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Appendix C Methods and Metrics for Wildlife Studies
Pages 279-348

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From page 279...
... appendix C Methods and Metrics for Wildlife Studies A wide range of methods are available for assessing the ecological influences of wind-energy and aspects of the ecology and behavior of species that may be affected by wind-energy facilities; most of them are reviewed here. For additional information on methods readers are referred to syntheses presented in Anderson et al.
From page 280...
... 280 APPENDIX C conducted scavenger-removal experiments to correct estimates for potential biases. Study Design The most important element in designing a study is deciding on the study objective.
From page 281...
... 281 APPENDIX C characteristics of study sites may change in longer-term studies, and thus matching may be unreliable. When data are lacking before an impact, the control-impact design may be used.
From page 282...
... 282 APPENDIX C events at one or more points in space or time with space and time being the only experimental variable or treatment (Morrison et al.
From page 283...
... 283 APPENDIX C TABLE C-1 Study-Design Decision Matrix for Observational Studies Design Options Potential Recommended Study Design Study Conditions Design Conditions Modification Pre-impact data possible BACI Matching of Matched Reference area indicated BACI study sites on pair, design assessment with BACI and reference areas possible Pre-impact data not possible Impact-reference Matching of Matched Reference area indicated Impact-reference study sites on pair, design assessment with impact and reference reference areas possible Pre-impact data possible Before-after Reference area not indicated Impact-gradienta Small homogenous area of potential impact Sampling Plan Options Sampling Plan Recommended Use Haphazard/judgment sampling Preliminary reconnaissance Probability-based sampling: Simple random sampling Homogenous area with respect to impact indicators and covariates Stratified random sampling Strata well defined and relatively permanent, and study of short duration Systematic sampling Heterogeneous area with respect to impact indicators and covariates, and study of long duration Parameters to Measure Parameter Empirical Description Abundance/relative use Use per unit area and/or per unit time as an indexb Mortality Carcasses per unit area and/or per unit time Reproduction Young per breeding pair of adults Habitat use Use as a function of availability Covariates Vegetation, topography, structure, distance, species, weather, season, etc. aImpact-gradient design can be used in conjunction with BACI, impact reference, and before after designs.
From page 284...
... 284 APPENDIX C studies often estimate animal use as a surrogate for abundance. Animal use can be estimated by a variety of methods such as counting the animals detected from a given set of observation points, the amount of time spent by individual animals within a survey plot, the number of animals seen moving past a particular point, the number of targets passing through a radar beam, the number of targets within altitude bands, the number of nests present in a given area, the number of animals trapped or netted, the number of calls detected, or the amount of sign (e.g., tracks or scat)
From page 285...
... 28 APPENDIX C vacant territories, suggesting a relatively healthy population. Nevertheless, the relatively high fatalities attributable to the wind-energy facilities resulted in a population without sufficient floaters to ensure stability, making the population susceptible to future declines should fatalities increase for any reason.
From page 286...
... 286 APPENDIX C TABLE C-2 Remote-Sensing Tools for Detecting, Tracking, and Quantifying Flying Birds, Bats, and Insects Identificationa Equipment Range + Bird bats vs. insects Small marine radar 30 m-6 km with proper siting of unit – Birds vs.
From page 287...
... 28 APPENDIX C Passage Rates Height Information Cost Good to excellent Unmodified marine Specialized, expensive if done radar antenna in vertical correctly surveillance: yes Parabolic antenna: yes Good in the infrequent Very coarse with poor low Data are cheap; skilled labor cases where a radar siting altitude coverage for analysis happens to be opportune Excellent when altitude of Coarse when calibrated Expensive if high-quality target is known with vertically pointing equipment used radar and then used alone Yes Same as last Rather expensive if high quality equipment used Yes but light may affect Same as last Inexpensive but labor-intensive flying animals 2 days before and 2 days Very crude A good telescope of at after full moon and with no least 20× is required; cloud cover labor-intensive Poor Crude High Only some species call Microphones: Recording equipment and quantification is Single: no inexpensive, analysis expensive assumption-ridden Arrays: possible No, only presence/absence; Some; depends on Moderate costs too many unknowns at microphones and placement present state of knowledge ties, including both remote sensing (including passive acoustic recording, ultrasonic bat detectors, radar, moon-watching, ceilometer, reflectance infrared imaging, thermal infrared imaging, and radiotelemetry) and capture approaches are presented later in this appendix.
From page 288...
... 288 APPENDIX C Estimating Abundance Using Molecular Markers Estimates of population size, population structure, genetic diversity, and effective population size are important parameters for assessing life histories of natural populations and for managing endangered and threatened species at risk (Dinsmore and Johnson 2005; Lancia et al.
From page 289...
... 28 APPENDIX C For example, using this approach, Puechmaille and Petit (2007) compared estimates of colony sizes of the lesser horseshoe bat (Rhinolophus hipposideros)
From page 290...
... 20 APPENDIX C modern population sizes of 10,000 and 56,000 individuals (Roman and Palumbi 2003)
From page 291...
... 21 APPENDIX C diversity and high population structuring. The implications of these and other studies using molecular markers (Avise 1992, 2004)
From page 292...
... 22 APPENDIX C impacts relative to other potentially developable sites, as well as evaluating impacts from an absolute perspective. Studies to address this question are usually short-term and do not qualify as either monitoring or research.
From page 293...
... 23 APPENDIX C species diversity and does not consider whether the species present are at high risk from impact. For example, the approach increases the possibility that areas with a single important species, such as a grassland area with relatively low species diversity but important habitat for a species at risk or of special concern, might actually appear to be a good site for wind-energy development when compared to an area with higher species diversity.
From page 294...
... 24 APPENDIX C bats. Tucker (1996)
From page 295...
... 2 APPENDIX C The importance of micro-siting studies is important for a variety of species, and is illustrated by several bird studies at existing wind-energy facilities. Orloff and Flannery (1992)
From page 296...
... 26 APPENDIX C Post-construction Studies Post-construction studies should focus on determination of impacts and evaluation of actual risk versus predicted risk, evaluation of causal mechanisms of impact, evaluation of mitigation and reclamation measures, and evaluation of the ecological or biological significance of the impacts. A relatively small number of post-construction studies of wind-energy facilities have been conducted.
From page 297...
... 2 APPENDIX C The estimation procedure for fatalities is important and one approach is described later in this appendix. Post-construction surveys at wind-energy facilities in the United States have provided relatively little information on the extent of bat fatalities.
From page 298...
... 28 APPENDIX C (1999) suggested modifying the BACI design by applying the treatment and control in the first year to the selected subset of turbines and switching the treatment and control turbines the second year, sometimes referred to as a crossover experiment.
From page 299...
... 2 APPENDIX C energy development (e.g., prairie grouse and large mammals, including black bear)
From page 300...
... 300 APPENDIX C construct a demographic model of the group of birds using the APWRA in an effort to evaluate the significance of estimated eagle fatalities. Mensurative studies have limited statistical inference because they are not true experiments, and thus must include randomization, replication, and controls (Manly 2001)
From page 301...
... 301 APPENDIX C general nature of impacts on birds and bats is similar to that discussed for wildlife earlier in this appendix. The methods discussed below include observational, remote-sensing (including passive acoustic recording of bird calls, ultrasonic detection of bat calls, radar-imaging, moon-watching, ceilometry, night-vision observations, reflectance-infrared imaging, thermal-infrared imaging, radiotelemetry)
From page 302...
... 302 APPENDIX C Most of the sounds, especially from birds, are audible, and there is a long history of detecting and recognizing birds by listening for their species-specific calls and songs. Today, as a result of the intense and dedicated efforts of many amateurs and scientists, the songs of all North American birds and a significant number of their calls are documented and available (Old Bird, Inc.
From page 303...
... 303 APPENDIX C magnitude more; but the elaborate method has a 30 dB greater gain than the simple method and covers ten times the volume of sky. Simple methods can provide a determination of species presence for known call types (or species-group presence for call types associated with a species group, for example thrushes)
From page 304...
... 304 APPENDIX C The functions of flight calls are not well understood, but they usually are assumed to serve to maintain flock cohesion (Hamilton 1962) or maintain spacing (Graber 1968)
From page 305...
... 30 APPENDIX C levels, monitoring activity of bats in different habitats, and for educating the public (Fenton 2000, 2004)
From page 306...
... 306 APPENDIX C and then plays back the original signal at a slower rate, while retaining virtually all of the original characteristics. Thus, the resulting signal is longer and the frequency will be lower than the original signal.
From page 307...
... 30 APPENDIX C by Reynolds (2006) , however, revealed that the microphones that he used could consistently detect ultrasonic signals up to 22 m distant.
From page 308...
... 308 APPENDIX C imply absence of bats, only that the call may not have been detected. These observations are consistent with Gruver's (2002)
From page 309...
... 30 APPENDIX C information on the activity of some species within the range of detection, because there is no practical way to install ultrasonic detectors in the rotorswept area. Instead, they need to be mounted on meteorological towers at comparable heights to the rotor-swept zone to access both migratory and foraging behavior of bats where they are most at risk at wind-energy facilities.
From page 310...
... 310 APPENDIX C Bat detectors offer alternatives to more traditional methods, such as mist-netting and harp-trapping,2 to determine the presence of many insectivorous bat species, especially in environments and in situations where it is not possible to capture them or make direct observations (e.g., open areas near wind turbines and above tree canopies)
From page 311...
... 311 APPENDIX C ful information on species composition at wind-energy facilities and other areas of interest. Recent developments using time-expanded recordings of search calls produced by echolocating bats hold promise for improving the identification of species (e.g., Preatoni et al.
From page 312...
... 312 APPENDIX C dependently, and coordinate all methods and follow a prescribed protocol for sharing information to optimize detection and recognition within the largest space possible. This type of cross-validation would greatly improve the present state of knowledge by providing information on, for example, types of radar returns coincident with acoustic species-specific identification, acoustic locations associated with radar returns, and the proportion of radar targets that are bats.
From page 313...
... 313 APPENDIX C processing software required to analyze the data. Significant advances in hardware and software development have occurred in the past few years, and rates of improvements are expected to increase.
From page 314...
... 314 APPENDIX C Radar has been valuable not only for descriptive studies of daily and seasonal movements of flying animals, but technically has also been used to answer important questions related to orientation, aerodynamics, and habitat selection of migrants. During the past two decades, radar has been increasingly used in risk-assessment studies related to projects that could potentially impact species that are migratory, endangered, threatened, or of special concern (Cooper 1996; Gauthreaux and Belser 2003a, 2005; Larkin 2005b)
From page 315...
... 31 APPENDIX C the radar beam, measuring the altitude of targets is impossible in horizontal surveillance mode. To address this limitation, the radar can be tilted 90° so that the sweep of the antenna is vertical.
From page 316...
... 316 APPENDIX C ing below 50 m were missed by marine radar, but when birds were flying above 50 m, only 8% went undetected by the radar (Knust et al.
From page 317...
... 31 APPENDIX C the radar, and the characteristics of the echo produced by the reflector target compared to some reference standard. The transmitter power of the marine radar should be as high as possible (25 kW or greater)
From page 318...
... 318 APPENDIX C A B FIGURE C-2 (A) A frame from a Furuno 2155-BB radar with a parabolic dish (4° beam width)
From page 319...
... 31 APPENDIX C calculated, and this information can be used to assign targets to categories based on flight speed (Harmata et al.
From page 320...
... 320 APPENDIX C facility in northeastern West Virginia from September 3 through October 17, 2003 for approximately 6 hours per night on 45 nights. Vehicle-mounted radars (X-band Furuno Model FR-1510 MKIII)
From page 321...
... 321 APPENDIX C 470 m agl in fall, and 14% of the targets were below 125 m agl in the spring and 6.5% were below 125 m agl in the fall. Mean flight directions were toward the NNE (31°)
From page 322...
... 322 APPENDIX C TABLE C-4 Percentage of Radar Echoes Flying Between Ground Clutter and 125-127 m Above Ground Level Location Spring Fall Reference Nantucket Sound, MA 21.8 7.7 Curry and Kerlinger LLC and ESS Group (2004) New York 3.8 4 Cooper et al.
From page 323...
... 323 APPENDIX C NOAA and the National Climatic Data Center (NCDC) in Asheville, North Carolina, have archived data from each WSR-88D station since 1995, although there are several gaps in the archived records.
From page 324...
... 324 APPENDIX C C-3a COLOR FIGURE C-3 (A) Base reflectivity image from WSR-88D Level II data showing the night during the fall of 2005 with the highest density of bird migration (ca.
From page 325...
... 32 APPENDIX C FIGURE C-3 (C) Spectrum width display from WSR-88D Level II data that corresponds to displays in Figures C-3A and B
From page 326...
... 326 APPENDIX C Detection of Biological Targets on the WSR-88D Aerial biological targets are readily detected by the WSR-88D, and several investigators have detailed its use for studying bird migration (Gauthreaux and Belser 1998, 1999, 2003b; Diehl and Larkin 2005) , bird roosts (Russell and Gauthreaux 1998; Russell et al.
From page 327...
... 32 APPENDIX C FIGURE C-4 NEXRAD, WSR-88D Doppler radar images of Brazilian free-tailed bats dispersing nightly from selected cave and bridge roosts in south-central Texas. SOURCE: Kunz 2004; National Oceanic and Atmospheric Administration, National Weather Service.
From page 328...
... 328 APPENDIX C can also be used to quantify the density of birds and to delimit locations of post-breeding, nocturnal roost sites of birds such as purple martins (Progne subis) and other species.
From page 329...
... 32 APPENDIX C risk assessment studies of wind-energy development. The pulse lengths of the radar are relatively long and the resolution of the data is rather coarse.
From page 330...
... 330 APPENDIX C in the density of migration displayed on the radar. This is not surprising because the frequency of flight calling by birds increases when the sky is overcast and the cloud ceiling low.
From page 331...
... 331 APPENDIX C in direction. No kills of migrants were recorded at either of the ceilometers during a two-year study.
From page 332...
... 332 APPENDIX C FIGURE C-6 Thermal infrared image of foraging Brazilian free-tailed bats in southcentral Texas. SOURCE: Thomas Kunz, Boston University.
From page 333...
... 333 APPENDIX C passerines out to a distance of 50-250 m and a pigeon out to 250-300 m. A 5° lens could detect a pigeon out to 600 m and a 3° lens could detect a duck out to 3 km.
From page 334...
... 334 APPENDIX C Thermal infrared imaging has proven valuable for censusing roost sites for the presence and seasonal activity of bats near proposed or developed wind-energy facilities, as well as for observing their flight activity (commuting, foraging, and migratory activity) in the vicinity of wind turbines (Desholm 2003; Horn and Arnett 2005; Horn et al.
From page 335...
... 33 APPENDIX C moving rotor blades, as if the bats were "inspecting" or being attracted to the blades, possibly by insects that also were in the vicinity of the rotors. Other images suggest that some bats may have followed the tips of the turbine blades, or were possibly caught in the blade-tip vortices (Figure C-9)
From page 336...
... 336 APPENDIX C et al. 2003; Betke et al.
From page 337...
... 33 APPENDIX C observed the dispersal of light-tagged E fuscus and postulated that individuals navigated to feeding grounds by following acoustic cues produced by calling frogs and stridulating insects.
From page 338...
... 338 APPENDIX C Stable lsotopes and Genetic Markers Stable isotopes used to assess geographic variation in patterns of precipitation and the unique stable-isotope signatures that are transferred from precipitation to biological primary producers (plants) and ultimately to consumers (herbivores and carnivores)
From page 339...
... 33 APPENDIX C species can aid in the identification of birds and bats (or parts thereof) from the carcass remains of individuals found during fatality searches.
From page 340...
... 340 APPENDIX C FIGURE C-11 Multiple stacked horizontal mist nets used for capturing bats and birds from ground level into the forest subcanopy. SOURCE: Hodgkison et al.
From page 341...
... 341 APPENDIX C (Burnham et al.
From page 342...
... 342 APPENDIX C ence areas. Search plots at wind-energy facilities may take many shapes from circular to rectangular and typically contain one or more turbines, depending on the spacing of individual turbines.
From page 343...
... 343 APPENDIX C And for birds only: • Feather Spot: 10 or more feathers at one location indicating predation or scavenging. Some bat and bird fatalities that are discovered and used in fatalityrate estimation may not be related to wind-energy projects, even though the cause of death cannot be determined.
From page 344...
... 344 APPENDIX C carcasses were removed with the first 24 hours, 48% were removed within 48 hours, and by the 18th day more than 90% of the test carcasses were removed. The rate of removal for small birds appears to be less than for bats, and weekly or biweekly searches for birds may be adequate.
From page 345...
... 34 APPENDIX C est (e.g., one year) for which the cause of death is either unknown or is attributed to the facility n number of search plots k number of turbines searched (includes the turbines centered within each search plot and a proportion of the number of turbines adja cent to search plots to account for the effect of adjacent turbines within the arch plot buffer area)
From page 346...
... 346 APPENDIX C carcasses will be left, the collection of data ends, or is censored. The probability of finding a carcass decreases with time, by convention to the right from the origin, and thus the data are said to be "right-censored." Erickson et al.
From page 347...
... 34 APPENDIX C TABLE C-5 Neotropical Migrant Species that Have Shown a Negative Population Trend During the Time Period 1978-1987 Common Name Scientific Name Trend, %/year Broad-winged Hawk –2.3 Buteo platypterus Black-billed Cuckoo –5.9 Coccyzus erythrophthalmus Yellow-billed Cuckoo –5.0 Coccyzus americanus Chuck-will's Widow –2.0 Caprimulgus carolinensis Whip-poor-will –0.8 Caprimulgus ociferus Olive-sided Flycatchera –5.7 Contopus borealis Eastern Wood-peweea –0.7 Contopus irens Acadian Flycatcher –1.3 Empidonax irescens Least Flycatchera –0.2 Empidonax minimus Great crested Flycatchera –0.3 Myiarchus crinitus Veerya –2.4 Catharus fuscescens Swainson's Thrusha –0.2 Catharus ustulatus Wood Thrusha –4.0 Hylocichla mustelina Gray Catbird –1.4 Dumetella carolinensis White-eyed Vireo –1.2 Vireo griseus Solitary Vireoa –0.1 Vireo solitarius Yellow-throated Vireo –0.9 Vireo flaifrons Blue-winged Warbler –1.0 Vermiora pinus Golden-winged Warblera –1.9 Vermiora chrysoptera Tennessee Warbler –11.6 Vermiora peregrina Northern Parula –2.1 Parula americana Chestnut-sided Warblera –3.8 Dendroica pensylanica Cape May Warbler –2.3 Dendroica tigrina Black-throated Green Warblera –3.1 Dendroica irens Blackburnian Warblera –1.1 Dendroica fusca Yellow-throated Warbler –0.4 Dendroica dominica Prairie Warbler –0.4 Dendroica discolor Bay-breasted Warbler –15.8 Dendroica castanea Blackpoll Warbler –6.3 Dendroica striata Cerulean Warblera –0.9 Dendroica cerulea American Redstarta –1.2 Setophaga ruticilla Worm-eating Warblera –2.0 Helmitheros ermiorus Ovenbirda –1.0 Seiurus aurocapillus Louisiana Waterthrush –0.4 Seiurus motacilla Kentucky Warblera –1.6 Oporornis formosus Mourning Warblera –1.6 Oporornis philadelphia Common Yellowthroat –1.9 Geothlypis trichas Wilson's Warbler –6.5 Wilsonia pusilla Canada Warblera –2.7 Wilsonia canadensis Summer Tanager –0.8 Piranga rubra Scarlet Tanagera –1.2 Piranga oliacea Rose-breasted Grosbeaka –1.4 Pheucticus ludoicianus Indigo Bunting –0.7 Passerina cyanea Baltimore Oriole –2.9 Icterus galbula aDenotes species that breed in the Mid-Atlantic Highlands. All others are known from migration records only.
From page 348...
... 348 APPENDIX C TABLE C-6 Bird Species of Conservation Concern that Potentially Occupy Ridge-Top Habitats in the Mid-Atlantic Highlandsa Statusb Common Name Scientific Name Bald Eagle MD-T Haliaeetus leucocephalus Peregrine Falcon MD-I, VA-T, PA-E Falco peregrinus Northern Goshawk MD-E Accipter gentilis Olive-sided Flycatcher MD-E Contopus cooperi Alder Flycatcher MD-I, VA-SC Empidonx alnorum Sedge Wren MD-E, VA-SC, PA-E Cistothorus platensis Winter Wren VA-SC Troglodytes troglodytes Appalachian Bewick's Wren VA-E Thyromanes bewickii altus Golden-crowned Kinglet VA-SC Regulus satrapa Red-breasted Nuthatch VA-SC Sitta canadensis Blackburnian Warbler MD-T Dendroica fusca Blackpoll Warbker PA-E Dendroica striata Magnolia Warbler VA-SC Dendroica magnolia Swainson's Warbler MD-E, VA-SC Limnothlypis swainsonii Mourning Warbler MD-E, VA-SC Oporornis philadelphia Nashville Warbler MD-I Vermiora ruficapilla Hermit Thrush VA-SC Catharus guttatus Red Crossbill VA-SC Loxia curirostra aWV has no statutes requiring the development of State Endangered and Threatened species lists. bMD = Maryland, PA = Pennsylvania, VA = Virginia, E = Endangered, T = Threatened, SC = "Species of Special Concern", I = "In Need of Conservation." SOURCES: VA (Roble 2006)

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