This Week’s Creature Feature: Vernal Pools
In very early spring, melting snow and ice leave pools of water in the woods. By early summer, the pools dry up not to be seen until the next spring. The seasonal collections of water, called vernal or ephemeral pools, are the breeding ground for insects, crustaceans and amphibians of the woods.
The density of amphibians in a mature eastern woods is estimated to vary widely, between 200 and 8,000 per acre. Several species can reproduce only in vernal pools. Obligate amphibians in Maryland include the first salamander to arrive to the pools, the spotted salamander. These creatures actually walk through the snow looking for a vernal pool to begin the breeding cycle. Though seldom seen, salamanders support the health of the forest.
Other obligate animals are the marbled salamander, mole salamander, wood frog and fairy shrimp.
Some vernal pools are over 100 years old and have become an established amphibian breeding migration route. These pools do not look like much; they may seem just a mushy place to walk through.
You may be tempted to prevent collections of water on your property. But by avoiding flat-grading forests or filling in low spots, you help the lifecycle of amphibians continue. Look and you might be surprised what creatures you can find in those pools of water.
At Jug Bay Wetlands Sanctuary, extensive studies are made of the vernal pools. Visitors help with collecting and measuring newts and salamanders. Learn more at 410-741-9330.