Research

For 2 years, H. T. Harvey & Associates performed in-depth field research at the Montezuma Hills Wind Resource Area in central California. The goals of our research were to compare the effectiveness of techniques used to detect the nocturnal activities of migrating bats and birds and to understand the relationships between bird and bat activity patterns and mortality at two wind energy facilities. Focusing on the fall migration period, our team of experts monitored bird and bat nocturnal activity using marine radar, full-spectrum acoustic detection methods, and night-vision techniques; we coupled these efforts with intensive daily fatality surveys at 24 turbines at each facility.

Our research project evaluated the relative merits of the three nocturnal monitoring techniques for quantifying species composition and passage rates of night-migrating birds and bats. Our ecologists successfully modeled the relationships between observed fatality levels and bird and bat activity rates, weather variables, and habitat characteristics. This information improves the understanding of the numbers of migrant birds and bats in the airspace of the wind facility, and allows us to find correlations between fatalities with various factors like wind speed and direction or proximity to habitat elements. Using this information we have been able to improve the process of wind turbine siting and permitting throughout California.H.T. Harvey & Associates continues to conduct wind research projects at various facilities in the United States.

Here is a link to the report on the California Energy Commission website.