On the first night of an Outward Bound camping trip, a teenager was found staring up to the skies…with tearful eyes. She had never before seen the stars and hadn’t realized the awesome beauty above her all those years. She was from an urban city environment where artificial lighting, buildings, and indoor living was the norm. Please take a moment and wrap your head around her emotional experience.
One half of the natural world is always dark. Creatures have evolved throughout the ages to perform all their survival needs while the dark turns to light which turns to back to dark. Circadian rhythm describes the 24 hour biological process, keyed to the lightness-darkness cycle, by which organisms recognize and anticipate various environmental changes, like darkness and falling temperatures, and prepare for their various survival needs, like finding food, avoiding predators, and getting rest, using these changes. The better an organism is able to capitalize on these daily changes determines the level of selective advantage it has for survival and pro-creation. So patterns of feeding, sleeping, hiding, migration, hibernation, and reproduction have become dependent upon the circadian rhythm, and the defining element of circadian rhythm is the light/dark cycle.
Enter artificial light. Street lights, driveway lights, porch lights, landscape lights, vehicle lights, business lights, security lights, and on and on. All this lighting effects the environment in unnatural ways, disrupting the natural biological processes entrained within the circadian rhythm of all of us, and the other creatures with which we live.
So, what’s the big deal?
Disruption of circadian rhythms results in unnatural “time shiftings” of creatures various survival activities: feeding times may shift to times when food is less plentiful and/or predators are more prevalent; reproductive processes like the release of pheromone attractant shift to when the opposite sex is unavailable or non-responsive; sleep/rest times become erratic, causing high levels of stress, a lowering of health levels, and shorter lifespans. Activity triggers may get muffled, causing delays and/or advances in migratory actions, resulting in arrivals that no longer coincide with usually available food or nesting sites. A good example of the influence of artificial light upon species survival is your porch light. See all those insects flitting about that light? They’re naturally supposed to be in another place, feeding upon their normal food source and becoming food for other creatures; but they’re doomed to flit about, depleting their energy stores and falling, exhausted, to the ground…and by so doing, are not feeding other creatures (Bats, whip-o-wills, owls).
So consider turning off those night-time lights that are not really needed. Or maybe look into some lighting options that are more environmentally friendly to our night-time creatures; some can be found here: http://darksky.org/lighting/.
And go out in the woods, find a place away from the city lights and become awestruck again, like the city gal, with the brilliant dark skies above you!!