Why did the Salamander Cross the Road?
To get to the other side, of course! But why?
Every year across the region thousands of our cold-blooded friends make their way from their upland winter homes to the ponds where they were born. These lowland vernal pools are a specific type of wetland that occurs on a seasonal basis with a defined wet and dry cycle; wet through spring and early summer, then dry for most of the rest of the year. These basin-shaped areas fill with water from rain and spring thaw run-off. Because no fish are usually present within them, and no water flows in or out of them as with a lake or pond, the eggs and young of many amphibian species find safe harbor here. They are usually filled with all the things a young amphibian needs to get a good start in life - such as fairy shrimp, and a host of insect larvae.
Frogs, newts and salamanders are all members of the group we call amphibians. Amphibians get their name from their unique life cycle that takes place partly on the land (terrestrial) and partly in water (aquatic). Amphibians are vertebrates (have a spine), have smooth, slimy skin, can breathe through their skin, are cold blooded, and have a complex life cycle including a mostly aquatic gill-breathing stage followed by a lung-breathing stage.
Unfortunately for the amphibians, we’ve placed our roads right in between the two habitats they need to survive as a species. Moving the roads isn’t a possibility. But we can help these very special animals in other ways by supporting seasonal wetland habitat, monitoring habitats for indications of successful reproduction of species, and even by creating special culverts and tunnels that allow the amphibians to reach their natal pools without the risk of getting run over by vehicles.
Wood frog eggs
The Big Night
As the weather begins to warm and spring rains begin to fall, the migration of amphibians begins. These migratory events occur in what biologists call “The Big Night,” which usually occurs near or on the first warm evening during or shortly after a spring rain. It is a pretty specific culmination of events that triggers the amphibians movement to their breeding pools, so it is nearly impossible to predict with precision. But, if temperatures are above 40 degrees, and it is raining and dark, and it is between March and May, amphibians are probably on the move! The timing of their movements means most of us miss what’s happening right around us - not many will brave rainy, cool spring nights with flashlights in hand to count salamanders. In some years as much as 90% of the migratory amphibian population will make their journey during the first five nights after the first Big Night of the year.
If you miss The Big Night, don’t despair - you can find these amazing animals in vernal ponds throughout the spring and into early June. Finding and identifying the eggs and young of these animals can be accomplished by careful observation with a good resource, such as The Harris Center’s printable PDF guide to identifying amphibian egg masses. Just remember that the best protection is observation - take only pictures and leave only footprints - make notes and drawings of your discoveries such as the location, date and time of your discovery, but leave eggs and young animals in place!
Amphibian populations in Vermont are ranked by species according to their known numbers in the wild from S1 (5 or fewer known breeding populations) to S5 (widespread and abundant). Reporting sightings of these fragile animals helps biologists understand how many remain in the wild. While it may be too late for this year, make a plan now to get involved next spring. Be sure to report sightings of amphibians or their eggs and young to a regional conservation organization such as the Vermont Center for Ecostudies or the Vermont Reptile and Amphibian Atlas. You can also check out North Branch Nature Center’s Amphibian Road Crossing project.
The Spotted Salamander can live for 20 years and grow to be 9" long. It's rarely seen except during breeding. A mole salamander, they live in tunnels most of the year.
The Eastern Newt has four stages of development. The most commonly noticed is the juvenile red eft stage, which can last as long as 8 years!
The Spring Peeper is a tiny frog measuring about an inch, featuring a characteristic X on its back. Peepers make a distinctive "peep" noise when calling for mates that many of us associate with the coming of spring.
Gray Tree Frogs are masters of camouflage as adults - their gray bodies blend perfectly with tree bark and lichens, but as juveniles they are a delightful bright green color.
The Wood Frog spends most of its time in the woods underground, especially in rodent tunnels. Like the Gray Tree Frog and Spring Peeper, it creates an antifreeze-like substance that allows 65% of its body water to be converted to ice during the winter.
All photo credits: Michael Clough