Kiley BriggsViews:
A Long Winter Without Herps
It’s early February, there is over three feet of snow in my yard here in northern Vermont, and air temperatures haven’t been above freezing in over a month. As a herpetologist, winters here often mean I go more than five months without seeing a reptile or amphibian. I enjoy a long winter, but not my inability to see my favorite animals that comes with it. To end my herp dry spell early, I did the opposite of what you’d expect. Instead of heading south to find warmth and snakes, I went north to Canada to spend an evening in an icy river on one of the coldest nights of the year in search of giant aquatic salamanders called Mudpuppies.
If that sounds counterintuitive, you can imagine the looks I got at customs. Salamanders? In mid-winter? In a frozen river? It sounds far-fetched—unless you know Mudpuppies.
What exactly is a Mudpuppy?
All salamanders have an aquatic larval stage with feathery external gills, and most eventually lose the gills and metamorphose into terrestrial adults. Mudpuppies are different. They are fully aquatic their entire lives and retain those gills into adulthood. Adults are gray or tan with dark mottling, can grow over a foot long, and sport bright red gills on the sides of their heads reminiscent of feather dusters.
There’s also a common point of confusion: many people use “mudpuppy” to refer to the larvae of any salamander, much like how larval frogs are called tadpoles. A true Mudpuppy, Necturus maculosus, belongs to a group of aquatic salamanders called waterdogs, which occur across much of the eastern United States. Mudpuppies have even been introduced to a few places, including parts of the Connecticut River and some lakes in Maine.
Life Beneath Ice and Snow
Surviving winter is no small feat for cold-blooded animals. Some species avoid extreme cold, while others have adaptations to endure it. For example, Wood Frogs and some other amphibians endure the cold by using chemistry to cool below freezing temperatures without freezing, but if they do freeze, they can survive that, too (to a point). Wood Turtles avoid the cold by seeking refuge in streams where they hunker down in spots that won’t quite freeze.
If you ask what Mudpuppies do to endure the cold, I might jokingly answer, “absolutely nothing!” Mudpuppies seem to thrive in harsh winter conditions, but by being fully aquatic, they are protected from lethal freezing temperatures. What sets them apart from other northern species is that mid-winter is the Mudpuppy’s active season, and it’s when they are easiest to observe. I use the word “easiest” loosely, though. They are not an easy salamander to find, except at one spot in Oxford Mills, Ontario.
A Tradition Called Mudpuppy Night
Normally, I wouldn’t share a precise location for a species online. But Mudpuppies in Oxford Mills are a special case. Since 1999, Fred Schueler and Aleta Karstad have hosted a weekly event every Friday night all winter called “Mudpuppy Night.” Anyone is welcome to join them in counting Mudpuppies beneath a small dam where the animals congregate to forage during the winter months.
The fast-moving water below the dam stays mostly ice-free, allowing intrepid biologists to wade into the river while onlookers peer in from the frozen shore with flashlights. In earlier years, over 100 Mudpuppies could be seen on a good night. More recently, a couple dozen is more typical—possibly due to the arrival of invasive rusty crayfish.
A Small Town, a Cold River, and a Community
On my most recent visit, temperatures were expected to drop to -7°F by morning, and heavy snow was falling. Undeterred, about a dozen of us showed up, including several children around eight years old—all excited to stand along an icy river in the dark and count salamanders. What started as a curiosity long before the weekly counts in 1999 has turned into a sort of a local attraction – and great business for the one restaurant in town, conveniently located across the street.
But why are Mudpuppies so visible in winter? It might not be that they’re more active, but rather that they’re easier to observe. One theory is that many of their predators are less active in such cold conditions, making Mudpuppies bolder and more likely to leave their rocky shelters. They also continue to feed even when water temperatures hover just above freezing, and dormant frogs too cold to move are definitely on the menu. Like most other amphibians, anything that moves and fits in their mouth is food. During my time spent as a research technician studying Mudpuppies in Vermont, we routinely captured Mudpuppies that had eaten crayfish while in our traps (the traps often contained a Mudpuppy, a pair or two of crayfish claws, and zero crayfish bodies).
Counting Salamanders, Year After Year
Traditionally, Mudpuppy Nights focused on spotlighting and counting salamanders, and occasionally catching a few for educational purposes. In recent years, researchers have begun using the site for more formal studies. During my visit, a graduate student was capturing and microchipping Mudpuppies to estimate population size. So far, he has tagged around 200 individuals—and continues to catch mostly untagged ones, suggesting a much larger population.
My first two trips to Mudpuppy Night were for research. This time, I went purely for the experience. I’m genuinely impressed by Fred and Aleta’s nearly 30-year commitment to weekly Mudpuppy counts, and by the community of enthusiasts and scientists they’ve built around this unusual winter tradition. Long-term datasets like this are rare—especially when they require standing in a Canadian river on the coldest nights of the year.
Standing in the Cold for Something Worth Protecting
Anyone can sign up for Mudpuppy Night. It’s free, but donations are encouraged. Just reach out to Fred and Aleta to inquire about openings—and be prepared to meet their Canadian generosity and hospitality in kind.
Looking to learn more about Mudpuppies?
