Alligators could crawl into region sooner than you think

By EJ Haas COLUMBIA MISSOURIAN

Missouri is currently too cold to foster crocodilian life, so there’s no reason to fear alligators in your backyard yet.

But in just a few decades, they might become as common as the armadillos that have recently moved from the South to the Midwest.

CaseyHolliday,anassociate professor of anatomy at MU who studies the buildandevolutionofanimalheads,explainswhyit couldtakejust30yearsfor alligatorstoshowupinthe Missouri River and the Lake of the Ozarks.

Climate change

Over the course of 50 million years, the Earth has begun to heat back up —aprocessacceleratedby human-induced climate change — making way for alligators to head north.

Theplanetwasdefinitely hotter 50 million years agothanitisnow,Holliday explained. It then cooled offoverthecourseofabout 20 million years, and during the Ice Ages, alligators were pushed southward. As temperatures rise again, they are likely to head back north.

They move with the frost line, Holliday said, whichisbasicallyaninvisible line near the north of Louisiana and up toward North Carolina where temperatures are chillier.

“So much during the winter that certain ani- mals don’t get past that line, and that tends to include gators and armadillos in particular,” he said.

“Over the last 30 years, we’ve started to see armadillos and alligators kind of move north.”

Alligators have already moved into the waters of southern Arkansas and southern Tennessee. Right now, it’s too cold north of those borders for them to survive, Holliday said. But in a warmer future, they could be found in backwater draws around the Missouri and Mississippi rivers, as well as in lakes, ponds and swampy areas.

Crocodilian evolution

Crocodilians — crocodiles, alligators, caimans and the critically endangered gharial — have a longhistoryontheplanet, roughly 220 million years, Holliday said.

The clade or lineage that exists today is largely aquatic. In North America, two of the species — American alligators and American crocodiles — are native.

Thosetwospeciesdiffer biologically,aswellasaes- thetically because of their different head shapes, Holliday explained. Crocodiles have more pointed snouts, and behaviorally, they tend to be more aggressive than alligators.

The size of these reptiles has also diminished over time, particularly the alligators that were hunted for leather. Larger alligators were hunted more, thus making their smaller counterparts more likely to reproduce and pass on their genes.

These days, Holliday said, 10 feet is about the longest they reach.

“Fifty to 100 years ago, there used to be lots of 13foot alligators,” he said.

Alligator interactions

FormostofU.S.history, alligators have largely been found in the waterways of Florida and Georgia, and the Gulf Coast in Texas and Louisiana.

“Aspeoplekeepmoving into particularly Florida and developing neighborhoods into the swamp lands,theyencroachupon alligator turf, and that’s ledtomoreinteractionsin the past 50 to 100 years,” Holliday said.

Interactions are even more likely to occur as areas where people are unfamiliar with alligators may soon be their habitat.

However, alligator interactions don’t have to be as dangerous as the February encounter in southeast Florida that killed an 85-year-old woman. Holliday listed several courses of action that can prevent anegativeexperiencewith an alligator.

“Keep your distance,” he said. “You don’t mess with them, you don’t feed them, you don’t swim out toward them. Just keep your distance like you would any wild animal.”