Get outside, Family!

Get outside, Family!

Monday, May 9, 2016

Meet a Vernal Pool

I’ve been obsessed with finding vernal pools, those mysterious ponds that appear in early spring where salamanders, frogs and many other critters lay their eggs. Why does this excite me? I’m a nature geek, of course. The other reason is that it’s another way to get my kids just a little more interested in what’s going on outdoors.
Late winter hike -- Will we find a vernal pool?

I’m constantly saying things to my boys like, “Do you hear that jingling sound? It’s the Spring Peepers!”, and we’ve muddied a lot of shoes walking around ponds looking for eggs. I got really excited when my younger son and I went exploring in the woods across from the school bus stop and realized we were ankle deep in water. I was sure we’d found a vernal pool.

But because I wasn’t 100 percent sure, and I like to be accurate, I went looking for a guide. I found one in Betsy Leppo, zoologist with the Pennsylvania Natural Heritage Program, who created this webinar for the Penn State Extension. It gives a detailed description of species, geology, vegetation and soil of vernal pools, and how to protect them. More for conservation professionals than nature moms, the presentation left me with a few questions. So I contacted Leppo and she kindly agreed to help.

What fascinates me about vernal pools or ponds is that they appear like magic in spots that may be bone dry by late summer, or at least much less wet. They are created from ice melt and rains, Leppo explained, and a true vernal pool has no permanent inlet or outlet of water. They can be found in a land depression in the middle of the woods, as part of a swamp or marsh, among small shrubs or in a field.

A vernal pool can be as small as “little leafy puddles you can jump across,” Leppo says, or “large wetland thickets where you can easily fill your hip waders.” 

These conditions mean there are no fish, making it a great place for amphibians, reptiles and other creatures to lay eggs without fear their babies will be gobbled up. Many species depend upon these unique waters, in fact. Some salamanders and frogs return to the same vernal pool from which they hatched.

In late winter, creatures begin emerging from the nearby woodlands where they spend the rest of their adult lives, sometimes crossing snow and ice to arrive at a pond to breed. In March and April – long before leaves are on the trees and much at all is sprouting from the ground -- a vernal pool is a busy amphibian baby nursery.

Taking a mud break. 
So how do we know when we’ve found a vernal pool? Leppo says the sure way is to locate one of the species that breed almost exclusively in these waters. In Pennsylvania, that would be four types of mole salamanders, as well as the Eastern Spadefoot frog, the Wood Frog and two crustaceans – fairy shrimp and clam shrimp.

Shrimp?! I had no idea there was anything that could be called a shrimp in the water around here! And I’m not at all sure how to identify species of salamander or frog. First you have to find a salamander or frog, which can pretty hard to do. This is where a field guide is really handy, especially an online guide that also features sound clips of frog mating calls, like http://www.paherps.com/.

There are many other animals that live around and breed in vernal pools, including species of toad, turtle, frog and newt. The noisy Spring Peeper is another one. Many insects and tiny crustraceans tend to thrive in these waters, creating what Leppo calls a “vernal pool soup” that feeds the larger animals as they develop.  

My original hope for a vernal pool – the puddle across from the bus stop – turned out to have been only a puddle that had pretty much dried up in a few days, which isn’t long enough for creatures to hatch and grow. A nearby marsh seemed like another good possibility. We did find squirmy black mosquito babies and other teeny spots swimming around. And lots of snails. But no tadpoles yet.
Not sure what this is, but it looks cool.

We will keep looking. At the very least, we are having fun squishing around in the mud.


More Vernal Pool Resources:
Pennsylvania Natural Heritage Program



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