LIFE IN WOODLAND STREAMS

          The day after a few days of storms and heavy rains in Lancaster County, Pennsylvania in July of 2025, I visited a couple of  brooks in a local woodland.  Unlike the muddy water that flooded farmland, roads and towns in Lancaster County, the water in those woodland brooks ran clear and was within its normal water level.  Carpets of dead, fallen leaves, and the roots of trees and other plants, plus networks of fungi in forest floors, held the soil down in the woods.  I could see the rocky bottoms of both brooks, and some of the aquatic creatures that live in them.
     Several beautiful male black-winged damselflies were the first critters I saw.  Some of them were  "dancing" in the sunlight, low over the flowing waters of the brooks.  Those striking insects have four black wings and a long, thin abdomen that glows iridescent-green in the sunlight.  The males' dancing [fluttering] intimidates other males, but draws the grayish, camouflaged females to the males for spawning in the water.
     Wingless damselfly larvae hatch under rocks on stream bottoms and feed entirely on other kinds of small, aquatic invertebrates.  After a year, each larva climbs out of the running brook, sheds its larval exoskeleton, and flies off to feed on flying insects and find a mate for spawning.  Some of these damselflies, however, get caught and eaten by a variety of fly-catching birds.   
     When I peered into the clear, flowing water of those woodland brooks, I saw the shadows of several small, slender fish on the stony bottoms.  Those fish are grayish-brown on top and, therefore, blend into the stony bottoms of those little, woods waterways of clear water that they prefer.  Several black-nosed dace, each with a black stripe on each flank from nose to tail, were the most numerous of the fish.  But there also were some minnows and young white suckers in the water as well.  The dace and minnows undulated easily into the current in mid-stream and watched for invertebrates in that flow.  The suckers, however, have down-turned mouths they use to suck food off the bottoms of streams.  Some of these fish might be eaten by kingfishers and a variety of herons and egrets.   
     A few water striders skated across the surfaces of the slower parts of those brooks.  These insects catch other insects that fall onto the waters' surfaces, and suck out their juices.  Striders use their middle pair of legs to push, or row, across the waters' surfaces, and the other two pairs to skate over the water, without breaking through the water's surface tension.             
     I saw a few crayfish walking among the rocks on the stream bottoms.  These crustaceans scavenge plant and animal materials from the bottoms of the waterways.  But they are hard to see on the bottoms because they blend in to the stones so well.  However, some of these critters get eaten by herons, raccoons, mink and other predators.  
     In spite of floodwaters in local croplands and towns from storms, little waterways in woods still ran clear and clean, much to the health of creatures living in them.  Containing storm water and holding down soil is healthy for people and wildlife 

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