Wednesday, October 17th, 2018

Troubles arise when pet turtles are released/Part two in a four part series detailing invasive species

Posted on March 07, 2016 in News
By USM Free Press

By Haley Depner/Contributor

The pet trade is responsible for earning this species a nomination by the International Union for Conservation of Nature (IUCN) as one of the 100 “World’s Worst” invasive species. The red-eared slider turtle (Trachemys scripta elegans) has inundated ponds and wetlands around the globe. Is Maine next on their list?

If you ever bought an aquatic turtle from a pet store as a kid, or knew someone who did, you probably will recognize the red eared slider turtle. They get this common name from the red stripe that begins behind their eyes and runs along the sides of the head, and from their habit of sliding off whatever they are basking on when disturbed. The shell and the marginal scutes (scales at the edge of the shell) of this species are smooth. Their heads are blunt and shaped like the bow of a boat. Red eared sliders can grow to have a plastron (the bottom half of the shell) length of about a foot, with males being smaller than females. The carapace (top half of the shell), head, limbs and tail are green in hatchlings and darken to a dusky or ebony brown as the turtle matures. The plastron is bright yellow with a spot on each scute that matches the carapace.

Originally the red eared slider turtle was found only in the southern central United States east of the Rocky Mountains.

The IUCN reported that these turtles have been transplanted across the United States and the globe, establishing populations throughout the U.S. and on every continent except Antarctica. According to the IUCN, this species prefers shallow, sluggish waters with soft beds, plenty of sunlight and large areas of vegetation, though as generalists with a fairly broad omnivorous diet, they can survive in a wide range of aquatic habitats.

Their spread is owed widely to the pet trade. Derek Yorks, a wildlife biologist with the Maine Department of Inland Fisheries and Wildlife’s Reptile-Amphibian-Invertebrate Group, explained that red-eared sliders have “been very popular pets for many decades. People buy them and basically the turtles often outgrow the aquarium and kind of get big and stinky and hard to care for.  A lot of times people just end up releasing them, thinking that they’re doing a good thing for the turtle, and, you know, thinking that there’s nothing wrong with it.” Yorks emphasized that “they’re kind of an emerging problem in Maine, but they’ve been around for a while and been popular as pets in the US going back to at least the 1960s, if not earlier. In the last decade or so, some other states in New England have certainly started to see more and more sliders; particularly in ponds and lakes closer to urban areas. It’s this kind of cumulative effect of people releasing these unwanted pets and then they’re suddenly gaining you know, two or three, or half a dozen of them in a pond, and they start to reproduce and the numbers grow from there. We don’t know of any ponds in Maine right now where there are big reproducing populations of sliders but in other states, down in Massachusetts, Rhode Island, Connecticut, it’s becoming more and more common. We’re hoping to avoid that kind of a problem here.”

According to Yorks, the impacts of red-eared sliders on Maine ecosystems has so far been “probably quite negligible, since, like I said, we don’t know of any sites where there are large populations of sliders. But, in places where they do occur, they are in competition with other turtle species. They’re competing for food resources, basking sites, which are limited, you know, good rocks and logs to sit on in the sun, and there has been work in other parts of the country and in Europe where sliders are well established and reproducing, demonstrating some of those effects. But right now in Maine, it’s still at kind of the initial phase of them becoming established and we are hoping to avoid a full on invasion by them.

“Pretty much the only way you’ll know of their presence [in Maine] is by seeing them.” Yorks recommends those looking for red eared sliders in the wild to watch basking spaces favored by painted turtles (Chrysemys picta picta). Painted turtles are the number one kind of turtle you are likely to see basking in ponds or lakes where you are also likely to get red eared sliders. If you are familiar with painted turtles, and you start seeing some turtles basking right out there on the same logs and rocks with the painted turtles that are just much bigger, those could be sliders. If you have binoculars, you can really easily see that red mark on the side of their head, compared to the painted turtles with the yellow mark. You’re just gonna have to see them, really, either in the water, or sometimes you’d see a female when she is out to lay her eggs.”

Yorks emphasizes that “the biggest thing that people can do [to control red eared slider populations] is not releasing them into the wild. That goes for anywhere, except for in their native range, of course. That’s controlling their spread.” Yorks adds that “if they’re already there in some places where they are invading, usually when there’s direct concern about the impacts on an ecosystem and other species, particularly other turtle species, typically an animal control specialist or wildlife biologist, they do sometimes remove the turtles with [live] trapping. . . that would be the only feasible way of removing sliders and it would be a fairly intensive effort, going out there every day or every other day and checking traps, and baiting the traps, and doing something with the sliders if you are removing them. It’s not an impossible task if you found out they are in one local place and you really wanna reduce the numbers or try to eliminate them entirely. . . If it’s lots and lots of places, then it becomes a whole other effort, you have to scale things up. There’s not a lot of that going on just because it’s a lot of time and therefore a lot of money to deal with a problem on a really big scale.”

In an effort to slow the spread of the red-eared slider, many states have taken measures to control the trade of this species. In 2010, sales of red-eared slider turtles became restricted in Maine. The Maine Inland Fisheries and Wildlife (IFW) wrote that “Beginning on January 1, 2010, the Commissioner will remove the red-eared slider from the list of Unrestricted Fish and Wildlife Species. On this date, it will no longer be legal for commercial pet shops to possess or offer for sale the red-eared slider. The department has become aware of escaped or released populations of these non-native turtles in the wild. By removing the turtle from the unrestricted list, the Department seeks to minimize or prevent any further occurrence of this potentially invasive species. Red-eared sliders legally possessed by individuals prior to January 1, 2010 may continue to be possessed, but may not be sold, transferred, traded, or released.”

This law change has made it difficult for red-eared slider turtle owners in Maine, even those who own their turtles legally, to rehome those reptiles if need be. Yorks suggests Mainers looking to rehome their red-eared sliders to contact the Maine IFW. “We get pretty frequent requests from people who have sliders,” he said. “A lot of times people don’t even know they are illegal, and had moved here from another state. We have some people that are willing to take them. It’s tough, though, because not a lot of people want them and a lot of the people that we had on our list who are willing to take them have already taken on some and can’t really take on more.”

Yorks adds that “another option is finding someone or a turtle rescue organization that is outside of the state of Maine in a state where sliders are not prohibited that is willing to take the slider. For instance, if there is someone in New Hampshire [willing to take the turtle], sliders are not illegal there. . . [then] that slider can just be transferred to this other person in New Hampshire. That’s not the only state, there’s many states where they are perfectly legal, but that doesn’t mean that they’re not invasive in those states. It’s really good to get an idea of what’s gonna happen with that turtle. Are they gonna keep it themselves forever? Are they just gonna turn around and release it in a pond? There’s a lot of things that could happen with it. The responsible thing to do is look into it a little bit and ask a few questions to find out what is gonna happen with this turtle I transfer to somebody I may not know that well.”

Far more of these turtles are being surrendered than adopted. Many animal shelters outside of Maine that accept reptiles no longer accept red-eared sliders as there are so many that need homes and so few people who are willing to adopt them. Always call animal shelters before bringing in an animal for surrender to be sure they accept the species.

If you are a Mainer interested in adopting a red-eared slider in need of a home, Yorks encourages you to contact him at his office, (207) 941-4475. “Basically, through my office we have inquiries. It ranges, sometimes it’s several in a month, sometimes many months go by, but consistently many inquiries every year with people looking what to do with red eared sliders and I don’t have enough people to send them to. Like I said, most of the folks that want to take them on already have done so. So if anyone is interested in taking one and they are willing to apply for a permit and agree that they are gonna keep this turtle and not release it, then it’s definitely a possibility.” You can fill out an application for a General Wildlife Possession Permit at “We’re always looking for folks who are responsible and willing to take on sliders. I always explain to anyone who is thinking about it there’s a reason or two why people don’t always wanna keep these things. They need pretty big aquariums, and if you don’t keep that aquarium really, really, clean, it doesn’t smell good.”

“Unfortunately, I don’t think we’re at the end of having to worry about red eared sliders in Maine,” said Yorks. “Us having them not on the unrestricted list and restricting the trade of that species in Maine is a big help. They’re not coming into Maine through every pet store across the state, so we should start to see numbers dwindle. However, one factor to consider is that they’re long lived animals and someone could have a slider for one, two, three decades so there’s gonna be kind of a lag in seeing there has been a lag, since they were restricted- and the other factor is that other states are not restricting sliders. Right over the border in New Hampshire they are not restricted, but they are restricted in Massachusetts, but they haven’t been for very long, similar to Maine.” In New England, this species is also restricted in Vermont and Rhode Island and unrestricted in Connecticut. “Basically it’s kind of a patchwork,” said Yorks, “so there’s a lot of places where you can still go out and buy these things. People transfer them over state lines, often don’t even look to see what the laws and regulations are around it. A lot of people say they moved to Maine and they brought their pet slider, they don’t always know it’s a restricted species, for many years sometimes.”



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