Under conditions of low visibility, due to fog or dense clouds, birds seem to be attracted to the lights and collide with the tower or the dozens of guy wires often found on tall towers. Massive mortality, including the death of more than 1,000 birds on a single night at a single tower, has been recorded more than three dozen times at towers exceeding 500 ft in height. The cumulative impact of these collisions on bird populations on a national, regional, or species scale is unknown but probably accounts for at least 2 million deaths annually. Bird-tower collisions have become of concern due to a rapid increase in the construction of telecommunications towers for cellular phones and digital television. A simple solution to this problem may exist.
Research is needed to find solutions.
Joint funding is probably necessary for this research, which will also require the cooperation of these agencies and private organizations. What is known about this problem As of June 1999, over 40,000 lighted towers and tower farms were registered in the FAA database of obstacles in the United States that exceed 200 feet in height. FAA regulations require that towers that stand 200 feet or higher have lights so pilots can avoid them. Taller towers often have guy wires to keep them standing. This combination of lights and guy wires is the source of bird mortality at such towers.