Environment

How Light Pollution affects the wildlife.

To understand light pollution, it's important to know there are two different types: First, there is astronomical light pollution that obscures the view of the night sky, and the second kind is ecological light pollution, which alters natural light systems in terrestrial and aquatic ecosystems.

"Light pollution started to be identified in the 1800s when we realized that birds flew into the sides of lighthouses and consequently died," says Travis Longcore, science director of the Urban Wildlands Group, research associate professor at the USC geography department and a lecturer at the UCLA Institute of the Environment in Los Angeles. (Beginning in the 1940s, radio and television towers become "the spiral of death for birds that regrettably hit the guy-wires," he added.)

Twenty years later, it was discovered that artificial coastal lighting in Florida was disorienting and disrupting the rhythm of sea turtles that bury their eggs in the sand. When the eggs hatch, the hatchlings must go toward the water and beachside nests for their survival, but the babies were being distracted by the light and diverted from their natural course, often ending up facing dehydration, being eaten by predators or even wandering along the highway.

As more animals encountered night lighting, it became evident that while night light might benefit people, it wasn't helping wildlife. Light pollution has had disastrous effects on migrating birds, resulting in millions dying each year, and that figure increases with the combination of outdoor light and fog. Birds use the light at the horizon to migrate at night. When the birds see a brightly lit building, they become confused and fly around and around — in essence becoming trapped in the light — eventually dropping dead from exhaustion.

The term photopollution — artificial light that has adverse effects on wildlife — was coined in a watershed paper by Dutch ecologist F.J. Verheijen in 1985. In the paper, Verheijen says that many nocturnally active animals need a natural light field between sunset and sunrise as a requirement for survival.

"When we think about the night and the extent of light pollution in the last 20 years, it's growing far faster than the human population and has changed the environment significantly," explained Longcore.

"What if we woke up one morning to realize that all conservation planning of the last 30 years told only half the story - the daytime story."

Ecological Consequences of Artificial Night Lighting by Catherine Rich and Travis Longcoreat Amazon www.amazon.com/Ecological-Consequences-Artificial-Night-Lighting/dp/1559631295/ref=sr_1_3?ie=UTF8&s=books&qid=1265048342&sr=8-3

Notice even the Tree is affected by the streetlight.

Impact on Trees:

www.ces.purdue.edu/extmedia/FNR/FNR-FAQ-17.pdf