Dark Skies

What is light pollution?

Light pollution is the presence of unwanted, inappropriate, or excessive artificial lighting which has shown to have negative affects on humans, animals, and ecosystems. 

Light pollution from nearby construction reaches saline wetlands of Audubon's Gillmor Sanctuary in Salt Lake County, Utah, on October 1, 2019. Photo by Evan Barrientos/Audubon RockiesLight pollution from nearby construction reaches saline wetlands of Audubon's Gillmor Sanctuary in Salt Lake County, Utah, on October 1, 2019.© Evan Barrientos/Audubon Rockies

How does artificial light at night affect our world?

For billions of years, life on earth has depended on the natural rhythm of day and night for migration, reproduction, nourishment, sleep, and protection. Artificial light at night (ALAN) produced by humans has interrupted this cycle and is causing detrimental effects. 

Light and Migration

The Salt Lake Valley is on the Pacific Flyway, and the ecosystem of the Great Salt Lake is a crucial stopping point for many migrants to refuel their energy stores. Each spring and fall, millions of birds migrate thousands of miles, many of which travel at night to take advantage of calmer skies, cooler temperatures, and protection from birds of prey. These birds use celestial cues to navigate to their final destination, but artificial light at night has complicated this already dangerous activity. Bright, dense lights disorient birds, drawing them into big cities where they are more likely to collide with windows on tall buildings, and forcing them to expend more energy than they have, causing them to die of exhaustion.

Aud APA 2021 Sandhill Crane A1 14505 2 TS Photo Janelle Schroeder

What can you do?

Research has shown that implementing safer outdoor lighting can reduce light pollution and the harmful effects of ALAN on wildlife. The best thing you can do is to turn your lights completely off during migration season which is March-May and September-November from 11 pm - 6 am. For any lighting that needs to remain on at night, you can still make a valuable impact by following the steps below.

  1. Light only what you need when you need it. Reduce the quantity of lights to only cover the area needed. Consider using automatic timers and motion sensors. 
  2. Use warm bulbs only as bright as you need. Energy efficient bulbs, such as LEDs can save you money and come in a wide color spectrum. Choose bulbs that have a “warm” color temperature no more than 3000 Kelvins. Birds are less attracted to warmer colors like red and yellow than they are to brighter blue light. 
  3. Shield lights and direct the light downward. Examples of acceptable and unacceptable lighting fixtures can be found here.
  4. Take the Lights Out Pledge! Encourage your neighbors to do the same! 

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