Vernal Pools

Take a hike at Cedar Run on the White Trail on a warm spring evening and make your way to the observation platform. Allow a few minutes to close your eyes and just listen. You may hear the sounds of crickets chirping but most likely, you are hearing the sounds of the spring peepers, or Pseudacris cruifer, a chorus frog native to the eastern part of North America.

Spring Peeper in sphagnum moss (photo by Zac Tait)

These tiny amphibians are only about one and a half inches big, can range in color from tan to gray to partly green and are easily identified by a dark X shape on their back. Their peeping sounds manifest when they close off their nostril and mouth and squeeze the air out of their lungs which passes the air over their vocal cords and inflates the sac under their chin, making that distinctive chirping sound.

Standing on that observation deck, now open your eyes and take a panoramic view of the habitat. Take a really good look off to the perimeter in the taller grasses and you will notice what appears to be just a puddle.

These are called vernal pools and are essential to the hatching of spring peeper eggs. A vernal pool is a temporary ponding of water.

Fish cannot survive in these types of pools so when a female Pseudacris crucifer lays about 1,000 eggs between April to May, their chances of survival greatly increase from lack of predation. Once hatched and matured, the new spring peepers will hop over to the creek and spend their days eating insects that annoy humans, staying close to the ground, hiding in fallen logs or under damp leaves so the Barred owl can’t eat them. You may be surprised by one hopping up a tree or onto your leg but don’t be alarmed, these frogs are unlikely to bite!

Spring Peeper (photo by Zac Tait)

In the heat of August and September, the vernal pool dries up and is no longer needed as a safe haven for the eggs. As the weather cools into late fall, Pseudacris crucifer has eaten all the bugs they want and now its time to hibernate. This amphibian will slow down its body systems, their skin produces a type of antifreeze to protect their organs during hibernation and they go to sleep for the winter. When spring comes and the weather warms up, the cycle repeats, all thanks to that nursery, the vernal pool.

–Lee Yeash, Environmental Educator