Grantee Research Project Results
Biological Impacts of Green Energy Development: Assessing Regional Sources of Bat Mortality at Wind Turbine Sites Using Stable Isotopes and Population GeneticsEPA Grant Number: FP917494
Title: Biological Impacts of Green Energy Development: Assessing Regional Sources of Bat Mortality at Wind Turbine Sites Using Stable Isotopes and Population Genetics
Investigators: Pylant, Cortney L
Institution: Frostburg State University
EPA Project Officer: Just, Theodore J.
Project Period: August 29, 2012 through August 28, 2014
Project Amount: $84,000
RFA: STAR Graduate Fellowships (2012)
Research Category: Academic Fellowships , Fellowship - Biological Sciences
Mortality of migratory tree bats has been an unanticipated impact of wind energy development. To date, virtually nothing is known about the population genetics of bat species impacted by wind turbine mortality, nor is it clear where these bats originate. The proposed research helps to address these unknowns for the hoary bat (L. cinereus), one of the most common fatalities at wind energy facilities in the eastern United States, by establishing baseline data on how large and diverse populations are; quantifying whether current rates of wind turbine mortality are associated with reductions in genetic diversity; and revealing whether bats are being killed locally or while on migration.Approach:
Fur and tissue samples will be collected from bats killed at wind energy facilities in central Appalachia during both spring and fall migration. Genetic analysis of tissue samples will be conducted to determine the effective population size and temporal stability of bat populations experiencing mortality. Stable hydrogen isotope analysis will be performed on fur samples to determine whether the bats killed are from local bat populations or those across a broad geographic extent. Combining datasets will allow increased confidence in the determination of population genetic structure and refinement of geographic assignment and will provide information crucial to determining the cumulative biological impact of wind turbines on migratory bats in central Appalachia.Expected Results:
The migratory patterns of hoary bats seem to suggest two general populations in North America. Based on genetic research of bats with similar life histories, it is expected that hoary bats will exhibit subpopulation structure rather than a single large breeding population. During the fall migration, some hoary bats appear to funnel southward along the east coast, potentially establishing the central Appalachians as an important migration corridor. In light of what is known regarding hoary bat migration, it is expected that the majority of hair samples from bats killed at wind energy facilities in the central Appalachians will exhibit stable hydrogen isotope values indicative of summering grounds primarily in the eastern regions of the United States and Canada. Because some degree of uncertainty is inherent in geographic assignment based on stable isotope values, evidence of subpopulation structure may be used to constrain assignments and refine models.
Potential to Further Environmental/Human Health Protection
As the primary predators of night-flying insects, bats are vitally important in controlling insect-related crop damage and preventing the spread of insect-borne plant and human pathogens. Predation of agricultural pests by bats in the United States alone prevents more than $3.7 billion of crop damage per year, thereby reducing pesticide application and its effects on public and environmental health. The information gained from this research will inform how best to design and site wind farms such that they promote ecological sustainability with minimal negative impacts on local natural resources.Supplemental Keywords:
population genetics, stable hydrogen isotopes, wind energy