Small Wonders: Inconspicuous amphibians are among the most abundant creatures in local woods
Ben Moyer
Some signs of spring are so familiar that they’re a part of human culture. People often tell neighbors or co-workers about their first robin sighting, the emergence of daffodils, or spring peeper frogs calling from a wet meadow near their home.
But most spring indicators are subtle; they go on about their secretive business every year yet are seldom seen. If we are fortunate enough to notice these elements of local ecology, further study reveals amazing insights. Television documentaries aren’t the only doorway to natural wonder. Often, our own backdoor leads to marvels too.
The unusually warm days of early March brought an impulse to enlarge one of our vegetable gardens. Woodlands border our place on three sides, so sunlight is limited. To make the most of solar exposure, I’ve placed small raised-bed gardens where the sun’s rays penetrate the trees for a few hours around midday during the growing season.
To enlarge one of the beds, I had to roll back the railroad ties I use as borders, realign them, add a few more, then fill in the enlarged space with topsoil.
When I rolled back the line of ties, I was surprised to find clumps of salamanders nestled into the wet, compacted soil beneath. These small amphibians were startling in their abundance. I found about 40 in a span of 50 feet, most in tight, tangled groups of three or four.
All were of the same species-the eastern red-backed salamander-also known simply as the “redback” salamander. It’s a small lungless salamander that lives in sloping woodlands throughout the Great Lake region, southeastern Canada, New England, and south through West Virginia to central North Carolina.
They are slender animals, half the length of a finger. Their distinguishing mark is the brick-red stripe that runs down their back, from the base of the skull to midway along the tail.
“Lungless,” here, should be explained. About 500 species of salamanders, nearly all native to the Western Hemisphere have no lungs. To “breathe” they must respire through their moist, permeable skin. That respiration can’t happen unless the skin remains moist, so red-backed salamanders spend periods of drought, even dry sunny days, tucked away under logs, moss, or rocks where dampness aids their “breathing.”
Like all salamanders in our part of the world, they’re also inactive during winter. But this period is shorter for red-backed salamanders than for any other salamanders in our region. Herpetologists have found red-backed salamanders becoming active as early as late-January and remaining so until the end of December. The ones I found under railroad ties beside my garden in early March appeared sluggish at first but were quite active and mobile. When I tried to pick them up, they skittered through my fingers and scurried under any nearby leaf or clod. Since the air conditions were dry and brightly sunny, I suspect these salamanders were waiting out the arid “heat,” and had already been “awake” for days, if not weeks-a very early but invisible sign of an uncommonly early spring.
I’d already done some reading about red-backed salamanders because of an earlier surprise encounter with the same species. That bit of study prompted new appreciation for this secretive creature.
Several autumns ago, during the snowy tail-end of Hurricane Sandy, which dumped a foot of wet slush in our mountains, I shot a turkey gobbler that had 11 red-backed salamanders crammed inside its crop, the organ birds use to store food before it’s ground in the gizzard for digestion. Even though it had been chilly and stormy for days, those redbacks must have been active, or at least accessible beneath the shallow leaf litter where a hungry turkey could scratch them out, when that late autumn storm roared through.
The most unexpected thing I learned about the species is that red-backed salamanders are often the most abundant vertebrate animal in woodlands in this part of the world, where the density of redbacks can exceed one per square meter. Studies have found that the combined mass of red-backed salamanders in regional forests equals that of mice and shrews and can be twice the mass of all forest birds combined.
The salamanders sprung one more surprise when I tried to gather a few for a photo and a closer look. As I grasped one wriggling body, it slipped through my grasp and I squeezed at the tail, which broke off between my fingertips. This ploy was a living example of what’s known to biologists as “caudal autonomy,” a defensive tactic of some amphibians and reptiles in which the tail breaks away so the rest of the animal can escape. Often, the castoff tail wriggles and writhes to attract the attacker’s attention. That’s exactly what this discarded appendage did. It behaved as if it had a wound-up rubber band inside, and it tumbled around while its owner scampered off. A new tail grows back but is often shorter than the original.
It’s doubtful that red-backed salamanders will ever dominate a conversation about spring signs. But this little-known creature probably numbers in the hundreds of thousands in local woods, where it can astound any who contemplate its secrets.
Ben Moyer is a member of the Pennsylvania Outdoor Writers Association and the Outdoor Writers Association of America.