What's That in the Vernal Pond?


What an animal! For just about 50 weeks of the year a mysterious creature is lurking underground. Now is the time to see evidence of their secretive existence!

The Jefferson Salamander has the earliest breeding period of any mole salamander. During the last few chilly raining nights of winter, these amazing creatures emerge from their underground homes to visit many of the vernal pools in the parks. Males and females locate each other with a chemical cue and, once together, partake in an elaborate courtship ritual that resembles a dance; they rub snouts, clasp each other, and swim around with tails waving. If all goes well, the female will pick up the male’s spermatophore and her eggs will be fertilized! The magic begins a few days later when the female lays up to 250 eggs by attaching them to vegetation. The eggs are the evidence that these subterranean creatures exist.

Each year, I marvel at hundreds of the small clusters of Jefferson Salamander eggs found in the vernal pools at Woodland Mound and look forward to watching the egg clutches develop over the next four to six weeks. Rain, shine, freezing or warm, the eggs always seem to make it to spring. Once the larvae hatch, they will live in the vernal pools for three to four months. While in these fishless pools, the gilled larvae will essentially play the ecological role of fish. As they continue to grow, reaching densities of dozens per-meter-squared of pool, they consume many macroinvertebrates. Since these larvae have such high densities in vernal pools and love to eat anything they can fit into their mouth, some ecologists believe they could be important at shaping what invertebrates live in vernal pools. Maybe even reducing densities of larval mosquitos!

Jefferson Salamander Adult

Once the larvae grow large enough, they undergo what is called metamorphosis, which essentially means they turn into juvenile salamanders that will now breathe air. On rainy nights during the spring these juvenile salamanders will re-enter the woods, grow big and strong, and often times return to the pool they grew up in eventually. At least we get to enjoy them during that single week of breeding each year!

Janice Milanovich, Naturalist