By Marca Leigh
Late summer evenings. Bats flitting through the air snapping up mosquitoes long after dragonflies have gone to sleep. Streetlights swarming with fluttering, fairy like moths, drawn to what they perceive is the moon. Blinking phosphorescent fireflies float across open stretches of grass, hoping to attract a mate.
An art photographer takes time lapse images of fireflies in upstate New York, and brings up the point that if these are the insects you CAN see in the dark, imagine how many more are out there you cannot. There is a whole world out there while we are dreaming. However, human activity is making it harder and harder for them to do their job. We can change that with just a few adjustments.
The majority of land birds migrate at night, and some birds communicate, sing and mate only in the wee hours. Listen at dusk for the mockingbird calling or the robin’s spring song. “Ornithologists estimate that five billion birds migrate in North America alone each fall!”
So much is going on that we are unaware of while we are sleeping (or working the late shift). Pollination, migration, communication, mating rituals. Nature has evolved for millennia relying on the night: The safe dark skies, cool air, using the moon as a guide.
But as humans chip away at the darkness in the form of bright outdoor lighting- AKA light pollution – our evening wildlife is dwindling in numbers. The crazy spinning moths we are used to seeing are actually confused, much as we would be if we went outside to find 10 moons in the sky! Light pollution negatively affects migrating birds that navigate by the moon, bats who eat pests like mosquitoes seek dim skies, and lightning bugs/fireflies need the dark so that their glowing abdomens may attract a mate.
Amphibians like frogs and toads also mate during the nighttime: “Glare from artificial lights can also impact wetland habitats that are home to amphibians such as frogs and toads, whose nighttime croaking is part of the breeding ritual. Artificial lights disrupt this nocturnal activity, interfering with reproduction and reducing populations.” Bright lighting draws baby sea turtles away from the ocean, leading to their demise, and even causes crickets to chirp during the day, disrupting their mating rituals.
It turns out that moths are excellent pollinators, and tend to some plants to which bees and butterflies are not drawn. A recent study found that nocturnal visits to plants was reduced by 62 percent in areas with artificial illumination compared to dark areas”
One of the benefits to humans is the beauty of night blooming flowers like the well known Moonflower, Evening Primrose and Four O’clocks , and moths like Saturniids, most notably the lovely Luna moth.
Another benefit to controlling light pollution is our own view of the night sky. As darkness fades away to the bright glow of cities, we are slowly stealing the stars from our own eyes. Some people have never even seen the Milky Way, and yet we are right beneath it. The darkness of our night skies is now measured by a “Bortle Scale”… we can find ours and others all over the world online here. Currently our area ranges from 5-8, with 1 being the naturally dark sky. https://astrobackyard.com/the-bortle-scale/
But what’s encouraging is that light pollution is reversible, and there are steps we can immediately take to lessen our impact while still finding our own way through the dark.
Downward facing outdoor lighting not only helps nature, but saves energy and therefore cost. Dimmer and warmer porch lighting and using motion detection security lights are another solution. The International Dark Sky association has multiple excellent resources for improving the way we light the outdoors.
They not only have a plethora of helpful information in regards to lighting, they also list places across the US and all over the world that are official “dark sky” places you can visit, and REALLY see the stars. Those currently closest to Connecticut are in Pennsylvania and Maine, but hopefully there will be more as the word spreads.
We can make requests of our municipalities and energy companies to implement these lighting practices. We can also encourage dimmer, warmer bulbs shining downward only for streetlights and signage, and replace floodlights with sensory detection bulbs for security areas. Lastly, we can make more of a detailed plan for natural areas that may not need lighting at all.
With all the interest in pollinators pathways these days, it makes sense that we also give the nocturnal shift a leg up by dimming our lights and allowing the evening sky to “shine”.
Sources:
https://www.nature.com/articles/s42003-022-03331-x
https://web.colby.edu/mainebirds/2011/11/09/nocturnal-migration/
https://abcbirds.org/blog20/nighttime-singers/
https://sciencing.com/parts-firefly-bug-8555263.html
https://www.darksky.org/light-pollution/wildlife/
https://www.sciencedaily.com/releases/2021/11/211102111005.htm
https://en.m.wikipedia.org/wiki/Saturniidae
https://www.darksky.org/light-is-energy-estimating-the-impact-of-light-pollution-on-climate-change/
https://www.darksky.org/our-work/conservation/idsp/finder/
https://www.darksky.org/get-involved/
https://www.scientificamerican.com/article/nocturnal-pollinators-go-dark-under-street-lamps/
This article gives a very poetic and “enlightening” story of all that is “out there” in the dark that most of us don’t even think about. Nighttime light pollution is an issue that we must become aware of and work to reduce. Thanks Marca Leigh for this beautifully written story of night life.