Ecological Light Pollution“Artificial light that alters the natural patterns of light and dark

in an ecosystem”

Various forms of light pollution:•Lighted buildings•Street lights•Car head lights•Neon signs

Effects the following aspects of a variety of animal and insect species:•Behavior•Communication•Foraging•Reproduction

New York City (photo by broddi)PowerPoint Created by: Christie Christakos

BehaviorEcological trap = the environment changes faster than a species has time to

react and adapt to it

Arthropods (dragonfly, lacewing beetles, wasps, and crickets) can misconstrue dark buildings, asphalt roads, glass windows, and cars for water

because polarized light reflects off these surfaces (possibly causing their death)

“Aquatic insects are the foundation of many food webs. Therefore, reductions in their numbers may alter entire ecosystems and the services they provide”.

(Ecological Society of America 2009)

Dragonfly (photo by BluAlien)

Communication

Lampyridae (fireflies or glow-worms)• Use bioluminescent flashes as a form of sexual communication• Artificial light reduces the males’ visibility of the females’ signal

Predator-Prey Relationships• unexpected change in artificial light levels benefits predators whose prey is

attracted to lightex. Bats prey on insects, such as tympanate moths, which are

attracted to light• Researchers attribute light pollution as the main cause of the decrease of North

American moths

Lampyriade (photo by Say~cheese) Moths attracted to light (photo by Mudeth)

Reproduction• Singing is a way for male birds to attract female birds

Turdus Migratoius (photo by cosmicsailor)

Turdus migratorius (American Robin) begin to sing their “morning chorus” earlier in the day in areas with a low level of artificial light

Foraging•An unexpected change in light pollution leads to an increase in foraging time for species that forage during the day, which may increase predation

(Longcore 2004)

What is NYC doing to reduce light pollution?

National Dark Sky Week• occurs on the week of the new moon in April since a full moon increases

the light pollution (Barlow 2003)• people are asked to reduce their artificial lighting usage and turn off any

unnecessary lights as a way of appreciating the sky and raising awareness

Energy Efficient Lighting Tactics• Motion sensor lights in unoccupied rooms• Reduction of neon signs and unshielded traffic lights

Times Square (Photo by Toni Shi)

Bibliography

• Barlow, Jennifer. 2003-2009. Natural Dark Sky Week. http://www.ndsw.org/• Longcore, Travis, and Catherine Rich. "Ecological light pollution." Frontiers

in Ecology & the Environment 2, no. 4 (May 2004): 191-198. Environment Complete, EBSCOhost (accessed February 7, 2009).

• Ecological Society of America. 2009. Polarized Light Leads Animals Astray: 'Ecological Traps' Cause Animal Behaviors That Can Lead To Death.