It’s firefly season in the Blue Ridge, and the decline in the firefly population is more apparent than ever.

As the sun goes down, they begin to blink and glow along the water, in the trees, and across open fields. Some species twinkle in unison, others off and on. One of nature’s loveliest light shows enchants onlookers of all ages, especially in the Smoky Mountains, which is home to about 20 percent of the 100 or so species found in the United States.

But many of those who have long delighted in this essential feature of a humid East Coast summer say something feels different. Casual observers and scientists alike are seeing fewer fireflies, and studies show that habitat loss, rising temperatures, light pollution, and drought threaten these beloved bugs. Some populations are already dwindling, including about 18 species in the U.S. and Canada.

“We’ve been hearing anecdotal reports of fireflies’ population declining for years,” said Sarah Lower, a biologist at Bucknell University. “Every time I would go out and give a scientific talk somewhere, somebody would raise their hand and say, ‘You know, I’ve been out in my yard, and when I’m with a kid I remember there being fireflies everywhere, now I don’t see them.’”

Lower and Darin J. McNeil, a wildlife ecologist at the University of Kentucky, examined firefly population patterns last summer, using citizen science data collected nationwide to draw connections with environmental conditions. Though their observations don’t specifically confirm a decline, they suggest reasons we might be seeing fewer fireflies in some places.

Climate change is already reshaping the Southeast with hotter, drier summers — conditions that could push fireflies past their limits. In some wetter regions, though, they may find new habitat. McNeil said these changing patterns are impacting firefly populations already.

“They’re very, very sensitive to temperature and weather and things like that,” McNeil said, regarding the decline in the firefly population. “In Southern areas where we expect it to get quite warm — and maybe get outside the comfort zone of fireflies — we might expect the fireflies are going to do poorly.”

Read the full article about reversing the decline in the firefly population by Katie Myers at Grist.