Wednesday, August 16, 2017  

A Summer Night's Symphony


As spring turns to summer, and the heat of the day has peaked and fallen, familiar sounds begin to slide away like the quality of the fading light of dusk. One by one, the outdoor sounds of daytime begin to hush — the mowers and trimmers go silent, as do the tractors in the fields. The boats and jet skis are docked. The kids have dinner and settle for the evening. Night falls gently on the Northern Neck and Middle Peninsula. What replaces the busy daytime hum are nocturnal sounds to sooth the soul and spark the imagination.
    Whether over the water or across the fields, sound travels far here. It could be the thump-thump of cars rolling over a bridge in the distance, or a bit of music and mingled laughter from a party somewhere out there. (Maybe it’s a wedding. It could be “My Girl,” playing for the first dance.) Then there are the natural sounds — waves breaking on the shore, the campfire crackle, the singing of insects and night birds, the love songs of frogs, the goodnight calls of small animals, or the random summer storm. Take a seat on the porch, around the fire pit, or on the pier, and listen as sound by sound, the night reveals its strange and soothing symphony. Whether man-crafted or nature-made, it’s a composition that’s home grown — a collection of notes like no other. It can be a relaxing, rich harmony or a startling cacophony. Without visual cues, listening becomes more acute. Imagination is stirred as a rhapsody of tones project from the shadows. It’s the music of the night.
    Science tells us that sound is amplified when it travels over water. Those reverberations of traffic, music or wildlife can seem so close, yet the source is unseen, possibly miles away. The reason is that the water cools the air above its surface, which then slows down the sound waves. This causes refraction or bending of the sound wave so that more sound reaches the listener. Also, sound waves skimming the surface of the water can add to the amplification effect, if the water is calm.   
    Even when the water is calm, waves continue to brush the shore — providing nature’s perfect lullaby. Physics says waves are energy. Think of a long rope laid on the ground. Pick up one end and give it a snap. There’s a ripple effect all the way down the length of rope — just like waves. The energy is released at the other end of the rope, just as the energy of waves is released on shores. In the simplest of terms, waves are the result of wind and weather, tides and surface disturbances (like boats and birds).
    It’s a lively place in the backyard at night. While the humans may be winding down around the campfire, the nighttime world is tuning up. The percussive snap, crackle and pop of the blazing fire can be the accompaniment. The sounds made by fire are the result of the perfect mixture of fuel, oxygen and heat. A spark applied to wood, with the right circulation of air, produces ignition at about 300 degrees Fahrenheit. Wood burns when the volatile gases inside reach temperatures around 500 degrees. The heat causes tiny pockets of fluids, such as water and sap, to boil and then vaporize into steam. The steam causes tiny explosions when pressure causes the wood to split. The roar of a fire is the rushing of air with the release of heat.
    As evening unwinds, insects form a chorus of communication with buzzing, chirping and whirring. It turns out that insects are great communicators. They may be recognizing other members of the same species or locating mates. They may be giving directions for the location of food or warning of danger. Most accomplish the task by rubbing body parts together; and the males are making all of the music, at least in the groups of well-known singers such as cicadas, crickets and katydids. The cicadas start the insect chorale with their ascending zing-zing-zing sounds coming from the trees. Even people unfamiliar with the appearance of these large green insects will remember the empty shells left by the cicadas as they transform into their winged adult forms. Later in the evening, male crickets join in by rubbing their wings together, dragging a small peg on one wing across a row of ridges on the other (like a bow on a fiddle). The sound is described as a trill or chirp, perfectly spaced in cadence and heard for miles all summer long. Late at night, katydids, the last singers of the evening, take over and continue their strains until the wee hours of the morning. Katydids are large green insects that are more commonly heard than seen. They resemble a leaf and easily hide within the upper crowns of hardwood trees. They are named for the rhythmic song they sing in summer. The males sing in quick bursts of two, three or four notes that sound like kay-tee-did, or kay-tee-did-did. Neighboring males often alternate their chirps, creating a synchronized call and response medley pulsating back and forth between tree tops.
    Our winged friends won’t be left out of the opus. It seems there is a burst of sound and fury just when we expect our birds to be resting. Whip-poor-wills and their relatives are famous for calling their own names, over and over again, sometimes into the thousands of times without stopping. Northern mockingbirds are well-known night callers, especially if there is a full moon. Enthusiastic mockingbirds can stay up all night, mimicking every bird song in the book, as well as other sounds such as bells, whistles and sirens. Owls make another kind of noise in the night, which can range from the hooting of great horned owls to the whinnyings of screech owls. If the call is coming from a wetland, it is probably from one of two night herons, the black-crowned or yellow-crowned. They make squawks and cackles, and sometimes scary noises that will startle the calmest of listeners. Following sunset, around barns and boathouses, in the eaves of garages and even in some attics, bats (not birds, but mammals), squeak and shriek, anticipating their nocturnal flight in search of food. Their leathery wings produce just a whoosh and a flutter.
    Wherever there are marshes, wetlands, shallow pools, ponds, or even heavy rain puddles, there is sure to be a cacophony of croaking amphibians. That’s the sound of frog love. Virginia is home to 27 species of frogs and toads — like the barking tree frog, green tree frog, spring peeper, chorus frog or American bullfrog. Although they choose a variety of habitats, one thing they have in common is that they mate and lay eggs in water. They call out with gusto to potential mates and the more damp it is at night, the happier they are, and the louder they croak. Their enthusiastic refrain is considered an excellent indicator of environmental health and water quality. Frogs also provide natural pest control service by consuming countless numbers of insects every year — 2015 was named Virginia’s year of the frog.
    Sometimes piercing the darkness, and slightly alarming, are the rustlings and calls of animals as they emerge from their daytime hiding spaces. Raccoons, as well as cats, both domestic and feral, will root through the landscape looking for tasty morsels like small birds, eggs or mice. Foxes will bark, howl and yelp, depending on whether they are calling out a warning or attracting mates. There are bobcats roaming around in the more rural locales, and they call into the night with screams and cries.
    Nature’s melody begins to fade with the distant approach of a summer evening storm. Signaled by silent lightning in the distance, a thunderstorm may stir up in a lazy span of hours or a matter of minutes. Lightning can be visible up to 100 miles away. Silent lightning, often called heat lightning, is simply lightening so far away that the sound of thunder dissipates before it reaches the observer. A thunderstorm travels at speeds up to 60 miles per hour or sits nearly stationary. The rumble of approaching thunder and the first splatter of raindrops signal the finale of the evening’s entertainment. With crash-boom percussion, a light show, gusting winds and a deluge of lashing rain, the performance reaches its crescendo and quiet begins to descend.
    Although the night is usually associated with tranquility, it can also be vibrant with sound and motion. The music of the night creates its own experience free from the distraction of visual cues. It is always enriching to listen to the shadows; imagine the life that exists within them. Relax and enjoy a summer night’s symphony.