Sidney A. Gauthreaux, Jr. and Carroll G. Belser, Department
of Biological Sciences, Clemson University, mentioned that hundreds of species
of birds typically migrate at night, and it is well known that fires and
man-made lights attract birds during migration, particularly when the sky is
cloudy and the ceiling is low. During fall migration they monitored flight
behavior on 14 evenings near a television tower with red lights, near a
television tower with white strobe lights, and over a control area that had no
tower. They used an image intensifier to monitor birds flying overhead, and
coded the flight behavior of migrants into the following categories: linear
flight (straight) and nonlinear flight (pause-hover, curved, or circling).
During the fall study the number of birds showing nonlinear flight near the
tower with red lighting was significantly greater than those flying near the
tower with white strobes. The greater number of birds near the tower with red
lights is likely the result of "attraction" to the constantly
illuminated lights on towers with red light arrays and the proportion of the
time the birds showed nonlinear flight behavior. In general, all animals and
plants, including humans, have biorhythms. Biorhythms caused by artificial
light are disturbing not only the growth of animals and plants, but also physiology
and reproductive activity. No one knows how the ecosystem disturbances caused
by artificial lighting are further revealed, but the bottom line is that
ecosystem disturbances can only occur constantly. (Fig.2)
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