Comparing big cats - differences/changes with time

[BlakeW39]

Thanks @Shadow for letting me back in.

So sorry for the late, late reply. Hope I can add something.

@Pckts ,

Cool video :) We're definitely in agreement that jaguars are aquatic compared to other cats. Especially in the Pantanal and other floodplains habitats.

Big cats adapt to their habitats and available prey base -- and thus populations of big cats vary at the specific and subspecific levels. It should stand to reason, then, that jaguar populations would vary to a degree based on adaptations to their indigenous environments.

This is what we indeed see; jaguars, like all big cats, vary in morphology (i.e. size, etc.) and behavior based upon their environments. This variance, however, is only slight -- all the populations of a big cat share a similar ecological goal, but are adaptable to do so under differing circumstances. Jaguars in wetlands have adapted to their habitat physically by developing proportionally shorter limbs with large paws, a larger skull presumably for increased predation on reptiles, and larger size. But these differences aren't extreme, and don't indicate intense specialization that would lead to speciation of a semi-aquatic 'otter-like' felid.

Before I adress a second point, I want to say that livestock, like cattle, aren't really comparable wild ungulata. Livestock are easy prey in comparison and should be classified separately, from my humble perspective :)

On jaguar predation and prey preferences: jaguars, as I have stated numerous times, are the most generalist of the big cats.

Jaguars are highly generalistic. Jaguars, unlike other big cats, seem not to be very selective or specialized in their predation; in the study of over 3,000 jaguar hunts from across their range, they were seen to have not selected prey based upon morphology at all, but rather upon 'socio-ecological and behavioral traits' -- they hunt prey based upon its abundance. The result was that jaguars showed no preference of predation upon large ungulata, as is the case in every other extant large cat. They also took small prey relative to their body size -- on average, prey taken was only half the jaguar's body mass, which is a contrast to other large felids, who usually take prey comparable to or a bit greater than their own respective size.

So, jaguars are the most generalized predators of the big cats, and they aren't selective in their prey preferences based on morphology to a significant extent. If jaguars are so generalistic, and take prey based on its abundance and availability, it would stand to reason that they would prey on mostly caiman and capybara where they are most common, or anteater where they are common, and so on. Likewise, they take relatively small prey relative to their size and tapirs indeed fell outside of their preferred prey across their range.

Jaguars were the only pantherines to have survived the Quarternary extinctions, and the only very large big cat to survive. Why is this? While other big cats specialized in hunting megafauna that was quickly disappearing, the jaguar was able to adapt its diet to feeding on a variety of generally smaller prey, and correspondingly downsize the process -- which implies it was less specialized in these large herbivores to begin with. Afterall, South America lost ~87% of its megafauna, much more than any other region aside from the Sahul (Australasia). If the jaguar depended greatly upon it, it should have gone extinct. Perhaps the jaguar specialized less in large mammals because unlike on other continents, ungulata weren't as dominant and notoungulates and xenarthrans were present as well, and so because there were more forms, specialization was less advantageous..? Only a theory.

A good study which supports these claims: https://www.frontiersin.org/articles/10....00148/full Reply