Park birds may have benefited from Clean Air Act

Park birds may have benefited from Clean Air Act

Frances Figart

By Frances Figart, Creative Services Director

Warblers like this Black-throated Green Warbler are at the highest risk of illness and death from ground-level ozone, which not only harms avian respiratory systems but also damages vegetation that they depend on for food and shelter. Photo courtesy of Warren Lynn.

It is likely that the work of land managers and scientists in Great Smoky Mountains National Park may have helped to preserve large numbers of species of birds. According to a paper published recently in the Proceedings of the National Academy of Sciences, since 1980, requirements set forth in the Clean Air act passed 50 years ago may be to thank for saving 1.5 billion birds across the globe that otherwise would have been lost.

“Our research shows that the benefits of environmental regulation have likely been underestimated,” said Ivan Rudik, a Cornell economist and one of the paper's lead authors. “Reducing pollution has positive impacts in unexpected places and provides an additional policy lever for conservation efforts.”

Great Smoky Mountains National Park may be one of those unexpected places. “The park is interested in trends in the populations: which species are increasing, which species are decreasing, and whether there are certain areas or habitats where many species are increasing or decreasing together,” said Paul E. Super, the Science Coordinator helping to facilitate research in the park.

Finches, warblers, and sparrows are at the highest risk of illness and death from ground-level ozone, which not only harms avian respiratory systems but also damages vegetation that they depend on for food and shelter. These species may have benefited from the Clean Air act’s ozone restrictions in many regions—including the Smokies.

“Ozone is considered a secondary pollutant,” said NPS Air Resource Specialist Jim Renfro, who works to reduce pollution and improve the Smokies air quality. “It’s not emitted directly by sources but formed by the reaction of sunlight on nitrogen oxides and volatile organic compounds.” 

Renfro says GSMNP has been monitoring ozone since the early 1980s. Five monitors throughout the park report data to the Environmental Protection Agency (EPA), which measures compliance with its public health standards in terms of meeting (attainment) or not meeting (non-attainment) any particular standard.

Great Smoky Mountains National Park has been monitoring ozone since the early 1980s. Five monitors like this one at Look Rock report data to the Environmental Protection Agency. Photo courtesy of NPS

“The park was designated ‘non-attainment’ for violating the 1997 ozone National Ambient Air Quality Standard,” he said. “The Tennessee-side of the park was part of the Knoxville non-attainment area; the North Carolina-side of the park—comprised of just the portions of Haywood and Swain Counties inside the park—was named ‘the Great Smoky Mountains National Park non-attainment area.’”

Though the park doesn’t have exact numbers of bird species lost or preserved, it gets some good information from annual volunteer counts such as the Breeding Bird Survey and the Christmas Bird Count. The park has also benefited from a number of bird surveys by independent researchers. “These retrospective studies—revisiting sites across a long period—will help us understand what is happening with our bird populations,” Super said.

Renfro says ozone levels have dropped 39 percent since the late 1990s due to reductions in nitrogen oxide emissions from power plants, motor vehicles, and industrial sources throughout the U.S. The entire park was finally designated in ‘attainment’ by the EPA in 2015 for meeting the current standard. But GSMNP’s ozone levels remain under scrutiny to ensure the park stays in compliance.   

As the world continues to face species decline, it becomes more and more critical for land managers and scientists alike to collaborate to understand the causes of wildlife loss and discover solutions.

Related Posts
  1. Bird Brain? Not so fast... By mid-March, birds like the Louisiana water thrush and the blue-headed vireo will be returning to the Great Smoky Mountains. They will have traveled hundreds of miles, mostly at night — perhaps across the Gulf of Mexico — from as far awa
  2. Smokies LIVE: Bringing the Smokies to You Smokies LIVE: Bringing the Smokies to You
  3. Welcome to Smokies LIVE Welcome to Smokies LIVE
  4. Video Feature: Nature Marches On Video Feature: Nature Marches On
Related Products