You know those rainy nights at this time of year, when there is still a chill in the air, and it has been raining steadily all afternoon, continuing well past sunset? Those nights when most people have no desire to be out and about? Well, just staying home is good thing.
Those are big nights for Spotted Salamanders, Wood Frogs, and other migratory amphibians. They migrate en masse to their breeding sites, traveling hundreds of feet over the forest floor, and unfortunately, across roads. If you are out driving on one of those nights, you are bound to pass a wetland and flatten several critters in their quest for mates. Even drivers in the know can’t avoid all of them.
Upon reaching their breeding sites — small, forested wetlands, often called “vernal pools” — they spend several days going about the work of multiplying. They swim around, borrow under leaf letter and downed woody debris, find each other, nudge each other, clasp each other, deposit spermatophores (males), pick up spermatophores (females), and deposit their eggs (gelatinous masses submerged in the wetland and attached to twigs and other vegetation). Then, with the next warm-enough, rainy night, they start their migration back into forested uplands, and, sadly, back across roads, while their eggs incubate and, several weeks later, hatch.
In the Berkshires, three such species of salamanders grace us with this ancient ritual: Spotted, Blue-spotted, and Jefferson Salamanders. Wood Frogs are on a similar schedule. Perhaps you have heard the duck-like croaking at this time of year, usually coming from forested wetlands on the warmer days. Those are Wood Frogs (watch the video below), calling for mates, and to us, announcing the onset of spring.
In Massachusetts, the Spotted Salamander is still considered common, but the Jefferson and Blue-spotted are listed as Species of Special Concern. This group of salamanders belong to the Ambystoma genus and are commonly referred to as “mole salamanders.” The genus evolved 30 million years ago (give or take), but over the past 100 years, the automobile has come on the scene faster than they can adjust. It only takes one tire.
The first town to install tunnels for salamanders in North America, to enable safe crossing under roads, was Amherst, Massachusetts. In 1987, two tunnels were constructed, 200 feet apart, on Henry Street, along with drift fences for guidance. It was a collaborative effort by the Amherst Department of Public Works, the University of Massachusetts, the Massachusetts Audubon Society, and local residents. Hundreds of salamanders and wood frogs successfully pass through the tunnels every spring.
The Hitchcock Center for the Environment continues to rally volunteers on “big nights” to monitor the migration at Henry Street and bear witness to this rite of spring. Their outgoing voicemail in March and April gives their prognosis for the evening, alerting callers if a “big night” is nigh. “Big nights” on Henry Street draw so many local residents that the salamanders deserve to be recognized as community organizers.
These early spring nights of steady rain are also big nights for the people who study these critters (herpetologists — studiers of amphibians and reptiles – or some other species of biologist). They break out their rain gear and water-resistant headlamps. Their smart phones ping constantly with news from excited observers at other sites. They are a rare breed, mostly unbeknownst to the vast majority of people, who are instinctively indoors, warm, dry, and probably asleep. If you do venture out in such weather and encounter a driver traveling about 10 miles per hour and swerving every which way, it is not for lack of concern for the safety of others on the road. It is quite the opposite.
For more information on Blue and Spotted salamanders:
For more information on Jefferson Salamanders: