Lights Out for Birds: How to Reduce Nighttime Window Collisions During Fall Migration

Q: Why do birds hit windows at night during migration?

Birds migrate at night using starlight and moonlight for navigation. Artificial lights from buildings overwhelm these natural light sources, causing disorientation. Disoriented birds may not recognize glass as a solid barrier and collide with it.

Q: How does light pollution affect migratory birds?

Light pollution affects migratory birds in three ways. It interferes with their navigation by hiding natural celestial light. It attracts birds toward bright areas and causes them to circle until exhausted. It also increases collision risk because glass near lights reflects sky or trees that birds cannot identify as solid surfaces.

Q: How can I prevent birds from hitting my windows at night?

Turn off or dim all nonessential outdoor lighting after 11:00 PM during migration season. Close curtains and blinds to stop indoor light from spilling outside. For safety lighting, install shields that direct light downward and use motion sensors or timers.

Q: Do I need to turn off all outdoor lights to help migrating birds?

No. Lights required for safety can remain on if they are modified properly. Add shielding so light points downward, and install motion sensors or timers so lights activate only when needed.

Q: Can turning off lights for a short time help migrating birds?

Yes. Turning off bright lights for 20 to 30 minutes can sharply reduce the density of birds gathered around a lit area. Even short periods of darkness have a measurable effect.

Q: What is the Lights Out program for migratory birds?

The Lights Out program is a conservation initiative that encourages cities, businesses, and homeowners to reduce artificial lighting during bird migration seasons. More than 20 cities across the United States participate in this program.

Q: How do I join a Lights Out bird migration campaign in my city?

Search for local Lights Out pledge campaigns run by environmental organizations or Audubon chapters. You can also contact local representatives to express support for stronger lighting ordinances in your area.

Q: Does closing curtains at night help migrating birds?

Yes. Closing curtains or blinds prevents indoor light from spilling outside. This is one of the simplest and most affordable bird safe lighting practices for homeowners.

Every autumn, billions of birds embark on one of nature’s most arduous journeys. However, as these migratory birds traverse our brightly illuminated human world, this brilliant adaptation has become a fatal vulnerability. The contrast between natural darkness and artificial light can disorient them, leading to dangerous consequences.

Here is the hopeful truth: you can help fix this issue.

How Does City Lighting Disorient Migrating Birds?

Light pollution significantly impacts nocturnal migratory birds in three primary ways. Understanding these effects is crucial for protecting these vulnerable species during their journeys.

1. Interference with Navigation

Artificial light overpowers starlight and moonlight, effectively removing the essential visual references that birds rely on for orientation. This disruption can lead to confusion and misdirection during migration.

2. Attraction and Extended Hovering

Birds are naturally drawn to strong light sources. As a result, they may circle and hover repeatedly around illuminated structures, which prevents them from continuing their migration. This behavior can be detrimental to their survival.

3. Increased Collision Risk

Glass surfaces near light sources can reflect the sky, nearby trees, or the light itself. Unfortunately, birds often fail to recognize these reflections as solid obstacles, leading to dangerous collisions. Interestingly, turning off bright lights for just 20 to 30 minutes can significantly reduce the density of birds gathered around a lit area. Even brief periods of darkness can yield measurable results.

Your Backyard Lights Matter Most for Migrating Birds

Did you know that 56% of bird-window collisions in the United States occur at low-rise buildings of just 1 to 2 stories? Surprisingly, 44% of these incidents happen at residential homes, while high-rise buildings account for less than 1% of collisions. This statistic highlights the critical importance of your backyard in protecting migrating birds.

Small songbirds often fly at low altitudes, seeking refuge in trees and shrubs across urban, suburban, and rural landscapes. Even low-intensity artificial light at night can significantly disrupt their natural nocturnal behavior. Affected birds become increasingly agitated, frequently looking up and fluttering their wings as if attempting to take off.

For these small-bodied songbirds, this unnecessary restlessness can severely deplete their energy reserves, leading to weight loss and increased vulnerability.

As a backyard birder, you can take the following actions to help:

Turn off unnecessary outdoor and indoor lights during migration seasons in spring and fall, especially from 11:00 PM to 6:00 AM.
Add shielding to essential fixtures to direct light downward, preventing it from scattering upward or sideways.
Use warm-toned bulbs with yellow or orange hues, and avoid cool blue or white light.
Install motion sensors or timers so lights activate only when needed.
Close curtains and blinds at night to prevent indoor light from spilling outside.
Apply collision markers or decals to windows to help birds recognize glass as a barrier.

How to Effectively Reduce Light Pollution During Migration Season

1. Turn Off or Dim Nonessential Lights

To help migrating birds navigate safely, it's crucial to switch off all outdoor lights that are not essential after 11:00 PM. This includes decorative lighting, landscape illumination, and spotlights aimed at trees or gardens. These areas can inadvertently serve as temporary night paths for birds, leading them off course.

2. Modify Essential Lighting for Safety

If certain lights must remain on for safety reasons, you can still minimize light pollution through thoughtful design choices. Here are some effective strategies:

Add shielding to direct light downward, preventing it from scattering upward or sideways.
Install motion sensors or timers so lights activate only when someone is present, reducing unnecessary illumination.

3. Close Curtains and Blinds at Night

One of the simplest and most affordable methods to protect migratory birds is to draw curtains or blinds at night. This action prevents indoor light from escaping outside, which can disorient birds during their migration.

4. Reevaluate Your Garden Lighting Needs

Before making changes to your garden lighting, take a moment to assess your actual requirements. Consider which areas truly need light, how bright the light should be, and whether it needs to remain on throughout the night. Remember, brighter bulbs are not always necessary. Leaving some areas dark not only saves energy but also helps preserve migration corridors for birds.

When Is Light Reduction Most Important for Migrating Birds?

Timing is crucial for bird migration, as it directly impacts their journey. Understanding when to reduce light can significantly aid these birds during their travels.

Fall migration generally runs from August 15 to November 30, with the busiest periods occurring in September and October.
Spring migration typically lasts from mid-March to early June, peaking in April and May.

During the hours of 11:00 PM to 6:00 AM, bird migration is at its most active. This critical window is when reducing artificial lighting can make the greatest difference for migrating birds.

How to Effectively Participate in a Lights Out Program

By taking individual actions, you can significantly support broader conservation efforts aimed at protecting migrating birds.

1. Sign a Lights Out Pledge Today

Many cities and environmental groups actively run Lights Out pledge campaigns. To make a positive impact, check for programs in your area and commit to the pledge. Reducing light pollution during migration season is a small step that can lead to a substantial difference for birds passing through your community.

2. Share Your Backyard Birding Experience with Others

Your personal observations from backyard birding can be incredibly persuasive. By sharing your knowledge about bird-safe lighting practices with neighbors and friends, you can raise awareness. Additionally, consider joining a local Audubon chapter to engage in organized advocacy and conservation activities that further support these efforts.

FAQ

Why Do Birds Hit Windows at Night During Migration?

Birds rely on starlight and moonlight for navigation during their nighttime migrations. However, artificial lights from buildings can overwhelm these natural light sources, leading to disorientation. As a result, disoriented birds may fail to recognize glass as a solid barrier, which increases the likelihood of collisions.

white brown and gray bird on black metal wire

Photo by Abdul Rehman Khalid on Unsplash

How Does Light Pollution Affect Migratory Birds?

Light pollution impacts migratory birds in three significant ways. Firstly, it interferes with their navigation by obscuring natural celestial light. Secondly, it attracts birds toward brightly lit areas, causing them to circle until they become exhausted. Lastly, it raises the risk of collisions, as glass near lights can reflect the sky or trees, which birds may not identify as solid surfaces.

What Time of Night Do Birds Migrate Most Actively?

Nocturnal bird migration is most active between 11:00 PM and 6:00 AM. To effectively protect migrating birds, it is crucial to reduce artificial lighting during these hours.

When Is Bird Migration Season in North America?

Fall migration typically spans from August 15 to November 30, with peak activity occurring in September and October. Conversely, spring migration generally runs from mid-March to early June, peaking in April and May.

How Can I Prevent Birds from Hitting My Windows at Night?

To help prevent bird collisions, turn off or dim all nonessential outdoor lighting after 11:00 PM during migration season. Additionally, closing curtains and blinds can stop indoor light from spilling outside. For safety lighting, consider installing shields that direct light downward, and use motion sensors or timers to minimize unnecessary illumination.

Do I Need to Turn Off All Outdoor Lights to Help Migrating Birds?

No, it is not necessary to turn off all outdoor lights. Safety lights can remain on if they are properly modified. Adding shielding to ensure light points downward and installing motion sensors or timers can help activate lights only when needed.

Can Turning Off Lights for a Short Time Help Migrating Birds?

Yes, turning off bright lights for just 20 to 30 minutes can significantly reduce the density of birds gathered around a lit area. Even brief periods of darkness can have a measurable positive effect.

What Is the Lights Out Program for Migratory Birds?

The Lights Out program is a conservation initiative designed to encourage cities, businesses, and homeowners to reduce artificial lighting during bird migration seasons. Currently, more than 20 cities across the United States participate in this important program.

How Do I Join a Lights Out Bird Migration Campaign in My City?

To get involved, search for local Lights Out pledge campaigns organized by environmental organizations or Audubon chapters. Additionally, you can contact local representatives to express your support for stronger lighting ordinances in your area.

Does Closing Curtains at Night Help Migrating Birds?

Yes, closing curtains or blinds is an effective way to prevent indoor light from spilling outside. This simple and affordable practice is one of the best bird-safe lighting measures homeowners can adopt.