A large black snake slithered out onto the Belfast Rail Trail on Oct. 10, startling people who were walking, jogging and biking along the popular path. Foreign to Maine, the 3-foot-long reptile was a black rat snake, and it likely arrived in the area as a stowaway.
Each year, people report a handful of nonnative reptiles and amphibians spotted crawling and slithering through the Maine wilderness — from boa constrictors to tiny tropical lizards — said Derek Yorks, a biologist with Maine Department of Inland Fisheries and Wildlife that specializes in reptiles and amphibians.
Some of these creatures are pets that escaped or released by their owners, while others are stowaways, entering the state by vehicle or in shipments from far away places.
“There are a lot of ways small reptiles and amphibians can hitch rides,” Yorks said. “But with Maine being a place that has a cold winter that’s inhospitable to most reptiles and amphibians, there are very few species that stand any kind of chance of getting established here.”
Yorks thinks that the black rat snake spotted in Belfast was likely a stowaway transported by vehicle or trailer from a southern state where the species is common. Native to much of the United States, the non-venomous black rat snake can be found as far northeast as Massachusetts, where it’s extremely rare and listed as endangered. No established population of the rat snake has ever been recorded in Maine.
“It was really a surprising and dramatic sighting,” said Murray Carpenter of Belfast, who spotted the snake while riding his bike on the Belfast Rail Trail on Oct. 10.
It was a warm day, and Carpenter thinks the snake was out on the trail to bask in the sun. He stopped to take some photos and was joined by several other trail users.
“I was worried it was going to get run over, so I took a couple of pictures, then took a stick and hazed it back into the grass beside the trail,” he said.
A black rat snake slithers onto the Belfast Rail Trail on Oct. 10, in Belfast. The snake is not native to Maine and likely arrived in the area as a stowaway. Credit: Courtesy of Murray Carpenter
Carpenter thought the snake was a black racer, Maine’s only black snake. However, black racers are listed as endangered in Maine and are only found in specific areas in the southern part of the state.
Carpenter sent photos of the snake to Yorks, who identified it as a black rat snake — which is often confused with black racers because both species are big and black.
“In the picture, the posture it was in with its head raised and flattened out is classic rat snake behavior when threatened,” Yorks said. “Their body shape is a little different, too. If you did a cross section, it’s like a loaf of bread.”
Yorks has seen a black rat snake in Maine before. Back in 2014, he responded to a call about a black rat snake that hitched a ride from Virginia to Warren, Maine, in a trailer-load of old corrugated metal roofing.
“This guy down there makes sculptures out of scrap metal and he’d driven down to Virginia somewhere to pick up the old metal roofing,” he said. “On the way up, they found a snake that came out of the metal and got into the truck. Then, when unloading it in Maine, they found another snake that slithered out and into the bushes.”
Yorks was able to capture the snake and — through a bit of luck — he found someone who was traveling to Virginia and agreed to transport the snake back to the very town it came from.
That was a rare case, Yorks said. Often, nonnative reptiles are hard to find once they’ve escaped into the Maine wilderness. Yorks visited the Belfast Rail Trail to look for the rat snake spotted on Oct. 10, but he couldn’t find it.
“To find one snake in the world a few days after it’s been spotted — it’s very much like a needle in a haystack kind of odds,” he said. “But you can get lucky if you know what you’re looking for and you’re experienced searching for snakes.”
Other nonnative reptiles that Yorks has been called to handle in recent years include an iguana spotted on the streets of Portland, and a tegu, which is a large South American lizard, found loafing about in a yard in Camden.
He’s also called about large, nonnative snakes — often escaped or released pets — on a fairly regular basis. For example, in 2017, a 6-foot red tail boa constrictor was found roaming around Biddeford, and in 2016, a green anaconda was found in Westbrook, and was possibly spotted snacking on a beaver.
“And then you have to wonder how many of these things no one ever sees,” he said.
A few weeks ago, Yorks was called in to identify a small lizard that a UHaul employee found stowed away in one of the company’s moving trucks in Bangor.
“It was a brown anole, a really common lizard that you see everywhere in Florida and Georgia,” he said. “They had it in a coffee can.”
Yorks decided to keep the lizard as a pet because he already had another brown anole at home. That lizard had also been a stowaway, found in a pallet of lumber in Bangor last year. Yorks plans for the two lizards to be terrarium mates.
Often, reptiles and amphibians are unintentionally transported to Maine in shipments of tropical plants from nurseries in southern states.
“You’ll often get little tree frogs [that aren’t native to Maine] hanging out in Home Depot because of their tropical plant section,” Yorks said. “I’ve heard them calling.”
Due to the state’s cold winters, most stowaway reptiles and amphibians can’t last the winter in the Maine wilderness. And even if they could, other factors such as food availability, finding a mate and conditions required for egg incubation would likely prevent the species from becoming established.
The rat snake in Belfast may survive the winter, Yorks said, since its range extends into Massachusetts, proving it can weather snowy and cold conditions. But it will just be one snake alone in the Maine wilderness.