NOCTURNAL COLLISIONS "Faith is the bird that sees the light while the dawn is still dark." Unknown Author
		Bird mortality at human-built structures receives relatively little public attention, but structural hazards are actually responsible for more bird kills than higher profile catastrophes such as oil spills. Human-built structures have been recognized as a hazard to birds for more than a century. However, the accelerated rate of urban development in recent years has seen the proliferation of radio and televi-sion towers, office buildings, power lines, cooling towers, emission stacks, and residential housing, all of which represent an increasing threat to flying birds

In the dark, and especially in foggy or rainy weather, the combination of glass and light becomes deadly. Confused by artificial lights, blinded by weather, and unable to see glass, birds by the hundreds and even thousands can be injured or killed in one night at one building. Over 140 different species of birds have collided with buildings in Toronto alone. One expert estimates that across North America, up to 100 million birds die in collisions each year. Many species that collide frequently are known to be in long-term decline and some are already designated officially as threatened. Compared to habitat loss, pollution, and over-hunting, the issue of building collisions is neither well-known nor adequately understood. Yet across North America, more birds die from collisions each year than succumbed to the Exxon Valdez oil spill. Birds migrating at night are strongly attracted to, or at least trapped by, sources of artificial light, particularly during periods of inclement weather. Approaching the lights of lighthouses, floodlit obstacles, ceilometers (light beams generally used at airports to determine the altitude of cloud cover), communication towers, or lighted tall buildings, they become vulnerable to collisions with the structures themselves. If collision is avoided, birds are still at risk of death or injury. Once inside a beam of light, birds are reluctant to fly out of the lighted area into the dark, and often continue to flap around in the beam of light until they drop to the ground with exhaustion. A secondary threat resulting from their aggregation at lighted structures is their increased vulnerability to predation. The difficulty of finding food once trapped in an urban environment may present an additional threat.