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 to reflect on her experience.
One half of the natural world is always dark. Creatures have evolved throughout the ages to perform all of their survival needs while the dark turns to light which turns back to dark. Circadian rhythm is the 24 hour lightness/darkness biological process by which organisms recognize, anticipate and use changes in light levels and prepare for their various survival needs…like finding food, avoiding predators, and getting rest. The better an organism is able to capitalize on these daily changes determines the 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 creatures, including humans.
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 supposed to be in another place, feeding and pollinating their normal food sources 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…nor are they pollinating food and flowers, disrupting the entire ecosystem.
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/.
Be awestruck again, like the city girl, with the brilliant dark skies above you!