It’s a rainy, early spring night in a small town 15 minutes north of Portland. On what is typically a dark and quiet road, a high-pitched chorus reverberates through the damp air. The strobing red and blue lights of a police car illuminate dozens of children and adults sporting reflective vests and toting flashlights. With eyes cast downward, they step gingerly along the strip where the woods meet the road. “There’s one!” a child shouts, picking up something small and ferrying it across the road.

To motorists who encounter this strange scene, it might appear to be an unusual and ill-timed Easter egg hunt. In fact, this is a much different cause for celebration in the community of Cumberland. This is Big Night.

Big Night is the night — or series of nights — when amphibians migrate en masse from the woods to temporary bodies of water called vernal pools to mate and lay eggs. For this exodus to occur, the nighttime conditions need to be just right — rain or plentiful moisture, mostly thawed ground and temperatures above 45 degrees.

When these three elements align in late March or early April, the Chebeague & Cumberland Land Trust (CCLT) summons volunteers to the Frog Pond and Salamander Swamp on Range Road in Cumberland. These permanently conserved wetlands are the migratory destination for hundreds of spotted salamanders, wood frogs, tree frogs, green frogs, leopard frogs and spring peepers each spring. (The peepers are the source of the high-pitched chorus people often associate with spring.) The problem at this location, as at many amphibian migratory pathways, is that a road intersects their route.

Since 2010, CCLT has invited community members to witness this natural spectacle and to help reduce the number of frogs and salamanders killed by vehicles before they reach their breeding grounds. A town police officer slows traffic while volunteers gently pick up the amphibians and carry them in their hands or a container across the road to the vernal pool.

In addition to escorting the amphibians to safety, CCLT and its volunteers have been collecting data at the Range Road site for the past five years as part of Maine Big Night, a nonprofit community science project. Citizen scientists at designated sites across the state track weather conditions; numbers and types of amphibians found alive, dead and injured; and traffic volume to help determine the impact of roads on amphibian populations and develop solutions.

Because these migrations happen only at night, many are unaware of their existence. Wildlife-friendly road design, temporary road closures and caution signs for motorists are some potential solutions that can help reduce fatalities during the spring migration season. Avoiding driving on rainy spring nights will also help protect these fragile vertebrates.

Why all the effort to keep some tiny, cold-blooded creatures from being squished in the road? As voracious insect eaters and a food source for many birds and mammals, amphibians are a critical link in the food chain. According to Sally Stockwell, director of conservation at Maine Audubon, they are becoming less common and more stressed due to habitat loss, pollution (such as road salt), lighting, road mortality and increased rates of disease, perhaps related to a warming climate. “Anything we can do to assist these fellow critters in safely reaching their breeding pools will help them persist over time,” she says.

While the work of the CCLT volunteers is serious, it’s also a joyful and educational community event. Leah McDonald, a CCLT board member who has been attending Big Night with her two daughters for more than 10 years, says the event marks the coming of spring for her family. “It’s so magical for all ages,” she says. “It makes me feel like a little kid again. The enthusiasm from all the people that show up — it’s almost like they’re unfurling from hibernation like the frogs and salamanders.”

More info about CCLT’s Big Night event can be found at ccltmaine.org/bignight. More info about the statewide Maine Big Night project, including how to become a certified volunteer and adopt a site, can be found at mainebignight.org. Check with your local land trust or other conservation organizations to learn about Big Night educational events in your community.