Lights out!

Air pollution, water pollution, soil pollution…these are in the news frequently. But have you ever considered the effects of light pollution? Light pollution occurs when artificial light is used at night to illuminate buildings, roads, and other areas to the point where you cannot see the stars. It is estimated that 99% of US residents live in areas with enough Artificial Light At Night (ALAN) to make the stars dim or invisible. This light adversely affects wildlife in significant ways, affecting the feeding, breeding, migrating, and predation on insects, birds, bats, amphibians and even plants. Why does this matter? While conservation-minded gardeners are installing native plants and providing habitat for butterflies, caterpillars, and birds, their yard lighting may be decreasing the survival of the animals they are trying to help. Take a common example, the moth. Those of us of a certain age remember driving at night past dark fields and having the windshield splattered with flying insects. This rarely happens anymore. It is estimated that 75% of the biomass of flying insects that was present in 1990 is gone. Everyone knows that moths tend to gather around street lights and porch lights; they become so distracted that they cannot feed or breed. Moth larvae make up a significant portion of the caterpillars fed to baby birds, and if the moths don't breed, the birds won't eat. Fireflies are also distracted by lights and will be unable to find mates. Lights, especially large outdoor groupings of them, interfere with migrating bird navigation and increase the number of building collisions. "Lights out Cleveland" is a movement to encourage less ALAN especially during peak migration times (March 15-June 15 and August 15-November 15). Volunteers actively work to rescue injured birds that have hit buildings. Bug zappers, which emit a light to attract insects, rarely zap their targeted biting insects. One study showed that of a total 13,789 deceased insects, only 31 were the biting ones the zapper was intended to kill. The rest were moths and other night fliers. What can you do to make the night safer for these "little things that run the world" (E.O. Wilson)? Shade your lighted windows at night. Use motion sensor lights outside, lighting areas only when you need to. Warmer spectrum lights—amber, orange, and red—are not seen by most insects, although fireflies are negatively affected by the yellow, amber, and green lights. Direct your outdoor lighting down with cones and keep it low to the ground. You don't necessarily need to change your bulbs — there are "gels" available that insert into a light fixture and change the color of the visible light. Check out the website for Dark Sky International (darksky.org). It describes light pollution as something that "disrupts wildlife, impacts human health, wastes money and energy, contributes to climate change, and blocks our view of the universe." There are many ideas on the site for adjusting your outdoor lighting to decrease the amount of ALAN you produce and help the ecology in your yard. Let's flip that switch!