Deborah and I were out hiking yesterday on the ridges and hollows around Roaring Run Creek in Armstrong County. We were looking for, among other things, “vernal pools.” These are small, shallow, temporary puddles and ponds that form in basins which fill up with spring rain water. These pools typically form in the same spots year after year and are extremely important sites in which many amphibian species (including many frogs, toads, and salamanders) lay their eggs and in which the early, aquatic life stages of these species grow and develop.
These pools exist on an incredibly delicate razor’s edge of existence. They must be big enough to last long enough (i.e. not dry up) until the tadpoles etc have enough time to grow into their terrestrial life forms, but they can’t be so large that they persist year round (because then they could be colonized by fish and aquatic snakes that would gobble up the amphibian eggs as fast as they could be laid!) The regular occurrence of these pools is also quite important since many mature frogs, toads, and salamanders actually return to the same pool in which they were born to lay their own eggs! It has been such a dry spring, that we were concerned that these pools might not be formed or might be so small that they will dry up before the tadpoles can completely develop.
The good news is that we saw some very healthy vernal pools! There were large masses of salamander and frog eggs in them, too! Many of the egg masses were bright green with symbiotic algae (which have been shown to actually help to nourish the developing embryo inside the egg!).
More news next week!