Size comparisons

[LonePredator]

(04-20-2022, 02:20 AM)Twico5 Wrote:

(04-19-2022, 08:19 PM)LoveAnimals Wrote:

(04-19-2022, 03:50 AM)Twico5 Wrote: You claimed that jaguars are on a different tier or level. I strongly disagree. In captivity they weigh the same. In places where both cats have similar mean prey weights, they will also weigh around the same. I dont think theres a need to continue this because as i said from the very start i believe it is unfair for us to compare pantanal jags to any population of pumas and as long as you keep on bringing them up i will continue to say this. Pumas can be just as long and just as tall so if a population of jags and pumas are eating the same they WILL have similar body masses wether the jaguar wins in a fight or not.

 
I suggest everyone to stop mention this "winning a fight" topic, we are on wildfact and we don't want discussions here to turn into VS debates at Carnivora trash forum level. 

Regarding the rest, the idea that jaguars and cougars grow to the same size with the same food input is so wrong but nothing will stop the anti-jaguar crowd from spreading their misinformation. This study touches upon the fact that jaguars had to reduce their sizes after most of the large Pleistocene prey they relied on went extinct as a survival mechanism. As @GuateGojira correctly pointed out, the small jaguars we see in prey depleted areas of rainforests and deserts represent dwarfed forms.
"Compared with other large, solitary felids, jaguars have an unusual predator to prey body mass ratio. Their accessible prey weight range was 6–60 kg, preferred prey weight range was 45–85 kg, and mean mass of significantly preferred prey was 32 ± 13 kg leading to a predator to prey body mass ratio of 1:0.53, which is much less than that of other solitary felids (although 1:0.84 may be the relationship with the smallest jaguars)."
"These features, coupled with the reduction in jaguar body mass since the Pleistocene, suggest that the loss of larger potential prey items within the preferred and accessible weight ranges at the end-Pleistocene still affects jaguar predatory behavior. It may be that jaguars survived this mass extinction event by preferentially preying on relatively small species."
"The decline in range since the mid-Pleistocene was accompanied by a 15–20% reduction in body mass and a change in limb proportions, such that extant jaguars have shorter metapodials, perhaps as a response to hunting in more closed habitats (Kurten, 1973)."
"Jaguars differ markedly from leopards in being about twice the mass with shorter, more robust limb bones, and relatively wider forepaws that are comparable in relative dimensions to those of lions Panthera leo (Gonyea, 1976; Meachen-Samuels and Van Valkenburgh, 2009b). Across their range, jaguars exhibit up to 100% variation in body mass (Sunquist and Sunquist, 2002) and this is likely to impact their hunting decisions, with the smallest forms being more similar to leopards in the size of their prey. This variability was also reflected in the diet of the populations, with the forest jaguars having a significantly lower mean weight of vertebrate prey at 5.8 kg, compared to 89 kg (including livestock) for floodplain jaguars (Hoogesteijn and Mondolfi, 1996).'
"During the late Pleistocene, there were more than 50 additional species of large (>40 kg) herbivores in the Americas (Kurtén and Anderson, 1980; Greenwood, 2009), and so jaguars evolved in ecosystems with a much higher diversity and availability of potential prey than found today. This is in contrast to Africa, where extant large carnivores prey upon herbivore communities that were similar in abundance, richness and diversity to those which occurred at the end of the Pleistocene (Lyons et al., 2004). This difference likely explains why the predator to prey body mass of jaguars is much smaller than other large solitary felids (Figure 9). For example, jaguars are often considered to be ecologically similar to leopards (Sunquist and Sunquist, 2002), yet jaguars preferentially prey on smaller species than leopards (Figure 9), despite jaguars having a larger body size. )"
"Important jaguar prey species, such as peccaries, spotted paca and nine-banded armadillo are heavily hunted by humans (Redford, 1992; Jorgenson and Redford, 1993). Given the importance of prey in determining predator densities (Fuller and Sievert, 2001; Karanth et al., 2004; Hayward et al., 2007b), reduced prey abundance has been, and probably still is, keeping jaguar populations below densities at which they evolved. Thus we reiterate that the “empty forests syndrome” (Redford, 1992; Wilkie et al., 2011) can have cascading impacts on all trophic levels, including apex predators (Steinmetz et al., 2013)."
Source: https://www.frontiersin.org/articles/10....00148/full
That paper clearly shows how jaguars in many areas outside of floodplain environments have to live on suboptimal prey which is often times too small to support large jaguar populations and at times also have hunting pressure from humans. Jaguars can only dwarf so much before dying to lack of prey, I believe @Dark Jaguar posted on here the case of a very small adult male jaguar from Caatinga which ended up starving to date.
That paper also touches upon what anyone with common sense already knows, that despite having on average similar shoulder heights as leopards or cougars, jaguars can grow to develop twice their body mass and overall larger skeletal structures, because they suffered a reduction on limb size due to dwarfing post-Pleistocene, yet they are still undoubtedly much larger animals.
Leopards for example have had access to large and plentiful ungulate prey in Africa and Asia since the Pleistocene and their sizes have never been comparable to the sizes of modern jaguars who have access to more optimal prey base like the Pantanal. And based on the fossil record we know that the sizes we see today in the Pantanal were the standard sizes of jaguars across their entire range during the Pleistocene, with the largest jaguars being larger than the largest jaguars alive today (with Mesembrina being able to tier with exceptionally large lions or tigers of today at 240+ kgs) . We even know of the existence of a giant subspecies that had previously been confused for the American lion due to its great 200+ kg size: Panthera onca mesembrina.
It's frustrating how much misinformation the same people constantly spend their times spreading on these forums regarding jaguars. If you are a cougar or a leopard fan and you're salty that they don't grow as large as jaguars then you don't actually like those species, you like the fantasy you've created in your head about them. I'm a leopard enthusiast myself but unlike a couple of people from this forum I don't feel the need to degrade jaguars to hype up my favorite cat. In my opinion the mods here could do better with tackling the constant anti-jaguar bias of some people. No wonder other people like Balam and Dark Jaguar have stopped contributing to this forum, it gets frustrating.

I am not mindlessly spreading misinfo about Jaguars. I’ve been posting studies to prove my points.

 “Their accessible prey weight range was 6–60 kg, preferred prey weight range was 45–85 kg, and mean mass of significantly preferred prey was 32 ± 13 kg leading to a predator to prey body mass ratio of 1:0.53, which is much less than that of other solitary felids (although 1:0.84 may be the relationship with the smallest jaguars)." Ok. You do realize that pantanal Jaguars have a predator to prey body mass ratio of like 1:1 right? This is one of the many points that I posted evidence for. 

Just because you think that Pleistocene jags got to 240kg doesn’t mean it’s wrong to discuss or compare puma and jaguar sizes. I don’t care if jaguars are 240kg giant tiger sized cats that shrunk because their prey died out because this discussion is not about them, it was always about modern jaguars and modern pumas. 

There is nothing wrong with comparing the sizes of ANY two animals wether it be jaguar and puma or leopard and tiger as long as I’m at least using studies and valid evidence as proof for my claims and as long as I’m not mindlessly saying things I believe to be true. It seems to me that this only wrong, not because I’m not debating properly or because I’m not posting evidence but rather because this is a comparison between PUMA and jaguar. I don’t have an anti-jaguar bias, this is clear by the opinions I’ve given on how a fight would go between these two cats. Please read the screenshots and papers I include in my posts instead of calling me anti-jaguar

What are you even trying to prove though? Are you claiming that Cougars are bigger than Jaguars? Or are you trying to claim that Cougars would be bigger in a this or that hypothetical scenario? Reply