Assessing the Influence of Landscape Characteristics on Bat Fatalities at South Texas Wind Energy Facilities
Date
2022-12
Authors
Kimes, Houston
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Abstract
Although wind energy is a viable renewable energy source, strikes by wind turbine blades unintentionally cause bat fatalities. Previous research has suggested siting of wind energy facilities, and turbine placement within facilities, influence the number of bat fatalities; however, there is a knowledge gap regarding the reasons for the variability. This study occurred in Texas, the leading producer of wind energy and home to the greatest diversity and largest colonies of bats in the United States. The objective of my thesis was to assess the influence of landscape characteristics surrounding wind energy facilities and around specific turbines on the number of bat fatalities. I systematically searched 200 wind turbines and collected 1,067 bat carcasses at Hidalgo and Los Vientos Wind Energy Facilities from 2017–2018; I found Tadarida brasiliensis (n = 577), Lasiurus intermedius (n = 203), L. ega (n = 69), Nycticeius humeralis (n = 51), L. xanthinus (n = 30), L. cinereus (n = 18), L. blossevilli (n = 2) Myotis velifer (n = 2), Nyctinomops macrotis (n = 1), Perimyotis subflavus (n = 1), and unknown spp. (n = 113). I used Fragstats and ArcGIS Pro to acquire landscape metrics at the two facilities and among the 100 wind turbines at each facility at multiple scales (100 m, 500 m, 1 km, 5 km, and 25 km). Landscape characteristics included landcover types such as barren, crops, herbaceous, developed, shrub/scrub, hay/pasture, forest, wetlands, and open water, proximity to water sources, elevation and degree of slope. Using generalized linear models, zero-inflated and negative binomial models, and AIC model selection, results indicate that landscape characteristics at the broadest scale (5 km and 25 km) examined were most strongly associated with estimated bat fatality rates. I suggest wind farms should be constructed in areas that consist of uniform and connected habitat throughout the facility, without the presence of fragmented water sources. Managers should also implement mitigation efforts and pre/post-construction assessments to potentially reduce bat fatalities.
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Keywords
bats, wind, wind energy, landscape, GIS
Citation
Kimes, H. L. (2022). Assessing the influence of landscape characteristics on bat fatalities at South Texas wind energy facilities (Unpublished thesis). Texas State University, San Marcos, Texas.