Wildlife & the Night

Animals have evolved to use natural light cues like moonlight and starlight to guide critical behaviors like feeding, mating, and migrating. Artificial light can disrupt those cues in detrimental ways:

• Artificial light can cause animals to migrate too early or too late, missing critical climate conditions needed for foraging, breeding, and nesting.
• 80% of North American bird species migrate at night, using celestial cues to navigate. Artificial light can disorient them, leading to fatal collisions, exhaustion, and exposure to predators. 
• When insects, like moths, are drawn into lights, their ability to pollinate is disrupted because they spend less time feeding and reproducing, become easy targets for predators, or die of exhaustion.

Even small increases in nighttime light can ripple through entire ecosystems. Protecting darkness helps maintain the balance these species depend on.

Most birds migrate at night using the moon and stars to navigate. Bright lights confuse them, causing them to fly around buildings until they drop from exhaustion or fly into buildings and die from window strikes. The photo below, courtesy of FLAP, shows dead birds collected over the course of a year after hitting lit windows in Toronto.

(photo credit: FLAP Fatal Light Awareness Program)

(photo credit: Sean Fitzgerald)

You can do your part to protect wildlife from the dangers of light at night:

🔴 Use head lamps with a red light option. Red light wavelengths are less disruptive to wildlife (and better for our human eyes, too!)

💡Only use outdoor lights when you need to.

🌌 Turn off lights from 11:00 p.m. to 6:00 a.m.

👇 Add a shield to direct your light source.

⏱️ If possible, use motion-activated lights or timers.

Read more: Shining Some Light on the Vanishing Night

Read more: How Artificial Light Affects Us