Avian & Biological Studies for the Proposed Sunshine Wind Park

Transcription

1 Avian & Biological Studies for the Proposed Coconino County, Arizona Prepared for: Sunshine Arizona Wind Energy, LLC 1016 West University Drive, Suite 108 Flagstaff, AZ Prepared by: Western EcoSystems Technology, Inc Central Avenue Cheyenne, Wyoming Colorado Plateau Research Station Northern Arizona University Box 5614 Flagstaff, AZ Ecological Monitoring & Assessment Program Northern Arizona University Box 5845 Flagstaff, AZ May 2006

2 EXECUTIVE SUMMARY Sunshine Arizona Wind Energy, LLC, is evaluating the feasibility of developing a wind power project in Coconino County, Arizona. The proposed project site for the is located approximately 35 miles east of Flagstaff, Arizona and is bisected by Interstate 40 at the Meteor Crater exit. The current proposal is construction of approximately MW turbines (60 MW total capacity) primarily on private and tribal ranch lands managed for livestock production. A biological resources study plan was developed for the site that was designed to provide site specific data to better understand the risk to avian and bat species from the proposed development. The objectives of the study were to provide information on avian and bat use of the study area that is (1) useful in evaluating the potential impact from the wind project; (2) that will help in designing a wind project that is less likely to expose avian and bat species to risk of turbine collisions; and (3) provide baseline information for post-construction studies that will advance understanding of wind farm and wildlife interactions in the Southwest. The study plan was developed with input from personnel at NAU, USFWS, AZGFD, Northern Arizona Audubon Society, and other studies for wind energy development throughout the U.S. The avian portion of the field study included field surveys for birds with particular focus on migrant and wintering raptors and summer breeding residents. The bat surveys will be completed in the Fall of 2006; a subsequent report will address results of the bat surveys. The project area is within the Great Basin Desert Scrub ecozone of the larger Arizona/New Mexico Plateau. This ecozone consists primarily of broad flat plains with scattered sandstone outcrops, scattered larger mesas, and some narrow and steep canyons. There is little topographic relief to the ecozone which is very dry with approximately 12 inches of precipitation a year coming primarily during the monsoon season (July-August). The project area is at approximately 5,500 feet elevation and located in the central portion of the ecozone where there is no influence from the Pinyon-Juniper Woodland ecozone to the west. The dominant vegetation types of the project area are desert scrub and grassland characterized by saltbush, sagebrush, snakeweed, rabbit brush, yucca, and grama. The majority the project area has been continuously used for cattle grazing since the 1870s. Study Components and Methods The avian study consisted of three components: (1) fixed point surveys - point count surveys with particular focus on raptors and other large birds; (2) paired-plot point counts - point count surveys with particular focus on breeding passerines; and (3) in-transit surveys - recorded observations of birds and other wildlife made while observers traveled between survey points. The objective of the fixed-point surveys was to estimate spatial and temporal use of the site by birds and in particular raptors and other large birds. Point counts were conducted at nine fixed stations in the proposed development area. Each station was a variable circular plot centered on the observation point marked in the field. All birds observed were recorded; however, the survey effort was concentrated within an 800 m (0.5 mi) radius circle around the observation point. Survey periods at each point were 30 minutes long and surveys were conducted once a week WEST, Inc. i

3 between December 3, 2004 and May 19, 2005 and September 13 to November 29, Data recorded for each bird observed included: species or best possible identification; number of individuals; sex and age class; distance from observation point when first observed; closest distance; altitude above ground; behavior; and habitat(s) where the bird was observed. The objective of the paired-plot surveys was to estimate relative abundance of breeding passerines in the project area. The survey design was to locate one survey point at a proposed turbine location and a second (or paired plot) 250 m away in a random direction from the first plot. Presumably the paired plots would be located in areas where no turbines would be constructed. Fourteen paired-plots were established over the study area. Ten minute point count surveys were conducted four times at each of the points during the summer breeding season. During a given survey day, observers on site traveled between fixed point locations and covered areas of the site not included in the standardized surveys. Observations made during these travel periods included avian species and other types of wildlife (mammals, reptiles) and in particular pronghorn, an AZGFD sensitive species. In addition, five trips to the nearby Diablo Canyon were made during the course of the study for general surveys. Results Three seasons, winter , spring and fall 2005, of weekly avian surveys and summer breeding bird surveys were conducted at the. A total of minute point count surveys were conducted at the fixed-point survey locations. During the surveys, a total of 5,012 individual birds in 1,061 groups were observed of 35 avian species and 6 unidentified bird types (e.g., unidentified buteo). Passerines were the most numerous group observed with horned lark the most numerous passerine observed. Passerines comprised nearly 95% of all groups observed and 98% of all birds observed. Raptors comprised approximately 3% of all groups and less than 0.9% of all birds observed. All other birds combined (doves, other non-passerine species, waterfowl, shorebirds, and unidentified birds) comprised approximately 2% of all groups and 0.6% of all birds observed. Avian use by species was calculated as the mean number of observations per 30-minute survey within 800 m of the survey point. For all three seasons, only two species were observed more than once per survey on average, horned lark and common raven. During the winter, the next two most abundant species were rock wren (0.18 detections/survey) and sage sparrow (0.15 detections/survey) or approximately one observed for every five surveys. In contrast during the winter, approximately horned larks and 1.12 common ravens were observed per survey. Horned lark and common raven comprised over 98% of the total bird use during the winter. During the spring Brewer s sparrow and rock wren (0.62 detections/survey) and unidentified sparrow (0.43/survey) were the next most abundant species observed after horned larks (5.35) and common raven (1.18). Horned lark and common raven comprised approximately 68% of the total bird use during the spring. In the fall, rock wren (0.62) and mountain bluebird (0.53) were the next most common species after horned lark (29.00) and common raven (1.84). Nearly 91% of the fall bird use of the site was by horned larks and common ravens. WEST, Inc. ii

4 Species composition is the mean use for a species divided by the total use for all species and frequency of occurrence is the percent of surveys where a particular species was observed. The top two species for all three seasons were horned lark and common raven, which together comprised from 68.3% in the spring to 98.4% in the winter of the total bird use. Horned lark were observed in over 80% of the surveys and common raven were observed in over 48% of the survey for all three seasons. Rock wren was the only other species observed in more than 25% of the surveys for one or more of the seasons, in the spring (28.4%) and fall (37.8%), but rock wrens only made up 6.5% of the total use in the spring and only 1.8% in the fall. In the spring, Brewer s sparrow comprised the same amount of use as the rock wren (6.5%) but was only observed in 1.2% of the surveys. The higher bird use for Brewer s sparrow was due to this species being observed in flocks more often than rock wrens. Four other species, rock wren in the winter (12.5%), black-throated sparrow in the spring (19.8%), loggerhead shrike (15.6%) and sage sparrow (11.1%) in the fall were observed in more than 10% of the surveys during a season. As a group, and due primarily to the abundance of horned lark, passerines comprised more than 95% of the avian use on site for all three seasons and were observed in more than 88% of all surveys for all seasons. Mean use for passerines was lowest in the spring (9.12) and higher in the fall (33.29) and winter (37.50) due to larger flocks of horned larks observed as opposed to individual or paired birds during the spring. Raptors as a group comprised less than 2% of the avian use of the site during each of the three seasons and were observed in as few as 7% of the surveys in the winter up to over 35% of the surveys in the fall. Raptor use was highest in the fall (0.58) but was not substantial in any season; only 43 total raptor observations were made during nearly 100 hours of standardized surveys on the site. Flight characteristics of observed birds were summarized to provide a relative risk of a species coming in contact with turbines. Most of the passerines observed, with the exception of common raven, mountain bluebirds, and unidentified sparrows, were regularly observed flying less than 25 meters above the ground. The larger birds tend to fly higher, and frequently flew greater than 25 meters high, which is within the primary zone of risk for turbine blades for most newer generation turbines. As a group, 50% of raptors observed flying (40 individuals) were in the zone of risk. Raptor species observed in the zone of risk more often included red-tailed hawk (66.7%; n=12) and American kestrel (53.9%; n=13). Flying passerines were observed within the zone of risk approximately 17% (4,233 individuals) of the time. Bird use was evenly distributed across the study area, which is typical of areas with fairly monotypic topographic and vegetative characteristics, except at station S5 (southeast) where use was twice as high as the highest use for the other stations. The higher use at station S5 was due to several large flocks of horned larks observed at this station. Because so few raptors were observed during the course of the study no concentrated raptor use areas could be detected. Raptor use across the study area was similar at all stations; the highest use was observed at stations N2 (northcentral) and S3 (southcentral). Between June 1 and July 14, 2005, four breeding bird surveys were conducted for the 14 turbine plots and the associated random (offset) point. 1,070 total observations in 806 different groups (flocks) were made of 13 avian species and an additional 1 unidentified bird types during the WEST, Inc. iii

5 paired-plot surveys. Horned lark was by far the most numerous species observed during the breeding bird surveys, comprising 76.2% of all groups and 79.7% of all birds observed. Passerines were the most common group observed comprising 96.9% of all groups and 97.1% of all birds observed. Raptors only comprised 0.4% of all groups and 0.3% of all birds observed. Other birds and unidentified birds comprised 2.7% of all groups and 2.6% of all birds observed. Avian use by species was calculated as the mean number of individuals per 10-minute survey within 400 m of the point for the paired plot surveys. The three most abundant species observed during surveys were the same for both the turbine and random points, horned lark (7.52 detections/ survey for turbine points and 7.64 for random points), rock wren (0.63 for turbine and 0.77 for random points), and common raven (0.36 for turbine and 0.34 for random points). Together these species comprised more than 94% of the total use for the turbine points and 95% of the total use for the random points. As expected, passerines were the most abundant group observed. The only raptor observed during the surveys was red-tailed hawk but all observations were greater than 400 m from the survey point so did not factor into the use estimates. Paired t- tests for the difference in use between the turbine and offset points did not show any significant differences, which would be expected in a topographically and vegetatively monotypic area. Several species were seen during the in-transit surveys that were not recorded during the standardized surveys. Fifteen raptors were observed incidentally in the project area including one golden eagl. Four raptors were seen in the Diablo Canyon area including one bald eagle, a species not recorded during the other surveys. Pronghorn, a species of concern for the AZGFD, were other non-avian wildlife of interest observed. Eighty-six pronghorn in 13 different groups were observed in the study area over the course of the study in areas to the south of I-40; no pronghorn were observed north of I-40. Discussion Results of the avian surveys on the site are typical of areas that are topographically and vegetatively monotypic where a few species are common and make up the majority of the observations. For the two species, horned lark and common raven, comprised the vast majority of avian use. The desert scrub vegetation type of the site is highly suited to horned larks with a prevalence of bare ground and short vegetation. Raptors were uncommon at the site; as a group, raptors comprised less than 1.7% of all bird use of the site. Over the course of all the fixed point, paired plot, and in-transit surveys (over 230 observer hours on site), 60 raptors were observed in 52 groups. The most common raptors observed were redtailed hawk and American kestrel. The low number of raptor observations resulted in low relative abundance (use) estimates and low exposure indices. The paired-plot surveys also showed relatively low species diversity on the site with one species, horned lark, making up the majority of the observations. Horned lark comprised well over 80% of total use for both turbine and random points. As expected due to similarity of plots in each pair, there were no significant differences in bird use between points. The paired-plot surveys were designed to target breeding passerine species that occupy the site and provide a baseline against which to compare results from post-construction surveys, if warranted. WEST, Inc. iv

6 For all birds, use was highest in the winter season when species such as horned lark tended to be observed in large flocks. Use was lowest in the spring when the species diversity increased as indicated by the number of species observed and the frequency of occurrence of species. This again is typical, as resident species break up into breeding territories (seen in smaller group sizes) and more migrants may be observed. Risk of Turbine Collision The species with the highest exposure indices and those that would be expected to be most at risk based on the data collected for the site, were horned lark and common raven. The majority of common ravens were observed in flight and within the zone of risk and horned lark was the most abundant species observed. These factors tend to drive up the exposure index estimate. While the exposure index is not a measure of absolute risk, it does provide a relative estimate of the chance a species may come in contact with turbine blades. An exposure index of zero does not necessarily mean that a species is not at risk, but it does indicate that based on the observations made of that species on the site, it is unlikely to be in the area of the turbine blades. Mortality studies at other wind plants have commonly found horned-lark casualties but few common ravens. Although ravens are often observed at wind plants within the zone of risk, they appear to be less susceptible to collision with wind turbines than other similar size birds (e.g., raptors, waterfowl). Horned lark is, however, a common casualty observed at other wind plants most likely due to the abundance of this species in habitats commonly found at wind plants. Passerines, resident and migrants, have been the most abundant avian fatality at wind projects, often comprising more than 80%. Given that passerines make up the vast majority of the avian observations on-site, passerines would likely make up the largest proportion of fatalities. Raptor use of the site was very low and raptors as a group do not appear to be at great risk from the proposed development. The number of raptors observed was too few to distinguish trends or concentrations in use of the site. Predictions of raptor mortality based on the low use estimates for the site are difficult to make, but it is not expected that the proposed development would result in substantial raptor mortality. Use by other groups of birds such as waterfowl, shorebirds, doves, and other non-passerine species was so low that trends or concentration areas could not be distinguished and these groups are not expected to be at risk from the proposed development. Turbine Siting Issues Based on the survey results there were no marked avian concentration areas or areas that would appear to pose a greater risk from development. No results were found that suggest further investigation or analysis to look for variable trends or that should be avoided by turbines. Future Study Issues Based on results from the fixed-point, paired plot, and in-transit surveys, raptor use estimates were very low and it does not appear as if a substantial number of raptors would nest in the area. The topography and vegetation of the site is not conducive to raptor nesting and a raptor nest survey of the project area does not appear warranted. Future studies, if needed should concentrate on documenting direct impacts such as mortality for a project in the U.S. Southwest, a little studied region. WEST, Inc. v

7 TABLE OF CONTENTS 1.0 INTRODUCTION AND BACKGROUND STUDY PLAN Study Area Study Components METHODS Fixed Point Surveys Paired-plot Surveys In-Transit Surveys General Wildlife Observations Big Game Observations Data Management and Quality Assurance/Quality Control (QA/QC) Statistical Analysis RESULTS Fixed-point Surveys Avian Use Species Composition and Frequency of Occurrence Flight Height Characteristics Exposure index Spatial Use Breeding Bird Surveys Avian Use In-transit Surveys General Wildlife and Big Game Species Observations DISCUSSION AND SUMMARY Avian Use and Diversity Risk of Turbine Collision Turbine Siting Issues Future Study Issues REFERENCES WEST, Inc. vi

8 LIST OF TABLES Table 1. Summary of fixed point surveys conducted and overall mean bird use and diversity by season Table 2. Avian species observed while conducting fixed-point surveys in the Sunshine Wind Park Table 3. Estimated mean use, percent composition, and frequency of occurrence for each species and group observed within 800m of the survey point for fixed-point surveys Table 4. Flight height characteristics of avian species and groups observed during the fixed-point surveys Table 5. Exposure indices calculated for species observed during fixed-point surveys Table 6. Avian species observed while conducting breeding bird surveys at the Sunshine Wind Park Table 7. Average use by species and group for observations within 400m of the plot center for turbine and offset points from the breeding bird surveys Table 8. Number of individuals and groups of avian species and other non-avian wildlife observed incidentally in the study area Table 9. Number of individuals and groups of avian species observed at Diablo Canyon LIST OF FIGURES Figure 1. Regional map showing the project location Figure 2. Map of the project area and fixed-point survey stations Figure 3. Map of the project area and paired-plot survey points Figure 4. Mean use (number detections/30-minute survey) for all birds, passerines and raptors by station (December November 2005) WEST, Inc. vii

9 1.0 INTRODUCTION AND BACKGROUND Sunshine Arizona Wind Energy, LLC ( SAWE ) is evaluating the feasibility of developing a wind power project in Coconino County, Arizona. SAWE is owned by Arizona investors and is managed by the principals for Foresight Wind Energy ( Foresight ), a San Francisco-CA based wind power project development company. The proposed project site for the Sunshine Wind Park is located approximately 35 miles east of Flagstaff, Arizona and is bisected by Interstate 40 at the Meteor Crater exit (Figure 1). The proposed development would be located on private and tribal ranchlands currently managed primarily for livestock production. Approximately onehalf of the site is north of I-40 and one-half south of I-40. The current proposal for the development would be construction of approximately MW turbines for a total capacity of 60 MW. Western EcoSystems Technology, Inc. (WEST) in cooperation with Ecological Monitoring and Assessment (EMA) Program of Northern Arizona University (NAU) developed an avian and biological survey protocol for a one-year baseline study of the site (CPRS et al. 2004). A Phase I biological evaluation of the site (Young and Poulton 2004) found that, based on available data, reconnaissance level visits, and interviews with agencies and stakeholders, the proposed site is expected to have low impacts to avian and other biological species due to anticipated low avian diversity and abundance. The baseline study was designed to provide site specific data to verify the preliminary findings and better understand the site. Field work for the baseline study was conducted by U.S. Geological Surveys Colorado Plateau Research Station (CPRS). The one year study included field surveys for avian species with particular focus on migrant and wintering raptors, breeding birds, and bats. The bat surveys will be completed in the Fall of 2006 and a subsequent report will address results of those surveys. The study was designed to characterize the avian and bat resources and use of the site and to estimate the potential impacts the project may have on these species. The study also included observations of other wildlife species on the site, including pronghorn, an Arizona Game and Fish Department (AZGFD) species of concern. The study plan was developed with input from personnel at NAU, the U.S. Fish and Wildlife Service (USFWS), the AZGFD, and Northern Arizona Audubon Society (NAAS), as well as expertise and experience of WEST implementing and conducting similar studies for wind energy development throughout the U.S. This report describes the study methods, primary data collection, results of statistical analyses, and a discussion of the results of the avian surveys. The report provides an estimate of the probable impacts from the proposed development on avian species using the project area, provides recommendations based on the primary data to help minimize impacts, and provides recommendations for post-construction avian monitoring of the site. Final surveys and data regarding bats will be reported following completion of the bat surveys in Fall WEST, Inc. 1

10 2.0 STUDY PLAN The principal goals of the baseline study were to: Provide baseline information on avian and bat use of the study area that is useful in evaluating the potential impact to birds and bats from wind power development in the area. Provide information on avian and bat use of the study area that will help in designing a wind plant that is less likely to expose avian and bat species to potential collisions with turbines. Provide baseline information to serve as a foundation for post-construction avian and biological studies that will advance understanding of wind farm avian interactions in the U.S. Southwest, a little studied region. Specific objectives of the avian component of the study were to (1) identify avian species using the study area during different seasons; (2) quantitatively and qualitatively describe the temporal and spatial use by avian species of the study area; (3) identify areas of high avian use within the study area (if any) which may pose a higher risk to avian species from the development; (4) identify areas or habitat features with avian species of concern (if any); and (5) assess migrant, winter and breeding bird use of the site. 2.1 Study Area The project area is within the Great Basin Desert Scrub ecozone (Brown 1994). The Great Basin Desert Scrub in northern Arizona is part of the larger Arizona/New Mexico Plateau. This physiographic province represents a large transitional area between the arid grasslands and low relief table lands of the Southwestern Tablelands province to the east and the dry shrubland and woodlands and higher relief tablelands of the Colorado Plateau to the north. The Great Basin Desert Scrub consists primarily of broad flat plains with scattered sandstone out crops, the occasional larger mesa, and some narrow and steep canyons. There is little topographic relief to the zone. Elevation ranges from roughly 3,500 to 6,000 feet as the general lay of the region slopes from east to west to higher elevation Pinyon-juniper Woodland. The project area is located at approximately 5,500 feet elevation. Water erosion is the dominant force determining topography. The ecozone is very dry with approximately 12 inches of precipitation a year coming primarily during the monsoon season in July and August. Due to the location of the project area with the central portion of the ecozone, there is little, if any, influence from the Pinyon-Juniper Woodland transitional area to the west. The dominant vegetation types of the are desert scrub and open grassland. The site is characterized by common desert scrub species including saltbush (Atriplex canescens), sagebrush (Artemisia tridentata), snakeweed (Gutierrezia sarothrae), rabbit brush (Chrysothamnus nauseosus), grama (Bromus spp.), yucca (Yucca baccata). The open grassland areas are dominated by grama. The majority the project area is used for cattle grazing and has been continuously used for that purpose since the 1870s. WEST, Inc. 2

11 The study area for the avian surveys is primarily the proposed wind power development area (Figure 1). The survey plots were located within the boundary of the area proposed for development. Some reconnaissance level surveys were conducted in the adjoining area of Diablo Canyon (see Figure 2). Each survey station included a fixed point and an adjacent buffer of variable width in which observations of birds were recorded (see below). 2.2 Study Components The overall field study consisted of observations of wildlife on the site, avian species, large game, bats, and general wildlife observations. The avian study consisted of three components: 1. Fixed Point Surveys - point count surveys with particular focus on raptors and other large birds; 2. Paired-plot Point Counts - variable circular plot surveys with particular focus on breeding passerine birds; 3. In-transit Surveys - recorded observations of birds (and other wildlife) made while observers were traveling between points on-site. The bat surveys will be completed in Fall General wildlife observations were recorded of other wildlife (amphibians, reptiles, mammals) while observers were on-site for other surveys. A raptor nest survey was initially considered if warranted based on results of fixed point and intransit surveys (see Young and Poulton 2004). However, based on the results of the avian surveys (see below), raptor use estimates were very low and it does not appear as if a substantial number of raptors would nest in the area. 3.0 METHODS The avian survey components consisted of weekly fixed point surveys of all birds, paired-plot surveys for breeding birds, and in transit observations. 3.1 Fixed Point Surveys The objective of the fixed-point surveys was to estimate the spatial and temporal use of the site by birds and in particular raptors and other large birds. Point counts (variable circular plots) were conducted on the development area using methods described by Reynolds et al. (1980) and Bibby et al. (1992). The points were selected to survey as much of the project area as possible without overlap of area surveyed from each point. All birds seen during the point counts were recorded; however, the emphasis of the surveys was locating and counting raptors and other large birds (e.g., waterfowl, corvids, and upland gamebirds). Nine survey points were established over the study area (Figure 2). Initially, the fixed-point locations were plotted on a map of the study area to insure that adequate coverage of the site was gained with minimal overlap of surveyed area. Approximate UTM coordinates for each of the mapped points were determined using ArcView software. These coordinates were used to locate the points in the field. Due to the flatness and accessibility of the site, the original point WEST, Inc. 3

12 locations were determined adequate in that they provided good visibility in 360 o around each point and were all surveying new area (i.e. no overlap of surveyed area). The fixed-points were permanently (life of project) marked in the field to minimize error in locating the points during subsequent surveys. Each survey plot was a variable circular plot centered on the observation point marked in the field. All birds observed were recorded; however, the survey effort was concentrated within an approximate 800 m (0.5 mi) radius circle centered on the observation point. Observations of birds beyond the 800 m radius were recorded, but were not included in the analysis of the data within the plot. Survey periods at each point were 30 minutes long. All raptors and other large birds observed during the survey were assigned a unique observation number. The date; start and end time of the observation period; and weather information such as temperature, wind speed, wind direction, and cloud cover were recorded for each survey. Species or best possible identification, number of individuals, sex and age class (if possible), distance from plot center when first observed, closest distance, altitude above ground, activity (behavior), and habitat(s) were recorded for each bird observed. The behavior of each raptor/large bird observed and the habitat in which or over which the bird occurred were recorded. Behavior categories include perched, soaring, flapping, flushed, circling/soaring, hunting, gliding, and other (noted in comments). Habitats were recorded as grassland, desert scrub, rock outcrop, stock pond, and other (noted in comments). Approximate flight height at first observation and the approximate lowest and highest flight heights were recorded to the nearest meter or 5-meter interval. Any comments or unusual observations were noted in the comments section. 3.2 Paired-plot Surveys During the summer breeding season (June - July) point count surveys were conducted which focused on breeding passerine species on the site. The survey design was to locate one survey point at a proposed turbine location and a second (or paired plot) 250 m away in a random direction from the first plot. Presumably the paired (or random) plots would be located in areas where no turbines would be constructed. Fourteen paired-plots were established over the study area. Figure 3. Point count surveys were conducted four times at each of the points during the breeding season. All birds seen or heard were recorded. For each observation the approximate horizontal distance between the observer and the bird was recorded. For auditory observations (when a birds was heard but not seen), the observer estimated the distance to a tree, bush, rock outcrop, or other location where they thought the bird was located. Each survey was for ten minutes with the survey period subdivided into 3 periods: 0-4 minutes, 4-7 minutes and 7-10 minutes. The survey began 1 minute after arriving at a station. Flyover species were also recorded, but no estimates of distance were recorded for flyovers. Additional notes were taken including: (1) whether the detection was aural, visual or both; (2) whether detections were songs or calls, and (3) whether it was believed that the bird was also detected at the paired point count station (to minimize double-counting individuals). Birds flushed while walking between point count stations were counted and noted on incidental bird observations forms. WEST, Inc. 4

13 3.3 In-Transit Surveys During a given survey day, observers on site were traveling between fixed point locations and covering areas of the site not included in the standardized surveys. Observations made during these travel periods are useful in helping describe bird use of the site and may also be important in identifying high bird use areas not identified by the fixed-point surveys. All raptors, other large birds, unusual or unique observations (e.g., large flocks), any species of concern, and species not previously seen on site which are observed between fixed-point stations were recorded on an in-transit datasheet. Data similar to the fixed-point surveys were recorded for each observation. 3.4 General Wildlife Observations The objective of recording general wildlife observations on the site was to document wildlife other than avian species which may be using the site and potentially affected by the proposed development. General wildlife observations were made any time observers were on site conducting other study components or traveling between survey locations. All mammals, reptiles, and amphibians sighted or heard while field observers were on site were recorded on data sheets for incidental observations. The data recorded were similar to those recorded during the standard surveys including a unique observation number, date, time, species, number, sex/age class, height above ground (for bats or birds), and habitat were recorded. 3.5 Big Game Observations Observations of big game species seen while conducting surveys on site were also recorded. Preliminary project investigations indicate the project area is a summer and winter range for pronghorn, a species of concern in Arizona. The objective of recording this data was to provide baseline information about pronghorn in the project area and to estimate seasonal variation in use by this species if possible. 3.6 Data Management and Quality Assurance/Quality Control (QA/QC) A database was established to store, retrieve and organize field observations. Data from field forms was keyed into the electronic data files using a pre-defined format that made subsequent data analysis straightforward. All field data forms, field notebooks, and electronic data files have been retained for future reference. QA/QC measures were implemented in all stages of the study, including in the field, during data entry and analysis, and report writing. Observers were responsible for inspecting his or her data forms for completeness, accuracy, and legibility. A sample of records from the electronic files was compared to the raw data forms and any errors found were corrected. Any irregular codes detected, or any data suspected as questionable, were discussed with the observer and study team leader. Any errors or suspect data identified in later stages of analysis were traced back to the raw data forms, and appropriate changes in all steps made. WEST, Inc. 5

14 3.7 Statistical Analysis Statistics/data generated for the avian surveys included the following: Species lists and observations by season; Relative use by species, species groups, and season; Mean frequency of occurrence by species, species groups, and season Species composition by species, species groups, and season; Mean flight characteristics by species and species group; Exposure indices by species and species group; Species lists and observations of other wildlife observed in the study area The number of raptors and other species seen during each point count survey was standardized to a unit area and unit time searched. Avian use by species was calculated as the mean number of observations by species per 30-minute survey within 800 m of the survey point for large birds and within 200 m of the survey point for small birds. For example, if 4 raptors are seen during the 30 minutes at a point with a viewing area of 2.01 km 2, these data were standardized to 4/2.01 = 1.98 raptors/km 2 in a 30-minute survey. The frequency of occurrence by species was calculated as the percent of surveys in which a particular species was observed. Species composition was represented by the mean use for a species divided by the total use for all species and multiplied by 100 to provide percent composition. Frequency of occurrence and percent composition provide relative estimates of the avian diversity of the study area. A particular species may have high use estimates of the site based on just a few observations of large flocks, however, the frequency of occurrence will indicate that it occurs during very few of the surveys and therefore, may be less likely affected by the project. A relative index to collision exposure (R) was calculated for bird species observed during the fixed-point surveys using the following formula: R = A*P f *P t Where A = mean relative use for species i (observations within 800 m of observer) averaged across all surveys, P f = proportion of all observations of species i where activity was recorded as flying (an index to the approximate percentage of time species i spends flying during the daylight period), and P t = proportion of all flight height observations of species i within the rotor-swept area (RSA). This index does not account for differences in behavior other than flight characteristics (i.e., flight heights and percent of birds observed flying). Data were plotted (means) to illustrate differences in bird use between seasons and stations. Seasons were defined as follows: spring, March 1 - May 31; fall, September 1 - October 31; and winter, November 1 - February 28. WEST, Inc. 6

15 4.0 RESULTS Three seasons, winter , spring and fall 2005, of weekly avian surveys and summer breeding bird surveys were conducted at the. 4.1 Fixed-point Surveys Surveys were conducted at nine fixed-point count stations within the study area (Figure 2) approximately once each week between December 3, 2004 and May 19, 2005 and from September 13 to November 29, A total of minute point count surveys were conducted (Table 1). A total of 35 avian species and an additional 6 unidentified bird types (best possible identifications, e.g., unidentified sparrow) were observed during the fixed-point surveys (Table 2). 5,012 total observations in 1,061 different groups 1 were recorded during the fixed-point surveys (Table 2). These are raw counts of observations, that are not standardized by the number of hours of observation or survey plot, but do provide an overall list of what was observed. These counts likely contain duplicate sightings of the same birds. Passerines were the most numerous group observed with horned lark by far the most numerous passerine observed. Passerines comprised nearly 95% of all groups observed and 98% of all birds observed. The rest of the taxonomic groups comprised a small percentage of the groups and birds observed. For example, raptors comprised approximately 3% of all groups and less than 0.9% of all birds observed. All other birds combined (doves, other non-passerine species, waterfowl, shorebirds, and unidentified birds) comprised approximately 2% of all groups and 0.6% of all birds observed (Table 2) Avian Use To standardize the data for comparison between points, seasons, and other studies; avian use, frequency of occurrence, and species composition were calculated from observations within 800 m of the survey point. Avian use by species was calculated as the mean number of observations per 30-minute survey (Table 3). Because individual birds were not marked, counts do not distinguish between individuals; rather, they provide an estimate of avian use of the study area. For example, if one red-tailed hawk was observed during five surveys, it is unknown if this was the same bird seen five times or five different birds seen once. But this does provide an index of how often or frequent red-tailed hawks occur in the study area, and therefore are at risk of being affected by the proposed project. References to abundance are the use estimates and not absolute density or numbers of individuals. Use varied across seasons (Table 3). For all three seasons, based on use, only two species were observed more than once per survey on average, horned lark and common raven. During the winter, the next two most abundant species were rock wren (0.18 detections/survey) and sage sparrow (0.15 detections/survey) or approximately one observed for every five surveys. In contrast during the winter, approximately 36 horned larks were observed per survey. Horned 1 Group is defined as an observation of a species of bird regardless of number seen together. For example, a flock of eight horned larks flying together is considered a group as well as an individual horned lark observed by itself. WEST, Inc. 7

16 lark and common raven comprised over 98% of the total bird use during the winter (Table 3). During the spring Brewer s sparrow and rock wren (0.62 detections/survey) and unidentified sparrow (0.43) were the next most abundant species observed after horned larks and common raven. Horned lark and common raven comprised approximately 68% of the total bird use during the spring (Table 3). In the fall, rock wren (0.62) and mountain bluebird (0.53) were the next most common species after horned lark and common raven (Table 3). Nearly 91% of the fall bird use of the site was by horned larks and common ravens. Passerines as a group had the highest use in all three seasons and comprised over 95% of the total bird use in all three seasons. Raptors had the second highest use in all three seasons but comprised less than 2% of the total bird use in all three seasons (Table 3). Mean use for passerines was lowest in the spring. The higher fall and winter use estimates were likely due to larger flocks of horned larks observed as opposed to individual or pairs of birds during the spring. Raptor use was highest in the fall (Table 3) but was not substantial in any season; only 43 total raptor observations (Table 2) were made during nearly 100 hours of standardized surveys on the site Species Composition and Frequency of Occurrence Species composition is represented by the mean use for a species divided by the total use for all species (Table 3). Frequency of occurrence was calculated as the percent of surveys where a particular species was observed (Table 3). The top two species for all three seasons were horned lark and common raven, which together comprised from 68.3% in the spring to 98.4% in the winter of the total bird use. Horned lark were observed in over 80% of the surveys for all three seasons and common raven were observed in between 48% and 57% of the survey for the three seasons. Rock wren was the only other species observed in more than 25% of the surveys for one or more of the seasons, in the spring (28.4%) and fall (37.8%). But rock wrens only made up 6.5% of the total use in the spring and only 1.8% in the fall. In the spring, Brewer s sparrow comprised the same amount of use as the rock wren (6.5%) but was only observed in 1.2% of the surveys. The higher bird use for Brewer s sparrow was due this species being observed in flocks more often than rock wrens (see Table 2). Four other species, rock wren in the winter (12.5%), black-throated sparrow in the spring (19.8%), loggerhead shrike (15.6%) and sage sparrow (11.1%) in the fall were observed in more than 10% of the surveys during a season (Table 3). As a group, and due primarily to the abundance of horned lark, passerines comprised more than 95% of the avian use on site for all three seasons (Table 3) and were observed in more than 88% of all surveys for all seasons (Table 3). Raptors as a group comprised less than 2% of the avian use of the site during each of the three seasons and were observed in as few as 6.9% of the surveys in the winter up to over 35% of the surveys in the fall (Table 3). An additional index of species diversity is the mean number of species observed per survey. In general, the mean number of species per survey was similar for all three seasons with the most in the fall (2.87) followed by spring (2.59) and winter (1.69) (Table 1) Flight Height Characteristics The proportion of observations of a bird species flying within the rotor swept area provides a rough estimate of the propensity of that species to fly within the area occupied by the turbine WEST, Inc. 8

17 rotors (Table 4). Most of the modern turbines and tower heights have a maximum height with the blade pointed up of approximately 120 m. Using an estimated range of tower heights and rotor diameters, the zone of risk included the area from approximately 25 m above ground level (AGL) to 125 m AGL, which is the union of rotor swept area heights for smaller and larger turbines as well as variable tower heights. This range was a conservative estimate that included a small buffer of approximately 5 m on the upper and lower limits. Most of the passerines observed, with the exception of common raven, mountain bluebirds, and unidentified sparrows, were regularly observed flying less than 25 meters above the ground (Table 4). The larger birds tend to fly higher, and frequently flew greater than 25 meters high, which is within the primary zone of influence for turbine blades for most newer generation turbines. As a group, 50% of raptors observed flying were observed in the zone of risk. Raptor species observed in the zone of risk more often included red-tailed hawk (66.7%), American kestrel (53.9%), and unidentified hawk (100.0%). Flying passerines were observed within the zone of risk approximately 17% of the time (Table 4). Waterfowl and unidentified birds were always observed within the zone of risk but based only on one or two groups of individuals Exposure index The exposure index is a relative measure of the risk of each species observed on-site during the fixed-point surveys coming in contact with a turbine, based on the use (measure of abundance) of the site by the species and the flight characteristics observed for that species. Horned lark and common raven had the highest exposure indices (Table 5). These two species were commonly observed on site and often observed flying. Of the raptors, red-tailed hawk and American kestrel had the highest exposure indices. Most of the other raptors were seen less frequently (i.e., use was lower) which reduced their exposure index Spatial Use Use by station was plotted to look for concentrations or differences in avian use across the study area (Figure 4). In general, bird use was evenly distributed across the study area, which is typical of areas with fairly monotypic topographic and vegetative characteristics, except at station S5 where use about twice as high as the highest use for the other stations. The higher use at station S5 was due to several large flocks of horned larks observed at this station. Because so few raptors were observed during the course of the study no concentrated raptor use areas could be detected. Raptor use across the study area was similar at all stations; the highest use was observed at stations N2 and S3 (Figures 2 and 4). 4.2 Breeding Bird Surveys Between June 1 and July 14, 2005 four breeding bird surveys were conducted for each turbine and random or offset point for the 14 paired points. 1,070 total observations in 806 different groups (flocks) were observed during the paired-plot surveys (Table 6). These are simply raw counts of observations, that were not standardized by the number of hours of observation or distance from observer, but do provide an overall list of species and numbers observed. Because individual birds were not marked, these counts do not distinguish between individuals; rather, they provide an estimate of use. A total of 13 avian species and an additional 1 unidentified bird type (best possible identifications, e.g. unidentified buteo) were observed during the paired-plot surveys (Table 6). Three of these species were not observed during the fixed point surveys, WEST, Inc. 9

18 American robin, house finch, and common nighthawk. Horned lark were by far the most numerous species observed, comprising 76.2% of all groups and 79.7% of all birds observed. Passerines were the most common group observed comprising 96.9% of all groups and 97.1% of all birds observed. Raptors only comprised 0.4% of all groups and 0.3% of all birds observed. Shorebirds, other birds, and unidentified birds only comprised 2.7% of all groups and 2.6% of all birds observed Avian Use Avian use by species was calculated as the mean number of observations per 10-minute survey within 250 m of the point (Table 7). Based on use, the three most abundant species observed during the breeding bird surveys were the same for both the turbine and random points, horned lark (7.52 detections/10-minute survey for turbine points and 7.64 for random points), rock wren (0.63 for turbines and 0.77 for random points), and common raven (0.36 for turbines and 0.34 for random points). Together these species comprised more than 94% of the total use for the turbine points and over 95% of the total use for the random points. As expected, passerines were the most abundant group observed. The only raptor observed during the surveys was red-tailed hawks but all observations were greater than 400 m from the survey point so were not factored in to the use estimates (Table 6). The paired-plot survey was set up so that one point of each pair was located at a proposed turbine location and one point off-set approximately 250 m in a random direction. This design enables post construction displacement effect monitoring, if necessary. Use was calculated separately for turbine points and offset or random points by taxonomic group and avian species for possible future use in understanding possible displacement effects (Table 7). Paired t-tests for the difference in use between the turbine and offset points did not show any significant differences (Table 7) which would be expected in a topographically and vegetatively monotypic area. 4.3 In-transit Surveys During periods when observers were on site for surveys, species observed while traveling between survey stations were recorded. This information provides a general but broader sample of the study area. In addition, five trips to the nearby Diablo Canyon were made during the course of the study for general surveys. Several species were seen during the in-transit surveys that were not recorded during the fixedpoint or paired-plot surveys (Table 8). Fifteen raptors were observed incidentally in the project area including one golden eagle. Four raptors were seen in the Diablo Canyon area including one bald eagle which was a species not recorded during the standardized surveys (Table 9). 4.4 General Wildlife and Big Game Species Observations Other non-avian wildlife observed in the project area included a variety of mammals and a few reptile species (Table 8). Of interest were observations of pronghorn, a species of concern for the AZGFD. Eighty-six pronghorn in 13 different groups were observed in the study area over the course of the study in areas to the south of I-40; no pronghorn were observed north of I-40. Other than the single bald eagle observed at Diablo Canyon, no other threatened or endangered or sensitive species were observed during the study. WEST, Inc. 10

19 5.0 DISCUSSION AND SUMMARY 5.1 Avian Use and Diversity Based on the fixed-point surveys over all seasons, horned lark made up the vast majority of bird observations on the. Horned larks were observed in greater than 80% of the surveys and comprised over 55% of all avian use at the site for all seasons. During the winter horned lark made up over 95% of the bird use of the site. Only a few other species were seen in more than 5% of the surveys with the second most common species being common raven. These results are typical of areas that are topographically and vegetatively monotypic where a few species are common. The desert scrub vegetation type of the site is highly suited to horned larks with a prevalence of bare ground and short vegetation. Raptors were uncommon at the site. Over the course of all the fixed point and paired plot surveys and in-transit observations, 60 raptors were observed in 52 groups. The most common raptors observed were red-tailed hawk and American kestrel. The low number of raptor observations resulted in low relative abundance (use) estimates and low exposure indices. As a group, raptors comprised less than 1.7% of all bird use of the site. Passerines were the most common with over 95% of all bird use at the site for all seasons. For all birds, use was highest in the winter season when species such as horned lark tended to be observed in large flocks. Use was lowest in the spring when the species diversity increased as indicated by the number of species observed and the frequency of occurrence (see Table 3). This again is typical, as resident species may break up into breeding territories (seen in smaller group sizes) and more migrants may be observed. As with the fixed-point surveys, the paired-plot surveys also showed relatively low species diversity on the site with one species, horned lark, making up the majority of the observations. Horned lark comprised well over 80% of total use for both turbine and random points. As expected due to similarity of plots in each pair in terms of topography and vegetation, there were no significant differences in bird use between points. The paired-plot surveys were designed to target breeding passerine species that occupy the site and provide a baseline against which to compare results from post-construction surveys. 5.2 Risk of Turbine Collision The species with the highest exposure indices for the site were horned lark and common raven (see Table 5). The majority of common ravens were observed within the zone of risk and observed in flight. Horned lark was by far the most abundant species observed and the majority were observed in flight. These factors tend to drive up the exposure index estimate. While the exposure index is not a measure of absolute risk, it does provide a relative estimate of the chance a species may come in contact with turbine blades. An exposure index of zero does not necessarily mean that a species is not at risk, but it does indicate that based on the observations made of that species on the site, it is unlikely to be in the area of the turbine blades for much of the time. WEST, Inc. 11

20 Mortality studies at other wind plants have commonly found horned-lark casualties but few common ravens (see Erickson et al. 2001). Although ravens are often observed at wind plants within the zone of risk, they appear to be less susceptible to collision with wind turbines than other similar size birds (e.g., raptors, waterfowl). Horned lark is, however, a common casualty observed at other wind plants most likely due to the abundance of this species in habitats commonly found at wind plants. Raptor use of the site was very low and raptors as a group do not appear to be at great risk from the proposed development. There are few areas within the project area suitable for raptor nesting or foraging. There were some prairie dog colonies located primarily north of I-40 but these did not appear to experience increased raptor use based on the surveys. In general the number of raptors observed was too few to distinguish trends or concentrations in use of the site. American kestrels and red-tailed hawks have been recorded fatalities at other wind projects in the U.S. (see Erickson et al. 2001) however, use by these species at the was so low that they would not be expected to be at great risk. Predictions of raptor mortality based on the low use estimates for the site are difficult to make, but overall, it is not expected that the proposed development would result in substantial raptor mortality. As with raptors, use by other groups of birds such as waterfowl, shorebirds, doves, and other non-passerine species was so low that trends or concentration areas could not be distinguished easily. These groups are not expected to be at risk from the proposed development. Passerines (perching birds) have been the most abundant avian fatality at some other projects studied (see Erickson et al. 2001), often comprising more than 80% of the avian fatalities. Both migrant and resident passerine fatalities have been observed. Given that passerines make up the vast majority of the avian observations on-site, passerines would likely make up the largest proportion of fatalities. Common species such as horned larks and possibly rock wren (confirmed casualties at other wind plants) would be most at risk. Nocturnal migrating species may also be at risk, but are not be expected to be found in large numbers based on data collected at other projects (i.e., no large mortality events documented, see Erickson et al. 2001). 5.3 Turbine Siting Issues Overall the results of the avian surveys were typical of areas with monotypic vegetation type and topography. The site is generally flat and the dominant vegetation type is desert scrub. The primary vegetative diversity is located around the development at Meteor Crater Exit of I-40. Diablo Canyon provides some topographic relief but is approximately 1 mile west of the site. Based on the survey results there were no marked avian concentration areas or areas that would appear to pose a greater risk from development. No results were found that might suggest some further investigation or detailed analysis to look for variable trends. 5.4 Future Study Issues Initially, a survey for raptor nests was a proposed component of study that might be warranted if raptor use of the site was high or concentrated (see CPRS et al. 2004). Based on results from the fixed-point, paired plot, and in-transit surveys, raptor use estimates were very low and it does not appear as if a substantial number of raptors would nest in the area. The topography and WEST, Inc. 12

21 vegetation of the site is not conducive to raptor nesting. The nearest likely area for raptor nests would be Diablo Canyon approximately one mile west of the site. At this time it does not appear as if a raptor nest survey of the project area would be warranted. Once a project layout has been developed, it could be evaluated for areas where turbines come closest to Diablo Canyon and these areas investigated on foot for nesting raptors. 6.0 REFERENCES Bibby, C.J., N.D. Burgess, and D.A. Hill Bird Census Techniques. Academic Press, New York. 257 pp. Brown, D.E., ed Biotic communities: southwestern United States and northwestern Mexico. University of Utah Press, Salt Lake City, Utah. Colorado Plateau Research Station (CPRS) and Ecological Monitoring and Assessment Program (EMA) Northern Arizona University (NAU), and Western EcoSystems Technology, Inc. (WEST) Avian and Biological Baseline Study Plan, Coconino County, Arizona. Prepared for Foresight Wind Energy, San Francisco, California. Erickson, W.P., G.D. Johnson, M.D. Strickland, D.P. Young, Jr., K.J. Sernka, R.E. Good Avian Collisions with Wind Turbines: A Summary of Existing Studies and Comparisons to Other Sources of Avian Collision Mortality in the United States. National Wind Coordinating Committee (NWCC) Resource Document. August Reynolds, R.T., J.M. Scott, and R.A. Nussbaum A Variable Circular-Plot Method for Estimating Bird Numbers. Condor 82(3): Young, Jr., D.P. and V. Poulton Phase I Biological Report, Evaluation Of Biological Resource Issues Associated With The, Coconino County, Arizona, November Prepared for Sunshine Arizona Wind Energy, LLC, Flagstaff, Arizona. WEST, Inc. 13

22 Table 1. Summary of fixed point surveys conducted and overall mean bird use and diversity by season. Number of Number of Number of Mean Number of Species Season Visits Surveys Species Use a per Survey b Winter Spring Fall Overall a mean number of bird observations per 30-minute survey b mean number of bird species observed during each 30-minute survey WEST, Inc. 14

23 Table 2. Avian species observed while conducting fixed-point surveys in the. Winter Spring Fall Total Species/Group # individs # groups # individs # groups # individs # groups # individs # groups Waterfowl green-winged teal Shorebirds killdeer Raptors/Vultures Accipiters Cooper's hawk Buteos red-tailed hawk Harriers northern harrier Eagles golden eagle Falcons American kestrel prairie falcon Other Raptors unidentified hawk unidentified raptor Vultures turkey vulture Passerines Bewick's wren Brewer's sparrow Say's phoebe Scott's oriole black-headed grosbeak black-throated sparrow common raven dark-eyed junco gray flycatcher green-tailed towhee horned lark lark bunting lesser goldfinch loggerhead shrike mountain bluebird northern mockingbird WEST, Inc. 15

24 Table 2. Avian species observed while conducting fixed-point surveys in the. Winter Spring Fall Total Species/Group # individs # groups # individs # groups # individs # groups # individs # groups rock wren sage sparrow spotted towhee unidentified sparrow vesper sparrow violet-green swallow white-crowned sparrow Doves mourning dove Other Birds broad-tailed hummingbird greater roadrunner northern flicker Unidentified Birds unidentified bird unidentified large bird Subtotal WEST, Inc. 16

25 Table 3. Estimated mean use, percent composition, and frequency of occurrence for each species and group observed within 800m of the survey point for fixed-point surveys. Winter Spring Fall Species/Group use % comp % freq use % comp % freq use % comp % freq Waterfowl green-winged teal Shorebirds killdeer Raptors/Vultures Accipiters Cooper's hawk Buteos red-tailed hawk Harriers northern harrier Eagles golden eagle Falcon American kestrel prairie falcon Other - Raptors unidentified hawk unidentified raptor Vultures turkey vulture Passerines Bewick's wren black-headed grosbeak black-throated sparrow Brewer's sparrow common raven dark-eyed junco gray flycatcher green-tailed towhee horned lark lark bunting lesser goldfinch loggerhead shrike mountain bluebird northern mockingbird rock wren sage sparrow Say's phoebe Scott's oriole spotted towhee unidentified sparrow vesper sparrow violet-green swallow white-crowned sparrow WEST, Inc. 17

26 Table 3. Estimated mean use, percent composition, and frequency of occurrence for each species and group observed within 800m of the survey point for fixed-point surveys. Winter Spring Fall Species/Group use % comp % freq use % comp % freq use % comp % freq Doves/Pigeons mourning dove Other Birds broad-tailed hummingbird greater roadrunner northern flicker Unidentified Birds unidentified bird unidentified large bird Overall WEST, Inc. 18

27 Table 4. Flight height characteristics of avian species and groups observed during the fixed-point surveys. Species/Group Number groups Number birds Percent of birds <25 m m > 125 m flying flying flying Waterfowl green-winged teal Shorebirds killdeer Raptors/Vultures Accipiters Cooper's hawk Buteos red-tailed hawk Harriers northern harrier Eagles golden eagle Falcons American kestrel prairie falcon Other Raptors unidentified hawk unidentified raptor Vultures turkey vulture Passerines Bewick's wren black-headed grosbeak black-throated sparrow Brewer's sparrow common raven dark-eyed junco gray flycatcher green-tailed towhee horned lark lark bunting lesser goldfinch loggerhead shrike mountain bluebird northern mockingbird rock wren WEST, Inc. 19

28 Table 4. Flight height characteristics of avian species and groups observed during the fixed-point surveys. Species/Group Number groups flying Number birds flying Percent of birds flying <25 m m > 125 m sage sparrow Say's phoebe Scott's oriole spotted towhee unidentified sparrow vesper sparrow violet-green swallow white-crowned sparrow Doves mourning dove Others Birds broad-tailed hummingbird greater roadrunner northern flicker Unidentified Birds unidentified bird unidentified large bird Overall WEST, Inc. 20

29 Table 5. Exposure indices calculated for species observed during fixed-point surveys. Species Mean use Percent flying Percent flying within RSA Exposure Index horned lark common raven unidentified sparrow mountain bluebird red-tailed hawk American kestrel green-winged teal unidentified large bird northern harrier turkey vulture loggerhead shrike unidentified bird unidentified hawk rock wren Brewer's sparrow black-throated sparrow sage sparrow vesper sparrow mourning dove white-crowned sparrow dark-eyed junco green-tailed towhee lark bunting killdeer northern flicker prairie falcon Say's phoebe black-headed grosbeak Cooper's hawk gray flycatcher greater roadrunner broad-tailed hummingbird golden eagle lesser goldfinch Scott's oriole spotted towhee violet-green swallow northern mockingbird N/A N/A Bewick's wren N/A N/A unidentified raptor N/A N/A WEST, Inc. 21

30 Table 6. Avian species observed while conducting breeding bird surveys at the. Species/Group Number of individuals Number of groups Shorebirds killdeer 2 2 Raptors red-tailed hawk 3 3 Passerines American robin 1 1 Say's phoebe black-throated sparrow common raven horned lark house finch 3 1 loggerhead shrike 1 1 northern mockingbird 1 1 rock wren Doves/Pigeons mourning dove 1 1 Other Birds common nighthawk 2 2 Unidentified Birds unidentified bird All Birds WEST, Inc. 22

31 Table 7. Average use by species and group for observations within 400m of the plot center for turbine and offset points from the breeding bird surveys. Mean Use Paired Group Turbine Random Difference t-test Shorebirds killdeer Raptors red-tailed hawk N/A N/A N/A N/A Passerines American robin black-throated sparrow common raven house finch horned lark loggerhead shrike northern mockingbird rock wren Say's phoebe Doves/Pigeons mourning dove Other Birds common nighthawk Unidentified Birds unidentified Birds All Birds WEST, Inc. 23

32 Table 8. Number of individuals and groups of avian species and other non-avian wildlife observed incidentally in the study area. Species Observations Groups Birds horned lark common raven house sparrow rock wren sage sparrow Brewer's sparrow 53 2 brown-headed cowbird 50 1 black-throated sparrow 22 9 house finch 14 8 loggerhead shrike Say's phoebe 13 8 Brewer's blackbird 13 1 vesper sparrow 12 9 killdeer 11 6 great-tailed grackle 11 5 white-crowned sparrow 6 4 Bewick's wren 5 5 sage thrasher 5 4 American wigeon 5 1 green-winged teal 5 1 northern mockingbird 4 4 red-tailed hawk 4 4 spotted towhee 4 4 mourning dove 4 3 lark bunting 4 1 yellow-headed blackbird 4 1 American kestrel 3 3 American robin 3 2 western kingbird 3 2 Cooper's hawk 2 2 dark-eyed junco 2 2 northern harrier 2 2 unidentified raptor 2 2 canyon wren 2 1 red-naped sapsucker 2 1 savannah sparrow 2 1 western bluebird 2 1 American coot 1 1 black-headed grosbeak 1 1 blue-throated hummingbird 1 1 Cassin's finch 1 1 common nighthawk 1 1 WEST, Inc. 24

33 Table 8. Number of individuals and groups of avian species and other non-avian wildlife observed incidentally in the study area. Species Observations Groups golden eagle 1 1 gray flycatcher 1 1 greater roadrunner 1 1 lark sparrow 1 1 northern flicker 1 1 prairie falcon 1 1 tree swallow 1 1 unidentified sparrow 1 1 western tanager 1 1 Wilson's snipe 1 1 Wilson's warbler 1 1 yellow warbler 1 1 yellow-rumped warbler 1 1 Avian Subtotal Mammals Gunnison's Prairie Dog a Pronghorn b desert cottontail rabbit coyote c 10 6 black-tailed jack rabbit 5 5 Elk d 2 1 Woodrat e 2 2 beaver 1 1 badger f 1 1 Mammal Subtotal Reptiles short-horned lizard 2 2 collared lizard 1 1 Reptile Subtotal 3 3 Other white-lined sphinx moth 12 1 a subtotal includes observed individuals only; three sets of burrows also observed b subtotal includes observed individuals only; 6 tracks and 3 scat piles also observed c subtotal includes observed individuals only; 6 scat piles, 2 tracks, dead individual also observed d subtotal includes observed individuals only; scat and dead individual also observed e two middens for wood rats were observed. f tracks of a badger and skull were observed. WEST, Inc. 25

34 Table 9. Number of individuals and groups of avian species observed at Diablo Canyon. Species Observations Groups horned lark 64 5 dark-eyed junco 33 4 common raven 27 5 mountain bluebird 16 1 rock wren 14 4 house finch 12 2 canyon wren 9 4 Bewick's wren 7 4 white-crowned sparrow 7 2 crissal thrasher 5 2 ruby-crowned kinglet 3 1 savannah sparrow 3 1 chipping sparrow 2 1 green-tailed towhee 2 1 red-tailed hawk 2 1 American kestrel 1 1 bald eagle 1 1 black-throated sparrow 1 1 greater roadrunner 1 1 sage sparrow 1 1 sage thrasher 1 1 Say's phoebe 1 1 song sparrow 1 1 spotted towhee 1 1 vesper sparrow 1 1 Overall a A cliff swallow nest was found along with a single dead mourning dove. WEST, Inc. 26

35 Figure 1. Regional map showing the project location. WEST, Inc. 27

36 Figure 2. Map of the project area and fixed-point survey stations. WEST, Inc. 28

37 Figure 3. Map of the project area and paired-plot survey points. WEST, Inc. 29