On Spring's 'Big Night,' Frogs And Salamanders Brave Busy Streets

Apr 22, 2015

After a long and frigid winter, the sound of spring peepers singing from beaver bogs is a welcome one for New Englanders. But before frogs can start their songs spring, a massive migration has to take place. On a handful of spring nights, millions of amphibians mobilize all at once.

It’s called Big Night. Generally speaking, it’s the first rainy spring night after the ground has thawed and the temperature hovers in the forties.

“Thousands and thousands and thousands of salamanders and frogs all moving at the same time en masse to their breeding pools, and it’s just exquisite and most people don’t even know that it’s happening,” says Brett Thelen Science Director at the Harris Center for Conservation Education. Earlier this week in Keene, she was the tour guide to Big Night.

There are a handful of these nights every year, and when these animals are moving, driving long distances after dark is a cardinal sin in the eyes of people who know about this migration.

While they can't stop traffic, Thelen's crossing brigade does what it can to slow drivers down.
Credit Sam Evans-Brown / NHPR

  “It doesn’t take a lot of cars to do a lot of damage. They get hit once and then that’s it for them. So we have  organized volunteers, the salamander crossing brigades, who come out and they basically are going to walk back and forth along this stretch of road looking for frogs and salamanders who are trying to cross, and they’re going to move them across by hand,” says Thelen.

Red Efts (the juvenile form of the Eastern Newt) are a common crosser of roads.
Credit Sam Evans-Brown / NHPR

Spottys and Wood Frogs

Thelen coordinates about a hundred volunteers at more than a dozen crossings throughout the Monadnock region. She keeps a five-day salamander forecast and when the conditions are right, she mobilizes her crew a few times a year.

They set up Salamander crossing signs at crossing hotspots and patrol the road with headlamps and buckets. In Keene about a dozen volunteers arrive, including a few families, and many of them on foot. Kids squeal as peepers hop onto their shirt-fronts and marvel at wood-frogs.

In New England, the star of Big Night amphibians is the spotted Salamander. They are around 6 inches long, black with orangey-yellow spots. Chances are you haven’t seen one before, because though they can live to be 20-years old, they spend 95 percent of their life underground.

“When people see a spotted salamander, it really blows their mind,” says Thelen

She tells the story of a young family that drove through the crossing slowly, but then the car stopped abruptly, and the father leapt out.

“And he said ‘I’ve lived here 28-years and I’ve never seen this, I’ve never seen it!’” she recounts, “He was getting ready to pull his toddler out of her car-seat right in the middle of the road because he was so excited.”

Wood frogs, a common frog most easily identified by it quack-like call, are another frequently spotted crosser. Wood frogs are famous for being able to freeze solid during the winter, and restart their hearts when spring rolls around.

Worrying About the Common Stuff

“The thing that you find – particularly when you learn to spot them on the roads during spring migration – it makes you not want to drive your car,” says David Patrick the director of Conservation with the Nature Conservancy. “Roads are a problem for an incredible variety of biodiversity, but amphibians and reptiles – these slow moving species that need to move between wetlands and uplands – they’re some of the animals that we’re most worried about.”

Estimates for how many frogs and salamanders are squashed on Big Night vary.

Thelen’s volunteers use the less-than-perfect methodology of just counting how many live salamanders they helped across the road vs. how many they found dead. This year they estimated about 75 percent of the critters at the Monadnock crossings made it to safety.

"I think one of the problems we have with conservation and the way we manage and consider biodiversity is we worry about the rare stuff, which I think we should be doing. But we're a little bit less worried about the common stuff, but I think we should be worried about the common stuff too."

One more scientific treatment found that on quiet roads closer to 10 percent of amphibians get run over, but on busy roads it’s more like 50 percent.

“We tend to say ‘well, they’re still there, why worry, they haven’t gone extinct yet,’” says Patrick. “I think one of the problems we have with conservation and the way we manage and consider biodiversity is we worry about the rare stuff, which I think we should be doing. But we’re a little bit less worried about the common stuff, but I think we should be worried about the common stuff too.”

A "spotty" is given a boost across the road
Credit Brett Thelen

Frogs and salamanders produce huge numbers of eggs and offspring, the vast majority of which are eaten by other animals. Squashing a quarter of them on the roads before they can reproduce shrinks that foundation of the food chain.

Thelen’s crossing brigades in the Monadnock region were the only outfit in the state out helping amphibians across the road on Big Night.

Now all that’s left to do is to listen to the frogs that made it safely to their pools and puddles, as they sing, and try to reel in a mate for this spring.