Invasive little pet turtles

Red-Eared Sliders

From ecoRI News (ecori.org)

They are the most popular pet turtle in the United States and available at pet shops around the world, but because Red-Eared Sliders live for about 30 years, they are often released where they don’t belong after pet owners tire of them. As a result, they are considered one of the world’s 100 most invasive species by the International Union for the Conservation of Nature.

Southern New England isn’t immune to the problems they cause.

“I hear the same story again and again,” said herpetologist Scott Buchanan, a wildlife biologist for the Rhode Island Department of Environmental Management. “‘We bought this turtle for a few dollars when Johnny was 8, he had it for 10 years and now he’s going to college, so we put it in a local pond.’ That’s been the story for hundreds and thousands of kids in recent decades.”

Red-Eared Sliders are native to the Southeast and south-central United States and northern Mexico, where they are commonly found in a variety of ponds and wetlands. Buchanan said they are tolerant of human disturbance and tolerant of pollution, and they are dietary generalists, so they can live almost anywhere. And they do. They breed throughout much of Australia as a result of pets being released, and in Southeast Asia they are raised as an agricultural crop and have displaced numerous native species. In the Northeast, they live in the same habitat as Eastern Painted Turtles, one of the area’s most common species, but they grow about 50 percent larger. Numerous studies suggest that sliders outcompete native turtles for food, nesting, and basking sites.

Despite concerns about their impact on native turtle populations, red-eared sliders are still legal to buy in Rhode Island and most of the United States, though Buchanan said that in the Ocean State they may only be sold by a licensed pet dealer and can’t be transported across state lines. Those who buy a slider must keep it indoors and must never release it into the wild, including into a private pond.

“But people often aren’t aware of the regulations, or they don’t bother to look at them, or they just don’t follow them,” Buchanan said. “We see lots of evidence of sliders, especially in parts of the state where there are lots of people. The abundance of Red-Eared Sliders in Rhode Island is tied to human population density, which means mostly Providence and the surrounding communities. But I’ve also found them in Newport and Narragansett and elsewhere.”

Sliders are especially common in the ponds at Roger Williams Park, in Providence, and in the Blackstone River.

While conducting research for his doctorate at the University of Rhode Island from 2013 to 2016, Buchanan surveyed ponds throughout the state looking for spotted turtles, a species of conservation concern in the region. During his research, he also documented other turtle species, including many red-eared sliders.

“The good news was that while spotted turtles can occupy the same habitat as red-eared sliders, I found a greater probability of occupancy by spotted turtles at the opposite end of the human density spectrum as I found sliders,” he said. “Spotted turtles tend to occur where human population density is low, so at least at this moment in time, we would not expect red-eared sliders to be directly competing with populations of spotted turtles.”

Nonetheless, Buchanan advocates what he calls a “containment policy” to keep the sliders from expanding their range in the state.

“It’s mostly about public education,” he said. “We want to make sure people know not to release them in their local wetlands. If we found sliders in an important conservation area — Arcadia, for example — we might consider removing them, though we’re not doing that now.

“They’re well-established in Rhode Island now, so the thought of eradicating them does not seem like a feasible management solution. We just have to live with them, but we also have to try to minimize their spread and colonization of new wetlands.”

No other non-native turtle from the pet trade besides the Red-Eared Slider has been found to be a common sight in the wild in Rhode Island, though Buchanan said he recently had a report of a Russian tortoise — another popular pet — that was discovered wandering around Coventry.

For those who want to get rid of a pet Red-Eared Slider, Buchanan doesn’t offer any easy alternatives.

“You’ve got to be committed to housing that turtle for 30 or 40 years until it dies,” he said. “That’s why this is such a problematic issue. It’s easy to buy a teeny turtle for ten bucks and think it’s no big deal, but that animal is going to live for a long time. When you purchase it, you have to be responsible for it for the rest of the turtle’s life.”

Rhode Island resident and author Todd McLeish runs a wildlife blog.

Todd McLeish: Amphibians and reptiles under stress in New England

A northern leopard frog, a species that has been disappearing

From ecoRI News (ecori.org)

When Scott Buchanan was hired as a wildlife biologist at the Rhode Island Department of Environmental Management last year, he became the first full-time herpetologist on the state payroll. It’s a sign, he said, that reptiles and amphibians are in need of management and conservation in the state.

“To be in herpetology is to be on the front lines of the global biodiversity crisis,” he said. “We’re at risk of losing, globally, roughly half of the reptile and amphibian species on Earth in the next 100 years. Turtles and frogs are in a neck-and-neck competition for the unfortunate title of being the most endangered wildlife taxa.”

While Rhode Island’s reptiles and amphibians haven’t experienced the level of habitat loss and disease that occurs in Southeast Asia or the tropics, Buchanan said “the crisis is very real in New England. The mission is very urgent, and we need to do everything we can here in Rhode Island.”

About 40 species of turtles, snakes, frogs, toads, and salamanders call the Ocean State home. All face issues of habitat loss, road mortality, and disease, but turtles are also faced with high demand from collectors for the pet trade.

While monitoring a rare population of wood turtles this spring, herpetologist Lou Perrotti, director of conservation at the Roger Williams Park Zoo, observed a small specimen he estimated to be 5 or 6 years old.

“I love to see the little ones,” he said, “but I worry that someone would put this one in their pocket and take it home.”

It’s such a concern that Buchanan is co-chair of a collaborative group of biologists, law enforcement officials, and legal experts from up and down the East Coast working to combat the illegal trade in native turtles. The objective, he said, is to raise the profile of the issue and encourage the law-enforcement community to be aware that a black market in native turtles exists in the region.

The illegal trade in wildlife is valued at about $19 billion annually, according to the World Wildlife Fund’s TRAFFIC program, a network of organization that monitors the trade.

“It’s something I worry a lot about,” said Buchanan, who conducted research on spotted turtles for his doctorate at the University of Rhode Island. “If you know where they are, turtles are pretty easy to pick up, take home, keep alive, and get them into the black market. All of our native species are vulnerable, though some are more prized than others.”

A Pennsylvania man was arrested last year for smuggling 3,500 rare diamondback terrapins from marshes in New Jersey and selling them online. Although no cases have been adjudicated in Rhode Island, Buchanan said there is evidence of the illegal turtle trade in the state.

Buchanan is also involved in region-wide efforts to study spotted turtles and box turtles, two species that are considered to be of significant conservation concern. He is conducting surveys of both species in Rhode Island this spring to gather as much data as possible about their distribution, abundance, demography, and population genetics.

In collaboration with Roger Williams Park Zoo and Brown University, he is also investigating the presence of disease in local populations of reptiles and amphibians.

“We need to improve our understanding of where the diseases are and what species are harboring them to get a sense of their susceptibility,” Buchanan said. “There’s chytrid [a common amphibian disease in the tropics] in our environment, though our frogs don’t seem to be susceptible, but there hasn’t been a lot of testing. And there’s a similar disease for salamanders that has had bad outbreaks in Europe, and we’re worried about it coming overseas.”

Two species of amphibian — the eastern spadefoot toad and northern leopard frog — are on the verge of disappearing from Rhode Island. Both have only one known population. The toad is only found at one site in Richmond, though efforts are under way to create habitat to establish additional populations.

The northern leopard frog is found only on the border of Bristol and Warren, and Buchanan said there is little that can be done to help it recover.

“The northern leopard frog might be the best example of a species that’s about to disappear from the state,” he said, noting that the species faces multiple threats from habitat loss, pollution, and invasive species. “It could happen this year, next year, or in five years, but all indications are it’s going to happen soon. And there’s not a tool in my toolbox at the moment that I can use to confront the situation.”

Rhode Island resident and author Todd McLeish runs a wildlife blog.

Todd McLeish: How New England wildlife deals with extreme cold

River otters like to slide across the ice of a pond.

Via ecoRI News (ecori.org)

The recent extreme cold has New Englanders avoiding the outdoors as best as they can and loading on extra layers when they must go outside. Which raises the question of how wildlife fared during this unusually cold period.

Local biologists agree that most species of wildlife that spend their winters in Rhode Island are well adapted to weather the cold. They have evolved numerous strategies to deal with the conditions, from hibernation and torpor to thick fur coats and layers of fat.

Birds, for instance, have developed a number of adaptations that enable them to survive the extreme cold. According to Scott McWilliams, a physiological ecologist at the University of Rhode Island, ducks can stand on ice for hours at a time and swim around in the icy water without suffering frostbite in their feet thanks to a counter-current heat exchange system in their legs. The warm blood flowing down to their feet warms up the cold blood flowing back to their core, and the blood in their feet is so cold that the difference between their foot temperature and the ice ensures that they lose little heat through their feet.

Birds also huddle together to stay warm, fluff up their feathers to provide an insulating layer around them, and lower their body temperature to save energy.

But not all birds are prepared for the cold.

“Most sensible birds will migrate to warmer places, thereby avoiding having to contend with the cold,” McWilliams said.

Some of those that stick around, however, “are less well-insulated or otherwise poorly adapted to living in cold places.” He noted the Carolina wren, a southern species that has expanded its range northward in recent decades, as an example. Southern New England is at the northern part of its range, and during extreme and extended cold spells in Rhode Island, many of the birds don’t survive. That was the case during the winter of 2015, when the state had a record snowfall and Rhode Island’s Carolina wren population declined. When favorable weather returns, however, the wren population bounces back again until the next severe winter.

Cold-blooded creatures such as reptiles and amphibians — animals that can’t regulate their own body temperature — are also well prepared for extreme cold. Wood frogs, for instance, have what some scientists call “antifreeze” in their blood that enables their tissues to freeze solid without harmful effects. In some winters, the frogs experience several freeze-thaw cycles.

Herpetologist Scott Buchanan said adult painted turtles, snapping turtles, and spotted turtles are also extremely cold tolerant and will likely fare well. But some painted turtle hatchlings, which overwinter in their nest cavity, may die if the temperatures are extreme for an extended period of time.

“The invasive red-eared slider, on the other hand, is less tolerant of extreme cold — both the adults and hatchlings,” Buchanan said. “Hatchlings, which also overwinter in the nest, are more vulnerable to these cold periods and would exhibit a greater rate of mortality than painteds or snappers.

“From a conservation perspective, this would be a good thing, as it would slow down the invasion.”

Wildlife that lives in the upper layer of the soil or in the grass at the surface may be particularly vulnerable to extreme cold, especially cold temperatures without a thick layer of snow to serve as insulation. 

David Gregg, director of the Rhode Island Natural History Survey, speculated that the d that the dearth of leaves on the ground — thanks to two years of gypsy moth defoliation — may mean there will be less insulation for species that hibernate in the forest floor, such as box turtles and salamanders.

“Low temps and thin snow is also probably tough for small mammals like voles, which tunnel around in the grass,” Gregg said before the Jan. 4 blizzard. “Of course, that might make life easier for owls and hawks that need to be able to find voles.”

He also wondered about the impact of the cold weather on aquatic mammals, when all of the local ponds are frozen solid. During the week before New Year’s, he twice observed a muskrat wander up from a nearby frozen river to scratch for food in his lawn. And in the winter of 2015, a river otter emerged from the same frozen river to forage in Gregg’s compost pit.

Charles Brown, a wildlife biologist with the Rhode Island Department of Environmental Management, isn’t worried about those aquatic mammals, however. He said the range of muskrats, river otters, and beavers extends far to the north in Canada, where they likely experience much longer periods of extreme cold than they do in southern New England.

“So around here, they’re probably living the easy life,” he said.

Those animals typically gravitate to areas of moving water, like dams and spillways, during extreme cold, Brown said, and otters can even chew holes in the ice to gain access to pond water.

Brown is more concerned about how big brown bats will fare. He noted that most bat species that spend time in Rhode Island migrate to caves to hibernate or travel south to warmer climates to avoid the winter conditions. Big brown bats are the only species that lives in the state all year. And even those should survive without much difficulty.

“We’ve had some pretty cold winters in the past, but rarely have I ever seen any evidence of bats dying from exposure,” he said.

The big picture, according to Gregg, is that the creatures that winter in the state do so for a reason, and there’s probably a logical reason for those that don’t survive the chill.

“I think that hard cold like this helps to hold back the northward expansion of southern species, like fire ants, kudzu, and lizards,” he said. “The kind of animals and plants we think of as typical here are either helped or hurt in the appropriate ways by cold, so the net effect is good even though there are animals and plants that go up and others down.”

Rhode Island resident and author Todd McLeish runs a wildlife blog.