National Geographic Today
Turning off the lights saves energyand it can help save wildlife as well.
Light pollutionthe luminous orange glow that haloes cities and suburbsthreatens wildlife by disrupting biological rhythms and otherwise interfering with the behavior of nocturnal animals, new research shows. Now a movement is under way to turn off the lights, or at least turn them down, for the sake of all creatures that frequent the night.
"Wildlife species have evolved on this planet with biological rhythmschanging that has profound effects," said Travis Longcore, a biogeographer with the Urban Wildlands Group in Los Angeles, who with colleague Catherine Rich, co-organized a conference last year on "Ecological Consequences of Artificial Night Lighting."
Birds At Risk
Artificial lighting seems to be taking the largest toll on bird populations. Nocturnal birds use the moon and stars for navigation during their bi-annual migrations.
"When they fly through a brightly-lit area, they become disoriented," said Michael Mesure, executive director of the Fatal Light Awareness Program (FLAP), a Toronto-based environmental organization. The birds often crash into brilliantly-lit broadcast towers or buildings, or circle them until they drop from exhaustion.
"Over 450 bird species that migrate at night across North America are susceptible to collisions with night-lit towers, including threatened or endangered species like the cerulean warbler and Henslow's sparrow," Mesure said.
Sometimes whole flocks collide with over-lit structures. According to Mesure, over two consecutive nights in 1954, 50,000 birds died at Warner Robins Air Force Base, Georgia, when they followed lights straight into the ground. And in 1981, over 10,000 birds slammed into floodlit smokestacks at the Hydrox Generating Plant near Kingston, Ontario.
Seabirds are also at risk, said Bill Montevecchi, a marine ornithologist at Memorial University of Newfoundland, in St. John's, Canada.
Some, like the tiny Leach's storm petrel, feed offshore on bioluminescent planktonso are particularly drawn to light. The birds may be fatally attracted to lighthouses, offshore drilling platforms, and the high-intensity lamps used by fishermen to lure squid to the surface.
"It's not that we wouldn't expect birds to die from human activitiesbut it is our responsibility to minimize that mortality," said Montevecchi.
Reptiles Under the Spotlight
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