Chapter 8 - Aerial Corridors in Urban Environments: Light Pollution and Migratory Birds

Summary

In the UK, the Chiltern Railways reconstruction project discussed earlier involved adding a bat deterrent lighting system at the Wolvercote Tunnel section of the railway to account for the well-being of resident bats. The lighting installation helped to deter the bats from flying into the tunnel or traveling through the tunnel when a train was approaching. The lighting project thus helped the bats maintain their linear flight paths and specific flyways. Ambient and artificial light can have important and specific impacts not only on bats but also on birds, who may be thrown off course or distracted by different kinds of light. The Chiltern Railways project considered with critical awareness the impact of lighting on resident bats and installed lighting specifically to prevent the bats from entering the Wolvercote Tunnel, where they might otherwise collide with oncoming trains. In that case, the lighting was a helpful deterrent that could help save their lives. In other contexts, however, artificial light pollution can have detrimental effects, especially for species of migrating birds.

In fact, the light emitted from skyscrapers and other buildings in urban environments can be especially hazardous for birds. According to the Cornell Lab of Ornithology, within the United States, an “estimated 600 million birds are killed every year from collisions with some of the country's largest skyscrapers.” In particular, Chicago, Illinois; Houston, Texas; and Dallas, Texas, are among the most dangerous cities in the U.S. for migrating birds. These cities are “uniquely positioned in the heart of North America's most trafficked aerial corridors.” As Hilty et al. note, there has been “some discussion around aero-corridors […] although air space conservation is still in its infancy and terrestrial stepping-stone nonaerial corridors continue to be the focus of connectivity for most flying species.” Indeed, while this book has focused more on the issue of wildlife corridors in specific terrestrial landscapes, aerial corridors are an emerging area of focus for wildlife connectivity, and light pollution is one of the main disruptors for wildlife that must navigate them. This case considers the issue of light pollution and its impacts on aerial corridors for migrating birds and provides some possible suggestions for addressing this issue, with a focus on citizen education and “Lights Out” campaigns as possible starting points.