Blood laced with a natural antifreeze pumps through the veins of wood frogs. They rest suspended, somewhere between life and death, awaiting spring’s arrival in frozen winter forests. Beneath a blanket of decaying leaves, salamanders are waiting, too.
Tap, tap. It’s time for the race.
Each year in late March and early April, from New Jersey to Maine, forest-dwelling amphibians like spotted salamanders and wood frogs wake up from their winter homes and migrate during the night to vernal pools for breeding. Some animals travel through the woods, never to be seen by humans, while others cross broken habitat, trying sometimes fatal journeys across streets.
But some of them were waking up early late last month, the result of unseasonably warm weather, say reports from the New York State Department of Environmental Conservation. Volunteers helping to usher the amphibians across the street in the Hudson Valley last week saw wood frogs, spotted salamanders, four-toed salamanders and spring peepers. In some pools, male wood frogs are already calling for females that show up later.
When weather is warm and wet, as it has been recently and is in the forecasts for next week, hundreds to thousands of the animals migrate at once, in what’s called a “big night.”
“Although our Hudson Valley volunteers didn’t witness a ‘big night’ of migration last month, we did see early movement,” said Laura Heady, a conservationist who runs a program to protect estuaries and land in the Hudson Valley for the D.E.C. and Cornell University. “We may be experiencing seasonably cold temperatures over the next few days, but the current forecast suggests next week will be rainy and warm. If these conditions prove true, I suspect more amphibians will be back on the move.”
Some of these species, like spring peepers, are just traveling through the night, but others, like spotted salamanders and wood frogs, depend on the inconspicuous vernal pools, or “wicked big puddles,” as they are called in Massachusetts.
The lucky ones arrive just as the ice begins to break around the edges of the pools. There, adult amphibians go through courtship, mate and fertilize eggs. Then those eggs develop into adults themselves. All of this must happen fast — before the water dries up in the summer.
“It’s a race against dryness,” Ms. Heady said.
In some cases, it is also a game of Frogger. Slow-moving amphibians, just waking up, don’t always make it past even light traffic, said Ms. Heady.
Since 2009, more than 300 volunteers have ushered around 8,500 amphibians across the streets from just above New York City to Albany. They also counted 4,000 to 5,000 dead amphibians.
Mortality estimates vary but are “surprisingly high,” sometimes reaching nearly 40 percent in New York, said James Gibbs, a biologist at State University of New York College of Environmental Science and Forestry, said in an email. “These animals are facing a major new source of mortality in many areas as it is hard to get away from roads in New York State.”
People who want to help save the slippery night travelers can volunteer as crossing guards in New York and other Northeastern states. But they have to be ready to get wet, cold and slimy in the middle of the night, on a road that may or may not have any creatures to shepherd.
If you volunteer, you can expect to park your car safely off the road and wear safety gear and lights to make yourself visible. Bring a flashlight or headlamp, amphibian identification guide and a data form, to record how many you see alive or dead, how long you’re there, how much distance you covered and other information, like the amount of traffic. You should wash your hands, but avoid lotion, bug spray and hand sanitizer — amphibian skin is sensitive, and you may need to pick them up or nudge them along. Those who don’t want to get close can do a windshield survey and monitor traffic instead.
If weather permits next week, you could experience a big night.
“It’s really incredible if you love nature and you can withstand being out in the rain,” Ms. Heady said.
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