FORSMARK WINDFARM REPORT ON ORNITHOLOGICAL SURVEYS AND ANALYSES Prepared by. Natural Research Projects Ltd.

Transcription

1 FORSMARK WINDFARM REPORT ON ORNITHOLOGICAL SURVEYS AND ANALYSES Prepared by Natural Research Projects Ltd 24 December 2010 Author: Dr M McGrady Checked by: Dr Phil Whitfield Commissioned by: Vattenfall Vindkraft AB Natural Research Projects Ltd Brathens Business Park Hill of Brathens Glassel Banchory AB31 4BY

2 Summary Vantage Point watches were made over a proposed windfarm area at Forsmark to better understand White tailed eagle movement and provide data with which to model collision risk to eagles. Also, preliminary carcass removal experiments were undertaken to better understand how long birds killed by turbines might detectable in the field and how efficient searchers for carcasses might be in finding windfarm-related bird mortalities. In total 619 flight paths were recorded for White tailed eagles (245.9 hrs of observations); 1195 spot heights of flying eagles were recorded along those paths. Most flight paths were outside areas around proposed turbine locations where there would be a risk of collision. Data from these observations were used in the so called Band collision risk model. We ran the model using two different possible turbine heights (80 and 100 m at the hub) and assuming two different levels of avoidance by the eagles (95% and 98%). For the 80 m turbines, annual mortality was estimated to be 1.32 if eagles avoided turbines 95% of the time and 0.53 if eagles avoided turbines 98% of the time. For the 100 m turbines the values were 0.65 and 0.26 for assumed 95% and 98% avoidance, respectively. These estimates were lower than those made from data gathered at this site in 2008, but caution should be applied when making comparisons, as methods were different and the winter weather differed in the two years. The effects of the differences between the two studies in data collection and modelling are discussed. Two search plots were established in the proposed windfarm area and these contained open, scrub and woodland habitats. The naïve searcher was able to find 75% of carcasses that were placed out. Carcasses remained intact longer in the open than in the wooded areas. The mean day on which scavenging first occurred was 7.5 (n=8) and 17.4 (n=5) for the two plots. The mean day on which scavenging was first detected was 21 for open scrub (n=2), 17 days for bare ground (n=3) and 9.5 days for woodland (n=8). By Day % of carcasses were intact and 62.5% were completely missing or reduced to feathers; 18.75% had been partially scavenged. Scavengers or their signs noted in and around the plots were white-tailed eagle and red fox. Although limited in scope the results of the carcass removal experiments suggest that an effective search protocol can be developed for the land area of the windfarm. More effort is needed to devise a way of handling the possibility that some remains of collisions might land in the water.

3 Forsmark: White-tailed Eagle Study Introduction 1. The area of the proposed Forsmark windfarm ( the Development ) in Sweden is an important area for White-tailed eagles Haliaeetus albicilla (WTE), which breed in the vicinity (M. Green 2007, 2009, B. Helander and A. Sevastik pers. comm.) and winter there (B. Helander, A. Sevastik, J. Pettersson pers. comm.). A study of collision risk to WTEs was undertaken in , the results of which were reported in Pettersson and Sevastic (2009), and formed part of the Environmental Statement (Vattenfall Vindkraft AB 2009). 2. This study was initiated in late 2009 by Vattenfall Vindkraft and Natural Research Projects, Ltd (NRP) to gather data that would form the base of a future monitoring programme. 3. The work carried out this year included: systematic Vantage Point (VP) watches, Collision Risk Modelling (CRM), and carcass detection and removal trials. Study area 4. The Development is located at approximately (60.42 o N, o E), just east of the Forsmark Nuclear Power Station, and is comprised of group of islands (skerries) that have been joined to the mainland and to each other by a causeway. There is a manmade spit of land ( the South Pier ) to the south of the main circular group of islands. The circular group of islands and causeway enclose the Biotest basin into which flows water used to cool the nuclear reactors; there are two cooling water outlets, both in the northern part of the basin. The South Pier extends east from the road into open water (Appendix 1 Figure 1). 5. Vegetative cover is most developed on the skerries, where patches of trees (e.g Scots pine (Pinus sylvestris), spruce (Picea sp.), juniper (Juniperus sp.), birch (Betula sp), etc.) reach 5-7 m in height and understory vegetation can be dense. Other vegetative cover (willow (Salix), grasses, reeds, shrubs etc) is found on the skerries, the causeway between islands and the south pier. The south pier also supports a few small trees (including Scots pine and birch), but vegetation there is generally more sparse.

4 6. A proposed wind farm layout includes 15 turbines: four along the road leading out to the basin, three on the south pier and eight around the basin (Appendix 1 Figure 1). Methods Vantage Point Observation 7. Information on WTE flight activity was collected during timed watches from strategic VPs using the methods described by Band et al (2007), with modifications. The majority of observations were made using range finder binoculars (Vectronix IV and Vectronix 21, Vectronix AG, Heerbrugg, Switzerland) that were able to collect location (x, y) and height information (z) about the bird under observation at intervals along its flight path. The observer would then map the flight path in two dimensions, anchoring that path to relatively accurate location measurements (+/- 5 m) made by the binoculars, which were associated with relatively accurate height measurements (+/-3 mrad = approx +/- 3 m at 1000m). 8. Two VPs (Appendix 1 Figure 1) were used for observations made between 19 November 2009 and 14 October The surveyors were Jan Pettersson (JP) and Alf Sevastik (AS), both experienced observers of WTE at Forsmark. 9. Vantage Point locations were chosen by JP and AS based on field experience at the site to give the best view over the Development. The Huset Utloppet (Outlet) VP was located on the shore on the eastern side of the Biotest Basin (Sweden Grid RT 90 (region 25 gon V) , ) facing west. The Södra piren (South Pier) VP was located about a third of the way out the south pier facing N-NW ( , ). Observers positioned themselves to minimise their effects on bird behaviour. 10. Watches were undertaken during daylight hours in a variety of weather conditions, including variable cloud cover (0-100%) and wind speeds up to 18 m/sec. Watches were not made when it was deemed that poor visibility impeded data collection. Watches were spread throughout the daylight hours so as to allow for diurnal variation in activity rates and variation in day length. They varied in duration from 37 minutes to 6 hrs. In total hrs of observations were made; from the Outlet VP and 66.6 from the South Pier VP hrs of observation were during the breeding period (March - July), and during the non-breeding period (August - February). Table 1, Appendix 2).

5 11. The viewing arc was scanned constantly until a WTE was detected in flight. Once detected, the bird was targeted with the range finding binoculars. The binoculars use a laser to lock onto the target and once this is done measurements of location and height can be made by the binoculars and automatically saved in the binocular s memory for downloading later. If a lock was not achieved the height of the bird was estimated by the observer. Estimated heights were identified separately so as to distinguish them from heights measured using the binoculars. Eagles were followed until they ceased flying or were lost from view. The time the bird was initially detected was recorded to the nearest minute. The route followed by the bird was plotted in the field onto a 1:25,000 scale map, with the direction of flight indicated. Routes were plotted regardless of whether or not the bird was within the survey area. At the end of the day the field maps were corrected by using the location data collected by the binoculars. Information pertaining to each flight was recorded including date, time and age of bird, on field record sheets. These data were merged at the end of the day with data downloaded from the binoculars, and each record was cross-referenced to a flight path on a map. Collision Risk Modelling 12. Data from flight paths were used to undertake CRM. The Unpredictable Flight Method (UFM) was determined to be appropriate as flights were not in any particular direction and assumed to be random (Band et al 2007). 13. The CRMs used only observations collected within a 150m buffer (centred on the turbine tower) around each proposed turbine location. This size of buffer encompasses rotor blade length, possible shifts in proposed turbine location due to micrositing and, potential spatial errors in flight recording accuracy. 14. Field data included spot heights (measured using the range finding binoculars or estimated by the observer), plotted along mapped flight paths. So as to render these data useable in the CRM, the flight paths were divided half way between spot heights and the central height was assigned to the resulting length of flight path. 15. Flight duration within the 150 m buffer was calculated from the length of each flight path which fell within the buffer and a value for WTE flight speed of 13 m/sec (Provan and Whitfield 2007). 16. The Outlet VP (179.3 hrs) is assumed to only effectively overlook the basin turbines (6-13). South Pier VP (66.6 hrs) is assumed to overlook all turbines outside the basin,

6 plus the three turbines at the southwest of the basin (1-6, 12-15). (Appendix 1, Figure 2). 17. For the purposes of this study it was assumed that the turbines would be Siemens SWT models and two turbine heights were considered (80 m and 100 m at hub height). 18. A further assumption was that turbines would be inoperative for 13% of time due to wind speed and maintenance. 19. We ran the CRM assuming 98% avoidance and assuming 95% avoidance. Pettersson and Sevastik (2009) used 98% and 99% avoidance; Scottish Natural Heritage currently recommends a 95% avoidance rate (SNH 2010). 20. Table 2 Appendix 2 summarizes turbine and WTE parameters used in CRM. Turbines with their hubs at 80m have rotor swept heights of m above ground level (Total rotor diameter = 93 m); turbines with their hubs at 100m have rotor swept heights of m above ground level. Carcass removal trials 21. Post-construction searches around the turbines are proposed to determine whether there are collisions of WTE. However, there is evidence that searcher efficiency in windfarm studies can be influenced by height and type of vegetation (Morrison 2002). Also, carcasses can be removed by scavengers before they are discovered during searches (Johnson et al 2000). 22. Carcass Removal Trials were carried out with the aim of understanding searcher efficiency and the likely scale and source of scavenging at the Development. 23. Methodology followed Duffy and Steward (2008) and that used at the Saint Nikola Kavarna Wind Park, Bulgaria (NRP unpublished data), adapted for the situation at Forsmark, where areas of land around potential turbine locations can be relatively small, and are surrounded by water. 24. There were two objectives to the trials: to record the number of carcasses that could be found by a naïve observer searching the plots and to record the rate at which the carcasses disappeared from the plots. 25. Two survey plots (South Plot and North Plot) were chosen at proposed turbine sites on the causeway system surrounding the basin (Figure 1, Appendix 1). Each plot

7 measured roughly 50m x 130m. Due to the nature of the Forsmark site, where land area is small and surrounded by water, search plots were smaller than optimal (NPR unpublished data; for 80 m turbines search area should be 250m x 250m; for 100 m turbines: 290m x 290m). At Forsmark, this size would place some of the plot area in the sea or the Biotest Basin, or within difficult habitats to search, such as dense scrub or reed bed. The plots were chosen to include the three habitat types present at the site: bare ground, open scrub and woodland, to investigate the feasibility of the search methods in these habitats. The South Plot consisted of bare ground, chiefly compacted stone and rock, and open scrub, which was essentially regenerating woodland. The North Plot consisted of old growth woodland containing Scots pine, spruce, juniper and birch. 26. Carcasses of relatively large species were used in the trials as they were similar to the size of WTE carcasses or pieces of carcasses resulting from a collision. Eleven goose carcasses (seven greylag goose Anser anser, four Canada goose Branta canadensis) were obtained, the birds having been killed with steel shot in order to prevent any risk of lead poisoning to scavenging species. Five chicken (Gallus domesticus) carcasses (four hens and one cockerel) were also obtained for the trial. Three of the geese (two greylag geese, one Canada goose) were cut in two to simulate turbine damage, some carcasses were cut open to simulate minor turbine blade damage and two carcass parts were positioned off the ground in wooded areas to simulate casualties becoming caught in trees. Each plot had eight carcasses, or part carcasses laid out on 6 October Each carcass had its location recorded with a GPS and was fitted with an ID tag in case carcasses were moved by scavengers. 27. All the carcasses were visited on Days 1 to 5 after the day of positioning to check whether the carcasses remained intact and present. Thereafter, the carcasses were visited every second day until Day 26. Carcasses that showed any signs of having been scavenged were photographed (Appendix 1, Figures 6 and 7) and any movements of carcasses were recorded using GPS. Any scavengers or their signs seen in the plots were recorded. 28. In addition to the carcasses laid out in the two plots, three goose carcasses were positioned by reed beds close to the water s edge in order to test how quickly they were removed from this habitat.

8 29. Kevin Duffy who has experience in running such trials in Scotland and Bulgaria established the plots and directed the removal trials. Alf Sevastik performed the fieldwork. Results VP observations 30. A total of 619 flight paths were recorded for WTE during the study period (Appendix 1 Figure 3 and Appendix 2 Table 3). 392 flights were recorded during the non-breeding season; 227 during the breeding season. Flights recorded per month varied between 22 and 117. A total of 1195 spot heights (86.9% measured, 10.1% estimated) were recorded along those paths (mean=2.6 spot heights/flight path). No height was recorded for 170 flight paths. CRM 31. The majority of flightlines were outside the rotor swept height of the turbines. Appendix 1 Figure 4 shows flightlines that had spot heights that fell within the rotor swept height of the two turbine heights considered. (Note that these figures include all flights, including those > 150m from turbine locations). There were more flightlines that fell within the rotor swept height of the 80m turbines than fell within the rotor swept height of the 100 m turbines. 32. Table 4 Appendix 2 shows the duration of flights at risk height and within the 150 m buffers around turbine locations, and those durations adjusted for observational effort. 33. Tables 5-10 Appendix 2 show full results of the CRM for both 80 and 100m hub height turbines using observation data weighted for effort. Table 11 Appendix 2 summarizes the predicted WTE mortality (years/mortality) for the two turbine height options and assuming 95 and 98% avoidance rates by the eagles and compares them to the mortality estimated by Pettersson and Sevastik (2009). Table 12 Appendix 2 shows the same results expressed in terms of number of estimated mortalities per year. 34. Mortality can also be represented in map form, assigning to each turbine the proportion of the total mortality it contributes. Figure 5 Appendix 1 shows the relative risk each turbine poses to WTE, considering both 80m and 100m tower options.

9 Carcass removal trials 35. The naïve searcher was able to find 75% of carcasses that were placed out: 8 of 8 carcasses (100%) in the North Plot and 4 of 8 carcasses (50%) in the South Plot. 36. Carcasses were checked according to the method up to 23 days. Carcasses remained intact longer in the open (either bare ground or open scrub) South Plot than in the wooded (Old growth woodland) North Plot (Table 13 Appendix 2). None of the carcasses in the North Plot and three (37.5%) of the carcasses in the South Plot were untouched by scavengers. Of carcasses that showed at least some signs of scavenging, the mean day on which scavenging first occurred on the North Plot was 7.5 (n=8) and 17.4 (n=5) on the South Plot. 37. Of carcasses that showed at least some signs of scavenging, the mean day on which scavenging was first detected was 21 for open scrub (n=2), 17 days for bare ground (n=3) and 9.5 days for woodland (n=8). By Day 23 only three (18.75%) of the sixteen carcasses were left intact and ten (62.5%) were completely missing or reduced to feathers; three (18.75%) had been partially scavenged (Appendix 2, Table 15). 38. The three carcasses placed in reed beds were removed quicker (all were removed by day 5) than in scrub, bare ground or wooded habitats (Table 14, Appendix 2). One of three (33%) of carcasses placed in open scrub habitat, and two of five (40%) of carcasses placed on bare ground persisted for the 23 days of the trial. 39. There was no obvious difference in removal rate between whole and half goose carcasses, or between geese and chickens. The carcass that remained intact longest in the North Plot was placed 2m up in a tree. Despite being in a tree, this carcass was also partly scavenged. 40. Scavengers or their signs noted in and around the plots were white-tailed eagle and red fox. Discussion 41. There is considerable overlap when discussing VP observations and the CRM in that issues of quality and quantity of VP observation data have an effect on the results produced by the CRM.

10 VP observations/data collection 42. The large number of WTE flights recorded was in line with expectations. Pettersson and Sevastik (2009) recorded many WTE flights, many WTEs are known to winter around Forsmark and there are breeding pairs nearby. 43. Although WTEs can soar and fly at high elevations in some conditions, few high altitude flights were observed in the Development area. 44. The range finding binoculars have not typically been used in studies of bird flight and collision risk in the past. While the binoculars probably consistently locate the bird in space (x, y and z) more accurately than observers making estimations (within about 1.3 km), their use affected the collection of other data; few height data were gathered at the beginning of flightlines, flight heights were more difficult to measure at greater distances, and duration of flights was not recorded. The use of the range finding binoculars probably had the effect of increasing slightly the estimation of collision risk because some percentage of birds approaching the islands where turbines will be located were going there to perch and so more birds were probably descending rather ascending as they approached the islands (i.e. they were moving away from the risk envelope). Because spot heights were rare at the end of flight lines and some birds disappeared behind trees their lowest flight heights were not recorded and so the segment close to where turbines would be located was assigned a higher height value. 45. The use of the range finding binoculars in this study and that by Pettersson and Sevastik (2009) differs from methodology used in Scotland. As mentioned above, the use of range finding binoculars probably resulted in a slightly higher estimate of mortality. In using the range finding binoculars observers were unable to collect data that could generate flight speed estimates for each flight line, and so our calculations of duration of flights within the risk envelope are based on published values for WTE flight speed. 46. The temporal unit of the mortality estimate is one year, and so observations should be made over all turbine locations throughout the year in case of seasonal variation in flights. Total mortality estimate is the sum of the estimates of the individual turbines. Mortality estimates for individual turbines is related to the time eagles spend at risk height within the buffer of each turbine per observational effort. If eagles spend more time in this risk envelope the mortality estimate for that turbine will increase and so too will the total estimate. During the winter very few eagles flew in the area of the

11 turbines to the south of the Biotest Basin (i.e. those visible from the South Pier VP), and this was the reason for less effort being put into observations from the South Pier VP. If data from the non-breeding season (when rates of eagles flying within the risk envelope was low) had been collected and added the data from summer when rates were high, the overall annual rate would have been lower than what was used in the CRM, So, the lack of survey effort during winter from South Pier, when sea ice was present, coupled with assumed low rates of WTEs flying over sea ice, will have resulted in a higher predicted mortality, especially at the turbine locations where fullyear observations were not made. 47. It was not possible to locate VPs outside the development site; to do so would move the observer far from the Development and hamper data collection. However, mapped flightlines (Figure 3, Appendix 1) suggest that eagles may be avoiding the observer. This was also cited as a problem by Pettersson and Sevastik (2009). This problem can be overcome if VPs overlook one another. If avoidance of the observer by WTEs is occurring, then the validity of the CRM, especially with regards to turbine locations near the VP, is undermined. 48. The potential avoidance of observers mentioned above notwithstanding, it appears from the map of flightlines (Figures 3 and 4, Appendix 1) that eagles may be showing preference for certain corridors when flying into and out of the Biotest basin CRM 49. Results of the CRM using data collected in predict that assuming 95% avoidance the 80 m turbine option would result in a WTE mortality every 0.8 yrs, and assuming a 98% avoidance a WTE mortality would occur every 1.9 yrs. For the 100 m turbine option, assuming a 95% avoidance rate would result in a mortality every 1.5 yrs, and assuming a 98% avoidance rate a mortality would occur ever 3.5 yrs (Appendix 2, Tables 5-10). 50. The results of CRM from this study were lower than those reported by Pettersson and Sevastik (2009), Tables 11 and 12 compare the results of CRM from the two studies. Comparisons should be made with caution because there were differences between the two studies in methods and values for some parameters that were used in CRM, and the weather, at least during winter, was different between the years and may have influenced eagle flights patterns.

12 51. Avoidance rate, probably more than any other parameter, affects the outcome of the CRM. Current guidance (SNH 2010) is for a 95% avoidance rate by WTE. In 2009 a value of 98% avoidance was a common assumption of WTE behaviour, and was used in CRMs. 52. Pettersson and Sevastik (2009) used frequency of flights entering the risk envelope as a measure of risk of collision by WTE. This study used the actual length of the flightline that fell within the risk envelope multiplied by flight speed to calculate the total duration of eagle flights in the risk envelope, a more accurate estimate of risk. 53. As with the use of the 95% avoidance rate and flight duration within the risk envelope rather than flight frequency this study incorporates other parameters that aim to improve the mortality estimate. 54. Flight data showed that WTEs at Forsmark mostly fly at low elevations. This preference resulted in the CRM predicting that the 80m turbine tower option would cause more WTE mortalities than the 100m tower option (about twice as many). Pettersson and Sevastik (2009) also predicted that the 80m option would be less hazardous to WTEs. 55. Presence and distribution of sea ice could affect the distribution of eagles and their flight behaviour. Eagles can perch on sea ice and the distribution of potential prey (e.g. sea birds) can be affected by location and extent of open water. The winter of at Forsmark was relatively mild and contrasted with the winter of , which was very cold and characterised by long periods of snow cover and the formation of extensive sea ice around the site. The basin and some areas around it remained open due to warm water discharge from the reactors. The presence of sea ice in apparently affected the distribution of eagles in that they would often sit on the ice near its edge. 56. Raw data on eagle flights at Forsmark were different than those typically gathered for use in CRM. Band et al (2007) suggest a field data collection protocol that estimates flight height within height bands (e.g. <10 m, m, >100 m). We used a GIS to derive data from field observations for use in the CRM and relied on a published value of flight speed to calculate duration of flights within the 150 m buffer around turbine locations. Although no study has been undertaken to investigate the matter, it is our opinion that the difference in data collection methodologies did not result in significant differences in mortality estimates.

13 57. Systematic bias in flying behaviour close to islands (i.e. some proportion of eagles fly to the islands and perch or fly from the islands after perching) is likely to have resulted in a modest increase in predicted mortality because flight height data derived from spot heights would be higher than actual flight height (See paragraph 44). Carcass removal trials 58. Because land areas within the Development are small, search plots were smaller than the optimal size. Also search plots were, for operational reasons, not placed in areas where very dense scrub, reed bed or water occurred. It is hoped that alternative methods can be developed to allow for adequate cover of these habitat types and water once turbines are constructed. 59. That 75% of all carcasses were found by a naïve searcher suggests that a good proportion of fresh collision victims should be found. Of course this should be viewed in light of the removal rate by scavengers and eventually the level of search effort across the whole windfarm. 60. It was not expected that fewer carcasses would be found by the naïve searcher at the more open South Plot than at the North Plot, however carcasses were more obvious against the green ground vegetation found in the North Plot than against the greyish stony ground of the South Plot. 61. Scavenging rates can be affected by factors such as scavenger density and movement patterns, and availability of carcasses. Carcass availability can be affected by the amount or type of vegetation. Carcasses were removed from the North Plot faster than the South Plot. The main scavenger at the North Plot was fox, and a den was found in the vicinity. It may be that foxes use the wooded areas more and this may explain the more rapid removal rate. On the other hand, the wooded nature of the North Plot may have deterred avian scavengers. 62. Carcasses placed in reed bed/waterside habitats disappeared most rapidly. Carcass 14, an intact greylag goose, was reduced to a small feather patch only 24 hours after positioning. The area where it was put had been frequented by WTEs and these were flushed from there on several occasions. It is likely they WTEs were the principal scavenger and the carcass may have been carried off after being partly consumed. 63. Smallwood (2007) highlights biases that can occur in scavenger removal trials and the species used is a major factor. Smallwood suggests using species that are likely to be

14 killed by the windfarm under investigation and gives evidence that carcasses of geese, game species and poultry are more palatable to scavengers than those of raptors. If WTEs are one of the main scavengers at the site, but also an anticipated strike victim this may mean that the carcass trials using geese and chicken carcasses may not give a true picture of carcass removal by scavengers. 64. All carcasses at the South Plot were intact up to Day 15. This result is somewhat surprising as the South Plot was more open than the North Plot, and it could be expected that avian scavengers would be more likely to find carcasses there. However there were very few avian scavengers at Forsmark other than WTEs. It may be the case that the high level of use of the site by WTEs also deters smaller, more active, scavenging birds. 65. In summary, it is encouraging that, at least in one plot, carcasses remained present and intact for over two weeks. That they persisted longer on bare ground than in woodland suggests that there is a high chance that carcasses will be found in the immediate vicinity of some turbines (i.e. those with sparse vegetation around them), should they land there, especially if the inter-search interval is less than two weeks. Acknowledgements Mr. D.R.A. McLeod contributed significantly to the discussion about VP data quality and analyses, CRM and produced all maps. Literature cited Band, W., Madders, M., & Whitfield, D.P Developing field and analytical methods to assess avian collision risk at wind farms. In de Lucas, M. et al (2007) Birds and Wind Farms: risk assessment and mitigation. Quercus, Madrid, Spain Duffy, K. & Steward, M Turbine Search Methods and Carcass Removal Trials at the Braes of Doune Windfarm. Natural Research Information Note No.4. Natural Research website, Glutz von Blotzheim, U. N., Bauer, K. M. & Bezzel, E Handbuch der Vögel Mitteleuropas. Band 4. Akademische Verlagsgesellschfaft. Frankfurt. Green, M Forsmark site investigation bird monitoring in Forsmark SKB, Stockholm.

15 Green, M Forsmark site investigation bird monitoring in Forsmark SKB, Stockholm. Johnson, G.D., Young, D.P., Erickson, W.P., Clayton E., Derby, C.E., Strickland, M.D. & Good, R.E Wildlife monitoring studies fore the SeaWest windpower project, Carbon County, Wyoming Final report by WEST Inc. prepared for SeaWest Energy Corporation, San Diego, California & Bureau of Land Management, Rawlins District Office, Rawlins, Wyoming. Morrison, M Searcher bias and scavenging rates in bird/wind energy studies. NREL/SR Pettersson, J. & Sevastik, A White-tailed sea eagle study at the Biotest Basin at Forsmark, Sweden - following plans to build 15 wind turbines around the basin. English translation of report to Vattenfall in Swedish. Provan, S. & Whitfield, D., P Avian flight speeds and biometrics for use in collision risk modelling. Report to Scottish Natural Heritage from Natural Research (Projects) Ltd. Smallwood, K.S Estimating wind turbine-caused bird mortality. Journal of Wildlife Management 71: SNH Use of avoidance rates in the SNH wind farm collision risk model. Scottish Natural Heritage. Vattenfall Vindkraft AB (2009). Miljökonsekvensbeskrivning. Vindbruk i anslutning till Biotestsjön, Forsmark. (Environmental Statement)

16 Appendix 1 Figures List of Figures Figure 1. The study area with indicative layout of 15 turbines, VP locations and carcass search areas. Figure 2. Turbine locations (150m radius around location) within view of VPs at Forsmark. Figure 3. Flightlines of WTE recorded at Forsmark, November 2009 October Figure 4. WTE flights at rotor swept heights at Forsmark, November 2009 October Figure 5. Relative risk of WTE collision per turbine at Forsmark. Figure 6. Scavenged goose carcass. Figure 7. Scavenged goose carcass that was placed in a tree.

17 !( # Outlet VP 9!( 11!( 8!( 12!( 7!( 6!( 13!( 5!( 4!( # South Pier VP 3!( 2!( 1!( 15!( 14!( Copyright Lantmäteriet MS2008/08151 Figure 1: Study Area Key!( Turbine Locations # Vantage Points Carcass Search Plots Date produced: 08/12/10 Source: NRP LTD ± km

18 # Outlet VP # South Pier VP Outlet VP Turbine Visibility Figure 2: Turbine visibility from Outlet VP (top) and from South Pier VP (bottom) # Outlet VP South Pier VP 3# 2 1 South Pier VP Turbine Visibility Key # Vantage Points Turbines 150m buffer Date produced: 08/12/10 Source: NRP LTD km ± Copyright Lantmäteriet MS2008/08151

19 !( 7!( 10!( 9!( 6!( # 11!( 12!( 13!( 5!( 4!( 15!( 14!( Outlet VP 3!( 2!( 1!( Outlet VP Flightlines (179.3 hours of observation) Figure 3: Flightlines by source VP (Nov Oct 2010) !( 7!( 10!( 9!( 11!( 6!( 12!( 13!( 5!( 15!( 14!( 4!( # South Pier VP 3!( 2!( 1!( South Pier VP Flightlines (66.7 hours of observation) Key # Vantage Points!( Turbine Locations Flight lines Date produced: 08/12/10 Source: NRP LTD km ± Copyright Lantmäteriet MS2008/08151

20 Flightlines at rotor swept height - 80m hub Figure 4: Flightlines at Rotor Swept Height 80m hub - top 100m hub - bottom Flightlines at rotor swept height - 100m hub Key Flightlines Turbines 150m buffer Date produced: 08/12/10 Source: NRP LTD km ± Copyright Lantmäteriet MS2008/08151

21 Relative Collision Risk 80m hub Figure 5: Relative Risk of Turbine Collision 80m hub - top 100m hub - bottom Relative Collision Risk 100m hub Key Flightlines Relative Collision Risk Lower Higher Date produced: 08/12/10 Source: NRP LTD km ± Copyright Lantmäteriet MS2008/08151

22 Figure 6. Scavenged goose carcass Figure 7. Scavenged goose carcass that was placed in a tree.

23 breeding nonbreeding breeding non-breeding Appendix 2: Tables Table 1. Observational effort at Forsmark, Nov 2009 Oct VP Season Month/yr Number of observation bouts Total duration (hrs) 11/ / / / / / Huset Utloppet 10/ Total / / / / / Total Huset Utloppet Total / / / / Södra piren Total / / / / Total Södra piren Total Grand Total

24 breeding non-breeding Table 2. Turbine and WTE parameters used in the CRM at Forsmark. Turbine Parameters 80m turbine 100m turbine Blade length 45m 45m Hub diameter 3m 3m Max. rotor depth 2m 2m Max. chord 3.1m 3.5m Pitch Rotation period Turbine operation time 87% 87% Eagle Parameters Length 0.80m Wingspan 2.20m No. of days eagles potentially present/yr 365 No. of hours birds potentially present/day 12 Flight speed 13 m/sec Assumed avoidance rate 95% and 98% Table 3. Numbers of flight lines and spot heights collected per month at Forsmark, November 2009 October Month Season Total number of flights Number of spot heights Mean number of spot heights Nov Dec Jan Feb Aug Sep Oct Non-breeding season total Mar Apr May Jun Jul Breeding season total Total

25 Table 4. Observation time, flight duration at risk height, duration of flights at risk height per hour of effort per turbine at Forsmark, November 2009 to October (Duration at risk height based on 13m/s flight speed.). Turbine Observation Time (hrs) Duration (s) at risk height - 80m hub Duration (s) at risk height per hour of effort - 80m hub Duration (s) at risk height - 100m hub Duration (s) at risk height per hour of effort - 100m hub Table 5. Flight activity, observational effort and weighting used in CRM of 80 m turbines. Flight Activity Per Unit Time & Area Weighted By Observation Effort Turbine Observation effort (HaHr) Flying time at 'risk height' (Hahr^-1) Turbine Weighting Adjusted time at 'risk height' (Hahr^-1) E E E E E E E E E E E E E E E E E E E E E E E E E E-06 Totals E-05 Totals E-05

26 Table 6. Results of CRM for 80 m turbine tower height assuming a 95% avoidance rate. Mortality Estimate Flight risk volume (Vw) m^3 Rotor radius m^2 Combined rotor swept volume (Vr) m^3 Vr * (d + l) m^3 Bird occupancy (n) 0.06 hrs / yr Bird occupancy of rotor swept vol (b) bird-secs Bird transit time (t) 0.22 secs No. of transits through rotors per year Estimated no. of collisions per year After allowing for avoidance per year i.e. equivalent to one bird every 0.8 years Table 7. Results of CRM for 80 m turbine tower height assuming a 98% avoidance rate. Mortality Estimate Flight risk volume (Vw) m^3 Rotor radius m^2 Combined rotor swept volume (Vr) m^3 Vr * (d + l) m^3 Bird occupancy (n) 0.06 hrs / yr Bird occupancy of rotor swept vol (b) bird-secs Bird transit time (t) 0.22 secs No. of transits through rotors per year Estimated no. of collisions per year After allowing for avoidance per year i.e. equivalent to one bird every 1.9 years Table 8. Flight activity, observational effort and weighting used in CRM of 100 m turbines. Flight Activity Per Unit Time & Area Weighted By Observation Effort Turbine Observation effort (HaHr) Flying time at 'risk height' (Hahr^-1) Turbine Weighting Adjusted time at 'risk height' (Hahr^-1)

27 E E E E E E E E E E E E E E E E E E E E-06 Totals E-06 Totals E-06 Table 9. Results of CRM for 100 m turbine tower height assuming a 95% avoidance rate. Mortality Estimate Flight risk volume (Vw) m^3 Rotor radius m^2 Combined rotor swept volume (Vr) m^3 Vr * (d + l) m^3 Bird occupancy (n) 0.03 hrs / yr Bird occupancy of rotor swept vol (b) bird-secs Bird transit time (t) 0.22 secs No. of transits through rotors per year Estimated no. of collisions per year After allowing for avoidance per year i.e. equivalent to one bird every 1.5 years Table 10. Results of CRM for 100 m turbine tower height assuming a 98% avoidance rate. Mortality Estimate Flight risk volume (Vw) m^3 Rotor radius m^2 Combined rotor swept volume (Vr) m^3 Vr * (d + l) m^3 Bird occupancy (n) 0.03 hrs / yr Bird occupancy of rotor swept vol (b) bird-secs Bird transit time (t) 0.22 secs No. of transits through rotors per year Estimated no. of collisions per year After allowing for avoidance per year i.e. equivalent to one bird every 3.8 years

28 Table 11. CRM prediction of number of years per WTE mortality at the windfarm for turbines with hubs at 80m and 100m and assumed avoidance of 95 and 98% avoidance. Avoidance (%) This Study Avoidance (%) Pettersson & Sevastik 2009 Hub Height (m) *Note: Pettersson & Sevastik (2009) report predicted annual mortality (Table 12), Number of years per WTE mortality = 1/annual mortality. Table 12. CRM prediction of annual WTE mortality at the windfarm for turbines with hubs at 80m and 100m and assumed avoidance of 95 and 98% avoidance. Avoidance (%) This Study Avoidance (%) Pettersson & Sevastik 2009 Hub Height (m)

29 Table 13. Fate of carcasses at North and South plots at Forsmark in Days after positioning Comments Tag no. Species/part Habitat Plot Chicken (brown) OS S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I PS PS 2 Chicken (white) OS S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I 3 Chicken (brown) B/R S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I M - - Moved but un-eaten, Day 11 4 CG (intact) B/R S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I 5 CG (back half) B/R S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I M CG (whole, opened) B/R S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I 8 GJ (intact) OS S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I PS PS 9 GJ (front half) B/R S P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I PS - - Number remaining untouched GJ (intact) OW N P, I P, I P, I P, I P, I M Hen (dark, opened) OW N P, I P, I P, I P, I P, I P, I PS PS PS PS M GJ (back half) OW N P, I P, I P, I P, I P, I P, I M Positioned in tree, fell out day 5 13 GJ (intact) OW N P, I P, I P, I P, I P, I PS MC MC MC M Only one wing remaining Day GJ (back half) OW N P, I P, I P, I P, I P, I P, I PS FO FO FO FO FO FO FO 18 GJ (intact) OW N P, I P, I P, I P, I P, I P, I MC M Chicken (white) OW N P, I P, I P, I P, I P, I M Remains found Day 11 outside plot 21 CG (front half, one wing) OW N P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I P, I PS PS MC Positioned in tree, where remained Number remaining untouched Total number remaining untouched (all) Key: P Present; I (Intact no scavenging signs); M missing (nothing left); PS part scavenged; MC mainly consumed; FO feathers only remaining. Habitat: OS Open scrub; B/R Bare ground, rock, gravel or rubble; OW Old growth woodland

30 Table 14. Placement and fate of three goose carcasses placed in reed-bed/ waterside habitat. Carcass no. Species/part Location Grid location Day after placement GJ (intact) NW basin M, FO FO FO FO FO 15 CG (intact) SW basin P, I P, I P, I P, I M 20 GJ (front half) SW basin P, I P, I P, I P, I M Key: P Present; I (Intact no scavenging signs); M missing (nothing left); PS part scavenged; MC mainly consumed; FO feathers only remaining. Table 15. Status of carcasses during carcass removal trial period Day after positioning All carcasses/parts Present, Intact Present, part scavenged Scavenged, mostly consumed Scavenged, feathers left only Completely missing Chicken Present, Intact Present, part scavenged Scavenged, mostly consumed Scavenged, feathers left only Completely missing Goose/parts Present, Intact Present, part scavenged Scavenged, mostly consumed Scavenged, feathers left only Completely missing