Comparing Cats: A Discussion of Similarities & Differences

[Pckts]

(03-17-2022, 10:41 AM)dominusforti Wrote:

(03-17-2022, 03:59 AM)Pckts Wrote:

(03-17-2022, 02:59 AM)dominusforti Wrote: I feel like there is a lot of bias going on here...on both sides. Nevertheless, I agree with @SpinoRex in that lions and tigers are very similar, they belong to a rather osteologically homogeneous group (Panthera) and are within that group the most similar species to each other.

But, for the clavicles, first I will say that the difference is obviously statistically significant, all the other felids group together (with some variation) but the African lion and, crucially, the American lion, stand out as having significantly higher values. I'm not insinuating this makes them stronger but it's not worth debating the obvious truth that the difference is real and not caused by some kind of sampling error.

Fwiw, larger and more recurved claviculae are typically found in arboreal species, whereas terrestrial (especially cursorial) species tend to have reduced clavicles or lack them altogether.

So, the advantage would be something that helps scansorial taxa use their forelimbs to climb. The cost is a little less clear but it definitely isn't helping in the lion's cursorial habits. Therefore the adaptive reason would need to be something else. Possibly allowing lions to compensate for their general trend toward cursoriality while still needing to stalk, accelerate, and grapple large prey like the other pantherine felids.

How can there be no sampling error when you're comparing all females to mostly males and on top of that, one of the smallest sub species of Tigers, one being a stillborn as well.

I mean, in the nicest way possible but did you read through the paper? Because it explains why sexual dimorphism cannot explain the marked difference not just between lions and tigers but between both types of lion (two different species belonging to the lion ecomorph and lineage) and all other forms of felid. In a principal components analysis, "the lions [which they describe as the large, robust clavicular morph] and large fossil morphs clearlt separate themselves from the other felids, with the tigers overlapping with, although falling toward the large-end of the rest of the cats."

The difference between lions and all other felids was diagnostic enough for the researchers to deduce that large fossil morph had to be Panthera atrox, due to its lion-like values. P. leo plots closer to the giant P. atrox than it does with P. tigris, which overlaps with the other smaller felids and remains identifiably separate from P. leo on PC 1. The difference therefore seems much too significant to attribute to sexual dimorphism and, even to entertain that notion for a moment, the felids for which males and females were included did exhibit strong sex-based differences, and the single lioness clavicle is just as distinct from the tiger sample as the male lions were.

The paper compares the Tiger Clavicles used and mentioning them to be nearer to the size of a smaller pantherinae than it's large cat classification and of course this is because they are using one of the smallest sub species and females or even stillborns. This has nothing to do with whether sexual dimorphism plays a part or not.

Notice the statement below:

"Body size and weight of large pantherines, when
compared with respective clavicle sizes and morphologies, shows that the clavicle has been
reduced far more in P. tigris than in P. leo. This is
unexpected because P. tigris is on average significantly larger than P. leo, although they are closely"

So if you're using a standard Tigers weight which is 30-50% larger than the specimens used, of course this statement is true. But if you use the actual weights of this specific sub species or had larger Tiger samples on hand, the sizes would no doubt increase and who knows if they're actually reduced or not.

In regards to differences between sex's, they mention that they have no real samples to compare between Lions and Tigers and strictly use one female Lion as an outlier since her clavicle was one of the largest. This doesn't mean much since it could be a large female or just an outlier in general. On top of that, both Cheetah and Puma showed males to be larger than the females in regards to clavicles. This wasn't the case for every single one but for most. And since Puma and Cheetah generally don't have as much of a dimorphic difference as Tigers and Lions when it comes to weight and muscle build, they most likely wouldn't show as much of a difference regardless. But you can pretty much guarantee that if you took a 200kg Bengal Tiger Male and compared it to a 100kg or less Tigress, you will see major differences. 


Long story short, there absolutely is a sampling error here. The sample size itself is minuscule and when it comes to Tigers, the smaller sub species could obviously play a role in their conclusions like I explained above. Unfortunately they didn't have much to go off of but you would need Male and females from the same sub species, their weights and a real sample size to see what/if any differences there are. Reply