If visitors find locations in Utah’s National Parks, where very little man-made sounds are heard, it can be a breathtaking experience. A park visitor may canoe along riparian habitat and hear a variety of bird calls, or hike a trail and come around a bend to see a few deer jump over the sage-brush.

These types of experiences may also occur after dark when visitors participate in stargazing or a full-moon hike.

Mark and Sallie Shelton said, “Utah dark skies are our passion! The [dark] sky and quiet solitude are magical. Visitors, from around the world, are in awe when they get their first [heavenly] glimpse of [the Milky Way] and see the stars shining like diamonds on dark velvet.”

Protecting the quiet and darkness of our National Parks has become a priority for many managers and researchers.

Christopher Monz, professor in the Department of Environment and Society in the Quinney College of Natural Resource at USU joined with five other scientists who have all worked on issues of noise pollution and light pollution to compile the book, “Natural Quiet and Natural Darkness: The “New” Resources of the National Park.”

Monz explains, “[We wanted] to compile, in one place, the best science on both the social and ecological dimensions regarding the importance of the resources of darkness and quiet, and the consequences of them slowly disappearing in our most precious protected areas – the national parks.”

The book gathered many interesting findings.

One is the concept of “listening area” which is the distance an individual (human or animal) can hear normal sounds and calls that they’re evolved and adapted to. For a bird species, it might be a mating call, for deer, it might an alert response from a predator.

As noise increases the listening area may decrease dramatically.

Monz said, “In the United States noise from roads has increased threefold since 1970.”

A three-decibel increase in noise results in a 50 percent decrease in the listening area. If there is a 10 decibel increase, the result is a staggering 90 percent decrease in the listening area.

Monz explains, “If you put noise into the environment there is the potential for significant ecological implications, particularly for wildlife. They can no longer be reliant on the sense of hearing to carry out normal activities…some species will move out of those noisy areas to quieter environments which creates a displacement effect.”

For humans, this means we have less opportunities to engage with the sights and sounds of nature.

One success story outlined in the book occurred in Muir Woods National Monument in California. Monz said, “Simply by putting up signs which raised the visitor’s awareness of the environment they were in, and the importance of quiet for other visitors, the noise decreased by 2 decibels. This gave folks an opportunity to experience a better natural quiet environment and a little bit more biodiversity from the standpoint of hearing bird calls from the surrounding forest.”

The book also provides ideas for managing the resource of darkness in the National parks.

Monz said, “Right now 80% of the world’s population lives in locations where there is some compromise of natural darkness...most will never see the Milky Way.”

Cedar Breaks National Monument, which has the highest stargazing site at 10,500 feet, received an award from The International-Dark Sky Association (IDA) for preserving its Dark Skies.

The authors of “Natural Quiet and Natural Darkness” hope the book will get in the right hands to provide park managers with this easily accessible tool where they can find the best science and actionable ideas to increase quiet and darkness in our National Parks.