Improved air quality saved the lives of 1.5 billion birds

A recent study conducted by researchers from Cornell University and the University of Oregon found a federal program designed to reduce ozone pollution has saved the lives of 1.5 billion birds over the past 40 years.

To better understand the relationship between bird life and air pollution, researchers used models that combined bird observations from the Cornell Lab of Ornithology’s eBird program with ground-level pollution data and existing US regulations.

The team of researchers focused on a regulation called the NOx (nitrogen oxide) Budget Trading Program, which was implemented by the US Environmental Protection Agency to protect human health by limiting summertime emissions of ozone precursors from large industrial sources.

The findings suggest that ozone pollution is most detrimental to the small migratory birds, including sparrows, warblers and finches. Ozone pollution directly harms birds by damaging their respiratory systems, and indirectly harms their food sources by damaging plant life that these birds rely on for survival.

‘Not only can ozone cause direct physical damage to birds, but it also can compromise plant health and reduce numbers of the insects that birds consume,’ said study co-author, Amanda Rodewald.

There is, however, good news at the end of this seemingly dark tunnel, as Rodewald explained – ‘birds that cannot access high-quality habitat or food resources are less likely to survive or reproduce successfully. The good news here is that environmental policies intended to protect human health return important benefits for birds too.’

This new study shows that without the regulations and ozone-reduction efforts of the Clean Air Act, the loss of birdlife may have been 1.5 billion birds more.

Co-author Catherine Kling said, ‘This is the first large-scale evidence that ozone is associated with declines in bird abundance in the United States, and that regulations intended to save human lives also bring significant conservation benefits to birds.’