Ann Cameron Siegal
THE WASHINGTON POST – One rarely seen, colourful salamander species with clownish fixed smiles is prompting a lot of smiles among biologists in Maryland’s Department of Natural Resources (DNR) in the United States (US).
In the 1990s, as development, pollution and evolving land uses intruded on breeding sites, Eastern tiger salamanders – the largest land-dwelling salamanders in North America – almost became extinct in the state. These amphibians are making a significant comeback.
“Salamanders are one of the first species many of us encounter as kids,” noted Director Scott McDaniel at the Susquehannock Wildlife Society in Darlington. “Their seemingly smiling faces and bright colours excite the imagination as you flip a rock over or roll a log to find such a unique treasure hiding underneath.”
“Fluffy or feathered things get more attention than scaly, slimy things,” said DNR biologist Beth Schlimm, who works with numerous reptiles and amphibians. “I’m partial to the scaly, slimy things.”
Salamanders are scaleless, but some secrete a toxic, sticky substance from glands in their tails to ward off predators.
Like other amphibians, tiger salamanders are important to the ecosystem because they are predators to smaller organisms and prey for larger creatures.
“Since they partially breathe through their skin and require wetlands to breed, lay eggs and develop in their larval stages, they are indicators of a healthy habitat,” McDaniel said.
“Tiger salamanders are also very picky about which breeding pools they like,” said Emilio Concari, who volunteers with DNR population surveys.
Schlimm recently explored one of several seasonal wetland areas on Maryland’s Eastern Shore, where extensive vegetation management over the past decade helped restore natural breeding habitats of these salamanders.
“Female tiger salamanders need fishless freshwater ponds that have a lot of sunlight for their eggs,” Schlimm said. Egg masses attach to upright vegetation, so water depth is critical. “Too shallow, they dry out; too deep, and sun won’t get to the egg masses.”
Carefully making her way through knee-high water, Schlimm checked sites where their egg masses flourish. Egg mass counts are the most efficient method to answer the question: “How are Eastern tiger salamander populations doing in Maryland?”
“A really rough population estimate would be 1,000 to 2,000 individual tiger salamanders,” said DNR biologist Scott A Smith. They are concentrated in Caroline and Kent counties.