Safe Passage for Salamanders

Community scientists with the Harris Center’s Salamander Crossing Brigades program keep count of how many amphibians they cross (transport across the road) by species, along with basic data on weather, location, vehicle traffic, and volunteer effort. They also occasionally pause for pictures of their gorgeous study organisms – in this case, a spotted salamander (Ambystoma maculatum). Photo by Brett Amy Thelen.

Every year, on the first warm, rainy nights of spring, thousands of spotted salamanders, wood frogs, spring peepers, and other amphibians migrate en masse to their breeding wetlands in a phenomenon known as “Big Night.” In places where they must cross roads, roadkill is a grave conservation concern. It doesn’t take a lot of cars to do a lot of damage.

Amphibian tunnels and temporary road closures offer solutions, but before a community can invest in those kinds of wildlife-friendly road improvements, they must first identify – and quantify – their local amphibian crossing hotspots. (It doesn’t make a lot of sense to build a tunnel under a road used by 10 amphibians, but a crossing site that sees 1,000 amphibians in a single night – or plays host to rare species – is another story.)

Enter the Salamander Crossing Brigades, heroic community scientists who usher migrating amphibians across roads on rainy spring nights, collecting data as they go. Since 2007, the Harris Center for Conservation Education has trained and coordinated more than 1,800 Crossing Brigade volunteers, who have collectively provided safe passage for 70,000 individual amphibians (and counting!) at dozens of crossing sites throughout southwestern New Hampshire.

Many volunteers return, as do the salamanders, year after year. As one longtime Brigadier shared, “It's important for the earth, it feels really good to be doing something positive, and it's a hoot to know there are other slimy-fingered loonies out there in the middle of the night sharing the thrills and the heartaches.”

These photos – all taken by Harris Center staff and volunteers – capture a touch of the Big Night magic, and of the “slimy-fingered loonies” who revel in it each spring.

Find more information on the Harris Center’s Salamander Crossing Brigades page. (We recommend starting with the FAQ.)

Note: The Harris Center’s work is based in the Monadnock Region of southwest New Hampshire, and we do not recommend traveling long distances on migration nights, even (and perhaps especially) for the purposes of saving salamanders. If you’re interested in volunteering with an amphibian brigade but do not live in the Monadnock Region, we encourage you to check out this list of crossing brigade programs in the Northeast, to see if you can find one closer to home.

Reflective vests and bright lights are essential safety equipment for Big Nights. Here, mother-daughter team Amy (left) and Annora (right) Unger model how to dress for success while out on the salamander beat. Photo by Amy Unger.

A trio of spotted salamanders (Ambystoma maculatum), whose polka dots match the rain pants of the volunteer lending them a helping hand. Photo by Amy Unger.

On a good night at the North Lincoln Street crossing site in Keene, volunteers might count and cross upwards of 1,000 amphibians in as few as four hours – mostly wood frogs (Lithobates sylvaticus), pictured, and spring peepers (Pseudacris crucifer). Photo by Brett Amy Thelen.

The spots on adult spotted salamanders are like fingerprints on humans: each salamander has its own constellation of markings, which can be used to tell that individual apart from all others. The Harris Center maintains a photo database of individual spotted salamanders from a selection of their long-studied road crossing sites. Over time, these spot pattern records could provide meaningful information on year-to-year survival in spotted salamander populations that must cross roads to reach their breeding pools. Thus far, nearly 50 different salamanders have been recorded on more than one occasion by Harris Center volunteers – including this one, which was moved across North Lincoln Street in Keene five years in a row. Photo by Brett Amy Thelen.

Harris Center Science Director Brett Amy Thelen (right) works with longtime Salamander Brigade volunteers Daniel McIntyre (left) and Nora McIntyre (center) to photograph a spotted salamander spot pattern in March 2021. Photo by Tim Briggs.

Modified coolers known as “lightboxes” allow volunteers to take hands-free photos of spotted salamander spot patterns (much less wriggling) on grid paper backgrounds (for scale). Photo by Brett Amy Thelen.

At some sites, on some nights, there are so many amphibians crossing the road at once that it becomes more efficient to transport them in buckets than to move them one by one. Crossing Brigade volunteers are trained to ensure that their buckets – and their hands – are free of soap, detergent, hand sanitizer, and other chemical residues before using them to carry amphibians. Photo by Stephen Lowe.

Jefferson complex salamanders (Ambystoma jeffersonianum) have been identified as a Species of Greatest Conservation Need in New Hampshire; efforts to reduce road mortality take on added importance at the crossing sites where they still occur. Photo by Brett Amy Thelen.

In 2018, the Harris Center began working with the City of Keene to close the North Lincoln Street crossing site to vehicle traffic on Big Nights. Keene is the first community in New Hampshire to close roads for the protection of migrating amphibians, and their decision to do so was based in large part on data collected by Salamander Brigade volunteers. Over the past five years, these detours have not only provided safe passage for thousands of amphibians, but also offered a safe place for hundreds of people to experience the magic of the amphibian migration – including elders, toddlers, and others who would never have felt safe coming out to see amphibians cross a road if that road were open to traffic. After hearing about the Big Night detours, Chandrashekar Balakrishna brought his children – including daughter Anwita Chandra (pictured, with two American toads) – to North Lincoln Street to see what all the fuss was about. Their family hasn’t missed a migration night since. Photo by Chandrashekar Balakrishna.

Cold-hardy wood frogs (Lithobates sylvatica) are one of the first amphibian species to migrate each spring. Photo by Sam Moore.

The hands of three different Salamander Crossing Brigade volunteers provide a size comparison for three different salamander species commonly found at springtime road crossings: red eft (the juvenile form of the Eastern newt, Notophthalmus viridescens) at bottom-left; Eastern red-backed salamander (Plethodon cinereus) at top-left; and spotted salamander (Ambystoma maculatum) at right. At every volunteer training, Harris Center staff discuss the importance of handling amphibians minimally, gently, and with clean hands. Photo by Sarah Thomas.

A lone spotted salamander (Ambystoma maculatum) makes its way across North Lincoln Street in Keene on a night when the road was closed to traffic. In 2022, a new volunteer wrote to say, “I only made it out on one night, but it was so interesting, and my vision, for just a while, saw our world as their world, inconveniently covered in asphalt.” Photo by Tim Briggs.

This web extra accompanies the article Amphibian Eggs in Vernal Pools in the Spring 2023 issue of Northern Woodlands.