Montezuma Hills Wind Resource Area Bird and Bat Monitoring Research

Project Summary

For two years, Integral staff performed in-depth field research at the Montezuma Hills Wind Resource Area to compare monitoring techniques for nocturnal bird and bat activity and understand relationships between activity patterns and mortality at two wind energy facilities.

Location: Central California

Challenge

Wind facility operators needed a clearer understanding of how bird and bat activity patterns related to turbine mortality in order to improve siting and permitting decisions, which required reliable quantification of nocturnal activity during the fall migration period and a comparative evaluation of multiple monitoring techniques.

Our Role

Integral staff monitored bird and bat nocturnal activity using marine radar, full-spectrum acoustic detection methods, and night-vision techniques, coupled with intensive daily fatality surveys at 24 turbines at each facility. The team evaluated the relative merits of the three monitoring techniques for quantifying species composition and passage rates, and modeled relationships between observed fatality levels and bird and bat activity rates, weather variables, and habitat characteristics.

What We Delivered & Results

The research findings have improved understanding of migrant bird and bat numbers in wind facility airspace and identified correlations between fatalities and factors like wind speed, direction, and proximity to habitat elements, informing wind turbine siting and permitting throughout California. Integral staff continue wind research at various facilities nationwide, with findings published in a report available on the California Energy Commission website.