What’s so great about a vernal pool? A lot, it turns out. For us, it all started with a picture book. A beautifully illustrated picture book by Kimberly Ridley called The Secret Pool. It’s a book that is absolutely packed with information about vernal pools, seasonal ponds that provide a habitat for a variety of plants and animals. We had never heard of vernal pools before reading The Secret Pool last year, although I’m sure we’ve come across them during our forays into the woods. But now, my children and I are fascinated.

So of course we had to do a unit study.

According to the Stewardship Network of Ontario, “[Vernal pools] predictably appear with a seasonal rhythm – arriving and departing at the same general time and place, sometimes for thousands of years.”

Since vernal pools dry up in the summer months, certain predators such as fish are unable to survive in them. But the species that thrive there? They are amazing! Wood frogs, which freeze almost solid during the winter months, thaw out and breed in ephemeral ponds in spring. Spotted salamanders, blue-spotted salamanders and Jefferson salamanders, all quite uncommon in my area of Ontario, also breed in vernal pools. Tiny, inch-long fairy shrimp apparently make their homes in vernal pools as well.

Last spring, as the snow melted away and the temperatures warmed up, we spent hours tromping through the woods in search of vernal pools.

We’d veer off the trails to investigate every patch of melting snow and every single puddle that looked even the slightest bit promising. When we finally did find an amazing example of a vernal pool, however, it wasn’t because we were looking.

It was because we were listening.

We could hear them long before we could see them. Hundreds of little voices. A choir of several different species all at once.

Frogs.

Spring peepers, wood frogs and who knows what else. They were ready to breed and their calls filled the air. We ran through the forest, fighting our way through thorny undergrowth, not realizing that the trail curved around to the perfect viewing spot.

I’m not sure how long we watched and listened, but we were in no hurry to move on. We had gone on many hikes and spent many hours looking for a clear example of a vernal pool.

This pool exceeded our every expectation.

So in the coming months, as you’re walking through the woods, keep your eyes and ears open. You just might find one of nature’s most fascinating wetland habitats.

You might just find a vernal pool.