Vernal pools are neat. They are small (typically), temporary (usually) pools of water that fill in the fall, winter, or early spring. They come to life with the first warm rains of spring – when temperatures break the 40-degree mark – and salamanders and frogs begin what is one of the most dramatic mass-migrations in this part of the world.
Because vernal pools are temporary and usually isolated from other waters, they are fish free, making them a safe place for salamanders and frogs to lay eggs and get through their larval development. Vernal pools can produce thousands upon thousands of frogs and salamanders every year, making them a critically important part of forest ecosystems wherever they occur.