A new study suggests that oil and gas drilling sites are more dangerous to bird populations than wind turbines.

Concerns about bird populations surrounding the location of wind turbines are reportedly unfounded according to research conducted by Erik Katovich, an economist at the University of Geneva.

Katovich determined through an analysis of available data that while wind power has increased dramatically throughout the U.S., bird populations near the wind turbine locations have not declined as previously feared.

To make this determination, Katovich reviewed Christmas Bird Count data, which is a citizen science project led by the National Audubon Society wherein volunteers count birds they spot during the Christmas holiday. Once counted, those numbers are then compiled with records going back for more than a century.

Looking at that data, Katovich surmised that if wind turbines actually harmed bird populations, their numbers would decrease, which they had not. Instead, no effect had been found on bird populations surrounding wind turbine locations.

Katovich then looked at bird population numbers around oil and gas extraction locations where bird populations decreased by a reported 15% — driven away primarily, the author suspects, by increased noise, air pollution and the disturbance of rivers and ponds that many birds rely upon in areas surrounding new oil and gas drilling.

The study, “Quantifying the Effects of Energy Infrastructure on Bird Populations and Biodiversity,” appears in the journal Environmental Science & Technology.