Jaguars have long been an outlier in the feline world. It is unusual for a big cat to have a thickset body, well-developed head muscles, and substantial canines. And while tigers and lions prefer to grab the underside of their prey's neck and crush their windpipe until they suffocate, jaguars instead bite the nape of the neck, crushing the spinal column and braincase. Clearly, these big cats do things a little differently.
Previously, researchers had suggested that these adaptations had evolved for the predators to more efficiently take down reptiles – a behavior technically known as saurophagy – which would fit nicely with the observation that jaguars are the only known big cat to regularly prey on reptiles. But this doesn’t cover the fact that the cats only tend to prey on the cold-blooded creatures when living in environments where the animals are commonly found, such as wetlands. In other places, they go for different large-bodied prey.
The researchers of the latest study, published in the Journal of Natural History, argue that the adaptations seen in the morphology of jaguars is indicative of a predator that primarily hunts armored and dangerous prey, something known as durophagy, rather than being purely adapted to killing reptiles. They point to the defensive strategies of the jaguars' prey, from peccaries to giant anteaters, and the fact that reptiles only form the main basis of their diet in regions where such prey live in high numbers.
They suggest that the powerful jaws, thick canines, well-developed head muscles, and fatal bite directed at the braincase are a way for the cats to quickly and efficiently dispatch of the dangerous, armored prey. For example, where peccaries (large pig-like creatures) are common, the jaguars tend to favor these above all others, even if there are other easier meals to come by.
Peccaries are known to be highly aggressive and to defend themselves ruthlessly against predators, meaning that if a jaguar were to employ the same hunting technique as a lion, it would be put in harm’s way from the rest of the herd. Instead, by rapidly dispatching of the prey using a bite to the nape, it can retreat from the carcass if chased by the herd, and then return to claim its spoils when the danger is gone. So while these big cats might do things differently, it is nonetheless effective.