by Brenda Catlett, NTMN Class of 2018

Living in an urban environment, we have grown used to having limited visibility of the stars in the night sky, so light pollution is a concern that most of us don’t think about routinely.

We don’t realize how bright and expansive the stars in the night sky are until we travel to places far away from the city lights.  In places like the Davis Mountains in west Texas, we are awestruck and inspired by the magnitude and brightness of stars in the night sky. If we are lucky, we may even see the Milky Way. 

Besides limiting our view of stars in the night sky, artificial lighting in urban areas can create problems for people. Unwanted light shining in our windows from streetlights or neighbors’ security lights is annoying and can affect sleep. Misdirected lighting or too many lights on at night wastes energy. Too much brightness at night can create glare and reduce visibility for drivers and pedestrians. 

Light pollution affects birds, animals and insects too. Artificial light can be disruptive to many bird species migration patterns. Lights outside at night have also been known to confuse robins and other birds causing them to sing at night. Owls are particularly sensitive to light pollution. 

Moths and flying insects are attracted to lights at night, disrupting their cycle of feeding and reproduction. Outside lights reduce populations of moths and flying insects by as much as 30%, affecting the food supply for bats. Some slower flying species of bats avoid streetlights, making it harder for those bat species to find food. 

Texas is home to more species of bats than any other state, including the large brown bat and the most-common Mexican free-tailed bat. Bats are important pollinators and they eat an incredible number of insects, up to 1,200 an hour, including mosquitoes. Since bats are nocturnal, bats are upset by artificial light, especially near their roosting areas. 

Though light pollution is an inevitability of urban development, there are steps we can take around our homes to reduce the impact on people, bats, birds and insects.

• Minimize outdoor lighting at night.
• Use motion detector lighting that comes on only when needed.
• Install lighting low to the ground instead of up high. 
• Used focused lighting that shines down and not up.

Awareness of light pollution facilitates change and helps all of us advocate for better lighting design around our area to protect bat colonies, nocturnal birds, animals and insects with whom we share the planet.

For more information on light pollution visit the International Dark Sky Association website.