In times of global uncertainty, is there anything more comforting than watching big reptiles duking it out in a swamp?
Well, OK, in truth there are probably a fair number of more comforting things, but if nothing else such a primordial spectacle can seem to briefly transport us out of this roiled time of ours.
All this is to lead up to the following footage, captured at the Shallotte River Swamp Park in North Carolina, showing an American alligator – one of a number rescued from captivity and given sanctuary at the eco-park – making short work of one of the world’s most formidable turtles.
The unfortunate prey item is a common snapper, a well-armed, infamously feisty species widespread in the central and eastern US (and closely related to the Central and South American snapping turtles, and more distantly to the much bigger alligator snapping turtle of the American Southeast, one of the planet’s largest freshwater turtles). This robust beast exudes a dino vibe – gnarly beak, gnarly claws, ridged carapace, sawtooth tail – and specimens commonly weigh 20 or 30 pounds (9 or 14 kilograms), sometimes twice that. While eggs and young snappers are vulnerable to all sorts of predators, the well-armoured, well-armed, and ill-tempered adults don’t have all that much to worry about in the marshes and swamps they inhabit.
A large alligator, though, is definitely something to worry about: one of the few animals realistically posing a risk to a mature snapping turtle. (Others include black bears as well as North American river otters, which have been documented killing hibernating snappers. Oh, and people, too.)
According to the Charlotte Observer, a Swamp Park official suggested the snapper in this case may have nipped at the alligator and then paid the price. It’s unclear whether such a provocation was observed, but, unless it was, the more likely explanation is simply that the alligator keyed into the snapper and actively preyed upon it. Alligators have been documented dining on full-grown snappers before, and some turtles that survive their run-ins with gators bear bite marks on their rugged shells.
Turtles, more broadly, are a major component of the American alligator’s diet in most areas, with a diverse assortment – from sliders and cooters to softshells and mud turtles – falling on the gator menu alongside the occasional snapper. In coastal areas of the southeastern US, alligators – despite lacking the salt glands their crocodile cousins possess – regularly visit brackish estuaries, bays, and even inshore ocean waters, and they’ve been recorded snacking on sea turtles in these environments.
An alligator is one of the few animals that realistically poses a risk to a mature snapping turtle. Image © Shallotte River Swamp Park
Having a heck of a bite force and long, heavy jaws helps alligators crush turtle shells, not to mention other armoured prey such as crabs and crayfish. Indeed, it’s possible the signature broad, rounded snout shape of alligators (and their close Neotropical relatives the caimans) evolved at least in part to facilitate a turtle-heavy diet. Adam Rosenblatt, PhD, an ecologist at the University of North Florida who’s extensively studied alligators (as well as the mighty black caiman of South America), notes that turtles precede modern crocodilians on the evolutionary timeline. “Also, we know that gator diets change as they get bigger, with only adults really eating turtles consistently,” he wrote by email. “So clearly having big, powerful jaws is advantageous for eating prey with shells.”
That said, Rosenblatt emphasised a variety of selective pressures – not just a fondness for turtle meat – likely shaped the gator’s business end. For one thing, he said, research suggests that broad and flat snouts enhance swimming speed in crocodilians. And he referenced a 2012 PLoS One paper showing that body size, not jaw shape, seems to be the primary determining factor behind the punch packed by crocodilian jaws.
“Caimans and gators with broad jaws have almost the exact same bite force as comparably sized crocs with much narrower jaws,” Rosenblatt said, “which suggests that crocodilian ancestors from way back evolved strong bite forces first and then the variety of jaw shapes we see today in crocodilians evolved later.”
Another possible evolutionary factor shaping the alligator’s wide, bulky chops? Hardcore gator-on-gator aggression. “The broad and flat gator jaw shape gives them high resistance to bending and torsion,” Rosenblatt wrote. “This is very useful when gators fight with each other because they frequently bite each other by the jaw and then death roll to try and rip the other gator’s face off (essentially).”
He pointed to this video taken last month on a South Carolina golf course showing two brawling alligators as demonstration of that rough-and-rowdy fighting technique:
The thrashing, splashing dismantlement of a good-sized snapper by that Swamp Park alligator is only a recent example of the hoary predator-prey relationship between crocodilians and turtles. And hefty as snapping turtles and gators are, that relationship has manifested at bigger scales yet: The titanic Miocene South American turtle Stupendemys geographicus, which grew a shell close to three metres (about ten feet) long, had some epic crocodilians to deal with, most notably the giant caiman Purussaurus brasiliensis, better than nine metres (30 feet) long and boasting what a 2015 analysis reckoned might be a roughly seven-ton bite force. Scale-busting Stupendemys shells have been found with bite marks and even a lodged crocodilian tooth. Imagine seeing that kind of supersized showdown going down.
Lest you think the alligator/turtle interplay is all about eat-or-be-eaten – a snapping turtle likely isn’t opposed to snatching the odd alligator hatchling, on the other side of the table – let’s end on a warmer, fuzzier note. Alligators benefit turtles in a number of ways: In the Florida Everglades, for example, they nose out depressions in wetland muck –”gator holes”—which provide habitat for turtles and other critters, and furthermore a number of turtle species, notably the Florida redbelly, commonly lay their eggs in the mounds of alligator nests, including actively used ones.
And, finally, it’s not unusual in the wetlands of the southeastern US to see alligators and turtles basking peaceably together – and, on occasion, turtles basking peaceably on top of gators, those handy-dandy “floating logs.”
source: earthtouchnews.com
