There’s a magic in the night. With limited visual clues, smells and sounds kick in.
Until the trees leaf-out, I can still continue my nightly step outside and make stars twinkle when viewed through bare branches. To see the big sky is a real challenge. The west is a line of street lights. The east horizon is out over an empty corn field but a glow from an intersection on Hwy 12 hangs over the treetops, any cloud makes a bigger smear. My only open dark sky is limited to the edge of the cornfield but only if I stand with my back to the neighbor’s security light, and basically look straight up. A far cry from a night in the desert, it’s mind-boggling how many stars there are! Nothing like seeing the Milky Way to feel the immensity of space.
In the dark there are sounds I don’t hear during the day (or just don’t register). Coyotes yelping. Owls hooting. Announcements that the night shift is looking for food or mates, or escaping a stealthy predator.
This year’s theme for World Migratory Bird day is Dim the Lights for Birds at Night. Light pollution impacts hundreds of songbird species that migrate at night: an adaptation where darkness shields birds from aerial predators, cooler temps help birds regulate body temps from exertion; they can fly higher. But lights below also shine up and distract birds from their star compass. Drawn in, the lights become a fatal attraction especially among tall building where birds become “trapped” among the buildings and too often crash into the invisible walls of illuminated glass. Each year during migration, 5,000+ are recovered by volunteer “collision monitors” in Chicago. Most do not survive.
Sadly, light pollution doesn’t impact just birds. Biological creatures (including us) operate with circadian rhythms. There’s a reason we (and most animals) sleep at night. The nocturnal specialists operate in a parallel work-shift: owls are the aerial predators of night, hawks are the day shift. Bats feed on the night moths. And fireflies flash to find their mates. The adaptations are varied, but the goals are the same: find food, find mates, escape predators. Modern lights are the monkey-wrench in their behaviors.
If you’re a prey species you want to hide to avoid being eaten. If you’re a predator you want to find food. Ground lights in the garden attract insects, that will attract toads for easy pickings. While a toad is hard enough to see in the day due to its earthy coloring, it can be more easily be picked off by a predator at night in the light.
Birds are calmed by darkness. They don’t sing or move; night is their invisible cloak to escape detection from most nocturnal predators. But lights make birds restless which attracts attention of night predators.
Insects also get sucked into the light. To find out how buggy your yard is, hang up a sheet and shine a light behind it. All kinds of things fly in. It’s how moth surveys are conducted. Moths should be finding food or a mate, not flying around mindlessly entranced by light.
Night pollution also can affect plant health as well. Lights in trees attract insects in higher concentrations that can overload the tree. Afterall, the birds who would being eating those insects by day, have shut down for the night.
Yes, it’s complicated. Life is a complex, interwoven system and too often we don’t understand how things can get out of whack, but they do. Wildlife can’t turn off the lights, but we can. We just need to give a FLAP. *https://flap.org/