Protecting the dark skies across Central Texas

Editor's Note: This is Part One in a series looking at conservation measures for land and water resources in Hays County.

The Texas Hill Country Conservation Network created what it calls The Hill Country Land, Water, Sky and Natural Infrastructure Plan with the input of thousands of Texans — from experts to concerned residents. The purpose of the plan is to steward natural resources and expand opportunities for connecting to nature for those in all socioeconomic groups. The THCCN website stated the Texas Hill Country is composed of 18 Central Texas counties and 11 million acres and that the booming population growth paired with rapid development, the overuse of groundwater and changing climate patterns are impacting natural resources.

This conservation series is meant to complement the THCCNs Natural Infrastructure Plan by es-nected and are all part of the region’s natural infrastructure.

Cindy Luongo Cassidy — a leader within the International Dark Sky Association Texas Chapter, a founding member of the Hill Country Alliance Night Sky Team and president of the board for the Hays County Friends of the Night Sky — said artificial light at night can impact plants, animals and humans by disrupting reproduction, competition, immune system response and pollination.

Cassidy said most people tend to focus on land and water conservation. She personally had a hand in convincing the THCCN to add the dark sky conservation portion to the infrastructure plan.

“We made them understand that, in order to protect the land, and in order to protect the water, you have to protect the living things that are there—not just animals but the plants as well,” Cassidy said. “Almost every living thing on this planet needs natural light during the day and natural darkness at night.”

Hill Country Alliance Executive Director Katherine Romans said the Hill Country is becoming known for its dark skies and the ability to see the stars at night.

“The Hill Country has 12 designated dark sky places with 14 friends of the night sky groups. Those are volunteer-led groups that are based in counties around the region,” Romans said.

Louis Parks, vice chair of the Wimberley Valley Dark Sky Committee, said people need to be able to see the stars to understand the beauty of the night as well as nature and the world around them.

“The vast majority of the people — including kids — of Earth cannot see the Milky Way,” Parks said. “Most kids grow up and sometimes go through their whole life never really seeing the night sky ... and the kids we can at least try to help are right here in the Wimberley Valley, and in Hays County and in the Texas Hill Country.”

Hill Country Conservancy Director of Science and Stewardship Rachael Lindsey said dark sky conservation is a simple con-Saturday struct — one that, if mastered, has the ability to end light pollution overnight with minimal effort.

You can address light pollution “just by shielding lights, flipping switches, turning them off. Unlike most environmental challenges which take more detailed infrastructure investment to address,” Lindsey said.

According to the International Dark Sky Association website, there are five principles for responsible outdoor lighting.

Every light should have a clear purpose.

The beam should point directly at where it’s needed.

Light should be no brighter than necessary.

Light should only be used when needed — dimmed if possible and turned off when not in use.

Warm colored lighting should be used when possible.

“When you do these things you can see better, and when you see better you’re safer. You reduce the impact of those artificial lights on all living things — people, animals, plants — [and] you save money,” Cassidy said.

Cassidy said there are many animals that use the stars for navigation, including turtles and dung beetles. She added that animals are unbothered by the natural night lights like the moon and stars; the problem is man-made lights and sky glow.

According to the International Dark Sky Association, sky glow is the brightness of the night sky in a built-up area as a result of light pollution.

Cassidy said man-made light and sky glow can cause reproductive issues with both plants and animals. Similarly, pollination can be negatively impacted by artificial light.

“There are actually more pollinators at night than during the daytime,” Cassidy said. “So, flowering is controlled by what we call photoperiodism. It’s based on how dark it is ... or how light it is. They bloom in the dark, so with artificial light in an environment, night blooming plants that need that darkness to perform have decreased flowering. Their nocturnal pollinators have decreased food sources, and you get this downward spiral that’s to the detriment of both the plants and the pollina"

Cassidy added that moths are the primary nighttime pollinators and their abundance and diversity are significantly reduced by the presence of artificial light. She said studies have shown that at artificially lit sites, a smaller percentage of moths carry pollen than at dark or naturally lit sites.

“They don’t pick up as much pollen, and there aren’t as many of them,” Cassidy said.

Cassidy gave an example of mating in frogs. She said, at night, frogs croak to attract a mate, but when synthetic light is added to the equation, they stop.

“We’re squeezing their reproductive time into a few hours in the middle of the night,” Cassidy said.

Cassidy said a highly publicized issue with light pollution is the impact it has on mating fireflies. She said there are over 150 species of fireflies in North America alone, all with a specific way of blinking. They will only mate with those with the same blink.

“If there’s too much artificial light around, they can’t see each other to find each other to reproduce. That’s one of the big reasons for the demise of fireflies right now,” Cassidy said.

Cassidy said artificial light also negatively impacts competition in insects because they are drawn to the light the entire time it is on.

“They were not out competing for food. They were not out competing for mates. They were not out competing for a better place to raise their babies. They, in fact, often die there,” Cassidy said.

Cassidy said artificial light also causes circadian rhythm issues.

She said, in humans, the presence of manmade light causes the production of melatonin to cease. This is the chemical that assists with sleep and the rebuilding of the immune system. Cassidy noted there are quite a few birds that reduce their metabolic rate at night, and their bodies need that time for rest and rebuilding.

She said doves reduce their metabolic rate at night by about 25%, and sparrows by 50%. According to Cassidy, humans and their artificial light are impacting their ability to ward off illness and disease.

In addition to a daily rhythm, there is also a yearly rhythm. Cassidy pointed out that at certain times of the year, deer lose their antlers, plants bloom, bees pollinate plants and trees lose their leaves.

“All of these things are dependent on the amount of light you have in that area each day and the number of minutes of darkness that you have each day, so we get all of these things out of whack,” Cassidy said.

Hays County Friends of the Night Sky Board Member Soll Sussman said there is a new local program geared at dark sky conservation that was recently installed at the Freeman Ranch in town.

“We have just started the Sky Quality Meter project and hope to have a network of stations around the county feeding readings in town [that will be uploaded to] our own yet-to-be-developed Hays County dashboard that also will feed into the Globe at Night international monitoring of sky glow and light pollution around the world, a fantastic Citizen Science project,” Sussman stated.

According to Sussman, the program was developed by Texas State University graduate Amy Jackson, and is the first to be installed from this project — with more to be expected. He said the project is in its initial stages, so there are no public readings at this time.

Dripping Springs and Wimberley Valley are already certified International Dark Sky Places. Sussman said he hopes that, in the future, the entire county will have an increased knowledge of how to use outdoor lighting responsibly to reduce light pollution.

Cassidy became an outside consultant for Dripping Springs in the mid 2000s to assist in inspections for outdoor lighting based upon an outdoor lighting ordinance established by the city.

“In doing so, I found that there were things that still the general public did not quite understand, so I did a lot of research on ordinances all over the country, and I wrote a suggestive ordinance for [Dripping Springs],” Cassidy said. “That ordinance has been copied over and over throughout the state.”

Cassidy said Hays County Friends of the Night Sky is encouraging everyone to be aware of and participate in Lights Out Texas which protects migrating birds from light pollution. The program, which was originally started in Canada, has already been enacted in Dripping Springs.

Lights Out Hays County is part of the Lights Out Texas program which is a statewide initiative that aims to raise awareness of the risk light pollution poses to birds.

Businesses, residents, and governments are asked to turn off nonessential lights at night during bird migration from 11 p.m. to 6 a.m. in the migration periods of March 1 to June 15 and Aug. 15 to Nov. 30 each year.

Learn more about the program at txnsf.org/ lights-out-hays.