A few weeks ago, friends from D.C. were visiting for the weekend. As the evening wore on, we found ourselves outside discussing current events, the latest gossip, and our plans for the fall—when, inevitably, eyes turned toward the sky, and I heard something I often hear from friends visiting, “Wow! Look at all the stars.”
A week later, the Perseid meteor shower was at its peak. I walked out on my porch and, with no effort or pre-planning, I saw a “shooting star” streak across the sky. The cloud-free sky provided the perfect backdrop for a stellar show.
I tend to forget dark skies as one of the benefits of living in a rural area of the Piedmont. But it is certainly something special about where we live, and something that stands out to our friends and family who visit. A simple look at NASA’s 2012 Earth Observatory data of night lighting in the United States shows that it’s something much of our region enjoys (see map at right).
A combination of geography, reasonably good planning, zoning geared toward reducing light pollution, and the conservation ethic held by residents of the Piedmont, all work together to provide those dark skies.
But those dark skies are not a given. Many other areas of the country that once enjoyed clear views of the stars, have lost them due to encroaching development or lax lighting standards.
Locations such as Albemarle, Culpeper and Greene Counties have adopted ordinances to discourage light pollution and encourage energy conservation. And if we want to keep our dark skies, we need to stay informed and participate in community discussions on the subject.
Bottom line, just like we can appreciate a beautiful view during the day, we are also lucky to enjoy beautiful views at night. Take a few minutes to look up at the stars the next time you are out, and feel good that your membership and participation with PEC helps play a part in keeping those dark skies dark.
Effects of Lighting Pollution on Wildlife
An often overlooked impact is how light pollution affects our natural environment. Various biological rhythms of wildlife and plants have evolved with the natural light cycles. And artificial night lighting can disrupt those patterns, impacting migration, feeding, breeding, and even seasonal foliage changes.
Many bird species, such as warblers, vireos, thrushes, and tanagers, migrate at night using guiding lights from the moon, stars, and the setting sun. Migrating at night helps them avoid predation under the cover of darkness, provides cooler temperatures, and allows them to avoid daytime wind gusts that make it more difficult to maintain a steady course. However, artificial lights can attract and disorient these birds causing them to use up precious energy, and in some extreme cases, die. There is a phenomenon known as “towerkill,” where tall lit antenna towers have been known to attract migratory birds that fly near them in cloudy weather conditions, causing them to circle until they collide with each other or the structure.
Amphibians and reptiles
Some amphibians and reptiles use light for navigation when migrating to breeding grounds and artificial lights can disorient them. These secretive creatures forage and communicate under the cover of night. Without darkness, their foraging and calling has been shown to decrease, impacting their health and reducing reproduction. Melatonin disruptions due to extended exposure to light have also been documented in salamanders. And longer exposure to light reduces production, leading to a wide variety of physiological and behavioral problems.
Moths and other nocturnal insects
We have all seen the effect of night lights on moths and other nocturnal insects that seem insanely drawn to them, circling and colliding to their death. This phenomenon, called flight-tolight, is not well understood, but it is suspected that nocturnal insects use light from the moon and stars to navigate, and artificial lights mislead and disorient them. However, this isn’t the only effect our lights have on these beautiful nocturnal pollinators. Predators have been observed to hunt prey insects at artificial lights. There is also evidence that artificial night lighting can affect reproduction by inhibiting release of sex pheromones by female moths, suppress oviposition, or encourage females to lay eggs at unusually high densities in unsuitable areas near lights.
Even plants can be impacted by artificial light at night. Moths and bats are pollinators that are sometimes overlooked because they often work under the cover of night. Plant species that bloom at night depend on these night pollinators though, and can be indirectly affected if their populations are reduced or deterred by nearby light pollution. Night lighting on trees, especially in the red to infrared range of the spectrum, can encourage growth and photosynthesis beyond the time when it is safe to do so. Trees in our area lose their leaves in the autumn and go into a protective dormancy. When trees keep their leaves into winter they are susceptible to harsh weather conditions and may not survive.
So what can you do to help?
You can reduce your night light footprint by:
1) Using motion sensors or only turning on outdoor lights when needed,
2) Pointing lights downward and using shields that direct it to the intended area, and
3) Using more subtle lighting with lower wattage.
*Research provided by Julie Bolthouse, PEC Fauquier Land Use Officer.