Humans and salamanders gearing up for the Big Night

Jim McCracken’s first involvement with the Big Night began when he organized an evening of “salamander skits” while working at Massachusetts Audubon in 1988.

Some thirty-odd years later, after serving as environmental educator at the Philadelphia Zoo and working at the Natural Resources Trust of Easton, MA and the Montshire Museum, Jim is now the chair of Thetford’s conservation commission. And he has taken a lead in organizing not skits but a real life effort to save salamanders from death on their Big Night.  

The Big Night is a critical event in the lives of salamanders. It is how they reproduce their kind. These secretive amphibians lead subterranean lives in forests and are seldom seen. But, like almost all amphibians, they have to breed in water. They start their lives as eggs that hatch into free-swimming tadpoles. The swimmers grow legs and develop into miniature adults by the process of metamorphosis, usually in two or three months. Tadpoles are easy prey for fish; thus water bodies without fish are a vital resource. Temporary pools (aka vernal pools) that dry up in the summer do not support fish and are the salamanders’ best bet for survival, although they also breed in wetlands.

What makes it the Big Night? The short duration of vernal pools means that salamanders must get to these breeding grounds as soon as possible. When the air temperature exceeds forty degrees, their cold-blooded bodies are warm enough to move. But they need two other things – darkness for concealment, and rain. These animals breathe through their skins, and some salamander species have no lungs at all. To allow oxygen absorption, the skins of all salamanders have to remain moist. They cannot travel overland in dry weather.

Thus, the first rainy nights when air temperatures exceed forty degrees (Fahrenheit) prompt salamanders to move en masse, seeking the vernal pools or wetlands where they were born. Here they congregate to breed. This is the Big Night, which in reality happens as a series of Big Nights and not-so-big nights

Unfortunately vernal pools are often in flat areas where humans have decided to build roads. Dark-colored salamanders crawling on their bellies on a rainy night are almost impossible to see, and road crossings on the Big Night turn into scenes of major salamander carnage. One study found that even fifteen cars an hour were enough to wipe out over 50% of salamanders and other amphibians that attempted to cross. A salamander mortality between 50 and 100% was recorded on a paved rural road in New York. Cumulative road kill was enough to cause local extinction of salamander populations in Western Massachusetts in 25 years.

Why should we care? To quote Jim McCracken, “salamanders are so cool.” And indeed they are cool, and then some. The eastern United States is home to more salamander species than anywhere else globally, and there are about 180 salamander species in the U.S. as a whole. Although rarely seen, the number of salamanders in a forest is huge. It is estimated that their total biomass exceeds the sum of all the birds and small mammals. They are a major contributor to the cycling of carbon in forests and to the food web. The small red-backed salamander, for instance, is an important food source for many species of snakes, birds, and mammals. When attacked, it sheds all or part of its tail, leaving the predator with a juicy morsel while the salamander escapes.

The ability of salamanders to regenerate lost body parts extends beyond the tail to legs, eyes, and internal organs. This remarkable ability has caught the attention of scientists, who are studying the implications for human medicine. Furthermore, the moist, vulnerable skin of salamanders is protected by a mucus layer that turns out to have antimicrobial, antioxidant, and wound-healing activity. The components of mucus are being analyzed for potential as a new generation of therapeutics.

The Big Night as an occasion to help in amphibian conservation has been building for some time. Thetford resident Ginger Wallis has been braving wet spring nights for years. Jim has given presentations on Big Night at Thetford Academy and Thetford Elementary School. In Hartford, Ben Fletcher has been coordinating the Hartford Salamander Team who carry amphibians across roads and record species and numbers for the North Branch Nature Center in Montpelier.

Jim has been cautious in not involving too many volunteers in this first series of Big Night events in Thetford. He limited participation to a site on Academy Road and another on Tucker Hill Road. Even though the air temperature may be right and there is rain, salamanders do not leave their burrows if the ground is still frozen. Jim sought to “keep it small till we work out the kinks.” About ten people signed up, and Police Chief Mike Scruggs loaned some traffic cones and lights.

The first Big Night occasion in Thetford was organized for this past Saturday, April 1st. The forecast initially was for a rainy day with temperatures in the 50s Fahrenheit. However, after an overcast start, it became gloriously sunny, and the roads were dry. At 6:00 pm Jim contacted the volunteers to cancel. Nature’s caprice makes a Big Night event hard to organize.

Tantalizingly, the forecast for Wednesday April 5th promises “a 70% chance of showers, with a high near 49,” and at night “a 40% chance of showers with a low around 41” — maybe another opportunity. And if it doesn’t work out, there will be more. Let’s hope the volunteers don’t get discouraged, because the salamanders are not. They surely will have their Big Night before May is here.