Geography Reference
In-Depth Information
decision rendered bird-killing windows a breach of national environmental
law. In Chicago, San Francisco, Oakland, and throughout Minnesota, build-
ings that seek federal funds or environmental certii cation are required to re-
duce the collision risk that their windows pose. In response, architects are
incorporating into their designs sunshades, less rel ective windows, and win-
dows with texture or opaque portions to increase visibility to birds. Reduced
night lighting, which is especially attractive to migrating birds, often luring
entire l ocks into windows, is another part of a bird-friendly building design
that deserves its own commandment.
Do not light the night sky.
Light of ers security, hope, and joy to people. We feel
safe in a lighted space. We enjoy the colorful lights of a city from a prominent
overlook and take a certain amount of pride in the industry that has enabled
the outpouring of energy. Our sprits rise at the sight of holiday lights. Light's
magic, however, has a dark side. Today, cities glow eight to nine times brighter
than natural landscapes. Artii cial light threatens to erase the night from much
of the developed world. This phenomenon has astronomers on the run, seek-
ing darkness where they can study the night sky. They take increasingly long
trips because traditional observatories, such as Mount Wilson in the moun-
tains above Los Angeles, are awash in city light. Artii cial night light is also
increasingly recognized as disruptive to all forms of wildlife in our cities.
Like moths drawn to a l ame, birds, especially those that migrate at night,
can be attracted to the light of buildings. Many of them die from colliding
with towers, wires, windows, and walls. Collisions are especially frequent on
cloudy nights when birds cannot use the movements of stars as navigational
aids. Under these conditions birds rely on detecting the earth's magnetic i eld,
