Resource Documents — latest additions
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.
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
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
Author: Voigt, Christian; Lindecke, Oliver; Schönborn, Sophia; Kramer-Schadt, Stephanie; and Lehmann, David
Abstract. The killing of large numbers of migratory bats at wind turbines is a pressing conservation problem. Even though avoidance and mitigation measures could benefit from a better knowledge of the species’ migratory habits, we lack basic information about what habitats and corridors bats use during migration. We studied the isotopic niche dimensions of three bat species that are frequently killed at wind turbines in Germany: non-migratory Pipistrellus pipistrellus, mid-distance migratory Nyctalus noctula, and long-distance migratory Pipistrellus nathusii. We measured stable carbon and nitrogen isotope ratios (δ¹³C, δ¹⁵N) in five tissues that differed in isotopic retention time (fur, wing membrane tissue, muscle, liver, blood) to shed light on the species-specific habitat use during the autumn migration period using standard ellipse areas (SEAc). Further, we used stable isotope ratios of non-exchangeable hydrogen (δ²HK) in fur keratin to assess the breeding origin of bats. We inferred from isotopic composition (δ¹³C, δ¹⁵N) of fur keratin that isotopic niche dimensions of P. nathusii was distinct from that of N. noctula and P. pipistrellus, probably because P. nathusii was using more aquatic habitats than the other two species. Isoscape origin models supported that traveled distances before dying at wind turbines was largest for P. nathusii, intermediate for N. noctula, and shortest for P. pipistrellus. Isotopic niche dimensions calculated for each sample type separately reflected the species’ migratory behavior. Pipistrellus pipistrellus and N. noctula showed similar isotopic niche breadth across all tissue types, whereas SEAc values of P. nathusii increased in tissues with slow turnaround time. Isotopic data suggested that P. nathusii consistently used aquatic habitats throughout the autumn period, whereas N. noctula showed a stronger association with terrestrial habitats during autumn compared to the pre-migration period.
Christian C. Voigt, Oliver Lindecke, Sophia Schönborn, Stephanie Kramer-Schadt, and David Lehmann
Evolutionary Ecology Research Group, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany; and Central Repository for Natural Science Collections, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
Ecological Applications, 26(3), 2016, pp. 771–783
Author: Zimmerling, Ryan; and Francis, Charles
ABSTRACT: Wind turbines have been hypothesized to affect bat populations; however, no comprehensive analysis of bat mortality from the operation of wind turbines in Canada has been conducted. We used data from carcass searches for 64 wind farms, incorporating correction factors for scavenger removal, searcher efficiency, and carcasses that fell beyond the area searched to estimate bat collision mortality associated with wind turbines in Canada. On average, 15.5 ± 3.8 (95% CI) bats were killed per turbine per year at these sites (range = 0–103 bats/turbine/yr at individual wind farms). Based on 4,019 installed turbines (the no. installed in Canada by Dec 2013), an estimated 47,400 bats (95% CI = 32,100–62,700) are killed by wind turbines each year in Canada. Installed wind capacity is growing rapidly in Canada, and is predicted to increase approximately 3.5-fold over the next 15 years, which could lead to direct mortality of approximately 166,000 bats/year. Long-distance migratory bat species (e.g., hoary bat [Lasiurus cinereus], silver-haired bat [Lasionycteris noctivagans], eastern red bat [Lasiurus borealis]) accounted for 73% of all mortalities. These species are subject to additional mortality risks when they migrate into the United States. The little brown myotis (Myotis lucifugus), which was listed as Endangered in 2014 under the Species At Risk Act (SARA), accounted for 13% of all mortalities from wind turbines, with most of the mortality (87%) occurring in Ontario. Population-level impacts may become an issue for some bat species as numbers of turbines increase.
J. RYAN ZIMMERLING, Environment and Climate Change Canada, Canadian Wildlife Service, Gatineau, QC, Canada
CHARLES M. FRANCIS, Environment and Climate Change Canada, Canadian Wildlife Service, Ottawa, ON, Canada
The Journal of Wildlife Management; DOI: 10.1002/jwmg.21128
Volume 80, Issue 8, November 2016, Pages 1360–1369