Comparing the grappling ability of extant Ursids
Mar 23, 2020 9:04:54 GMT -5
King Kodiak, Montezuma, and 1 more like this
Post by theundertaker45 on Mar 23, 2020 9:04:54 GMT -5
Hello everyone, I don't know if this has been discussed already but I'd like to share another insightful study with you regarding the grappling ability of bears and other carnivores; to be precise: this time we will compare the dexterity/flexibility of their forelimbs and what this might mean to interspecific/intraspecific confrontations.
This is the abstract from the study I will attach below:
"Among the hunting strategies employed by members of the order Carnivora (Mammalia), two, stalk and ambush and sustained pursuit, are particularly prevalent among larger species of the order. It has been difficult to identify morphological traits that support this distinction and ecological observations have shown that most carnivorans adopt a continuum of strategies, depending on available habitat and prey. In this paper, the shape of the distal humerus articulation is analysed, with the aim of exploring the use of the forelimb in prey procurement, and as a guide to such behaviour among fossil carnivorans. The results suggest that manual manipulation and locomotion are conflicting functions. Elbow-joint morphology supports a division between grapplers (i.e. ambushers) and nongrapplers (i.e. pursuers). Joints of the former are characterized by being relatively wide and the latter, by being relatively narrow and box-like with pronounced stabilizing features. At intermediate and large body sizes, carnivorans show a pattern suggesting mutually exclusive feeding strategies that involve either grappling with prey or sustained pursuit. The former allows for large body sizes, such as pantherine felids and ursids; the latter includes species of only moderate size, such as hyenids and canids. Elbow-joint morphology is closely linked to phylogeny, but the morphology of the cheetah converges with that of nongrapplers, showing that strong selective forces may override the phylogenetic component. Two taxa of giant mustelids from the Miocene were analysed to test whether this sort of analysis is applicable to carnivorans of the past. The African Late Miocene species Ekorus ekakeran has a joint morphology comparable to that of modern-day nongrapplers. Two joint morphologies were found in the North American Late Oligocene-Early Miocene Megalictis ferox. The first morphology is comparable to that of modern pantherine cats and the second forms an intermediate between grapplers and nongrapplers that is not present in the modern carnivoran fauna."
Reading through the abstract you will realize that the author divides the species in two groups: grapplers (ambushers) and nongrapplers (pursuers). A grappler's forelimbs are characterized by wide and strong stability features which are helpful at tackling large game. The author determined a value for measuring the ability to subude, manipulate or excavate food items, a so called "PC2-Value", here is a personal comment from the author himself:
"Scoring intermediate or low on PC2 are carnivorans that use their forelimbs to subdue, manipulate or excavate food items. Among these are ursids, mustelids, procyonids and felids. Although not being full grapplers, intermediate scores on PC2 characterize small canids. Small canids and small grapplers do not, however, overlap and all canids score higher than other carnivorans of the same body mass."
This means that a lower PC2-value is signalizing better dexterity/flexibility in a species' forelimbs and the ability to adapt itself to problematic angles or problems in general that might occur when manipulating/subduing their prey item. Unfortunately they excluded the Asian black bear and the sun bear in this study, so I will just rank the other six species from lowest to highest (note that a lower value means being superior in this case):
1. Polar Bear: -7.999
2. Brown Bear: -7.045
3. Spectacled Bear: -6.517
4. Giant Panda: -6.034
5. American Black Bear: -5.521
6. Sloth Bear: -4.447
Other Species:
Lion: -0.531
Jaguar: -1.713
Leopard: +1.072
Cougar: +1.633
Grey Wolf: +10.470
Spotted Hyena: +8.006
Wolverine: -1.356
American Badger: -0.859
We can see that ursids have the best dexterity/flexibility in their forelimbs compared to other families which would allow them to adjust different grappling styles when being confronted with a difficult situation and fight their way out of dreadful angles which would explain why tigers aren't able to kill a brown bear in an ambush scenario even when attacking first. What this also means is that bears are theoretically the best contenders for bringing down large game, I say theoretically because many bear populations nowadays mostly rely on fish/fruits and don't regularly tackle big ungulates. This doesn't mean that they aren't capable of doing so, it means the exact opposite, they are the most gifted/talented family in grappling down an opponent which is a very useful trait in 1v1 confrontations.
An interesting observation from my side is that the most carnivorous of them all, the polar bear, excels all other bears in this department which should be no surprise as he regularly tackles huge prey and is reliant on habitually killing huge belugas/walruses. Another noteworthy point is that the three rather herbivorous ursid species have lower values than the rather carnivorous species. I guess that is mainly attributed to certain adaptions that they have evolved over the past thousands of years combined with an advantage regarding killing experience.
All in all we can say that bears are incomparable to other families regarding forelimb dexterity/flexibility (except hominids and cercopithecids, "monkeys" if you will) and they certainly should be considered superior grapplers to any other extant carnivore that's not part of their family.
Leave your comments/impressions here and have a nice day!
Study on Grappling Ability and Forearm Func....pdf (245.57 KB)
This is the abstract from the study I will attach below:
"Among the hunting strategies employed by members of the order Carnivora (Mammalia), two, stalk and ambush and sustained pursuit, are particularly prevalent among larger species of the order. It has been difficult to identify morphological traits that support this distinction and ecological observations have shown that most carnivorans adopt a continuum of strategies, depending on available habitat and prey. In this paper, the shape of the distal humerus articulation is analysed, with the aim of exploring the use of the forelimb in prey procurement, and as a guide to such behaviour among fossil carnivorans. The results suggest that manual manipulation and locomotion are conflicting functions. Elbow-joint morphology supports a division between grapplers (i.e. ambushers) and nongrapplers (i.e. pursuers). Joints of the former are characterized by being relatively wide and the latter, by being relatively narrow and box-like with pronounced stabilizing features. At intermediate and large body sizes, carnivorans show a pattern suggesting mutually exclusive feeding strategies that involve either grappling with prey or sustained pursuit. The former allows for large body sizes, such as pantherine felids and ursids; the latter includes species of only moderate size, such as hyenids and canids. Elbow-joint morphology is closely linked to phylogeny, but the morphology of the cheetah converges with that of nongrapplers, showing that strong selective forces may override the phylogenetic component. Two taxa of giant mustelids from the Miocene were analysed to test whether this sort of analysis is applicable to carnivorans of the past. The African Late Miocene species Ekorus ekakeran has a joint morphology comparable to that of modern-day nongrapplers. Two joint morphologies were found in the North American Late Oligocene-Early Miocene Megalictis ferox. The first morphology is comparable to that of modern pantherine cats and the second forms an intermediate between grapplers and nongrapplers that is not present in the modern carnivoran fauna."
Reading through the abstract you will realize that the author divides the species in two groups: grapplers (ambushers) and nongrapplers (pursuers). A grappler's forelimbs are characterized by wide and strong stability features which are helpful at tackling large game. The author determined a value for measuring the ability to subude, manipulate or excavate food items, a so called "PC2-Value", here is a personal comment from the author himself:
"Scoring intermediate or low on PC2 are carnivorans that use their forelimbs to subdue, manipulate or excavate food items. Among these are ursids, mustelids, procyonids and felids. Although not being full grapplers, intermediate scores on PC2 characterize small canids. Small canids and small grapplers do not, however, overlap and all canids score higher than other carnivorans of the same body mass."
This means that a lower PC2-value is signalizing better dexterity/flexibility in a species' forelimbs and the ability to adapt itself to problematic angles or problems in general that might occur when manipulating/subduing their prey item. Unfortunately they excluded the Asian black bear and the sun bear in this study, so I will just rank the other six species from lowest to highest (note that a lower value means being superior in this case):
1. Polar Bear: -7.999
2. Brown Bear: -7.045
3. Spectacled Bear: -6.517
4. Giant Panda: -6.034
5. American Black Bear: -5.521
6. Sloth Bear: -4.447
Other Species:
Lion: -0.531
Jaguar: -1.713
Leopard: +1.072
Cougar: +1.633
Grey Wolf: +10.470
Spotted Hyena: +8.006
Wolverine: -1.356
American Badger: -0.859
We can see that ursids have the best dexterity/flexibility in their forelimbs compared to other families which would allow them to adjust different grappling styles when being confronted with a difficult situation and fight their way out of dreadful angles which would explain why tigers aren't able to kill a brown bear in an ambush scenario even when attacking first. What this also means is that bears are theoretically the best contenders for bringing down large game, I say theoretically because many bear populations nowadays mostly rely on fish/fruits and don't regularly tackle big ungulates. This doesn't mean that they aren't capable of doing so, it means the exact opposite, they are the most gifted/talented family in grappling down an opponent which is a very useful trait in 1v1 confrontations.
An interesting observation from my side is that the most carnivorous of them all, the polar bear, excels all other bears in this department which should be no surprise as he regularly tackles huge prey and is reliant on habitually killing huge belugas/walruses. Another noteworthy point is that the three rather herbivorous ursid species have lower values than the rather carnivorous species. I guess that is mainly attributed to certain adaptions that they have evolved over the past thousands of years combined with an advantage regarding killing experience.
All in all we can say that bears are incomparable to other families regarding forelimb dexterity/flexibility (except hominids and cercopithecids, "monkeys" if you will) and they certainly should be considered superior grapplers to any other extant carnivore that's not part of their family.
Leave your comments/impressions here and have a nice day!
Study on Grappling Ability and Forearm Func....pdf (245.57 KB)
