By Debra Marnich, Stewardship Director, Chocorua Lake Conservancy Stewardship Director & Tara Schroeder, Education Coordinator, Green Mountain Conservation Group
You never know what secrets will be discovered in the dark of a Big Night, what stories will unfold, or what those stories will tell us.
Big Night road sign. | Tara Schroeder
On the evening of April 26, 2025 a group of Chocorua Lake Conservancy (CLC) and Green Mountain Conservation Group (GMCG) volunteers gathered in the parking lot at CLC’s Charlotte C. Browne Woods for an Amphibian Crossing Brigade, a citizen science endeavor in which volunteers help amphibians cross roads safely and record data about who is crossing. While they reviewed amphibian identification and wondered if tonight would really be the night, the perfect “Big Night storm” arrived. The ground was thawed, the temperature was 55 degrees, a light rain began, and as the group prepared, darkness fell. These four factors combined to make perfect conditions for amphibians to migrate from the upland forests to their spawning grounds in wetlands, rivers, and lakes.
Collecting amphibian identification sheets. | Tara Schroeder
This was CLC and GMCG’s second annual Big Night amphibian migration with support from the Harris Center for Conservation Education. Last year, we braved 40-degree temperatures and cold rain to help 250 amphibians across Washington Hill Road in Tamworth. This year, in the same location, our number of amphibian crossings doubled to a startling 526!
Why would anyone be out in the dark wandering around in a cold rain? For the amphibians! The Big Night amphibian migration phenomenon is not widely known because it happens on chilly, wet nights when folks would rather be tucked in front of the wood stove in a warm house, enjoying a book or TV. But whether we realize it or not, as this secretive migration is underway, humans play a major role in the success or failure of every amphibian trying to reach their breeding grounds. Habitat fragmentation by roads or developments and habitat destruction are both reasons why an amphibian may fail to reach its essential mating habitat. Habitat corridors that provide migration opportunities need to be identified, prioritized, recognized, and conserved as protected land. You can also imagine how this migration event on a dark, rainy night makes amphibians extraordinarily vulnerable to car collisions. While habitat loss has long-term consequences, motor vehicles are the major cause of amphibian deaths on Big Night migrations, which is where our hardy group of volunteers came in.
While habitat loss has long-term consequences, motor vehicles are the major cause of amphibian deaths on Big Night migrations, which is where our hardy group of volunteers came in. | Image from the Big Night crankie.
Tara Schroeder from Green Mountain Conservation Group. | Debra Marnich
As we wandered the road armed with headlamps and data sheets, the mystery of migration was preparing to unfold. One by one, frogs, salamanders, and other creatures of the night began to move, apprehensive at first, creeping onto the shoulder of the road, and then with a quick scuttle to the middle of the road. There to ensure the amphibians crossed the road safely, we moved closer with headlamps blazing. Like the proverbial deer, amphibians freeze in the bright light, allowing us to identify species, to record valuable data, and to ensure these species make it to the other side safely.
Northern two-lined salamander. | Debra Marnich
As we collected data this year, we were glad to see many of the species we encountered last year, including the spotted salamander, the red-backed salamander, eastern newt, wood frog, spring peepers, American toads, and green frogs, and excited to make some new discoveries. New to our list was the Northern two-lined salamander, Eurycea bislineata, a stream-dwelling salamander that is widespread and secure in New Hampshire.
However, the biggest surprise was the show-stopping appearance of a secretive spring salamander, Gyrinophilus porphyriticus. In New Hampshire, the spring salamander is generally found living in or near water, with a preference for the cold, well-oxygenated waters of springs and headwater streams found within forested areas across New Hampshire. You're most likely to find them tucked under rocks and logs within the stream or in the damp leaf litter and debris along the banks. During periods of rain, they may even venture further into the surrounding woodland, and that is how we came across this one. Because of its habitat requirements, this species is an indicator of excellent habitat and water quality.
Spring salamander. | Debra Marnich
While the spring salamander is considered secure in New Hampshire, it is not particularly abundant anywhere in the state. This makes each sighting a rare and special occasion for nature enthusiasts. Brett Amy Thelen, our partner at the Harris Center, said, "A spring salamander! We encounter that species so rarely that I don't even include them in my training materials. They primarily live in streams, but once in a rare while, on very rainy nights, I will find one on a road near a stream. Super cool sighting! I am also agog at the number of red-backed salamanders you found. We have never had anything like that at any of our crossings!" Wetland scientist Dr. Rick Van de Poll expressed his surprise, too. “I think I've had just one spring salamander on a crossing night in god knows, 40 years? That should tell you how lucky you all are!"
Big Night sandwich board sign. | Debra Marnich
CLC and GMCG launched an extensive public awareness campaign this year, creating sandwich board signs to alert the public when there would be potential Big Nights and when amphibian crossing brigades were in progress. We worked with partners in the watershed to raise awareness of these special migration events, including Tin Mountain Conservation Center who offers an annual training workshop and crossing brigade, and the Sandwich Conservation Commission who organized their first official brigade.
We also added a creative element to get the public involved. In partnership with Cook Memorial Library and the Yeoman’s Fund for the Arts, we invited local artists of every age to paint a public service announcement crankie about the phenomenon of Big Night, offered an interactive performance of the crankie, and used the artwork to create a video PSA that environmental organizations striving to increase awareness about Big Night could post on social media. And we went on WMWV’s Drive Time!
Spotted salamander. | Debra Marnich
We hope to build on these last two years' efforts so that in future years those interested can help identify other local hot spots where amphibians are crossing roads during migrations, start their own brigades, and rescue as many critters as possible. Collectively, this year’s brigades with partners helped to safely cross 818 amphibians at eight sites. Unfortunately, 131 mortalities were observed at these sites as well, a 13 percent rate of mortality. By working together, we can seek to reduce these mortality rates.
The story of nature is told while observing and discovering the habitat and species around us. Our important data was collected, recorded, and sent to the Harris Center to add to their collection of data from all over the state. However, the larger take-home message from our Big Night migration this year is a message that‘s written across the landscape. A large percentage of land on Washington Hill Road is protected by CLC and the State of NH and contains diversified, resilient habitats. The road itself is a potential barrier through a major wildlife habitat corridor. With continued efforts, such as the Big Night amphibian migration crossing, we can educate the community about priority wildlife corridors, how to promote and preserve them, and how to help the species whose survival depends on them.
Hooray to all the citizen scientists who participate in amphibian crossing brigades! | Image from the Big Night crankie
Banner image: Spring salamander. Photo: Debra Marnich