Light pollution is putting a real damper on the mating rituals of fireflies, a problem that majorly hurts their populations.
Just like light pollution affects our ability to see stars in the night sky, it also impacts a female firefly’s ability to see a potential mate.
In order to mate, male fireflies fly around and light their lanterns to attract the attention of a female on the ground. The female will light up if she wants to mate with a particular male.
“This is the precursor to meetings,” Avalon Owens, a research fellow at Harvard, told CBS News. “So they’re not going to mate unless they’ve had this little dance where they’ve exchanged these light signals.”
When male fireflies are putting on a show by street lights and other sources of light, the females might not be able to see the males because that fantastic light show is drowned out.
In a recent study, about half of firefly couples successfully mated in natural conditions, while not a single pair mated under bright lights.
Why light pollution’s effect on fireflies is concerning
Currently, in the U.S. and Canada, there are 18 species of fireflies that are designated as threatened, which means they’re at risk of becoming extinct within the next 10 years or so. On top of that, researchers believe that nearly one-third of the 170 firefly species in North America are threatened, but they don’t yet have enough data to know that for certain.
Some species of fireflies are in particular danger of extinction, like those in the American Southwest, and are being negatively affected by the decadeslong drought caused by the warming of the planet.
“I like people to think of firefly extinctions as sitting in a room of candles, and it’s beautiful,” Tufts University biology professor Sara Lewis told CBS. “And if one of those candles gets extinguished, you probably don’t even notice it, but if that continues, eventually, you are left sitting in complete darkness.”
What can I do to help the firefly population?
One thing you can do is limit light pollution by closing curtains at night and buying motion-activated porch lights.
Fireflies live underground as larvae for as much as two years before turning into the flying insects we know and love. They feed on worms and slugs that feed in more natural environments.
You can also avoid using chemicals on your lawn. You can also help by letting your lawn grow a little. Leave some leaves on the ground that the larvae can live under or let that lawn grow more than you normally would.
“It’s just keeping this a little unkempt for them,” Candace Fallon, a senior conservation biologist at the Xerces Society, an insect conservation group, told CBS. “So whether that’s not mowing a certain section or mowing infrequently. Maintaining native grass and tree cover and shrubs.”
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