News Brief

Daytime Light Pollution From Buildings May Harm Wildlife

Reflective surfaces pose previously unknown risks to wildlife, recent research finds.

Photo: Dreamstime, Inc.
Light pollution is usually defined as a problem of the night, when artificial lighting obscures our view of the stars and disorients migratory birds and other animals. A newly identified type of light pollution expands that definition to daytime, however, and may endanger the many animals that use water to find food and habitat, to orient themselves, or to find prey. Dark, glossy surfaces in the built environment—glass, asphalt, polished stone, photovoltaic panels, automobiles, and oil slicks, among others—all reflect polarized light, often more intensely than water, the chief natural source of polarized light in the environment.

According to a recent article in the journal Frontiers in Ecology and the Environment, artificial polarized light affects aquatic insects in particular but also waterbirds, turtles, reptiles, fish, crustaceans, and echinoderms. Reacting to light from artificial sources, birds become disoriented, and insects mate and lay eggs in inappropriate locations. Animals may fruitlessly seek to feed at parking lots full of shiny cars, and food webs can be altered when prey species are drawn in unusual concentrations to a polarized light source such as a glass curtainwall, where predators easily catch them and then themselves fall prey to other predators drawn to the easy feeding site.

The paper’s authors suggest reducing polarized light pollution by avoiding dark, shiny surfaces such as tinted glass on buildings and minimizing outdoor lighting, especially near bodies of water.

Published May 29, 2009

Wilmeth, M. (2009, May 29). Daytime Light Pollution From Buildings May Harm Wildlife. Retrieved from

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June 15, 2009 - 6:10 am

Hillary, here is a link to the abstract:

Polarized light pollution: a new kind of ecological photopollution

Gábor Horváth1, György Kriska2, Péter Malik1, and Bruce Robertson3,*

1Biooptics Laboratory, Department of Biological Physics, Physical Institute, Eötvös University, Budapest, Hungary

2Group for Methodology in Biology Teaching, Biological Institute, Eötvös University, Budapest, Hungary

3WK Kellogg Biological Station, Michigan State University, Hickory Corners, MI

The alteration of natural cycles of light and dark by artificial light sources has deleterious impacts on animals and ecosystems. Many animals can also exploit a unique characteristic of light – its direction of polarization – as a source of information. We introduce the term “polarized light pollution” (PLP) to focus attention on the ecological consequences of light that has been polarized through interaction with human-made objects. Unnatural polarized light sources can trigger maladapative behaviors in polarization-sensitive taxa and alter ecological interactions. PLP is an increasingly common byproduct of human technology, and mitigating its effects through selective use of building materials is a realistic solution. Our understanding of how most species use polarization vision is limited, but the capacity of PLP to drastically increase mortality and reproductive failure in animal populations suggests that PLP should become a focus for conservation biologists and resource managers alike.

June 12, 2009 - 2:10 pm

could you kindly cite the article title and authors. Thanks