when the bisons are at their weakest. Bull bison is the least prey choice for the bear, just too large and dangerous:

"On the basis of circumstantial evidence and an observed attack by 2 subadult brown bears that drew blood from a lone adult bison (Bison bison), brown bears are suspected to occasionally kill young bison, although none has been confirmed (M. Meagher 1973 and pers. commun.). Observations have also been made of individual brown bears testing lone bison by approaching them and then leaving when the bison ignored them, refused to run, and kept on feeding (M. Meagher pers. commun.). Healthy adult male bison may be too large and well armed for a bear to attack without risk of serious injury to itself. Testing likely helps a bear to identify a sick or weak animal. Bison also have a clumped distribution, especially during critical periods such as calving (Calef and Van Camp 1987), which may also make predation by bears difficult. In a review of historical material, Roe (1970) found evidence of brown bears scavenging on dead bison but it appears that predation was uncommon."

Stirling, I. and AE Derocher. 1990. Factors affecting the evolution and behavioral ecology of the modern bears. International Conference on Bear Research and Management 8:189–204.

beargorillarealm.proboards.com/post/805/thread


Here is a young grizzly that took a long time to kill a yearling plains bison

[Jiren]

That video you posted was a (2-4 subadult) smaller bear vs a bigger bison. There are reports on it.

Yeah, adult male bison are no joke. But bears have become habitual bison-killers (in general), though.

Adult bisons interact with Yellowstone grizzlies right? I found a recent (Dec 2020) study suggesting males average 413 (heaviest 717 lbs). What do you think about this average. Kodiaks average way higher than that..

[oldindigosilverback]

Feb 9, 2023 20:24:51 GMT -5 Jiren said:

Kodiak bear vs wood bison, who wins? I’m going Kodiak. Since Grizzlies already kill adult American bison.

I like to point out one thing. Grizzlies have more experience with bovines than Kodiak bears do.

However, a kodiak being a brown bear subspecies could eventually learn how to handle them in my opinion.

Back to topic, I think the bison wins more often than not too.

The only bears capable of taking down a full grown bull bison might be exceptionally large male brown and polar bears.

[oldindigosilverback]

Barren ground grizzlies have learn to take down musk oxens twice their weight although it is probably done by ambush as the latter is much heavier but they are way more carnivorous than the Kodiak bears are.

Peninsula Alaskan brown bears and Californian grizzlies can handle bisons better than Kodiak bears as well.

Van, the exceptionally large Peninsula Alaskan brown bear vs American bison bull? Who wins .

[Gorilla king]

Feb 10, 2023 19:26:00 GMT -5 Jiren said:

That video you posted was a (2-4 subadult) smaller bear vs a bigger bison. There are reports on it.

Yeah, adult male bison are no joke. But bears have become habitual bison-killers (in general), though.

Adult bisons interact with Yellowstone grizzlies right? I found a recent (Dec 2020) study suggesting males average 413 (heaviest 717 lbs). What do you think about this average. Kodiaks average way higher than that..

The bison was a yearling (1 year old), and that bear had trouble. A full grown healthy bison would murder a kodiak, just too large, durable, probably more stamina. Where do you see bears becoming "habitual bison killers" ? Bears stay clear of the bull bisons, barely any accounts on record,  5/6 at most, most likely at its weakeast.

Yellowstone grizzlies average 470 lbs:

Reply #3:

beargorillarealm.proboards.com/post/860/thread

Kodiaks average around 1050 lbs, still too small.

[oldindigosilverback]

/\ The male polar bears from Foxe Basin will stand the best chance to take down bull bisons. Even then it will not be easy.

[Gorilla king]

Feb 10, 2023 21:44:28 GMT -5 oldindigosilverback said:

/\ The male polar bears from Foxe Basin will stand the best chance to take down bull bisons. Even then it will not be easy.

Might be 50%, IMO.

[Gorilla king]

Of the bison carcasses, adult female bison "were the most consistently and heavily scavenged by grizzly bears."





In a review of historical material, Roe (1970) found evidence of brown bear scavenging on dead bison, but it appears that predation was uncommon.




Predation on bison by grizzly bears is rare, but some bears prey more on bison than others (Varley and Gunther 2002, Wyman 2002).