Salamander Big Night
What’s black with yellow spots and looks like a dinosaur? A spotted salamander, Ambystoma maculatum, of course. And on the first warm rainy night of spring, usually in early April here, you can see them in hundreds crossing the roads of the Island. It’s a wildlife spectacular of sorts.
At six to nine inches long, these gentle animals—actually amphibians, not reptiles— look something like a cigar or pencil when you spot them in your flashlight beam or car headlights. The stretch of Oceanville Road just before you get to the Settlement Quarry is perhaps Deer Isle’s premier spot for salamander watching, but any place where you can see an alder swamp from the highway is a likely spot.
The salamanders don’t make any noise. They don’t bite. Males and females look alike, at least to us. Except for the breeding period in spring when they gather to mate, we rarely see them. They lead their lives of quiet seclusion in the forest litter layer. It was discovered that the biomass of our most common salamander, the red-backed salamander, was equal to the biomass of all songbirds in a New Hampshire forest study. We may be unaware of salamanders in our midst, but you can be certain they play a significant part in the forest ecosystem.
The term vernal pool has been given increasing media attention lately. What’s a vernal pool? Strictly speaking, it’s a body of fresh water large enough for salamanders to lay their eggs in, but small enough that the pool will dry up before summer’s end. That means would-be predators like bullfrog tadpoles, which take two years to mature, cannot colonize the pool. Here on the Island we seem to have avoided bullfrog invasions, so any small pool of water will do for our salamanders.
After dark, take your flashlight and peer into such a pool and you will likely see it writhing with salamanders on their Big Night. Such a salamander Rave is called a congress. Next morning you will see globs of round eggs the size of bb shot attached to twigs in the water. Over the next weeks, tiny gilled salamanders will develop in the eggs. By summer’s end, they will have hatched, grown mature enough to have those feathery external gills reabsorbed, and off they go into the forest to burrow down into the rotting leaf layer.
You might even be fortunate enough to have a vernal pool in your own backyard. Some of our preserves have no vernal pools. Where IHT has been given adjoining conservation easements that do have such pools, you can be fairly confident that unseen, unheard, beneath your feet, the surrounding forest is well-supplied with salamanders.