In Spring Comes Vernal Pools

Spotted salamander   Image: Peter Paplanus/Creative Commons

I wrote earlier about amphibians on the move for mating during warm spring nights. They are headed for vernal pools.

These vernal (spring) pools are also known as intermittent or ephemeral ponds. These pools give eggs and tadpoles the best chances for survival. These are not year-round ponds and by summer they will dry up. That means they don't allow fish to survive ther. Fish are voracious eaters of egges and tadpoles, so that's what make vernal pools ideal places for amphibians.

These pools are created by snowmelt, spring rain and rising groundwater. It is estimated that New Jersey has 3,000 to 5,000 vernal pools. NJ had more snow this winter than last, so that should benefit amphibians.

There are several near me in woods that I often walk and so I will go out some warm spring evening after rain and listen for some frog chorus singers. I might see some amphibians crossing a road. This always makes me think "Why don't they just live in the woods and avoid the dangerous spring commute?"

Luckily, my local pools are in places that will not be developed. But many vernal pools get filled in, level, and built on or near as homes and businesses move in. The amphibians won't know that until the next spring when they make that journey and can't find the pool they expected. The mating still occurs and the eggs will still be laid but the location will be less hospitable to the offspring.