Aerial Insectivore Response to Acid Mine Drainage in Pennsylvania Streams

Acid Mine drainage (AMD) is the runoff of acidic water from metal or coal mines into aquatic ecosystems. Acid Mine Drainage increases stream acidification, metal concentrations, and sedimentation which can decrease food web complexity by negatively affecting insect and bird diversity. Stream acidification reduces acid-sensitive macroinvertebrate taxa that are important food sources to aerial insectivore birds foraging along riparian communities. Despite the known effects of acidification on stream biodiversity, little is known about the nest density of aerial insectivore birds foraging along riparian ecosystems impacted from AMD. This study quantified differences in water quality, nest density, and nest activity for all aerial insectivores nesting along ten sites that vary with respect to acid mine drainage in six creeks. The field water quality parameters that were taken were pH, temperature, depth, dissolved oxygen concentration, and conductivity using a sonde. Turbidity and Alkalinity were also measured from samples collected the same day. Nest density was recorded by taking under-bridge nest tallies, species of each nest, and recording whether the nest was active or not. Streams impacted from historical acid mine drainage were Catawissa Creek, Shamokin Creek, and Nescopeck Creek. Streams not impacted from AMD were Huntington Creek, Fishing Creek, and Roaring Creek. All data was collected between June 2018 until October 2018. Our data suggests AMD impacted sites had lower nesting densities and reduced number of active nests. Additionally, the water quality parameters recorded at sites impacted from AMD indicated reduced pH, alkalinity, dissolved oxygen concentration, and an increase in turbidity, and conductivity