Ozone pollution threatens bird populations to collapse: an imminent ecological threat?

While bird populations are declining, the factors associated with this decline are unclear. Based on laboratory experiments, air pollution has long been recognized as a factor causing oxidative stress and adversely affecting bird health. Recently, studies employing an epidemiological approach have reported significant declines in avian populations in Central Europe and the United States due to air pollution, and ozone in particular. We advocate that urgent actions are needed to mitigate these effects, which threaten biodiversity and environmental health, and propose a series of measures which can enlighten the path toward mitigating air pollution effects on avian populations.