This report presents the results of radar studies of fall nocturnal bird and bat migration conducted from 7 September - 15 October 2007 at the proposed Hatchet Ridge Wind Project, located in Shasta County, California. Each night we sampled at two stations (North and Saddle) within the proposed development area.
The primary goal of this study was to collect information on the nocturnal migration characteristics of birds and bats (i.e., targets) during the peak of passerine migration during fall. Specifically, the objectives of this study were to: (1) collect baseline information on migration characteristics (i.e., flight direction, migration passage rates, flight altitudes) of nocturnally migrating targets; and (2) estimate the number of targets that would pass within the rotor-swept area of the proposed wind turbines during the migratory season. We also evaluated the influence of weather and date on migration passage rates and flight altitudes.