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Publication Number: CEC-500-2008-037
Abstract:
Automated echolocation detectors were evaluated as a means of assessing patterns of bat activity at wind energy developments. The project was conducted at the Dillon Wind proposed wind energy development site in North Palm Springs, California. Echolocation detectors were attached at 2, 22, and 52 meters above ground on four meteorological towers to measure bat activity from October 25 to December 5, 2007. Bat activity during the sampling period was low, with a total of 61 detections resulting from 340 detector-nights of survey effort. Measured air temperature, wind speed, and wind direction were used in a modeling context to explain observed bat activity. Higher air temperatures and, to a lesser extent, lower wind speeds were important predictors of bat activity. Use of four meteorological towers produced precise estimates of mean bat activity at each of the three heights. Fewer towers would have resulted in relatively imprecise estimates, while more towers would not have appreciably improved precision during the sampling period. Additional towers have been installed, and concurrent echolocation and meteorological data collection will continue on-site until October 2008, which will allow bat activity-and the survey effort necessary to estimate it precisely-to be characterized throughout the year. In 2008, echolocation monitoring is being linked to fatality monitoring. Keywords: Bats, bat detectors, echolocation, fall bat activity , meteorological conditions, wind turbine preconstruction, bat mortality risk assessment, Riverside County, San Gorgonio Pass Wind Resource Area, survey effort, winter bat activity
Author(s): Ted Weller Commission Division: Technology Systems Division - R&D, PIER (500)
Office/Program: PIER: Public Interest Energy Research
PIER Program Area: Avian-Energy Mitigation Program
Date Published: September 2008
Date On Line:
09/09/2008
Acrobat PDF File Size: 40 pages,
1,000 kilobytes**
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