ADDISON COUNTY — Jim Andrews often receives reports of reptile and amphibian sightings from around the state. The Salisbury herpetologist is the coordinator of the Vermont Reptile & Amphibian Atlas, a nonprofit organization that collects and distributes herptile data to inform wildlife habitat stewardship. 

In recent weeks, however, Andrews has received some particularly noteworthy news — accounts of reptiles and amphibians active in late December, a time of year when those creatures have typically gone dormant for the winter.

“We got reports of wood frogs that were moving on the surface; a painted turtle was basking on the ice,” Andrews told the Independent. “For this particular time period, that’s really unusual.” 

During Vermont’s winter months, reptiles and amphibians find a spot to lay low until spring. Frogs and salamanders nestle under leaves, turtles plunge to the bottoms of ponds and rivers, and snakes seek out mammal burrows or other denning areas below the frost line. 

As herptiles wait for the winter months to pass, their metabolic and heart rates begin to slow down. They become lethargic and enter a state of dormancy known as brumation. Typically, reptiles and amphibians begin this process with the arrival of cooler temperatures and frosts in the fall and remain dormant until warmer weather arrives in the spring. 

But Andrews noted this winter Vermont experienced spring-like weather throughout the month of December, prompting some herptiles into activity earlier than usual. 

In Addison County, this past December brought little snowfall and abnormally warm temperatures. According to the National Weather Service, the temperature in Cornwall reached 55 degrees Fahrenheit on Dec. 19, a record high for the town on that day. 

“We had temperatures that were roughly 45 degrees Fahrenheit, the ground was thawed out, there was no snow cover. So, these guys thawed out and they were starting to move around,” Andrews said. “For that time period, and since we’ve been gathering data, this is the first time we’ve seen that.” 

DECEMBER SIGHTINGS

Andrews noted that while the organization has occasionally observed similar activity during an early spring thaw or warmer stretch in January, the herptile sightings reported in recent weeks are unique. 

“We’d never seen it for this particular time period, this late December time period,” he said. 

Throughout the last week of December, the Vermont Reptile & Amphibian Atlas heard reports of a wood frog spotted on the Pitch Pine Trail Salisbury, an American bullfrog active in Charlotte and a young painted turtle basking on the ice in Sharon. 

A WOOD FROG perches above the snow in Derby, Vt. late last month. The frog was one of several herptiles spotted throughout the state during the last week of December, a time of year when those creatures are typically dormant for the winter.   
Photo courtesy of Jim Andrews

Andrews noted that sightings of the wood frog and painted turtle were the first ever reports in the state of those herptiles being active during the last week of December. 

“In the case of the turtle, turtles are usually under the ice, and they may move around a bit, but they stay under the ice. But we lost the ice, and we lost the ice covering on most places,” Andrews explained. 

WARMING WINTERS

The herpetologist said the recent sightings appear reflective of a larger trend driven by climate change. 

The U.S. Environmental Protection Agency reports average winter temperatures throughout the country have increased by around three degrees Fahrenheit since 1896. 

And according to the 2021 Vermont Climate Assessment released by scientists at the University of Vermont, the state’s winter temperatures since 1960  have risen more quickly than the overall average annual temperature increase of 2 degrees Fahrenheit, while the state’s freeze-free period has also lengthened by three weeks since then. 

This abnormal winter weather can have a negative impact on local herptiles, Andrews said. 

“We get a little bit of snow, and then it warms up and we lose it. Then we get a little bit of snow, and the ground thaws out. These irregular patterns are not the same patterns that these species evolved with, and so in some cases, we can get some really mass die-offs,” he said.  

Andrews said there’s a variety of ways that irregular winter weather can hurt herptiles, such as a loss of snow cover, which acts as an insulator for hibernating reptiles and amphibians. 

“If you have a good snow layer on top of the soil, the ground sometimes doesn’t even freeze. It’s enough of an insulator, so that it keeps the ground at least from freezing very deep,” Andrews said. “When we lose that, and (herptiles) freeze, it can exceed the level of their antifreeze and they die, or it could get deep enough so that those creatures which are deeper in the soil, the ones that are not freeze tolerant, freeze and die.” 

Luke Groff is a herpetologist for the Vermont Fish & Wildlife Department. He said other challenges to herptiles posed by warmer winter weather could include a depletion of the resources animals rely on during hibernation.

“When they’re overwintering, a lot of species are dormant or not active but they’re still drawing on resources because they’re still alive, there’s still a heartbeat,” Groff explained. “(With) a warm-up in January, they’re going to draw on those resources faster. It just means they might go through the resources that they stockpile during the fall, and they might not have enough to get through the winter.” 

Groff said irregular winter weather could also create other problems for snakes if the creatures leave their dens during a warm-up and it snows while they’re out. 

“I could see them being trapped out of their den and then dying from exposure,” he said. 

Andrews noted that tough winters have at times led to die-offs among the state’s herptile populations. 

“In the past, I would say by and large, they’ve recovered,” he said. “Will they continue to recover? Can they keep up with these changes? I am concerned about that.” 

Andrews and Groff noted that climate change is just one of several threats the state’s reptiles and amphibians are facing. 

“These impacts of climate change aren’t happening in isolation. These animals are also impacted by habitat loss, disease, being hit on roads,” Groff said. “I would encourage folks to help out where they can; if there’s a turtle crossing the road and you can help out safely, if you can create or maintain habitats.” 

Groff said another way people can help protect species is by not interfering with wild animals. 

“Seeing a snake or a turtle basking on a log in the winter, it’s odd, but these are animals that know what they’re doing, they know what their body needs, so I’d recommend leaving wild animals in the wild,” he said. 

Andrews believes the most important thing people can do to help herptiles is to work collectively to tackle the climate crisis. 

“We just have to be more aggressive about preventing climate change. It’s going to happen, but the question is to what degree is it going to happen, and that depends on our actions,” he said.