In a world that's increasingly illuminated by artificial lights, we're rapidly losing our connection with the natural night sky. What's more, this transformation isn't just affecting our ability to stargaze; it's impacting the very ecosystems that rely on the dark of night. From wildlife and plants to insects and pollinators, the consequences of light pollution are far-reaching and alarming.
Let's explore the fascinating and concerning relationship between artificial light and pollinators, and we'll provide you with practical tips on how to reduce light pollution at home.
The Rise of Light Pollution
Over just a few decades, our once-dark night sky has been transformed into one that's bright and glowing due to artificial lights. Shockingly, in 2016, it was estimated that a staggering 80% of the world's population lived under the phenomenon known as "skyglow" – the brightening of the night sky in areas densely populated by humans.
This light pollution has reached such a level that, in the same year, the National Oceanic and Atmospheric Administration reported that one-third of humanity could no longer catch a glimpse of the Milky Way Galaxy, a soft glow of more than 100 billion stars obscured by human-produced light.
The Dark Side of Light Pollution
Artificial light pollution poses a grave threat to wildlife, disrupting their natural rhythms and behaviors. It throws off the circadian rhythms – the natural sleep-wake cycle repeating every 24 hours – of various species, affecting their migration, hibernation, and daily activities. While the impact of light pollution on birds and sea turtles is well-documented, the effect on insects, including pollinators, remains a topic in the early stages of study.
"Although not well-studied, we are beginning to more clearly understand the impact light pollution has on insects and pollinators. This topic is emerging in more and more conversations," says Melissa Burns, western monarch coordinator for the U.S. Fish and Wildlife Service. The limited research conducted so far indicates that artificial lighting significantly affects the behavior of insects and pollinators, subsequently impacting a plant's ability to produce fruit and reproduce.
Insects and Pollinators Under Artificial Light
In 2014, a group of scientists in the United Kingdom conducted a study on moths and streetlamps. Astonishingly, they found that 70% of the moths were drawn towards the streetlights and away from flowering plants, resulting in reduced plant pollination.
A separate study in 2017 found that nighttime pollinators were less likely to visit plants under artificial light, leading to decreased pollination and fruit production. Approximately 62% fewer insects visited plants in a meadow illuminated at night with LED streetlamps compared to a meadow naturally lit by the moon.
The presence of artificial light at night disrupts the nighttime routines of pollinators. Some are attracted to and disoriented by it, expending precious energy and becoming distracted from their pollination duties. Others are deterred by well-lit areas, avoiding them altogether. The result is a disruption in nighttime pollination and fewer plants producing fruit and reproducing.
Researchers aren't entirely sure why this happens, but several theories suggest that artificial lighting increases a nocturnal pollinator's risk of predation, making them easier targets. Additionally, their ability to see and avoid predators is reduced by the lighting.
Taking Action to Reduce Light Pollution
While more research is needed to fully understand the impact of artificial lights on plants and pollinators, there are steps each of us can take to mitigate light pollution:
1. Keep Light Indoors: Close blinds or curtains at night to prevent indoor light from escaping.
2. Choose Warmer-Colored Bulbs: Use light bulbs with warmer colors and minimize blue-violet light (light bulbs with a temperature of no more than 3000 kelvins).
3. Use Outdoor Light Mindfully: Control outdoor lighting with motion detectors, timers, or dimmers. Motion-triggered lights can address safety concerns.
4. Shield Outdoor Lights: Properly shield all outdoor lights to eliminate light pollution drifting into the sky.
5. Explore Dark Sky Places: Visit International Dark Sky Certified places to learn more about light pollution and experience the beauty of the night sky. The U.S. Fish and Wildlife Service manages two internationally certified places: Valle de Oro National Wildlife Refuge in New Mexico is certified as an Urban Dark Sky Place, and Lost Trail National Wildlife Refuge in Montana is certified as an International Dark Sky Sanctuary.
6. Plant a Moon Garden: Create a moon garden with plants that attract nighttime pollinators. This not only supports pollinators but also enhances your nighttime garden experience.
The impact of light pollution on pollinators and ecosystems is a growing concern. By taking small steps to reduce light pollution in our own lives, we can contribute to a healthier environment, support our invaluable pollinators, and ensure that future generations can still marvel at the wonders of the night sky.