Resource Documents: Wildlife (226 items)
Documents presented here are not the product of nor are they necessarily endorsed by National Wind Watch. These resource documents are provided to assist anyone wishing to research the issue of industrial wind power and the impacts of its development. The information should be evaluated by each reader to come to their own conclusions about the many areas of debate.
Reducing bat fatalities at wind facilities while improving the economic efficiency of operational mitigation
Author: Martin, Colleen; Arnett, Edward; Stevens, Richard; and Wallace, Mark
Concerns about cumulative population-level effects of bat fatalities at wind facilities have led to mitigation strategies to reduce turbine-related bat mortality. Operational mitigation that limits operation may reduce fatalities but also limits energy production. We incorporated both temperature and wind speed into an operational mitigation design fine-tuned to conditions when bats are most active in order to improve economic efficiency of mitigation. We conducted a 2-year study at the Sheffield Wind Facility in Sheffield, Vermont. Activity of bats is highest when winds speeds are low (< 6.0 m/s) and, in our region, when temperatures are above 9.5°C. We tested for a reduction in bat mortality when cut-in speed at treatment turbines was raised from 4.0 to 6.0 m/s whenever nightly wind speeds were < 6.0 m/s and temperatures were > 9.5°C. Mortalities at fully operational turbines were 1.52–4.45 times higher than at treatment turbines. During late spring and early fall, when overnight temperatures generally fell below 9.5°C, incorporating temperature into the operational mitigation design decreased energy losses by 18%. Energy lost from implementation of our design was < 3% for the study season and approximately 1% for the entire year. We recommend that operational mitigation be implemented during high-risk periods to minimize bat fatalities and reduce the probability of long-term population-level effects on bats.
Colleen M. Martin
Richard D. Stevens
Mark C. Wallace
Department of Natural Resources Management, Texas Tech University, Lubbock
Edward B. Arnett
Theodore Roosevelt Conservation Partnership, Loveland, Colorado
Published: 10 March 2017
Journal of Mammalogy (2017) 98 (2): 378-385.
Download original document: “Reducing bat fatalities at wind facilities while improving the economic efficiency of operational mitigation”
Author: Graff, Brianna; et al.
ABSTRACT: The Northern Great Plains (NGP) contains much of the remaining temperate grasslands, an ecosystem that is one of the most converted and least protected in the world. Within the NGP, the Prairie Pothole Region (PPR) provides important habitat for >50% of North America’s breeding waterfowl and many species of shorebirds, waterbirds, and grassland songbirds. This region also has high wind energy potential, but the effects of wind energy developments on migratory and resident bird and bat populations in the NGP remains understudied. This is troubling considering >2,200 wind turbines are actively generating power in the region and numerous wind energy projects have been proposed for development in the future. Our objectives were to estimate avian and bat fatality rates for wind turbines situated in cropland- and grassland-dominated landscapes, document species at high risk to direct mortality, and assess the influence of habitat variables on waterfowl mortality at 2 wind farms in the NGP. From 10 March to 7 June 2013–2014, we completed 2,398 searches around turbines for carcasses at the Tatanka Wind Farm (TAWF) and the Edgeley-Kulm Wind Farm (EKWF) in South Dakota and North Dakota. During spring, we found 92 turbine-related mortalities comprising 33 species and documented a greater diversity of species (n = 30) killed at TAWF (predominately grassland) than at EKWF (n = 9; predominately agricultural fields). After accounting for detection rates, we estimated spring mortality of 1.86 (SE = 0.22) deaths/megawatt (MW) at TAWF and 2.55 (SE = 0.51) deaths/MW at EKWF. Waterfowl spring (Mar–Jun) fatality rates were 0.79 (SE = 0.11) and 0.91 (SE = 0.10) deaths/MW at TAWF and EKWF, respectively. Our results suggest that future wind facility siting decisions consider avoiding grassland habitats and locate turbines in preexisting fragmented and converted habitat outside of high densities of breeding waterfowl and major migration corridors.
BRIANNA J. GRAFF, JONATHAN A. JENKS, JOSHUA D. STAFFORD, KENT C. JENSEN, and TROY W. GROVENBURG
Department of Natural Resource Management, South Dakota State University, and South Dakota Cooperative Fish and Wildlife Research Unit, US Geological Survey, Brookings, SD, USA
The Journal of Wildlife Management 80(4):736–745; 2016; DOI: 10.1002/jwmg.1051
Download original document: “Assessing Spring Direct Mortality to Avifauna from Wind Energy Facilities in the Dakotas”
Author: Kolar, Patrick; and Bechard, Marc
ABSTRACT: Quantifying the rate of turbine collision mortality for raptors has been the primary focus of research at wind energy projects in Europe and the United States. Breeding adults and fledglings may be especially prone to collisions, but few studies have assessed the consequences of increased mortality and indirect effects from this type of development activity on reproduction. We examined the influence of wind turbines and other factors on nest success and survival of radio-marked juveniles during the post-fledging period for 3 sympatric breeding Buteo species in the Columbia Plateau Ecoregion (CPE), Oregon, USA. Nest success for ferruginous hawks (Buteo regalis) decreased as the number of wind turbines within the home range buffer (32 km²) increased. There was no effect of turbines on nest success for red-tailed hawks (Buteo jamaicensis) or Swainson’s hawks (Buteo swainsoni). Of 60 nestlings radio-marked from all 3 species, we found no evidence that any were killed as a result of collisions with wind turbines after fledging. This was likely due, in part, to the limited size of the natal home range and the relatively short duration of the post-fledging period. However, juveniles of all 3 species hatched from nests in areas of greater turbine density were more likely to die from predation or starvation just after fledging and prior to becoming independent compared to those in areas of lower turbine density. Taken together, these results suggest that wind turbines affected reproductive efforts by all 3 species to some degree, but these effects were greater for ferruginous hawks compared to the other 2 congeneric species. The causes of this negative association are unknown but likely represent some combination of breeding adults being killed from turbine collisions, disturbed from activities associated with the increasing wind energy development in the area, or displaced from portions of their home range to minimize the risk of disturbance or death. The potential for these effects necessitate that planning of future wind energy facilities be considered at larger geographic scales beyond the placement of individual turbines to limit development near raptor breeding areas.
PATRICK S. KOLAR and MARC J. BECHARD
Raptor Research Center, Department of Biological Science, Boise State University, Boise, ID
The Journal of Wildlife Management; DOI: 10.1002/jwmg.21125
Volume 80, Issue 7, September 2016, Pages 1242–1255
Download original document: “Wind Energy, Nest Success, and Post-Fledging Survival of Buteo Hawks”
Author: Pylant, Cortney; et al.
An unanticipated impact of wind-energy development has been large-scale mortality of insectivorous bats. In eastern North America, where mortality rates are among the highest in the world, the hoary bat (Lasiurus cinereus) and the eastern red bat (L. borealis) comprise the majority of turbine-associated bat mortality. Both species are migratory tree bats with widespread distributions; however, little is known regarding the geographic origins of bats killed at wind-energy facilities or the diversity and population structure of affected species. We addressed these unknowns by measuring stable hydrogen isotope ratios (δ²H) and conducting population genetic analyses of bats killed at wind-energy facilities in the central Appalachian Mountains (USA) to determine the summering origins, effective size, structure, and temporal stability of populations. Our results indicate that ~1% of hoary bat mortalities and ~57% of red bat mortalities derive from non-local sources, with no relationship between the proportion of non-local bats and sex, location of mortality, or month of mortality. Additionally, our data indicate that hoary bats in our sample consist of an unstructured population with a small effective size (Ne) and either a stable or declining history. Red bats also showed no evidence of population genetic structure, but in contrast to hoary bats, the diversity contained in our red bat samples is consistent with a much larger Ne, that reflects a demographic expansion after a bottleneck. These results suggest that the impacts of mortality associated with intensive wind-energy development may affect bat species dissimilarly, with red bats potentially better able to absorb sustained mortality than hoary bats because of their larger Ne. Our results provide important baseline data and also illustrate the utility of stable isotopes and population genetics for monitoring bat populations affected by wind-energy development.
Cortney L. Pylant, David M. Nelson, Matthew C. Fitzpatrick, J. Edward Gates, and Stephen R. Keller
University of Maryland Center for Environmental Science, Appalachian Laboratory, Frostburg, MD; Department of Biology, Frostburg State University, Frostburg, MD; and Department of Plant Biology, University of Vermont, Burlington, VT
Ecological Applications, Volume 26, Issue 5, July 2016, Pages 1381–1395
Download original document: “Geographic origins and population genetics of bats killed at wind-energy facilities”