Adeline Murthy was out in the foothills of the Sangre de Cristo Mountains identifying frogs when she spotted a single glowing firefly floating by.
“My first reaction was like, ‘Oh look a firefly, how pretty,’ ” Murthy, Santa Fe County’s Open Space and Trails senior planner, said in a phone interview.
It wasn’t until her colleague Peggy Darr, who was out with her that night, told her that fireflies are a rare sight in New Mexico that Murthy realized she had stumbled upon something special.
These small glowing creatures have taken up residence at the Los Potreros Open Space — which serves as the backdrop for El Santuario de Chimayó.
They are a part of a newly discovered species that has not been scientifically named but is unofficially called the “Rio Grande flasher.” These luminescent insects have only been documented in a few places in New Mexico, primarily around the titular river.
Immediately after their discovery, Darr and Murthy rushed to report the sighting to the Western Firefly Project, which tracks firefly sightings in New Mexico, Utah, Wyoming, Idaho, Nevada and Colorado.
They were put in contact with Anna Walker, a firefly expert from the New Mexico Biopark Society.
“It was so exciting to see this happen because most of the time we hear about declines in fireflies and, you know, habitat destruction,” Walker said.
Darr and Murthy presented their discovery and the work that made it possible to the Santa Fe County Commission on July 26.
“It’s very exciting to have a brand-new species of fireflies,” said
District 2 Commissioner Anna Hansen. “I’ve never actually seen a firefly in New Mexico, so I’m thrilled.”
Walker said there are historical documents that show fireflies were present in New Mexico about
100 year ago, but it is unclear if this is the same species that has been spotted recently. She said that roughly two years ago, reports of fireflies being spotted in the state started coming in to the Western Firefly Project, allowing scientists to identify the insects.
Firefly experts say they made their appearance thanks to the county’s conservation efforts, which involved removing cattle from the area and the protection of its beaver population.
These unsuspecting rodents dramatically improved the area’s ecosystem and created a natural habitat for the fireflies, which need a permanent source of standing water to raise their larvae.
“Fireflies do require a pretty healthy habitat,” Walker said. “Without the beavers, this never would have happened. That just goes to show that’s a really great freshwater habitat now, and if the fireflies are showing up, there’s probably a host of other organisms that are also starting to utilize that space.”
While conservation experts say beavers are a vital part of the ecosystem in most of the U.S., some residents see them as a nuisance as their dams block acequias and irrigation canals.
Murthy said that is why the county has worked to help residents understand the importance of beavers and coexist with them.
“Beavers have a controversial presence,” Darr said. “So we did host two on-site public meetings to hear residents’ concerns about beavers and also to talk to them about the many positive things they can bring.”
Darr said beavers can help lower fire risks, keep rivers flowing year-round, keep the water clean, prevent flash flooding and create a habitat for native species like fireflies.
The county also installed fences around large trees to prevent beavers from cutting them down, put in devices that prevent them from building dams in acequia headgates and put up barriers that help prevent them from flooding roads or homes.
Removing cattle from the open space was also essential to making the habitat suitable for fireflies to thrive in.
Though there haven’t been many studies on the matter, Walker said most firefly experts agree that cattle and fireflies can’t seem to coexist.
She theorized this might be because cattle eat vital vegetation, pollute the water with their waste and compact the soil where fireflies would normally lay dormant throughout the year.
“For many years, cattle were getting into the Los Potreros wetland and were overgrazing,” Darr said during a County Commission meeting.
She said the county worked with the Rocky Mountain Youth Corps to set up wildlife-friendly fencing and has been able to keep cattle out of the open space for the last two years.
Before then, ranchers allowed their cattle to graze in the open space, even after Santa Fe County purchased the property in the early 2000s.
The Los Potreros Open Space is closed to the public. Although going out to get a glimpse of these fireflies may be enticing, Darr advised the public to stay away and not disturb their habitat.
“If we can conserve them now, and grow the population (from the handful of individuals we have found thus far), the County may offer community tours to see them in the future,” Darr said in an email.
If residents spot fireflies outside Los Potreros, they are encouraged report the sighting to the Western Firefly Project.