Why darkness may be the key to saving pollinators

In cities, suburbs, and even rural towns, the night sky is vanishing. Where once there was darkness — and stars — now there are streetlights, parking lot lamps, porch lights, billboards, and car headlights that turn night into permanent twilight. Scientists warn that our constant illumination is wreaking havoc on pollinators, those tireless creatures who keep ecosystems functioning and food crops thriving. Pollinator declines have made headlines for years. The shrinking number of honeybees, monarch butterflies, wild bees, moths, and bats are all well documented. While pesticides, habitat loss, and climate change are often blamed — and rightly so — researchers now say that light pollution is an overlooked but potent driver of pollinator decline. Nighttime is Pollination Time. When most people picture pollinators, they think of honeybees buzzing around a sunny garden. But a huge amount of pollination happens after dark. Moths, beetles, flies, and even some species of bats are crucial nighttime pollinators. They are responsible for fertilizing night-blooming plants like jasmine and evening primrose as well as many fruit trees, cacti, and crops. These creatures evolved with natural cycles of day and night. Darkness provides them with cues for when to feed, fly, and reproduce. When light pollution floods their habitats, it confuses them, alters their behavior, and disrupts their ability to do their work. Artificial light at night (ALAN) does not just brighten the sky; it rewires ecosystems. The following are examples: • Disoriented Pollinators: Many nocturnal insects navigate by the moon and stars. Streetlights and floodlights attract them, trapping them in endless circling flights until they die of exhaustion or predation. Fewer moths reach flowers, leaving plants under-pollinated. • Altered Flower Cycles: Some flowers open, release nectar, or emit fragrance only at night. Studies have found that light pollution can disrupt these cycles, making flowers bloom earlier or stay open later — missing the window when their pollinators are active. • Predator Advantage: Bright light makes nocturnal pollinators easier prey for bats, birds, and other predators. This added risk further suppresses pollinator activity, keeping them away from flowers. • Chain Reactions: When pollination rates fall, plants set fewer seeds and fruits. That, in turn, reduces food sources for other animals — including humans. In 2020, a study published in Nature found that light pollution reduced nighttime pollination by 62% in alpine meadows. The effect was not just a nighttime issue — daytime pollinators did not make up the difference. Fewer seeds were produced, meaning long-term declines in plant populations were likely. Pollinators are responsible for fertilizing three out of four flowering plants worldwide. Without robust pollination, ecosystems unravel. Wildflowers disappear. Fruits and vegetables become scarcer and more expensive. Entire food chains collapse — because pollination is not just about human food, it sustains berries for birds, seeds for rodents, and nectar for countless insects. Communities around the world are starting to wake up to the value of night, working to restore darkness. The International Dark-Sky Association works with towns and cities to adopt "dark sky friendly" lighting: fixtures that are shielded, directed downward, and turned off when not needed. Farmers are experimenting with reducing nighttime lighting around fields and orchards to encourage moth pollination. Early evidence suggests improved yields for night-blooming crops. Homeowners can have an influence too. Simple steps — like turning off porch lights when not needed, using motion sensors instead of all-night bulbs, and planting night-blooming flowers such as moonflowers, evening primrose, or night-flowering jasmine — can provide safe habitat for nighttime pollinators. Protecting natural darkness does not just help pollinators. Restoring darkness is a win-win for biodiversity, human well-being, and the planet. Humans being exposed to artificial light at night are linked to disrupted sleep cycles and health risks such as obesity, diabetes, and depression. Turning off unnecessary lights saves money and reduces greenhouse gas emissions. Darkness allows for stargazing, a sense of connection with the cosmos, and a slower rhythm of life that many find restorative. So, what can you do tonight? Start with your own home by turning off lights. Turn off outdoor lights when not in use, especially during peak pollinator months. Choose better fixtures by installing shielded lighting that points down, not out or up. Use warm-colored bulbs such as yellow (remove the blue light), which are less disruptive to insects. Talk about it with your friends and neighbors. Many people have never considered the ecological importance of darkness. We have spent decades bringing light to every corner of our world, assuming it was always a sign of progress. But nature — and we — need the night. Darkness is not just absence. It is a habitat. It is a signal. It is a timekeeper. For pollinators, it is essential. Perhaps the simplest path to saving pollinators is to embrace a little darkness. Ann Woolum is an Ohio State University Extension Hancock County Master Gardener Volunteer. Find us on Facebook at "Hancock County Master Gardener Volunteers."