Friday, April 19, 2024

NOTES FROM THE FALLEN TREE: Not Just Boggy Wastelands, Vernal Pools are Essential Habitats for Amphibians

As I write this, it is snowing outside, and school has been cancelled. However, many biologists are preparing for spring migrations. At first glance, vernal pools do not appear to be a valuable part of our ecosystems. They look like boggy waste places that house mosquito larvae and need to be drained.

In reality, they are an essential habitat for many species of amphibians. 

According to the New Jersey Department of Environmental Protection (NJDEP) document referenced below, a vernal pool is “an indentation in the ground that fills up with water for only a couple of months out of the year and then dries up completely or remains very shallow.” This unique feature does not allow fish to inhabit the pools.

Many amphibians, reptiles, plants, insects and other wildlife species will take advantage of these wetlands. In particular, some amphibian species, whose eggs deposited in these waters would normally be eaten by fish, have one less predator to worry about. 

Several amphibian species in New Jersey have evolved to become dependent on vernal pools for breeding habitats. When that happens, the species is considered to be an obligate vernal pool breeder. 

Amphibians are “animals that generally go through metamorphosis or a developmental change in form or structure of an animal occurring subsequent to birth or hatching.” The word amphibian actually comes from the Greek word “amphibious” which means “living a double life.” Members of this class are frogs and salamanders.

Since their skin is moist and glandular, they are more susceptible to the negative impacts from pollution to their aquatic environments. This makes them an important environmental indicator species that can tell us if there is something wrong with our environment. 

Many of these amphibians also have the added hazard of having to cross roadways on the first warm rainy night in spring to get to their vernal pool breeding habitats on which they have become so dependent.

This is where volunteers with the Conserve Wildlife Foundation of New Jersey will come in, organize and assist with guiding some of these animals across the road on the first “warm” rainy night in early spring. In some years, the migration of these animals has happened as early as February. 

While all wildlife holds value in our ecosystems, amphibians in particular are a sensitive species. Taking measures to protect their habitat is something everyone can benefit from in the long run. 

NJDEP Division of Fish & Wildlife – New Jersey’s Vernal Pools

Jennifer Correa-Kruegel, Warren County Naturalist
Jennifer Correa-Kruegel, Warren County Naturalist

Jennifer has a Masters in Parks and Resource Management from Slippery Rock University. She worked as a Park Naturalist for Hunterdon County Park System from 2003-2006 and then at the NJSOC full-time from 2006 - 2020, starting as the Program Coordinator and evolving to an Environmental Educator. Jen is a New Jersey native and has lived in Warren County with her family since 2004. She is excited to be offering programs to this community she has grown to love.