NEWS-HERALD (Willoughby, Ohio) 20 April 08 Spotting the salamanders - Romance among amphibians spells spring at the Arboretum (Janet Podolak)
It started for Tom Yates as a rainy-night rescue mission to keep critters from being squashed on the pavement of Kirtland-Chardon Road.
But now it's an annual rite of spring for nature lovers who come to witness a salamander mating ritual probably as old as mankind.
As horticulture supervisor at the Holden Arboretum's Lantern Court, Yates lived nearby and saw early spring's toads, frogs and salamanders being squashed on the highway.
"They used the road's latent heat to rev up their engines, but often ended up as flattened fauna when humans revved theirs," he wrote in a column for the Aboretum's newsletter.
That was back in 1979, after he'd noticed a pattern to the amphibian action, one that turned out to be a courtship custom.
After three or four 60-degree days with rainy evenings, the spotted salamanders crawled out of the woods in great numbers. One night he saw 11 spotted salamanders crawling on the Lantern Court driveway toward a small cement-bottom landscape pond on the 25-acre former estate.
"Spotted salamanders live underground in the woods and usually are very secretive," he said.
Yates knew something was going on and investigated further.
People often are surprised to discover that the black to gray-black salamanders sporting two long, irregular rows of yellow spots on their backs are 6 to 7-1/2 inches long.
"The spotted salamander is terrestrial but remains linked to life in water by its method of reproduction," he said.
After crawling out of the woods on a rainy spring night, the males and females go into a vernal pond to swim around together in a frenzied state. The males, apparently excited by the action, attach their spermatophore in pea-sized clumps on dead leaves in the pond bottom. The females swim over the clumps and take them into their bodies to fertilize the eggs that are there.
"The males crawl back into the woods almost immediately," Yates said. "But the females stay in the pond for awhile."
A day or two later, the eggs are deposited by the female salamander on the pond bottom. About six weeks later, they hatch into swimming larvae, similar to tadpoles but with red gills.
"The larvae remain in the water until August, when their metamorphosis into adults is complete," Yates said.
Spotted salamanders throughout this part of the country all migrate to seasonal vernal ponds on the same night.
A vernal pond has no fish life to threaten the larvae.
The young salamanders migrate back into the woods, where they burrow into the ground.
"They only migrate on rainy nights," Yates said.
That behavior is responsible for the group name: mole salamanders.
"As far as we know, they live to be about 15," Yates said. "They don't breed until they are about 5."
After a few years, Yates knew enough about the migration of the salamanders to be able to predict when it would happen.
And he began a sign-up list for those interested in joining him to watch.
This year's fickle spring weather made the prediction process more difficult, and the 2008 migration was the latest ever - and over two nights.
Only a handful of folks turned out on April 10, but as word spread people brought their families and came the next night, too. About 70 people witnessed the migration this year.
"Advance notice varies from a few hours to a day," he said. "It's happened as early as March 7."
To inquire about next spring's salamander migration, call the Holden Arboretum at (440) 946-4400.
Spotting the salamanders