+- WildFact (https://wildfact.com/forum)
+-- Forum: General Section (https://wildfact.com/forum/forum-general-section)
+--- Forum: Debate and Discussion about Wild Animals (https://wildfact.com/forum/forum-debate-and-discussion-about-wild-animals)
+--- Thread: Comparing grappling ability of extant Ursids (/topic-comparing-grappling-ability-of-extant-ursids)
Comparing grappling ability of extant Ursids - Silver - 05-17-2024
Hello there, im new to this forum as my first thread ill post an study for grappling ability of extant bears, I got this from domain of bears so credit goes to person who first posted it there
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
Heres the source:https://www.researchgate.net/publication/228546271_Locomotor_Evolution_in_the_Carnivora_Mammalia_Evidence_From_the_Elbow_Joint