Wildlife

Migrating Birds

Did you know that billions of birds migrate through the United States every year, and that most of them travel at night? It may come as a surprise, but under cover of darkness, these birds follow the stars, navigating their ancient flyways with stunning precision. Yet, there is a growing threat in our modern world: light pollution is throwing their journey into chaos, leading to exhaustion, disorientation, and even collisions with brightly lit buildings.

Light pollution is outpacing the growth of human population, brightening our night skies at an alarming rate, doubling every 10 years! Cities cast massive domes of artificial light which pull birds off-course, forcing them into unfamiliar landscapes where they become trapped, confused, or exhausted. Many collide with windows and buildings, unable to escape the glowing labyrinth. Each year, this crisis results in the tragic loss of hundreds of millions of birds.

But here is the good news: you can help!

A Simple Yet Powerful Solution

What if saving countless birds was as easy as flipping a switch? In 2017, the Audubon Society launched the Lights Out Program to combat this crisis. The initiative encourages people to reduce lighting from 11 PM to 6 AM during key migration periods. In Washington those periods are:

• Spring: April 15 – May 31

• Fall: September 1 – October 15

Cities nationwide including those in the Pacific Flyway such as Bend, Eugene, Portland, San Francisco, San Diego, and Salt Lake City, are joining the movement to dim unnecessary lights and save migrating birds. There are even ten statewide programs in the nation. But this effort needs to grow! 

A website that is helpful to learn when migratory birds are in your area is: Birdcast.info. This website hosts many features to include migratory forecasting tools, how many birds have already flown overhead, and what species of birds are migrating in your area.

To learn more about the Lights Out Program click here.

Nocturnal Species

Many animal species depend on the natural darkness of night to survive and thrive. Creatures like flying squirrels, owls, frogs, and bats rely on the night for essential behaviors such as hiding from predators, hunting, reproducing, and migrating. Artificial lighting disrupts these patterns, fragmenting habitats and ecosystems in ways that are often invisible and not well understood.

Take bats, for example. Some species tolerate light, while others avoid it entirely, but regardless of their tolerance, artificial light alters the delicate balance of their ecosystems.

The Big Brown Myotis (BBM)

The BBM is considered light-tolerant. These bats often exploit artificial light sources, using them to hunt insects that are drawn to the glow. While this may seem like an adaptation, it creates an ecological trap, a situation where predators benefit disproportionately, leading to a predator-prey imbalance. Insects, though often overlooked, are keystone species that play vital roles in pollination and maintaining the food chain.

Additionally, the blue-spectrum lights attract insects away from their natural habitats near water, where bats typically forage. This shift forces bats to separate their feeding grounds from their watering holes and roosting areas, disrupting the ecological harmony that once existed in a single location. 

The Little Brown Myotis (LBM)

In contrast, the LBM is highly light-intolerant and commonly found in aquatic and wetland areas throughout Chelan County. These bats require high habitat connectivity between their roosting and foraging areas, meaning they don’t travel far to hunt. A 2023 study found that LBMs avoid areas within 75 meters of artificial light, significantly reducing their hunting grounds.

As development expands and awareness of light pollution remains low, we are unintentionally fragmenting habitats in ways that are neither intuitive nor obvious. The consequences ripple through ecosystems, affecting not just bats but the entire web of nocturnal life.

Nocturnal Pollinators

Moths are often misunderstood and unfairly labeled as pests. Unlike butterflies, they aren’t celebrated in popular culture, and many people don’t feel the same affection toward them. This reflects a broader issue in our society: we tend to protect only the animals we find cute or charismatic, while others are left vulnerable.

Chelan County is home to many moth species that play a vital role as nocturnal pollinators. Species like the Cecropia Moth, Five-spotted Hawk Moth, and White-lined Hawk Moth work the night shift, helping plants reproduce while most of us sleep. But their efforts are being blocked by a growing threat—light pollution.

Artificial Light at Night (ALAN) attracts insects, creating what scientists call an ecological trap. Many of these trapped insects are moths, which often die as a result. ALAN also causes a predator-prey imbalance. Predators learn to hunt near light sources, making it even harder for moths to survive.

In areas affected by light pollution, moth pollination drops significantly. This leads to reduced fruit production and disrupts entire ecosystems. Since 1968, moth populations in the United States have declined by 30 percent. This is likely due to increased development and widespread use of artificial lighting.

Moths and other insects are especially drawn to blue-spectrum light. Lights with a cooler, whiter hue create a stronger ecological trap. Switching to warmer, amber-colored lighting (2700 Kelvin or lower) can help reduce insect attraction. As a bonus, fewer insects around your lights means fewer spiders and webs on your property.

Wetland Amphibians

Wetlands are among the richest habitats for wildlife. If you’ve ever camped near one, you’ve likely experienced the vibrant nighttime chorus: crickets chirping, owls hooting, fish splashing, and frogs croaking. These sounds are signs of a healthy, thriving ecosystem. But artificial light is rapidly fragmenting these environments, severely limiting their ability to function.

Frogs, for example, rely on true darkness to reproduce. Their mating calls are carefully timed with the night, and studies have shown that even low levels of light pollution can interfere with this process. As a result, amphibian reproduction drops, and frog populations begin to decline.

The disruption doesn’t stop there. Frogs are also hunters, feeding on insects that are drawn to artificial lights. This attraction pulls frogs away from their wetland homes, forcing them to travel farther to find food. In doing so, they risk exhaustion, lose connection to their habitat, and become more vulnerable to predators. The balance between predator and prey begins to shift, and the ecosystem suffers.

You might have seen this yourself—walls near buildings close to wetlands covered in frogs on warm summer nights. It’s not random. It’s a sign that light pollution is pulling wildlife out of their natural environment and into artificial spaces.

Even the youngest frogs are affected. Eggs laid in light-polluted wetlands hatch into tadpoles and begin their transformation into adult frogs. But under artificial light, this metamorphosis speeds up unnaturally. The frogs emerge smaller and weaker, with reduced chances of survival. The long-term result is higher mortality and a weakened population.

This story is unfolding in wetlands across Chelan County and beyond. It’s a quiet crisis, often overlooked, but deeply impactful. By protecting the night and reducing artificial light near wetlands, we can help restore the balance and ensure that the nighttime chorus continues for generations to come.

Mammals

When we think about light pollution, we often picture its impact on nocturnal animals, those that hunt, forage, and move under the cover of darkness. But the truth is, diurnal mammals, the ones active during the day, are also affected. Much like humans, they rely on natural cycles of light and dark to regulate their internal clocks.

Artificial light disrupts melatonin production and throws off the circadian rhythm. This desynchronization leads to sleep disturbances, increased stress, and a higher risk of disease. Animals that sleep less don’t just suffer physically, they also struggle to maintain normal behaviors, including foraging and predator avoidance.

Take mule deer, for example. These animals often choose to forage in well-lit areas, likely because the increased visibility helps them navigate. But this behavior comes with a hidden cost. Urban-adapted cougars have learned to use these lit environments to their advantage. They hide in the shadows, waiting for deer whose eyes haven’t adjusted to the contrast between light and dark. This makes the deer more vulnerable to ambush.

Interestingly, not all cougars behave the same way. Those living deep in the backcountry tend to avoid artificial light altogether, sticking to the natural rhythms of the wilderness. This contrast between urban and wild behavior shows just how deeply light pollution can reshape ecosystems, even changing predator-prey dynamics.

Salmon

Salmon travel hundreds of miles of river, both downstream and upstream, to complete their anadromous lifecycle. Along the way they contend with dams, erosion, silt, pollution and predators. Light pollution is one more obstacle that can tip the balance against their survival.

Artificial Light at Night (ALAN) brightens rivers and streams in ways that go beyond human convenience. When light scatters across the water, it removes the darkness salmon depend on for cover. Fish hesitate at brightly lit passages or abandon their migration entirely, leading to reduced spawning and shrinking populations.

Nighttime is prime migration time for salmon because darkness hides them from hunters. Under artificial lights, predators learn to stake out illuminated stretches of water. In Washington state, biologists have even observed cranes spearing salmon right beneath light traps. Other fish and wildlife follow the same pattern, turning lit riverbanks into feeding grounds.

Light pollution may not be the single largest threat to salmon, but it is a death by many cuts. We can remove one of those cuts today. Its easy, dont light waterways or property near water. Together, we can restore the night cover salmon need to complete their epic migrations and secure healthy runs for generations to come.