Alligators Are Lurching Toward Your Backyard

Which species will adapt to climate change—and which ones won’t.
Feb. 19 2013 3:05 PM

Alligators in Your Backyard

Thanks to climate change, the cold-blooded giants are lurching north.

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As average annual temperatures have increased in recent years, the zone in which alligators could plausibly both survive and reproduce has moved north. With the northernmost known population of gators so close to Virginia in the first place, it wouldn’t take much to get them established in a completely new state. Some locals already report sightings in the vicinity of Back Bay, southwest of Virginia Beach. Officially, there are no alligators in Virginia. But in practice, I don’t think the alligators have paid attention.

Last year, I put the word out that I was interested in alligator sightings within Virginia, and I was showered with emails reporting gators seen and in some cases even killed. Even the official, fully documented cases have been marching steadily north. There is little question that a grown alligator was documented only 5 miles from the Virginia border in 2011. Odds are that the species is now here in my home state. The question is how many of them have arrived and whether the spring temperatures are high enough to allow them to breed.

Arguing against the concept of global warming has become an exercise in absurdity. Last year was the warmest year on record in the Lower 48 states, and the weather is becoming hotter on the whole. This temperature shift has ecological consequences that tend to favor cold-blooded wildlife. The American alligator, the venomous cottonmouth snake, and the Carolina anole each find the northern limit of their range right around the Virginia/North Carolina border. All can now expand their ranges.

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Virginia biologist and blogger Kirk Mantay pointed out to me that just because an animal can move to a new habitat doesn’t mean that it will do so right away. Alligators won’t necessarily pour into Virginia; their movement will be gradual. First, you must have some gators that are unsatisfied with where they live or that have been pushed out of their previous territories by competition with other gators. Those alligators in dispersal will move outward and stop when they arrive in an area where there is plenty of food. It could take a decade until there are so many gators in the Old Dominion that it is no longer possible to deny their presence.

Yet odds are that alligators will be denied for as long as possible. Every government agency involved in monitoring or regulating wildlife in Virginia has a strong incentive to claim that alligators aren’t here. For what is to gain? As Mantay put it: “Once any (or each) agency acknowledges that the species exists in the state, then broad actions have to be taken to assess it.” He points out that government agencies would have to decide whether the species should be considered invasive in Virginia, endangered, or something else altogether. “Real plans, with real biologists, would have to be put in place, per state and federal laws. That will cost lots and lots of money.” It’s much easier to claim that every wild alligator spotted in Virginia is either a figment of someone’s imagination or an escaped pet.

It is impossible to precisely predict how far north the American alligator could spread. That will depend in part on how out of control global warming becomes. Perhaps their move will stop near the city of Virginia Beach, in the area where the animals are probably already living. But if temperatures climb high enough, vagabond gators could start cruising toward the James and Potomac rivers a few decades from now. Washington, D.C., is only about 150 miles away, as the crow flies, though longer as the gator might swim.

This expansion into Virginia is probably more historic to humans than it is to alligators. Gators and their ancestors have moved up and down what is now the mid-Atlantic coast many times over millions of years as the climate has warmed and cooled. So far, the current shift is modest by historical standards. But if the trend keeps going, then New York City had better keep an eye on its sewers.

Jackson Landers is the author of Eating Aliens. He recently spent a year and a half hunting and eating invasive species throughout North America. Email him here.

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