Light Pollution Shaina Meyer pot

What is light pollution?• The alteration of the natural quantity of light in the night environment due to the introduction of excess artificial light • Should be able to see around 2,500

Light Pollution

Shaina Meyer

What is light pollution?

• The alteration of the natural quantity of light in the night environment due to the introduction of excess artificial light

• Should be able to see around 2,500 stars under normal nighttime conditions

• Types

– Light Trespass

– Glare

– Over-illumination

– Sky Glow

New York City

Hong Kong

The World At Night

source: http://visibleearth.nasa.gov

Effects of Light Pollution

• Wastes energy

• Causes adverse health effects in humans

• Obscures view of the stars

• Interferes with astronomical observatories

• Disrupts ecosystems

Black-Capped Chickadee

Effects on Animal Behavior

Light Pollution…

• Disrupts visual orientation and ability to navigate

• Stimulates unusual behavior for season/time of day

Studies have shown these effects in:

• Insects

• Salamanders

• Frogs

• Turtles

• Birds

green turtle hatchling

Migratory Bird Navigation

Birds find their way by…

• Using the position of the sun during the day, the stars at night

– visual layout of the land

– smell (ex sea)

– sound (ex waves on shores, winds through mountain passes)

*Scientists do not really know which migration technique birds rely on most

• Location, route, and maybe techniques of migration are hard-wired into their brains

We are learning more about migration w/ better technology

– satellite transmitters

– GPS units

Light Pollution & Birds

• Hundreds of species of migrating birds fly at night including most songbirds and shorebirds

• Rely on constellations to guide them during seasonal migration

Problems:

– Sky glow reduces view of constellations

– Flying near bright lights of urban areas may short-circuit steering sense

• Birds fly off course toward lights on buildings, towers, lighthouses

• Birds attracted to light

– Reasons unclear – possibly use light as a reference

• When birds suddenly reach light’s source, become confused/blinded

• Cause birds to slam into windows, walls, floodlights, the ground

• Problem particularly acute w/ bad weather like rain or fog

“Tribute in Light”

• In constant lights birds

circle and hover in and

around lights

– Believed to be trying to

orient their flight to the light

which they mistake for the

moon or stars

– Over time build-up of

migrants all trying to adjust

course

– Increase chance of hitting

each other or falling from

exhaustion The white streaks in this image are in fact birds trapped in the "Tribute in Light" spots at the

Ground Zero Memorial on September 11, 2004.

North America At Night

North American Migration Flyways

source:

http://visibleearth.nasa.gov

source: http://www.birdnature.com/flyways.html

• Fatal Light Awareness

Program (FLAP)

– Toronto organization

trying to publicize problem

– Estimate at least 100

million birds killed

annually by manmade

structures

– Believe songbirds most at

risk b/c they fly at low

altitudes dominated by

artificial light

Song Sparrow

Bird Casualties Fall 2004

source: http://www.flap.org

source: http://www.flap.org

Graph shows the average number of migratory

birds collected on each day of the year (numbers

calculated using data compiled over 7 years)

Average Number of Migratory Birds Collected (2000-2006)

4337 965

2006

3428 1340

2005

1915 1131

2004

2149 1102

2003

2726 1202

2002

2347 733

2001

1326 976

2000

Fall Migratio n

Spring Migratio n Year

Migratory Birds Collected

Increasing awareness about the consequences of light pollution will encourage people to…

• Use different types of lighting

– Shielded

– Motion sensors

• Reduce amount/intensity of lighting

• Block lighting from outside environment

– ex Genzyme

*International Dark-Sky Association (IDA) at www.darksky.org

How this helps birds:

• Research in Toronto and Washington, D.C shows when building lights dimmed/turned off number of bird fatalities drops dramatically

– Tower without lights causes bird collisions but at least not attracting more birds

Birds & Light Pollution Model

What is already being done to

reduce light pollution?

– The intent of this credit is to “minimize light trespass from the building and site, reduce sky-glow to increase night sky access, improve nighttime visibility through glare reduction, and reduce development impact on nocturnal environments.”

turn down lights during migrations

– Adopted at 100 buildings in downtown Toronto since 1997

– Trying to raise awareness in Chicago and New York as well

• Educational drives to publicize impact of light on turtle hatchlings and

seabird fledglings

– Sponsored by National Park Service in Hawaii and county governments in

Florida

lighting types, power, use

– States including Texas, New Mexico, Arizona, Connecticut, Maine, California implement statewide light restriction programs

• National impact of programs is minimal, but it’s a start