Less Light At Night

Help reduce impacts of light pollution on wildlife

Reducing your backyard light usage can help wildlife. It also can help you sleep better and save you money. That’s a great combination…

U.S. light pollution map (from www.lightpollutionmap.info )

99% of Americans live in an area with light-polluted skies. Also, experts estimate that light pollution prevents 80% of Americans from seeing the Milky Way.

Light pollution comes from a wide variety of sources. A large portion of the light pollution sources are from residential homes and yards.

Person sleeping with light on (Photo by kargaltsev )

Light pollution affects humans by lowering melatonin production. This reduces our sleep quality. It impacts our circadian rhythms. And it increases conditions such as headaches, fatigue, and anxiety.

It also affects many wild animals. Many of them experience the same negative impact of reduced sleep/rest quality as we do. They also are impacted in a variety of other ways.

Black-and-White Warbler killed from a nighttime building collision.

Artificial nighttime light impacts birds during their nighttime migrations. Many of these birds navigate at least partially by starlight. They get confused by lights from buildings. The lights can make them disoriented and crash into buildings.

Bat flying late at night (cropped photo by Pollo )

In areas with lots of light pollution, bats will emerge later at night. They would emerge earlier without the light. This can cause them to miss feeding during the time when the insects they eat are the most numerous.

Barred Owl (photo by @ron_floyd_wildlife_photography )

Some bats avoid entering lit areas for fear of being detected and eaten by predators such as owls. Lots of other small mammals limit their activity in lit areas at night for the same reason.

Moth flight paths at a street light (photo by dbgg1979 )

Lights attract many insects, which can cause a variety of negative impacts. Moths are a great example of this. They die from overheating by staying on the light source too long. Often they succumb to exhaustion by continually fluttering around in the light source. Predators also hunt them. The predators have learned that lights attract many moths.

Firefly on ground after being swatted by a cat (photo by Famartin )

Lights disrupt nocturnal insect communication. “Fireflies” (also known as “lightning bugs”) are a great example of this.

Firefly light trails (photo by Mike Lewinski )

Fireflies use their bioluminescent flashes as the main way of signaling to mates. Outdoor lighting can reduce the firefly flashes' effectiveness. It can also lead them to flash less. Both lead to a reduction in signaling between potential mates.

The good news is that each of us can take simple actions to help this. These actions have immediate benefits. And these benefit our well-being as well as benefit the wildlife around us.

Red Fox and pup (photo by @chris.a.fraley )

Good star-viewing is an added bonus to a dark backyard at night (photo by John Brighenti )

If you have outdoor lights at your home, consider turning them off when you are not outside and don’t need them on. You can also put them on a timer so that they are only on during the hours when they regularly need to be on.

Downward shielded lights that minimize upward and outward light pollution

Most outdoor light fixtures are designed inefficiently. They emit light in all directions, including upwards into the sky. For these lights, consider replacing them. Use lights designed to direct light where you need it. Or, you can affix shields on the light that direct light to where you want it to shine.

Amber landscape lights

Also, you can replace the bulbs in your outdoor lights with warmer color bulbs. These include red, amber, or orange. Warmer color bulbs are less disruptive to wildlife.

White-Tailed Deer fawn (photo by @abrunophoto )

See the link below for more details on what you can do. Simple changes to your home's outdoor lighting can greatly help your wildlife neighbors and co-inhabitants.

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