Interspecies Conflict/Interspecies conflict
How many Mexican Gray Wolves would it take to bring down a American Bison?
American Black Bear vs Jaguar
Bull Shark vs alligator
American Alligator vs American Crocodile
Golden Eagle vs Bald Eagle
Grizzly bear/Kodiak Bear/polar bear vs guar
Q: How many Mexican Gray Wolves would it take to bring down a American Bison?
A: A Mexican gray wolf (Canis lupus baileyi) is only 2/3rd the weight of a typical grey wolf (Canis lupus). A pack of Mexican gray wolves can predate upon elk, but a bison is twice as heavy as an elk (and weighs as much as 25 of these wolves). Mexican gray wolves won't take on a dangerous herbivore the size of an American bison because of the risk, but if they were determined to do so anyway (and willing to sacrifice members in the process), it would take at least 10 to do so with any level of consistency.
American Black Bear vs Jaguar: The black bear will weigh about 70% more than the jaguar. Black bears aren't as aggressive or formidable as brown bears, but they are still capable fighters with the attributes shared by various bears (great strength & endurance, large paws & claws, durability). Jaguars are considered to be the strongest cat pound-for-pound, and have tremendously strong jaws that can bite through turtle shells & caiman armor. Jaguars use their stocky, muscular builds to effectively grab & control adversaries, and work themselves into a position to kill with a crushing bite to the skull or spine. The carnivorous jaguar will be more accustomed to combat than the omnivorous black bear, but it won't be large enough to deal with the ursid's offense (bites & paw swipes). A jaguar can compete with any animal in its weight range, but a black bear will usually be too heavy. Black bear wins.
Bull Shark vs Alligator: The alligator will weigh about 40% more than the bull shark. Sharks aren't adept at face-to-face conflict, but are great at ambushing prey (bite & retreat). Alligators are also ambush predators, and use their vice-like jaws to clamp onto prey with tremendous force & drag the victim into the water to drown. The bull shark's teeth are made to slice, and the alligator's teeth are made to hold. The alligator's hide will afford it some protection against the shark's bite, but the reptile's sides & belly will be vulnerable. The bull shark will have greater mobility, and will have a greater chance of landing a damaging bite. The alligator can rip off a fin or a tail with a "death roll" technique, but the typical "grab & drown" technique won't work as well on a shark as it would on a herbivore at the water's edge. An alligator's bite on the shark's sensitive nose might might turn things in the reptile's favor. The alligator will have the edge in water shallow enough to impede the bull shark's vertical movement, but open water will even things out. Close to 50/50.
American Alligator vs American Crocodile: The American crocodile is larger & heavier than the American alligator. Both have armored skin & super-strong bites, but size will matter here. Crocodiles are typically more aggressive as well. Close fight at parity, but crocodile wins at these weights. American crocodile wins.
Golden Eagle vs Bald Eagle: These birds will be the same size (the bald eagle can get slightly heavier). Both have the same weaponry (beak & talons), and both can be aggressive (slight edge in aggressiveness to the golden eagle). Probably a 50/50.
Grizzly Bear vs Gaur: A gaur will weigh over twice as much as a grizzly bear. Grizzly bears are strong, aggressive, & have great endurance & weaponry (jaws & swiping claws), but will be outmatched against a gaur. Gaurs are the largest wild bovids, and can exceed a ton in weight (with some specimens reportedly approaching 1 1/2 tons). They are muscular & powerful, and have large horns & sharp hooves. Bears don't have the lateral movement to avoid the charges of a large bovid, and won't be able to mount enough offense to consistently overpower one. A well-placed paw swipe from the bear might stun the gaur, but most encounters will be a domination by the much larger bovid. Gaur wins.
Kodiak Bear vs Gaur: The gaur will weigh almost 50% more than the Kodiak bear. The Kodiak is larger than the grizzly, and will have a better chance against the gaur, but the odds will still be against it. The bear can employ powerful paw swipes to deter the gaur, but it's mobility won't be great enough to get out of the way when the gaur charges in with its horns. A solid hit by the gaur can cause internal injuries to the bear, and the bear won't be strong enough to consistently control the bovid's head with its forepaws to prevent this from happening. The Kodiak might win on occasion (and I would give it the nod at parity), but it won't be favored here. Gaur wins.
Polar Bear vs Gaur: The gaur will weigh almost 50% more than the polar bear. Polar bears have tremendous strength in their bodies, but they aren't accustomed to tackling mobile animals larger than a muskox (I don't consider a walrus to be mobile). A gaur, which can weigh almost 3 times as much as a muskox, is too large & powerful for even the mighty polar bear. As with the other bears, the polar bear won't be quick enough to avoid the gaur's charges, and won't have the strength to consistently control the head of the gaur (or bring it down). The Pleistocene polar bear (Ursus maritimus tyrannus) would have a good chance to succeed, but not a modern polar bear. Gaur wins.