Kiley BriggsViews:
With over a foot of snow at my house in Northern Vermont, it’s
possible I won’t see bare ground here again until April, or even May. Likewise,
my odds of seeing a reptile or amphibian any time soon are astonishingly small.
On occasion, however, frogs, salamanders, lizards, and snakes do venture out into
the snow. That is often a very bad sign for the animal in question, but not
always. So, why do reptiles and amphibians sometimes roam when it seems way too
cold out?
One of the most common amphibian sightings mid-winter in Vermont is of the Spotted Salamander. Spotted Salamanders breed in the very early spring, sometimes when there is still some snow on the ground. They wait for environmental cues underground to tell them when the right time is to emerge. Typically, that happens some time between March and April, but sometimes they are tricked by mid-winter thaws. When the snow melts early, or if ground temperatures warm above seasonal norms, a few overly enthusiastic Spotted Salamanders may surface. If they make it to their breeding wetlands, they may find the water is still iced over. Sadly, freezing temperatures may return before the salamanders can make it back to shelter. Depending on how cold it gets and the quality of the shelter they can find, they may or may not survive. Spotted Salamanders aren’t the only amphibians sometimes tricked by mid-winter thaws. It happens to all our early season breeders, including Wood Frogs, Spring Peepers, and Blue-spotted Salamanders.
On at least one occasion, a non-native Red-eared Slider was spotted walking across ice in late winter. So far, we don’t have any known breeding populations of sliders in Vermont, but that will likely change. Sliders are sold in many pet stores, and because they are difficult to find homes for when owners no longer want them, some are illegally released into the wild. It is possible this slider had never experienced winter before and had limited survival instinct, but there is another possibility. As a southern species adapted to shorter winters, the biological clock of this turtle might have been set to a southern schedule. Environmental cues might have told the turtle it was time to emerge far too soon in the season to do so safely.
Other instances of turtles on ice are easier to explain. Otters are one of the few predators capable of finding turtles mid-winter and bringing them to the surface. We’ve heard accounts of otters batting Painted Turtles around the ice like hocky pucks. More recently, someone found a Wood Turtle upside down on river ice, with otter tracks all around it. The Wood Turtle was alive, to our relief, and the person who found it returned him to the water and watched him walk away. Wood Turtles are sometimes active mid-winter underwater, moving short distances occasionally. On rarer occasions, Wood Turtles can be seen basking on snow-encrusted streambanks if it is sunny and warm out. Some winter activity from turtles is normal, but if it is below freezing out and the turtle is above water, otters may be involved.
A few days ago, someone skiing at the Okemo Resort found an Eastern Gartersnake on the snow. Gartersnakes sometimes emerge in the early spring when there is still snow on the ground, even basking and breeding on, or next to snow. In early December, though, the snake was in some sort of trouble. It’s a little hard to guess what may have caused this snake to venture onto the snow. Perhaps its underground overwintering site was disturbed. Or, it might not have made it to a suitable overwintering site when the snow fell and sought to complete its journey on a ‘barely warm enough to move’ day. We did not hear what happened to the snake after the sighting.
Some salamanders are active all winter. Mudpuppies, for example, spend their entire lives underwater and are most active in the winter. So long as the water around them is fluid, not ice, they are good to go. My first full-time herp job, right out of college, was as a Mudpuppy research technician. Until that point, I never imagined my first herp job would involve trapping salamanders under over a foot of river ice. In that gig, we took great care to ensure the Mudpuppies were never exposed directly to freezing air. Some days, it was so cold outside that our skin would freeze instantly to wet metal, which could injure or kill a Mudpuppy. Stream species, such as Spring and Two-lined Salamanders, are sometimes active all winter too.
Disease can also play a part in winter activity in reptiles. To fight off infections, snakes need to stay as warm as possible. Unfortunately, snake fungal disease can have a serious impact on Timber Rattlesnakes, and the cool damp conditions in their hibernacula are perfect for the fungus. The fungus can cause awful lesions and blisters to grow on the snake’s skin, especially their face, and afflicted snakes will bask more often than normal. I’ve heard a couple times about Timber Rattlesnakes with serious fungal infections basking mid-winter on warm sunny days. Those snakes were doing what they could to fight off the infection, but doing so is a sign of desperation. Under normal circumstances, a Timber Rattlesnake should not leave its den willingly this far north until spring.
Sightings of reptiles and amphibians in snowy conditions are rare, but it happens. Sometimes the animal in question is behaving normally, sometimes it isn’t, and sometimes their behavior is a sign of more serious problems. While I’d love to see a Wood Turtle sunning itself on snow someday, or spend some more time working with Mudpuppies, I am resigned to be content with just birds and squirrels most winters.
To learn more about how reptiles and amphibians survive the
harsh conditions of northern winters, check out my earlier blog post, Winter Hideouts.
