Rain slashed through the cone of light from my headlamp. On a dreary night in April, I was on a mission to find salamanders and frogs. To my surprise, I ran into a bit of a mystery.
Observing amphibians is a spring ritual for me. When conditions are just right — rainy, dark and about 40 degrees Fahrenheit or warmer — certain salamanders and frogs cross Maine roadways as they migrate from their wintering grounds to breeding pools.
On those special nights, there’s a short list of creatures I might find. Wood frogs are common, as are spring peepers. But my favorite nighttime migrant is the spotted salamander (Ambystoma maculatum).
Not only is the spotted salamander Maine’s largest salamander, at 6 to 8 inches in length, it’s also quite flashy, with bright yellow spots. Lucky for me, a healthy population of them exist near my home in the woods.
Each spring, I watch dozens march across the road, and it never gets old.
This amphibian migration is so large and predictable that it has its own name: Maine’s Big Night. And I’m not the only person who’s enthusiastic about it.
Biologist Greg LeClair started a community science project to collect data about Maine’s Big Night in 2018, and it has grown steadily ever since. This year, about a thousand volunteers, scattered throughout the state, visited roadways to count frogs and salamanders in the rain.
In addition to gathering data, the community scientists help ferry amphibians across roads so they won’t be run over by vehicles. To do this safely, they erect signs and wear reflective vests and lights.
But let’s get back to my night of mystery. The temperatures hovered in the high 30s, not quite warm enough to push many cold-blooded creatures to move. Still, I hoped to see a few bold salamanders strutting across the road, and it wasn’t long before I got my wish.
I counted seven spotted salamanders in half an hour, plus a wood frog. Then I came across an amphibian that stumped me.
“What’s this?” I thought, crouching for a closer look.
The salamander looked like a spotted salamander. It was the same chunky shape and impressive size. But it had no spots.
Carefully, I plucked its soft body off the wet pavement and held it stretched across my palm, its long tail snaking up my wrist. It wiggled, legs flailing, but otherwise cooperated as I inspected its spot-free body.
It was paler gray than any spotted salamander I’d seen, and it was faintly mottled with brown, irregular splotches. In the bright headlamp light, it glowed purple.
The coloring confounded me, but everything else about it screamed spotted salamander. Having ferried hundreds of them across my road over the past few years, I consider myself fairly well acquainted with the species.
I snapped numerous photos of the spot-free salamander with my cellphone, then carried it across the road and let it go in the grass.
The next day, I searched online for an explanation. I didn’t find much.
The spots of a spotted salamander are often likened to fingerprints. Each salamander has a unique spot pattern. It’s believed that spot traits can be passed through genetics and influenced by the environment.
In a blog post, Matthew Burne, a conservation biologist and the president of the Vernal Pool Association, wrote: “Though rare, or at least uncommon, occasionally spotted salamanders are found that have almost no spots.”
At a specific location in eastern Massachusetts, Burne almost always finds at least one spotless specimen each year. This would support the idea that the abnormality is passed through genes. Or, since spotted salamanders can live more than 20 years in the wild, he could be counting the same one repeatedly.
Herpetological Resource and Management, a Michigan-based firm that offers services like species surveys and habitat mapping, also states that “rarely no spots are present” on spotted salamanders.
I found no mention of the spotless condition in the book “Maine Amphibians and Reptiles” by Malcolm L. Hunter, Aram J.K. Calhoun and Mark McCollough., but I found descriptions for other species of salamanders in Maine.
Could it be one of those?
After looking at my photos, a few friends suggested it could be a blue-spotted salamander (Ambystoma laterale) or a blue-spotted-Jefferson salamander hybrid. For a couple of days, I was convinced that was the answer.
Then, on another rainy night, I saw my first blue-spotted salamander. It was much smaller than my mystery salamander. And it was dusted with bright blue specks.
That threw me back to my first hypothesis: a spotless spotted salamander. After viewing some of my photos, LeClair agreed with me. It’s rare, he said, maybe a one in a thousand chance.
So, that’s my story and I’m sticking to it. I’ve got a rare salamander near my house, and I helped it cross the road safely.