Vernal poolin’ and the race against time!

Nature bummin’ with Kirk Gentalen—

Leif and Reid show their finds

When we left off last column, spotted salamanders and wood frogs were braving an evening of chilly rain to make their way to freshly thawed breeding ponds lovingly referred to as vernal pools. That was around the 30th of March and the race against time was officially on!

Fast forward 30 days and we find that much has changed! For one thing, the spotted salamanders and wood frogs that we amphibi-napped (snagged on our Amphibian cruise) have put on shows in classrooms at both the St. George and Hope Elementary Schools and were a hit at the latest Cub Scout Pack meeting. They’ve been held by more than 50 kids with more kids to visit! We are big fans of hands-on education, and thank the amphibians for their patience and the students for being kind with them!

Now, take a trip outside (always a good idea) to a local vernal pool and it’s clear that much has changed. Wood frogs have mated, laid eggs and after a quick three weeks they have hatched and the tiniest of tadpoles are now free to swim and find shelter and food in their home pools. A single wood frog egg mass (from a single female) may have up to 2,000 eggs in it—so there are literally gagillions of freshly hatched wood frog tadpoles in St. George as I type. The next generation is here! Welcome!

Spotted salamander egg mass

Spotted salamanders lay their egg masses when the wood frogs are about to hatch and are now the common egg masses found in the pools. A female may lay up to 250 eggs in a single mass and in those eggs young salamanders will remain for the next 4-6 weeks. Their development is easily observed through the translucent eggs as the enclosed embryos will change color, unfurl, and start to kick and twitch as hatching time approaches. When they hatch, the salamander larvae will have external gills for respiring in the water as they join any surviving wood frog larvae that have survived “the race” to this point.

The “race against time” really is the essence of what makes a pool a vernal pool! The frogs and salamanders lay these impressive amounts of eggs in pools that dry up every now and then. It could be every year, or every year or so—often enough to keep fish from living there. The amphibians must mate, lay eggs, and have their young hatch and develop into adults before the “well runs dry” so to speak. For wood frogs it’s two months as larvae—which has them leaving the pools in late June. For spotted salamanders it’s a month or two in this “phase” of life as well, which pushes their pool exodus to late July. The race continues for the next generation—a time to hope that they grow up fast.

My son Leif and I recently checked on pools near the Tenants Harbor marsh and over at the Maine Coast Heritage Trust Bamford Preserve on Long Cove, and we were not disappointed! For the visit to Bamford we invited some friends who live nearby—Andy, Drew, and Reid—to join in the exploration. Some things are just better when shared! Anyway, we found over 50 spotted salamander egg masses at Bamford and everyone seemed mesmerized by the jelly-like traits that the masses seem to have when in hand (or maybe it’s more jam-like traits). The masses are built to be out of the water for extended dry periods, and their congealedness is used to trap water within the mass itself. Gentle handling appears to have negligible impact on the masses. All in all there we found 100 spotted salamander masses in the four pools we surveyed in the Long Cove area that morning, which means at least 200 spotted salamanders are living in the area—get to know your neighbors!

Wood frog eggs ready to hatch

We were only to find one wood frog egg mass however, where we had found 18 last year. When the frogs were “laying down the (egg) masses” in early April the pool’s water levels appeared to be much lower than the past few Aprils. There are undoubtedly many factors that influence how many masses are laid by either species and water level at time of breeding seems to be one of them. The good news is that the one mass was hatching!

The days were good, the vernal pools were great and the company even better. It’s not too late to grab a friend (gently) and count the salamander egg masses at a pool near you. Some things are just better when shared! Enjoy!

PHOTOS: Kirk Gentalen

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