What is a Vernal Pool?

Do you remember being stuck in your home, only coming out for things you need, isolated from others? Ugh. But wait—you and all your friends just got an invitation for a huge, all-night, once-a-year PARTY! A party where you mingle in big crowds and find love with a special someone. Well…that’s what it’s like for our local mole salamanders, burrowing crayfish, and early spring frogs.

Their party invitations come on rainy nights with temperatures in the 40’s and 50’s. That night is the start of spring break for many creeping critters. But instead of the beach, everyone heads for sometimes-flooded low spots called vernal pools.

Some of us humans spied on the second night of the party. Here’s some gossip on who was there!

An odd procession of different kinds of mudbugs (burrowing crayfish) were scuttling along, starting their peak breeding season. They’re the ones that make the mud chimneys poking up out of moist ground. A big thank-you to these essential land lobsters—they dig burrows that are used by several of the other party-goers throughout the year.

So many frogs! Tiny spring peepers with X-shaped markings on their backs were slowly hopping and crawling to the water, where males swelled their little throats to peep out an irresistible, shrill love song. They were joined by even more tiny chorus frogs, whose females were treated to a different love song, more like a comb scraped by a thumbnail. We spotted several green frogs and a few gray tree frogs venturing out as well. In wooded areas, the star frogs of the evening were the larger wood frogs, with their distinctive dark eye makeup and incredibly fast, early breeding and egg laying. The males’ croaky laugh filled the air, and countless glowing frog eyes mirrored back our flashlights from the noisy flooded woods.

The BIG treat was the annual appearance of secretive underground salamanders, proving their existence to nonbelievers. In wooded areas with nearby small creeks and ditches, the chunky gray Streamside Salamanders were already in the latter part of their winter mating season, making a burst of overland travel now that the polar vortex weather was gone. In large, wooded areas with vernal pools, the slender gray Jefferson salamanders and the strikingly-colored spotted salamanders had both recently emerged, headed for those swampy forest ponds. The spotted salamanders were having their annual migration, filling the pools with balls of frenzied, writhing bodies called “congresses.” Males left their spermatophores on the bottom for lovestruck females to swim down and pull up into their bodies so they can lay eggs.

Would you like to see the party? Head to shallow ponds, ditches, and vernal pools in the next few weeks, especially on the next few warm, rainy nights. You can see and hear some of these critters (plus more that come a little later, like toads) and spot their bubbly-looking, jelly-like egg masses.

These ordinary-looking vernal pools are special and essential to the survival of many creatures. And the surrounding woods are the secret home of beautiful, underground salamanders. Let’s take care of these places, so that even though we can’t go to big gatherings, we can keep watching as the lovesick critters party on.