Vernal pools are temporary bodies of still water and begin forming after trees lose their leaves in the fall and their need for water diminishes. The additional water in the surrounding soil fills natural depressions on the land creating a vernal pool. The pools continue to collect water during the winter and spring but generally dry out and disappear in summer. Vernal pools may vary in size from a few square feet to multiple acres. Their ecological function is much like wetlands because that's what they are. Like other wetlands, vernal pools serve as birthing areas for animals but, because of the pools' temporary nature, the animals are generally limited to fast-maturing amphibians such as salamanders and wood frogs.
On my walk today, I went down into the Paint Branch stream valley to photograph a small vernal pool there:
I know some larger ones less than an hour away, and maybe I'll get around to photographing them sometime this spring.
On the walk home, I stopped back to check on the ring-necked ducks that have been there since last month. Originally there were four plus a redhead duck who hung around with them. Now the other males have moved on probably because, as Pam puts it, the lady duck has made her selection.