Night Life
Imagine you’re camping on a warm summer night just after sunset. The evening is peaceful and calm, far away from the bustle of the city. In the distance you see the tiny flickers of fireflies, trees swaying in the breeze, and the shimmer of hundreds of stars. You hear fire crackling, crickets chirping, and birds singing. Although your far from the city, light pollution from car headlights, electric lamps, and streetlights is still affecting every animal, plant, and insect around you.
Just like our circadian rhythms, animals and plants rely on cycles of light days and dark nights for a variety of reasons, including sleeping, eating, and reproducing. When there is too much light at night, this cycle can be thrown off and impact the ability for animals to sleep or hibernate, eat, hunt, reproduce, and have protection from predators. Today’s blog post is accompanied by a reading of the picture book Lights Out by Marsha Diane Arnold and Susan Reagan. This book follows animals on their journey to finding a place without light pollution and the challenges they face because of light pollution.
How Does Light Pollution Effect Different Animals?
What animals can you find in your neighborhood? Take a moment and quietly sit outside or go for a walk, during the day or the night, and see how many different animals you can find. What do you see and hear? All of these animals are in one way or another affected by light pollution. Nocturnal animals that live near roadways are like “deer-in-the-headlights,” being blinded and disoriented by the bright car lights and streetlights. Rabbits and other prey need the dark of night to use as a cover to hide from predators. There are three kinds of animals that are especially affected by light pollution though: birds, sea turtles, and insects.
Birds
Many birds migrate or hunt at night, including Canadian geese and owls. When they are traveling through the sky, they use stars and the moon to help them navigate. Artificial lights can cause them to turn off course and end up in cities. Millions of birds collide into buildings every year due to light pollution and many more miss the ideal migration time which can affect their ability to make nests, eat, and reproduce.
Sea Turtles
When sea turtles hatch, they use the shimmer of sun or moonlight on the surface of the water to guide them toward the ocean. However, when there is light pollution, the sea turtles get confused and end up moving toward the lights instead of the ocean. This puts them at risk of being eaten by predators or dying of dehydration.
Image from SEEturtles.org
Insects
When you think of pollinators, you might picture bees or butterflies, but nocturnal pollinators like moths play an important role in pollination. According to a study done in Europe, when plants were lit by artificial light, pollinators visited them 62% less compared to dark areas without artificial light. This caused a 13% decrease in how much fruit was produced in a studied plant.
Many insects are also drawn to light which can cause populations to decrease and can affect the production of crops and the animals that rely on insects for food.
What Can You do at Home to Help?
Plant a pollinator-friendly garden of any size of plants that are pollen and nectar-rich. Place this garden in the darkest area you can find.
If you have outdoor lights, like floodlights or path lights, turn them off when you’re not using them or before going to bed.
If you can’t turn outdoor lights off entirely, try getting motion sensors, angle the lights so they are only lighting the area you need, like a doorway or part of a driveway, or installing warm toned LEDs.
Sources:
https://www.darksky.org/light-pollution/wildlife/
https://cescos.fau.edu/observatory/lightpol-environ.html
https://www.ecori.org/pollution-contamination/2020/6/17/night-lights-do-nothing-to-calm-the-beasts
https://kids.niehs.nih.gov/topics/natural-world/wildlife/ecology/lighting/index.htm
By Amanda Leith
