Salamanders on the march
CHARLESTON, W.Va.-- Not all migrations in nature involve thousands of miles of flight, or marathon swims from the depths of an ocean to the spawning shoals of an inland river.
In the case of the spotted salamander, the annual migration from winter burrows to the seasonal pools in which they will mate and breed seldom involves a trek of more than a few hundred yards -- but it can still be a sight worth beholding.
"If you catch the migration during its peak, you can see hundreds of spotted salamanders crossing the road at night," said Master Naturalist Rob Bailey of South Charleston, who has been watching the yellow-speckled amphibians make their annual spring trek since his childhood.
Bailey, a retired Union Carbide laboratory technician, said his grandfather introduced him to the annual springtime crawl of the spotted salamander and other wonders of the natural world. "I've enjoyed doing this kind of thing ever since," sometimes in the company of his own grandchildren, he said.
Although spotted salamanders are the most abundant salamander species in the state, found in every county and every elevation, they are not that easy for people to, well, spot.
They spend most of their lives underground, emerging from burrows or from under rocks or fallen trees only at night to feed on worms, spiders and millipedes - or to march to the same mating pool in which they were born, by the same route each year, in late winter or early spring.
Spotted salamanders generally begin migrating to their vernal mating pools during the first relatively warm, rainy nights after the ground has thoroughly thawed.
During a brief period on Monday night, Bailey counted 17 spotted salamanders crossing a road in Kanawha State Forest, en route to their breeding pools.
"The migration has started, but it hasn't peaked yet," Bailey said. "That may happen this weekend, when it's expected to warm up a little."
After receiving an email from Bailey Monday night informing them that at least some spotted salamanders were on the move, fellow Master Naturalists Frank and Carolyn Barker got out of bed, dressed, grabbed flashlights and got to Kanawha State Forest shortly after midnight.
There, at the first vernal pool they checked, they saw a number of male spotted salamanders ganged up in piles called "congresses" or moving in and out of the leaves at the bottom of the pond. A few additional individuals were seen in small ponds along aptly named Spotted Salamander Trail.
"The females should arrive shortly after this gathering," said Carolyn Barker. "If the weather warms up and we get more rain, I am sure they will be moving."
While temperature and precipitation provide clues, catching the spotted salamanders during the peak of the spring migration "is more of a lucky guess," Barker said. "The first year Frank and I saw the migration, they were everywhere. There was a group of us walking in the rain with umbrellas and flashlights, checking out the vernal pools in the forest. It was raining all night, and I know people thought we were crazy, but it's still fun to us."
Soon, cottony masses of eggs, usually attached to a stick or a branch, will be seen under the surface of the vernal ponds used as breeding grounds by the spotted salamanders. The eggs hatch a few weeks after being deposited.
"Larval spotted salamanders have feathery gills on the outside of their bodies," Barker said. "They live underwater, feeding and growing for up to four months. Then they metamorphose into a juvenile form with lungs and strong legs," and emerge from the ponds and crawl into the forest.
The salamanders mature in two or three years, and begin their own annual migrations to the ponds of their birth to reproduce.
The Barkers plan to return to Kanawha State Forest this weekend to see how activity at the ponds is progressing with the expected arrival of female spotted salamanders. "We want to be there, as Frank calls it, when the dancing girls arrive," Carolyn Barker said.
The spring migration of the spotted salamander also marks the approximate start of mating season for other species of amphibians.
"Wood frogs will be having their mating frenzy, and spotted newts will be feasting on wood frog eggs," she said. "It's quite a sight to see when it all unfolds."
The duck-like songs of wood frogs can be heard echoing through the forest, along with the shrill, birdlike chirps of northern peepers -- tiny frogs marked with dark Xs on their backs.
Spotted salamanders are slate colored, with two irregular rows of round yellow spots on their backs, from head to tail. They can reach 8 inches in length, and have been known to live 20 years or more in the wild, and a decade or more longer in captivity.
According to the website for Marshall University's Herpetology Lab, female spotted salamanders deposit up to 250 eggs in gelatinous masses that are sometimes attached to submerged vegetation. Eggs generally hatch in four to six weeks, and larvae transform in two to four months.
Spotted salamanders are common throughout the eastern United States. In some urban areas, special steps are taken to protect the amphibians as they crawl across roads to reach their vernal breeding ponds. In Amherst, Mass., for instance, volunteers manned bucket brigades to carry the salamanders across a busy street until a pair of tunnels was installed under the roadway, allowing the salamanders to safely make the crossing on their own.
Reach Rick Steelhammer at firstname.lastname@example.org or 304-348-5169.