A Tiny Woodland Swamp

     For a couple of hours one day this June, I fancied myself in the Carboniferous or Amphibian Period of over 300 million years ago.  I was sitting in my car on a woodland road beside an inches- deep puddle on a forest floor in a woods on a sunny, warm day in southern Berks County, Pennsylvania.  A few large dragonflies alternately perched on sunlit skunk cabbage leaves and chased each other over the woodland pool that was about an eighth of an acre in size.  A few dozen small, metallic-green flies seemed to be spawning in the shallow water; perhaps a reason the dragonflies were there, to catch and eat some of those flies.  I saw a couple of small, green frogs perched on top of fallen dead tree leaves matted along the shore of the pool and some rounded wood frog tadpoles half-buried among fallen leaves in that same puddle.  Only a few months ago, I saw several adult wood frogs spawning in that puddle and some of their egg masses.  Soon some of those tads will be small frogs that will leave the puddle for life under moist, fallen leaves on the surrounding forest floor.
     The hot and humid Carboniferous or Amphibian Period lasted about 60 million years, between 359 million years ago to 299 million years ago.  This was the time of giant trees falling into swamps and being pushed down and down under tremendous pressure from water and mud, which turned the wood to coal.
     Amphibians of many kinds, some species up to 18 feet long, dominated the land at that time.  And some types of insects and other invertebrates were large, including dragonflies with 30 inch wingspans.  But after 60 million years, the Carboniferous rain forests collapsed.  The climate became cooler and drier, probably caused by ice ages and a dropping sea level.  Amphibians fared poorly and never recovered to their former glory.  And those large invertebrates became extinct, leaving the small ones we know today that are better adapted to the current climate.        
     The three or four dragonflies at this small, woodland swamp were of interest.  I never saw their species before.  They were large, had clear wings and thin, dull-grayish-white abdomens.  They also seemed to have blue eyes.  I looked them up on the internet and learned they are great blue skimmers, a species that lives among forest pools, puddles, ditches and even puddles on woodland paths, all places of shallow, still water in the woods of the eastern United States.  This is an unusual niche for skimmers, a branch of dragonflies that prefers ponds in open, sunny habitats where they have room to zip about after prey and mates.  Perhaps great skimmers couldn't compete with their skimmer relatives for space and food around open, sunny impoundments, so they adapted to small, shallow pools in the woods where other skimmers didn't and don't inhabit. 
     Eastern box turtles and wood turtles, both inhabitants of forest floors in the eastern United States, like to soak in these shallow puddles during hot, summer days.  Black bears also enjoy wallowing in these pools on hot days.
     I saw a few "shoreline" birds at this inch-deep pool in the woods.  They were one each of gray catbird, American robin and purple grackle, all species we commonly see on suburban lawns.  They all moved slowly along the water's edge, not all at once, and ate the invertebrates they found in the mud and water.  I think these kinds of birds were originally species of woodland edges near water.  The road where I sat was the edge.
     But the single bird that thrilled me the most was a veery, which is a kind of thrush, a little, brown phantom of bottomland forest floors.  I first saw that veery running and stopping, running and stopping, along a fallen log about 30 yards back in the woods, as a robin, which is another kind of thrush, would on a mowed lawn.  I looked at the veery with 16 power binoculars and noticed that he seemed to be staring back at me, perhaps in curiosity.  And I noted that the veery was a lovely bird that fit just right into its niche of leafy, woodland floors.     
     Veeries are brown on top, which blends them into their niche of dead-leaf-carpeted forest floors.  And they are off-white below with rows of faint spots on their chests.  They also have large, dark eyes that allow them to see well on the shaded forest floors.  After many years of changing to better fit into their niche, veeries, like all forms of life, are well built for where they live.
     It was pleasant to sit quietly by that woodland puddle and watch wildlife going about its daily routine.  And it was particularly enjoyable to imagine being millions of years back in time to the age of giant amphibians and monstrous dragonflies when logs became coal.