When we moved up here, we heard the low areas on the property described as “swamps” and had no idea what they were. Shallow, dry up to half the year, many choked with bushes and brambles, they were of little interest. Then we started hearing a loud roaring noise in the early spring, maybe a big machine, but when we tried to sneak up on one it would suddenly hush. Yes, now we know: spring peepers by the hundreds. “Bugs” by the millions for kids to collect and put into jars. And the migration of red salamanders up any waterway in the late spring: where were they headed and why? Gradually we figured it out, and you will too. The glaciers left chunks of ice which melted leaving shallow pools with no egress. They fill with snowmelt and rain, then slowly evaporate. They are too shallow and temporary to support fish, and therefore are the ideal safe spot for salamanders, frogs, shrimp (really!) and other invertebrates to quickly mature and mate.
Here is Peter Petokas’ recent article on vernal pools and their animals
Click on the link which follows, for another article on vernal pools