How Jaguars Survived the Ice Age

A jaguar at the St. Louis Zoo. Photo by Brian Switek.
A jaguar at the St. Louis Zoo. Photo by Brian Switek.

The mastodons, ground sloths, and sabercats are all gone. They all slipped into extinction around 10,000 or so years ago, along with an even wider variety of fantastic beasts and birds that fall under the category “megafauna.” But not all the Ice Age megamammals died out. We spend so much time mourning the losses that we often forget the survivors that carry whispers of the Pleistocene world. Among these resilient beasts is the jaguar.

Jaguars are old cats. They first evolved in Eurasia sometime around three million years ago before spreading both west and east, eventually inhabiting a range from southern England to Nebraska and down into South America. Today’s range of southern Arizona to Argentina—over 3.4 million square miles—is only a sliver of their Ice Age expansion. And it wasn’t just the jaguar’s range that shrunk. Today the spotted cats are about fifteen percent smaller than their Pleistocene predecessors.

Nevertheless, jaguars survived while the American lion, the sabercats, and other predators vanished. How? In order to investigate this question, biologist Matt Hayward and colleagues looked at the jaguar diet and how the cat’s prey preferences changed over time.

Drawing from 25 published studies documenting 3,214 jaguar kills, Hayward and coauthors found that jaguars are pretty finicky for apex predators. The big cat’s menu spans 111 species—ranging from cattle to rodents to monkeys to turtles—but, contrary to what has often been written about the cat, the jaguar is not really a generalist that hunts anything and everything.

The most common parts of the jaguar diet, Hayward and colleagues found, are capybara, wild pig, caiman, collared peccary, nine-banded armadillo, giant anteater, and white-nosed coati. These species account for 16-21% of the jaguar diet. The stats also showed that prey including peccaries, brocket deer, giant anteaters, and coatis which were hunted 85% of the time when they were present in the jaguar’s range. Crunching the numbers a bit further, the zoologists found that jaguars seemed to especially target capybara and giant anteater. On the other hand, jaguars never preyed upon tapirs and almost never touched primates.

Jaguars come out of all this as a paradox. They are burlier than leopards, yet they prefer to hunt a narrow range of prey that falls in the shallow end of what jaguars should be able to tackle. This might have something to do with why the cats have shrunk. Jaguars aren’t large enough to take on tapirs alone, yet human hunting on mid-range prey—such as deer—has made such herbivores too rare to rely upon. So despite their size, jaguars responded by picking out smaller prey which Hayward and coauthors dub “suboptimal” for what the cats initially evolved to do.

The jaguar’s not alone in this. Coyotes have gone through similar changes. The scrappy canids are Ice Age survivors, too, and they were significantly larger during the Ice Age. When all their competition disappeared, coyotes became smaller and ended up living on the fringes in a world heavily influenced by humans.

Flexibility made all the difference for these carnivores. Even though jaguars no longer prowl as much of the world as they once did, and are currently listed as “near threatened” on the IUCN Red List, they were able to persist where so many other carnivores perished by shifting their diets. “It may be that jaguars survived this mass extinction event by preferentially preying on relatively small species,” Hayward and coauthors write. The fossil record of cougars tells a similar story: By eating parts of carcasses other cats didn’t want, mountain lions were able to survive the tough times. And even though the cause of the loss of many Ice Age celebrities remains debated, the survivors are truly the animals we should be looking at in greater detail. How they succeeded may hold the secrets to why so many other species failed.

Reference:

Hayward, M., Kamler, J., Montgomery, R., Newlove, A., Rostro-García, S., Sales, L., Van Valkenburgh, B. 2016. Prey preferences of the jaguar Panthera onca reflect the Post-Pleistocene demise of large prey. Frontiers in Ecology and Evolution. doi: 10.3389/fevo.2015.00148

2 thoughts on “How Jaguars Survived the Ice Age

  1. I agree that more attention should be given those American species that survived the late Pleistocene extinction. ..especially herbivores. I write this because herbivores were and are the dietary base of the carnivores. Evidentally, when the herbivore base constricted at the end of the Pleistocene, various carnivores starved out. Some, like the saber-toothed cat, short faced bear and dire wolf disappeared entirely. Others–the jaguar, puma, American cheetah, American lion and timber wolf–likely suffered major extinctions over broad geographic regions–but managed to survive in other ranges where a suitable prey base continued to exist.

    So, to me, the central question is what happened to the herbivores–bison, elephants, ground sloths, horses, tapirs, camels. Of course bison continued on to survive in slightly altered form. Horses [wild asses, zebras, horses and camels [guanacos, vicunas, bactrian camels, dromedaries] continued to exist in other locations. Tapirs continued to exist in the southern Americas and southern Asia.

    Still, the American extinctions weren’t confined to North America. Elephants, horses and ground sloths died out in South America, too. Therefore, an extinction phenomenon which may or may not have been harsher in North America extended into South America, too. Still, the puma and jaguar, which seem to have gone to extinction in North America, continued to live in South America i.e. they found enough to eat. It wasn’t until the late Pleistocene event subsided that these cats repopulated North America. Geographically, the puma was more successful. Its present range extends from Northern British Columbia down to Tierra Fuego–one of the widest distributions of any mammal. The jaguar’s range was/is impressive but not so much as the puma. In recent historic times it lived in many of the southwestern and southeastern states down into Argentina.

    In my opinion, the end of the Ice Age was attended by major climate fluxes, affecting primarily the Northern Hemisphere. The Southern Hemisphere was less affected given the continuing existence of the Megafauna of Africa and southern Asia. In the Northern Hemisphere both grazers and browsers were affected and, even those herbivores that survived this period, likely went through near extinction events. Human hunters may have deepened this process but it seems altogether likely that humans would have suffered as well, likely going into extinction over broad areas.

    Still, in North America look at the large wild herbivores we presently have–whitetail, blackmail and mule deer. Bison. Elk. Moose. Caribou. Collared and White lipped peccary. Mountain sheep. Mountain goats. Black and brown bears , pronghorn antelope. Many of these species were abundant before the white man and most are abundant, now….BUT…the fact that many large predators went extinct in North America means that many of these now common herbivore species must have become very uncommon at one time.

  2. My comment isnt showing up here, so im gonna try posting again.

    I agree with most of your post, but theres one line that catched my attention.

    “Jaguars aren’t large enough to take on tapirs alone”

    I disagree, jaguars sometimes prey on cattle that weight more than tapir and are strong enough to pull a bull’s corpse if they want to. I even remenber people comparing them to bulldozers because of that.

    Not saying tapirs are easy prey, the jaguar will have a hard time catching one if it starts running or gets in deep water, they also bite like hell.

    Also, the prey base in certain areas might influence its diet, theres not much reason to try going after a tapir if the area is full of capybaras and caimans.

    And now for evidence of jaguars preying on tapirs:

    http://onca.tumblr.com/post/11217591051/o-trabalho-cient%C3%ADfico-com-a-panthera-onca-envolve

    http://41.media.tumblr.com/tumblr_lsscrsp70B1qklv9io3_1280.jpg

    I really doubt the jaguar scavenged this one, no reason for crushing the skull of a dead animal.

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