Analysis of Surveys to Predict Eagle Interactions with Wind Energy Facilities

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To minimize golden eagle fatalities in areas proposed for wind development, point count surveys are usually conducted to estimate bird use.

However, it is not clear how accurately data collected during surveys reflect actual use footprint by eagles. Boise State University, U.S. Fish and Wildlife Service, and USGS researchers examined high-intensity GPS telemetry data collected from individual eagles in California and compared results of hypothetical point counts to the amount of time eagles actually spent in hypothetical project areas. Sampling error was influenced by a combination of the project footprint size and the sampling type (random, systematic, or stratified); however, random sampling decreased error on both larger and smaller plots. Sampling intensity and sampling frequency both influenced the effectiveness of point count sampling. Although this work focuses on individual eagles and not eagle populations, analyses show both the utility of simulations to identify influences on error and potential improvements to point count sampling.

Sur, M., Belthoff, J.R., Bjerre, E.R., Millsap, B.A., Katzner, T.E., 2018, The utility of point count surveys to predict wildlife interactions with wind energy facilities- An example focused on golden eagles: Ecological Indicators, v. 88, p. 126-133, https://doi.org/10.1016/j.ecolind.2018.01.024.