Mortality of animals that fly into man-made structures has been studied for buildings, communication towers, and more recently, for large turbines that convert wind energy into electrical power (Johnson et al., 2000; Osborn et al., 1996). The development of wind energy at Buffalo Ridge, Lincoln and Pipestone Counties, Minnesota, was initiated in 1994. Three phases of development, identified by discrete locations, time of construction, and different developers, include phase II (P2; 143 turbines) and phase III (P3; 138 turbines). A state-ordered study of bird mortality at Buffalo Ridge (Johnson et al., 2000) incidentally found about three-fold more bats than birds in 1998 and 1999, but that monitoring project ended in 1999. Our purpose in this research was to extend the monitoring of P2 and P3 into 2000 using identical methods, and to analyze the data from all three years to test the following hypotheses:
H1: No difference exist among years in the species composition of bats killed.
H2: No differences exist among years in the relative mortality rate per turbine.
H3: No significant correlation exists between mortality rate and adjacent land-use type.
H4: Mortality is random with respect to time-of-year.
Herein we provide brief methods, results, interpretation, and all data collected (see Appendix 1). In addition to the final report, we have included a copy of our manuscript in preparation for submission to American Midland Naturalist. Because this manuscript is only a draft, we provide it to you as a courtesy and ask that it not be reproduced or published. As soon as they are available, you will be provided with a copy of the manuscript submitted for publication and a copy of the published version to be included into the final report on this grant. For a full introduction to the project and statement of hypotheses, see the attachement (Krenz et al. unpublished manuscript).