SPRING MIGRATION STUDY. Garden Peninsula Wind Energy Project. Delta County, Michigan

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1 SPRING MIGRATION STUDY Garden Peninsula Wind Energy Project Delta County, Michigan DRAFT September 2008 Report Prepared for: Heritage Sustainable Energy Report Prepared by: John Guarnaccia and Paul Kerlinger, Ph.D.* Curry & Kerlinger, LLC P.O. Box 453 Cape May Point, NJ (609) , fax * Primary Contact

2 Executive Summary SPRING MIGRATION STUDY Garden Peninsula Wind Energy Project Delta County, Michigan Heritage Sustainable Energy proposes a utility-scale wind-energy project for the Garden Peninsula, located in Delta County on the Upper Peninsula of Michigan. The number of wind turbines has not been determined, but a leasehold map provided to Curry & Kerlinger indicates that turbines would be erected on private lands in mainly agricultural areas on the western side of the peninsula, and possibly on Little Summer Island. For the purpose of analysis, we are assuming wind turbines with a nameplate capacity of approximately 2.0 MW. The turbine towers would likely be about 78.0 meters (256 feet) tall and have rotors of about 39.0 m (128 feet) long. With the rotor tip in the 12 o clock position, the wind turbines would reach a maximum height of about m (387 feet) above ground level (AGL). When in the 6 o clock position, rotor tips would be about 38.0 m (125 feet) AGL. However, larger turbines with nameplate capacities (up to 2.5 MW and more) reaching to m (500 feet) are being considered. To assess the Garden Peninsula s importance to raptor and songbird migration, two studies were conducted in spring 2008 at the southern end of the peninsula. The flight from Door Peninsula to the Garden Peninsula can be achieved by island hopping with the maximum overwater crossing being slightly greater than about four miles (7+ km). These studies sought to quantify: 1) the volume of raptor migration from the Door Peninsula in Wisconsin along an island-hopping route to the Garden Peninsula, and 2) the abundance and diversity of night-migrating songbirds that stopover on the peninsula. For the Raptor Migration Study, two hawk watches were established at the southern end of the Garden Peninsula, one near Fairport and the other on Burnt Bluff. Two hours of observation were conducted at each site on 23 days from April 30 to May 31. Data collected included species, number of individuals, date and time of observation, direction of flight, flight type, and flight height. These data were also collected for landbird and waterbird migrants noted. Observational details are provided in the report. The spring study confirmed that a relatively small number of northbound raptors of thirteen species use the Garden Peninsula on a migration track that departs Wisconsin s Door Peninsula. Raptor migration at Fairport (HW1) was measured at 7.3 birds/hour (335 birds in 46 hours), with about half of the raptors appearing to have used an island-hopping route from the Door Peninsula. At Burnt Bluff (HW2), raptor traffic was measured at 10.7 birds/hour (493 birds in 46 hours), with about one fifth of raptors apparently arriving over water from Wisconsin or other points. The greater raptor traffic rate at Burnt Bluff was probably attributable to resident Turkey Vultures, which were suspected to nest on the bluffs. Excluding vultures not judged to have Curry & Kerlinger, LLC September

3 originated from Wisconsin, the traffic rates would be similar 6.0 birds/hour at HW1 versus 6.5 birds/hour at HW2. Compared with Great Lakes raptor migration sites that are regularly monitored in spring, the migration rates recorded in the Garden Peninsula study were relatively low, about one tenth of that recorded at the Whitefish Point and Straits of Mackinaw hawk watches in Michigan. There are various reasons for this. The Garden Peninsula is not a spring migrant trap or bottleneck such as occurs at Whitefish Point and the Straits of Mackinaw. Both of these sites are at the southern shore of a large body of water as opposed to the Garden Peninsula, which is on a northern shore. It appears that only a small percentage of the raptors migrating across Wisconsin in spring are funneled into the Door Peninsula and cross to the Garden Peninsula. This study found that peak spring migration along Door-Garden Peninsula route occurred on southerly winds and involved mostly Broad-winged Hawks. There was also one instance of wind drift on northerly winds bringing Broad-wings to the Garden Peninsula possibly from the base of the Upper Peninsula. Regarding the fall raptor migration dynamic on the Garden Peninsula, a site visit conducted by Curry & Kerlinger on September 8-10, 2007, noted that migrating raptors were quite numerous (nine species recorded, about 450 individuals recorded in three days), especially toward the southern part of the peninsula and on Little Summer Island. The most numerous raptors were Broad-winged Hawk and Sharp-shinned Hawk. Interestingly, most of the raptors (and also many hundreds of Blue Jays, another daytime migrant) did not attempt crossing water to the Door Peninsula. Instead, they turned around at the southern end of the peninsula and headed back north along the peninsula s western side, a phenomenon that has also been recorded at other peninsulas, particularly Cape May, New Jersey, and Whitefish Point, Michigan. Therefore, hawk migration occurs along the Garden Peninsula in both the spring and fall seasons. But, the traffic is probably greater in fall, indicated by the fact that hawk watches along the western shore of Lake Michigan only operate in that season. This is similar to large flights of hawks along the north shore of several Great Lakes during fall. Flight height of raptors reaching the Garden Peninsula in spring was generally high (i.e., above the rotor-sweep area [RSA]). Given the low migration volume and the predominantly high flight altitude, collision risk to migrating raptors in spring would appear to be low. Regarding special-status species, the Michigan-threatened Bald Eagle was the third most abundant raptor recorded in the spring study (at about one bird/hour), after Turkey Vulture and Broad-winged Hawk. Given that only 35% of Bald Eagles recorded at Fairport were judged to have migrated from Wisconsin, it appears likely that some of the records were of resident birds recorded more than once or wandering individuals. Most Bald Eagles were recorded in the highheight zone, especially at Fairport. Regarding other special-status raptors, the 16 records of Michigan-threatened Merlin at Burnt Bluff (HW2) may have resulted from a pair nesting on the bluffs. Merlin height use at both observation points was predominantly low (below the RSA) and birds may have been hunting as opposed to migrating. The Michigan-endangered Peregrine Falcon was more frequent at HW1 Curry & Kerlinger, LLC September

4 (6 records) than at HW2 (one record). At HW1, five of the six Peregrines appeared to have originated from Wisconsin, indicating they were migrants. One-half (50%) of these birds were in the high altitude category, whereas 33% were in the middle category (i.e., in the RSA), and 17% were low. Other listed raptors (Michigan-threatened Osprey and special-concern Northern Harrier, Cooper s Hawk) and Northern Goshawk were infrequent, and their flight behavior did not suggest particular risk from wind farm operation.. For landbirds and waterbirds in spring, abundance and flight height did not suggest heightened risk of collision. Blue Jay was by far the most abundant landbird migrant, favoring an islandhopping route through Fairport (HW1). Blue Jay traffic at Burnt Bluff (HW2) was a third that at Fairport. Flight eight of Blue Jays and other landbirds was predominantly low. Waterbird diversity was greater at Fairport, where more birds were observed resting or foraging on the water, but migration traffic was about equal between sites. For the Stopover Ecology Study, six point counts were established within two miles (3.2 km) of the tip of the Garden Peninsula, with three in the vicinity of Fairport and three in the vicinity of Burnt Bluff. In each area, point counts sampled habitat use in forest, forest edge, and grassland. Point-count circles extended to the limit of visibility, as the goal of the study was to determine whether or not birds were making stopovers and, if so, in what numbers and habitats. Each circle was sampled for 15 minutes on 23 days from April 30 to May 31, beginning after dawn as soon as light allowed for bird identification. For each observation, the following data were collected: point-count number, date, time, bird species (using standard four-letter codes), number of individuals, and behavior (coded either F, in flight, or P, perched). Stopover of Neotropical migrants and related species was found to be minimal on the Garden Peninsula in spring. When all habitats were pooled, the highest daily diversity was 16 species, and the highest daily abundance was 19.2 birds/hour. On most days, these values were much lower. A published weather-surveillance radar study indicates that most of the migration occurs to the west of the peninsula. In fall, however, significant stopover may be expected, because the migration direction is perpendicular to the peninsula and headed over Lake Michigan. At dawn, birds over Lake Michigan in the vicinity of the Garden Peninsula apparently reorient themselves toward the peninsula. A September 2007 site visit conducted by Curry & Kerlinger qualitatively confirmed greater stopover on the Garden Peninsula in fall, as well as morning flight, essentially a continuation of the migration after dawn with many songbirds flying above the treetops on what appeared to be a reverse migration to the north within the peninsula. Regarding collision risk to night-migrating songbirds, the spring study does not suggest increased risk, because relatively few migrants stopped over. Risk would be greater in fall, when bird abundance is much greater, particularly at turbines located near lakeshore woodland, where migratory fallouts would be expected to be greatest. Finally, it is important to note that if the larger turbines, extending to 150 m, were to be used, risk to night migrants would be greater than if shorter turbines were used. Because turbines taller than about 125 m have never been erected or studied in North America, the increased risk associated with taller turbines is not known. Curry & Kerlinger, LLC September

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6 Table of Contents Executive Summary Introduction Raptor Migration Study Methodology Results Stopover Ecology of Night-Migrating Songbirds Methodology Results Interpretation of Results/Risk Assessment Raptor Migration Study Stopover Ecology of Night-Migrating Songbirds References 33 Figures Figure 1 Project Location in Michigan 6 Figure 2 Hawk Watch and Point-Count Locations 7 Figure Traffic Comparison at HW1 and HW2 12 Figure Flight Direction at HW1 21 Figure Flight Direction at HW2 21 Figure Flight Behavior at HW1 22 Figure Flight Behavior at HW2 22 Figure Height Use at HW1 23 Figure Height Use at HW2 23 Figure Raptor Passage from Wisconsin 24 Figure Diversity and Abundance of Selected Songbird Migrants, All Habitats 28 Tables Table Summary of Observer Effort 10 Table Summary of Birds Observed 11 Table Spring Raptor Traffic at HW1 and HW2 13 Table Spring Landbird Traffic at HW1 and HW2 14 Table Spring Waterbird Traffic at HW1 and HW2 17 Table Records of Night-Migrating Songbirds 27 Curry & Kerlinger, LLC September

7 Appendices Appendix A. Observation Periods and Weather Conditions during Raptor Migration Study Appendix B. Weather Conditions during Stopover Ecology Study Curry & Kerlinger, LLC September

8 Figure 1. Project Location in Michigan. Note locations of regional hawk watches discussed in Section 4.0 (green icons). Curry & Kerlinger, LLC September

9 Figure 2. Hawk Watch and Point-Count Locations Curry & Kerlinger, LLC September

10 1.0 Introduction Heritage Sustainable Energy is proposing a utility-scale wind-energy project for the Garden Peninsula, located in Delta County on the Upper Peninsula of Michigan. This Garden Peninsula separates northern Lake Michigan from Big Bay de Noc. A series of islands connect it with the Door Peninsula of Wisconsin. Heritage Sustainable Energy has not yet determined the number of wind turbines it would construct, but a leasehold map provided to Curry & Kerlinger indicates that turbines would be erected on private lands (i.e., not in the Lake Superior State Forest) in mainly agricultural areas on the western side of the peninsula, and possibly on Little Summer Island. For the purpose of analysis, we are assuming wind turbines with a nameplate capacity of 2.0 MW. The turbine towers would likely be about 78.0 meters (256 feet) tall and have rotors of about 39.0 m (128 feet) long. With the rotor tip in the 12 o clock position, the wind turbines would reach a maximum height of about m (387 feet) above ground level (AGL). When in the 6 o clock position, rotor tips would be about 38.0 m (125 feet) AGL. However, larger turbines with nameplate capacities (up to 2.5 MW and more) reaching to m (500 feet) may be used. The Garden Peninsula is considered a site where significant bird migration occurs (Chartier and Ziarno 2004). The peninsula is believed to serve as a migration corridor both spring and fall for raptors crossing to and from Wisconsin s Door Peninsula. Birds crossing in spring from Door County can accomplish the crossing by island hopping, but they still must make water crossings of slightly greater than 4 miles (7+ km) between some of the islands. Night-migrating songbirds may occasionally concentrate in the peninsula s wooded and brushy habitats during fallout events, when, in certain weather conditions, birds migrating on broad fronts over Lake Michigan redirect themselves to the nearest landfall at dawn or dusk. During such events, fallout would be expected to be greatest in lakeshore woodland and the edges of these woodlands. To assess the Garden Peninsula s importance to raptor and songbird migration, two studies were conducted in spring 2008 at the southern end of the peninsula. These studies sought to quantify: 1) the volume of raptor migration from the Door Peninsula in Wisconsin along an island-hopping route to the Garden Peninsula, and 2) the volume of night-migrating songbird stopover on the peninsula. These studies are reported below. 2.0 Raptor Migration Study 2.1 Methodology For this study, two hawk watches (identified in Figure 3) were established at the southern end of the Garden Peninsula. Hawk Watch 1 (HW1, coordinates , ) was located on the shore to the west of the town of Fairport and facing Little Summer Island. Hawk Watch 2 (HW2, coordinates , ) was located on Burnt Bluff at the edge of the bluffs that descend to Big Bay de Noc. The distance between the sites was 4.7 miles (7.5 km). Both observation points had clear views of migration proceeding from the Door Peninsiula to the Garden Peninsula. Curry & Kerlinger, LLC September

11 Two hours of observation were conducted at each site on 23 days from April 30 to May 31, amounting to five days per week, focusing on days when weather was likely to be optimal for migration. For details on observation periods and weather conditions, see Appendix A. Observations alternated between the two hawk watches, with the first two hours conducted at HW1 and the second two hours at HW2. The next day, observations commenced at HW2, then continued at HW1. Observations at the first site commenced at 10:00 a.m. At the second site, they commenced at around 12:15 p.m. Forty-six hours of observation were conducted at each hawk watch. To collect data, the observer scanned in a southerly direction, as this was the direction from which migrants would approach in spring. When a bird was sighted, it was observed with naked eye and binoculars as it moved through the observer s field of view. When more than one bird was in view at a time, all were followed until the required data were gathered. The observer recorded data on the provided datasheet as birds passed an imaginary line that ran approximately east to west of the observation location or a line approximately perpendicular to the main axis of migration. Data were also recorded for landbirds and waterbirds, but raptors received priority attention. The following data were collected and entered on a datasheet: Date: Recorded as month/day/year. Species: All raptor species were recorded using standard two-letter abbreviations. Landbirds and waterbirds were noted by standard four-letter codes. Class: Class was recorded to facilitate data analysis. The three bird-class abbreviations were R for raptors, L for landbirds, and W for waterbirds. Number: The number of individuals involved in a single observation was recorded; i.e., solitary bird = 1; flocks including mixed flocks were recorded together, with the total number of individuals (these individuals were not independent). In the case of mixed kettles of hawks, the number of each species was noted (i.e., a separate line for each species, or a note in the note column indicating how many individuals of each species). This level of detail was not used for recording landbirds or waterbirds, unless time permitted. Time: Time was recorded to the nearest minute, when a bird or flock passed within visual range. If a bird lingered for more than one minute, the beginning and ending times of the observation was separated by a hyphen. Military time was preferred (e.g., 0820, 1301; colon not required). Direction: The direction of flight in each observation was recorded in one of eight cardinal directions (N, NE, E, SE, S, SW, W, NW). If a bird or flock changed direction, this was noted by providing the new direction separated by a hyphen. Behavior: This refers to flight type, namely, D (Direct flight with few changes in direction, all less than 30 degrees), I (Indirect flight during which more than one circle was recorded, but more than 50% of flight is without such turns), S (Soaring flight during which more than 50% of the time is spent circling), H (Flight that appeared to be for hunting), and P (Birds that were perched). Curry & Kerlinger, LLC September

12 Height: Height in the fall study was divided into the following categories: L (Low) = <125 feet (<30 m); M (Medium/Moderate) = >125 feet (>30 m) but < 400 feet (<125 m); and H (High) = >400 feet (>125 m). Flight height categories were based on wind-turbine dimensions, with Height M corresponding to the rotor-swept area. Height can often be difficult to gauge. Therefore, if a bird appeared to be at the boundary between heights, it was recorded with two letters (LM or MH, etc.). If a bird moved from one height into another, it was recorded in the sequence the bird moved (e.g., LM, MH, HML, etc.). From Wisconsin: Birds that were observed crossing water to arrive at the Garden Peninsula were coded as FW (From Wisconsin). If a bird was not observed crossing water, it did not receive the FW code, even though it had probably originated from the Door Peninsula or other locations. Data were entered on the data sheet as birds were observed. Later, the data were logged into an Excel spreadsheet for subsequent analysis. 2.2 Results Table Summary of Observer Effort EFFORT HW1 HW2 COMBINED Begin date 30-Apr Apr Apr-2008 End date 31-May May May-2008 # observation days # observation hours Avg. obs. hours/day Table summarizes observer effort (for details, see Appendix A). Twenty-three days of observations were conducted from April 30 to May 31. Total observation hours were 92, with 46 hours conducted at each hawk watch (two hours per day). Curry & Kerlinger, LLC September

13 Table Summary of Birds Observed RAPTORS HW1 HW2 COMBINED # species # birds observed birds/hour # observations observations/hour birds/observation LANDBIRDS HW1 HW2 COMBINED # species # birds observed 1, ,615 birds/hour # observations observations/hour birds/observation WATERBIRDS HW1 HW2 COMBINED # species # birds observed birds/hour # observations observations/hour birds/observation ALL BIRDS HW1 HW2 COMBINED # species # birds observed 2,333 1,872 4,205 birds/hour # observations ,608 observations/hour birds/observation Curry & Kerlinger, LLC September

14 Table summarizes the number of birds observed by class (raptors, landbirds, and waterbirds). A total of 4,205 birds were observed in 1,608 observations (2.6 birds/observation), of which 19.7% (547) were raptors, 62.2% (800) were landbirds, and 18.1% (261) were waterbirds. Flocking (birds/observation) was not high for any bird group, but raptors were generally observed individually (1.5 birds/observation) more than landbirds (3.3) and waterbirds (2.9). As can be appreciated in Figure 2.2-1, raptor migration appeared to be slightly greater at HW2 (10.7 birds/hour) than at HW1 (7.3), but as will be explained below, that higher traffic at HW2 was attributable to resident Turkey Vultures. Landbird traffic, however, was nearly double at HW1 (35.3) as compared with HW2 (21.5). Waterbird traffic was virtually the same at the two hawk watches. Figure Traffic Comparison at HW1 and HW birds/hour HW1 HW2 Raptors Landbirds Waterbirds Tables through 5, detail results among bird types. Note that each table includes columns with the percentage of birds arriving from Wisconsin. Curry & Kerlinger, LLC September

15 Table Spring Raptor Traffic at HW1 and HW2 Raptors 1 #birds birds/hr HW1 HW2 % from WI #birds birds/hr % from WI % birds/hr Avg birds/hr Turkey Vulture % % 113% 3.23 Broad-winged Hawk % % 13% 2.60 Bald Eagle (MI-T) % % -8% 1.09 Sharp-shinned Hawk % % 20% 0.48 Red-tailed Hawk % % 517% 0.47 Northern Harrier (MI-SC) % % 7% 0.34 Merlin (MI-T) % % 300% 0.22 Unidentified Raptor % % -77% 0.17 Cooper's Hawk (MI-SC) % 0.09 American Kestrel % % -40% 0.09 Osprey (MI-T) % % 33% 0.08 Peregrine Falcon (MI-E) % % -83% 0.08 Rough-legged Hawk % % 100% 0.07 Northern Goshawk (MI-SC) % % 0.02 Total % % 47% State-listed species designated E (endangered), T (threatened), or SC (special-concern). Curry & Kerlinger, LLC September

16 Table Spring Landbird Traffic at HW1 and HW2 Raptors 1 #birds birds/hr HW1 HW2 % from WI #birds birds/hr % from WI % birds/hr Avg birds/hr Blue Jay % % -64% American Crow % % -8% 1.95 Cedar Waxwing % % 557% 1.73 American Goldfinch % % -16% 1.54 Common Raven % % 276% 1.09 Unidentified Songbirds % % -96% 1.03 European Starling % % -45% 0.83 Savannah Sparrow % % 586% 0.60 Red-winged Blackbird % % -91% 0.53 Tree Swallow % % -65% 0.50 Barn Swallow % % -61% 0.47 Northern Flicker % % -44% 0.42 Yellow-rumped Warbler % % 750% 0.41 Common Grackle % % -85% 0.25 American Robin % % -73% 0.21 Mourning Dove % % -73% 0.15 Chipping Sparrow % % 233% 0.14 Bobolink % % 1000% 0.13 Indigo Bunting % % 200% 0.13 N. Rough-winged Swallow % % -50% 0.13 Chimney Swift % % 167% 0.12 Red-bellied Woodpecker % % -63% 0.12 Brown-headed Cowbird % Curry & Kerlinger, LLC September

17 Cliff Swallow % % 700% 0.10 Yellow Warbler % % -88% 0.10 Eastern Kingbird % % -67% 0.09 Brown Thrasher % % 0.08 Ruby-throated Hummingbird % % 33% 0.08 Eastern Bluebird % % -80% 0.07 Eastern Meadowlark % % 100% 0.07 Bank Swallow % % -33% 0.05 Gray Catbird % % 0.05 Palm Warbler % 0.05 Hairy Woodpecker % 0.04 Pileated Woodpecker % % 200% 0.04 Rose-breasted Grosbeak % % 0% 0.04 Red-eyed Vireo % % 200% 0.04 Song Sparrow % % 0.04 Wild Turkey % 0.04 Baltimore Oriole % % 0.03 House Finch % % 0.03 House Wren % % -50% 0.03 Northern Cardinal % % 100% 0.03 Scarlet Tanager % % -50% 0.03 Downy Woodpecker % % 0% 0.02 Eastern Wood-Pewee % % 0.02 Purple Martin % % 0.02 American Redstart % 0.01 Black-billed Cuckoo % % 0.01 Blue-headed Vireo % 0.01 Lincoln's Sparrow % 0.01 Mourning Warbler % 0.01 Nashville Warbler % 0.01 Curry & Kerlinger, LLC September

18 Olive-sided Flycatcher % 0.01 Purple Finch % % 0.01 Ruby-crowned Kinglet % 0.01 Red-headed Woodpecker % % 0.01 Summer Tanager % 0.01 Swamp Sparrow % 0.01 Western Meadowlark (MI- SC) % % 0.01 Total 1, % % -39% State-listed species designated E (endangered), T (threatened), or SC (special-concern). Curry & Kerlinger, LLC September

19 Table Spring Waterbird Traffic at HW1 and HW2 HW1 HW2 Raptors 1 #birds birds/hr % from WI #birds birds/hr % from WI % birds/hr Avg birds/hr Double-crested Cormorant % % 458% 2.86 Ring-billed Gull % % 359% 1.76 American White Pelican % % -89% 0.97 Bonaparte's Gull % - - 0% -100% 0.60 Sandhill Crane % % -58% 0.40 Bufflehead % - - 0% -100% 0.27 Killdeer % - - 0% -100% 0.20 Red-breasted Merganser % - - 0% -100% 0.18 Common Loon (MI-T) % % -70% 0.14 Mallard % % -56% 0.14 Mute Swan % - - 0% -100% 0.13 Herring Gull % - - 0% -100% 0.12 Common Merganser % - - 0% -100% 0.11 Redhead % - - 0% -100% 0.09 Canada Goose % % -25% 0.08 Spotted Sandpiper % - - 0% -100% 0.05 Caspian Tern (MI-T) % % 100% 0.03 Great Blue Heron % - - 0% -100% 0.03 Long-tailed Duck % - - 0% -100% 0.03 Unidentified Waterbirds % - - 0% -100% 0.03 Gadwall % - - 0% -100% 0.02 Black-crowned Night-Heron (MI- SC) % - - 0% -100% 0.01 Great Black-backed Gull % - - 0% -100% 0.01 Curry & Kerlinger, LLC September

20 Solitary Sandpiper % - - 0% -100% 0.01 Total % % 4% State-listed species designated E (endangered), T (threatened), or SC (special-concern). Curry & Kerlinger, LLC September

21 Regarding raptors (Table 2.2-3), thirteen of the seventeen species recorded at Central-U.S. hawk watches were observed in the study. Black Vulture, Red-shouldered Hawk, Swainson s Hawk, and Golden Eagle were not observed. The number of species recorded at each site was the same (12), but Cooper s Hawk was not observed at HW1, and Northern Goshawk was not observed at HW2. Turkey Vulture was most abundant overall, with 297 birds recorded overall (35.9% of raptors), for an average of 3.2 birds/hour. As will be discussed, this high percentage probably represents resident birds counted on multiple occasions, particularly at HW2. Broad-winged Hawk was second in abundance, with 239 birds (28.9%), averaging 2.6 birds/hour, followed by Bald Eagle (Michigan threatened), with 100 birds (12.1%), averaging 1.1 birds/hour. All other species averaged less than one bird/hour. The numbers of some species were fairly even between sites. Examples are Broad-winged Hawk, Bald Eagle (Michigan threatened), Sharp-shinned Hawk, and Northern Harrier (Michigan special-concern). Other species were much more abundant at one site than the other. For example, twice as many Turkey Vultures, six times as many Red-tailed Hawks, and four times as many Merlins (Michigan threatened) were recorded at HW2 than at HW1. These differences may be attributable to resident birds having been attracted to Burnt Bluff for lift (either thermal or wind-deflected). For Merlin and Turkey Vultures, the bluffs probably provided nesting sites (Tom Tustison, personal communication) and soaring opportunities. Only Peregrine Falcon (Michigan endangered) was notably more abundant at HW1 (6 birds) than at HW2 (one bird). It is interesting to note that about one-half of the raptors recorded at HW1 were considered to be migrating from Wisconsin s Door Peninsula, whereas only 20% of birds recorded at HW2 were considered to be migrating from Wisconsin (see Table 2.2-3). At HW1, the observer (Tom Tustison, personal communication) noted that most raptors flew along the western side of Little Summer Island to make landfall to the west of the observation point. This appears to confirm that the island chain from the Door Peninsula serves as a migration route for some raptors. Most of the birds observed at Burnt Bluff appeared to have already made landfall, but some were recorded arriving over water. It was noted that some raptors at Burnt Bluff did not follow the peninsula north. Rather, they used the thermal lift generated over the bluff to gain height, which they then used to cross Big Bay de Noc to reach the mainland beyond. In other words, for some raptors, the tip of the Garden Peninsula appears to be another island in the island-hopping path northward. As already noted, raptor traffic rate at HW2 was greater than at HW1, but this difference is probably mostly attributable to resident Turkey Vultures. If resident vultures (i.e., birds not originating from Wisconsin) are excluded, the adjusted traffic rates are similar 6.0 birds/hour at HW1 versus 6.5 birds/hour at HW2. It is possible that if some of the Red-tailed Hawks observed at Burnt Bluff were residents, the migration rate there would have been less at that site. Blue Jay was by far the most abundant landbird recorded, averaging 14.5 birds/hour. The only other species recorded above one bird/hour were American Crow (2.0), Cedar Waxwing (1.7), Curry & Kerlinger, LLC September

22 American Goldfinch (1.5), and Common Raven (1.1). Most of the other fifty-plus species recorded were relatively scarce. While landbird traffic was higher at HW1 (35.3 birds/hour) than at HW2 (21.5), most of this difference was attributable to Blue Jays, which were recorded at 21.2 birds/hour at HW1 and at 7.7 birds/hour at HW2. With regard to migration route, landbirds demonstrated the same pattern as raptors, with more birds appearing to have originated from Wisconsin at HW1 (34%) than at HW2 (19%). Waterbird diversity was much higher at HW1 (24 species) than at HW2 (8 species). This difference probably owes to better quality habitat near Fairport. That the traffic rates were nearly the same between sites was due to larger numbers of Double-crested Cormorants and Ring-billed Gulls observed at HW2. Few waterbirds appeared to have originated from Wisconsin, but nearly all of those that did were observed at HW1, including nearly half of the Sandhill Cranes and nearly a third of the American White Pelicans. The following figures have been prepared to demonstrate flight behavior recorded during spring migration at the tip of the Garden Peninsula. Percentages were calculated based on the number of birds for which flight direction, strategy, and height was recorded. Figures and show flight direction. At HW1, flight direction was northerly for all bird groups, but strongly so for raptors and landbirds. At HW2, on the other hand, raptors and landbirds did not demonstrate a strong directional tendency. In fact, for a large proportion of raptors, a directional tendency could not be discerned (29.1% recorded as variable). The reason appears to be that raptors took advantage of thermal lift at Burnt Bluff to gain height, circling and changing direction to ascend on rising air currents (Tom Tustison, personal communication). Some of these birds were also likely to be residents of the area and counted more than once. Figures and illustrate flight strategy. At HW1, most raptors employed indirect flight strategy (more than one circle recorded, but more than 50% of flight without such turns). Landbirds, however, strongly favored direct flight (few changes in direction, all less than 30 degrees). Waterbirds also favored direct flight, but many were recorded on the water. At HW2, landbirds and waterbirds strongly favored direct flight, but raptors did not demonstrate a preference. More were recorded soaring at HW2 than at HW1, no doubt because they took advantage of thermal lift at Burnt Bluff. Regarding altitude of flight, it should be noted that when a bird or flock of birds was observed at more than one height, its presence in each height was recorded fractionally. For example, if a bird or flock was recorded ascending from low height to middle height, values of 0.5 were recorded in the two categories for that observation. Note that the middle height (code M) corresponds with the rotor-swept area of a wind turbine. Figures and illustrate flight height. At HW1, most raptors were recorded flying high, which is to be expected, as soaring hawks (such as Broad-wings) need height to glide long distances over water barriers. At HW2, more raptors were recorded using the high-height zone than the other zones. Landbirds, on the other hand, were recorded flying mainly in the lowheight zone at both hawk watches. At HW1, most waterbirds recorded flying were at high height, while at HW2 they were fairly evenly distributed between height categories. Curry & Kerlinger, LLC September

23 Figure Flight Direction at HW1 80.0% 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% N S E W Variable Raptors (N=330) 67.6% 14.0% 5.1% 3.5% 9.9% Landbirds (N=1534) 60.7% 17.4% 7.4% 7.9% 6.6% Waterbirds (N=299) 37.8% 22.6% 9.0% 26.3% 4.3% Figure Flight Direction at HW2 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% N S E W Variable Raptors (N=464) 24.3% 20.1% 18.4% 8.2% 29.1% Landbirds (N=889) 30.8% 16.7% 28.7% 15.7% 8.1% Waterbirds (N=387) 53.0% 25.3% 6.6% 12.5% 2.9% Curry & Kerlinger, LLC September

24 Figure Flight Behavior at HW % 90.0% 80.0% 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% Direct Indirect Soaring Hunting Perched Raptors (N=265) 27.6% 56.2% 14.7% 1.1% 0.4% Landbirds (N=1074) 89.3% 2.4% 0.5% 0.0% 7.8% Waterbirds (N=239) 37.6% 17.2% 13.8% 0.0% 31.4% Figure Flight Behavior at HW2 90.0% 80.0% 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% Direct Indirect Soaring Hunting Perched Raptors (N=265) 37.0% 31.0% 26.9% 4.0% 1.1% Landbirds (N=1074) 84.3% 3.1% 1.3% 0.1% 11.2% Waterbirds (N=239) 74.8% 19.3% 2.8% 3.1% 0.0% Curry & Kerlinger, LLC September

25 Figure Height Use at HW1 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Raptors (N=328) Landbirds (N=1535) Waterbirds (N=290) H 65.4% 16.2% 55.0% M 14.5% 24.8% 18.1% L 20.1% 59.0% 29.9% Figure Height Use at HW2 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Raptors (N=466) Landbirds (N=897) Waterbirds (N=383) H 44.0% 8.9% 28.8% M 23.7% 10.9% 39.5% L 32.3% 80.2% 31.7% Curry & Kerlinger, LLC September

26 Figure graphs the data for raptors classified as having arrived from Wisconsin (code FW). The three peaks correspond with Broad-winged Hawk passage. At HW1, small flocks of Broadwings (range of 1 to 18 birds) were observed on two days with southerly winds (for wind direction, see Appendix A). On May 15, 36 of the 38 Broad-wings observed in the morning at HW1 were determined to have crossed from Wisconsin. That afternoon, at HW2, no Broadwinged Hawks were recorded. On May 28, 35 of 36 Broad-wings recorded in the morning at HW1 were judged to have come from Wisconsin. That afternoon, at HW2, 53 Broad-wings were recorded (flocks of 1 to 8 birds), but none was judged to have crossed from Wisconsin (i.e., they were already on the Garden Peninsula). This appears to indicate that raptors arriving near Fairport do not follow a fixed track or path up the peninsula. Figure Raptor Passage from Wisconsin birds/hour HW1 HW /30/08 5/2/08 5/4/08 5/6/08 5/8/08 5/10/08 5/12/08 5/14/08 5/16/08 5/18/08 5/20/08 5/22/08 5/24/08 5/26/08 5/28/08 5/30/08 At HW2, on the morning of May 27, one flock of 31 Broad-wings was judged to have arrived from Wisconsin. Interestingly, winds were out of the north. When this flock reached the Garden Peninsula, it headed northeast, up the peninsula. Given the wind direction, it is conceivable that this flock was blown off course, not from the Door Peninsula, but from the mainland, possibly Menominee County at the base of the Upper Peninsula of Michigan. No Broad-wings were seen that afternoon at HW1. More data are required to improve understanding of spring raptor migration over water to the Garden Peninsula, but these few observations appear to strongly suggest that small numbers of Broad-wings only make the water crossing from the Door Peninsula when winds are southerly. Once they reach the Garden Peninsula, their route out of the peninsula varies. Northerly winds may also blow Broad-wings over to the Garden Peninsula, but in that case, birds are possibly using the peninsula to make up ground lost by wind drift. Curry & Kerlinger, LLC September

27 In the hawk-migration study, most of the special-status species recorded were raptors. These included the Michigan-endangered Peregrine Falcon, threatened Osprey, Bald Eagle, and Merlin, and special-concern Northern Harrier, Cooper s Hawk, and Northern Goshawk. Other specialstatus species were the Michigan threatened Common Loon and Caspian Tern and specialconcern Black-crowned Night-Heron and Western Meadowlark. The endangered Peregrine Falcon was mainly recorded at HW1, where five of six birds appeared to have migrated from the Door Peninsula. Height use was H 50%, M 33%, L 17%. The one bird recorded at HW2 used the high and middle height zones. The most common special-status species was the threatened Bald Eagle, recorded at about one bird/hour at both hawk watches (see Table 2.2-3). At HW1, most Bald Eagles were recorded in the high-height zone (H 73%, M 13%, L 14%). At HW2, half of the Bald Eagles used the highheight zone (H 50%, M 21%, L 29%). At HW1, 35% of Bald Eagles were judged to have migrated from the Door Peninsula. At HW2, the percentage was 19%. This may indicate that some of the Bald Eagle observations were of resident birds recorded more than once. The threatened Merlin was mostly recorded at HW2, where there were 16 records, as compared with 4 at HW1. 19% of the Merlins recorded at HW2 were judged to have crossed from Wisconsin, while at HW1 it was 50%. It was suspected that a pair of Merlins was nesting on Burnt Bluff, but a nest could not be located or confirmed (Tom Tustison, personal communication). At HW2, Merlins preferred the low-height zone (H 17%, M 13%, L 70%). At HW1, use of the low-height zone also predominated (H 17%, M 17%, L 67%). Among other threatened species, Common Loon was also mostly recorded at HW1, where there were ten records (H 75%, M 20%, L 5%), as opposed to HW2, where there were three (H 10%, M 30%, L 60%). Osprey, on the other hand, was relatively scarce at both hawk watches, with three birds recorded at HW1 (H 83%, M 17%, L 0%) and four at HW2 (H 58%, M10%, L 32%). Caspian Tern was scarce at both sites, with one bird at HW1 and two at HW2 (all recorded at low height). Northern Harrier was the most common among the special-concern species. Fifteen birds were recorded at HW1 (H 37%, M 21%, L 41%), and 16 birds were recorded at HW2 (H17%, M12%, L71%). All eight Cooper s Hawk records were from HW2, where half the birds were judged to have made a water crossing (H 38%, M 6%, 56%). The two Goshawks recorded were both at HW1 (H 0%, M 25%, L 75%). There was one record each of Black-crowned Night-Heron and Western Meadowlark at HW1. The actual numbers of special-status species migrating along the Garden Peninsula was likely greater than recorded during the study period, because the study period did not include every day of the entire migration season, nor did it include all hours of the day. Additionally, effort was divided between the hawk watches. Therefore, when the observer was at one hawk watch, he did not observe birds at the other. Curry & Kerlinger, LLC September

28 3.0 Stopover Ecology of Night-Migrating Songbirds 3.1 Methodology This study was designed to determine the magnitude of stopover by night-migrating songbirds and related species. Shown in Figure 3, six point counts were established within two miles (3.2 km) of the tip of the Garden Peninsula, with three in the vicinity of Fairport (F1, E1, and G1) and three in the vicinity of Burnt Bluff (F2, E2, and G2). In each area, point counts sampled habitat use in forest (F1 and F2), forest edge (E1 and E2), and grassland (G1 and G2). Center coordinates of point counts were: F , E , G , F , E , G , Point-count circles extended to the limit of visibility, as the goal of the study was to determine whether or not birds were making stopovers. Each point-count circle was sampled for 15 minutes on 23 days from April 30 to May 31 (goal of five days per week when weather was favorable for migration). The first point count was conducted as soon after dawn as light allowed for bird identification, generally between 5:45 and 6:30, slightly later on overcast days. Points were then sampled in a rotational manner such that, on the first day, those closest to Fairport were sampled first, followed by those near Burnt Bluff. The ones near Burnt Bluff were sampled first the following day. For each observation, the following data were collected: point-count number, date, time, bird species (using standard four-letter codes), number of individuals, and behavior (coded either F, in flight, or P, perched). 3.2 Results There were 924 observations of 1,797 landbirds (1.9 birds/observation) of 72 species. Of this number, 689 landbirds (38.3%) of 46 species were observed at the grassland sites (393 at G1, 296 at G2), 633 (35.2%) of 50 species at the forest-edge sites (172 at E1, 461 at E2), and 475 (26.4%) of 47 species at the forest sites (276 at F1, 199 at F2). Given the greater range of vision in grassland, a greater percentage of birds were observed in flight there (61%) than at forest-edge (48%) and forest (41%), but the percentage of perched bird was highest in forest (55%) than at forest edge (51%) and grassland (37%) 1. 1 In each habitat, there was a small percentage of birds that were heard, but it could not be determined if they were perched or in flight. Curry & Kerlinger, LLC September

29 Overall, the most abundant landbirds recorded were American Crow (287 records), European Starling (273), Blue Jay (176), and Red-winged Blackbird (121). Together, these four species made up 48% of all landbirds. These common species are not nocturnal migrants. To determine the magnitude of stopover by night-migrating songbirds, a subset of landbirds was examined. Shown in Table 3.2-1, these 32 species include Neotropical migrants and other night-migrating species that arrived on the Garden Peninsula in May. Some night-migrating songbirds, such as Yellow-rumped Warbler, were excluded from this analysis because they were already present on the peninsula when the study began. Table Records of Night-Migrating Songbirds Species (Taxonomic Order) Edge Forest Grassland Total Great-crested Flycatcher Eastern Kingbird Philadelphia Vireo Red-eyed Vireo House Wren Winter Wren Sedge Wren Swainson's Thrush Wood Thrush Gray Catbird Brown Thrasher Nashville Warbler Northern Parula Yellow Warbler Chestnut-sided Warbler Magnolia Warbler Cape May Warbler Black-throated Green Warbler Blackburnian Warbler Palm Warbler Black-and-white Warbler American Redstart Ovenbird Common Yellowthroat Wilson's Warbler Scarlet Tanager Eastern Towhee Lincoln's Sparrow White-crowned Sparrow Rose-breasted Grosbeak Indigo Bunting Baltimore Oriole species These 32 species made up 44% of all landbird species recorded, but their total number (210) was only 12% of all individuals. Only two species were relatively abundant: Ovenbird (52 records) and Black-throated Green Warbler (41). Most species were scarce. Curry & Kerlinger, LLC September

30 To illustrate migratory stopover on the Garden Peninsula, Figure has been prepared. It graphs the number of individuals and species recorded by date, based on the records indicated in Table Figure Diversity and Abundance of Selected Songbird Migrants, All Habitats Number species individuals /30/08 5/1/08 5/2/08 5/3/08 5/4/08 5/5/08 5/6/08 5/7/08 5/8/08 5/9/08 5/10/08 5/11/08 5/12/08 5/13/08 5/14/08 5/15/08 5/16/08 5/17/08 5/18/08 5/19/08 5/20/08 5/21/08 5/22/08 5/23/08 5/24/08 5/25/08 5/26/08 5/27/08 5/28/08 5/29/08 5/30/08 5/31/08 As this chart illustrates, the arrival of night-migrating songbirds did not commence until about mid May. The first significant wave of migrants occurred on May 14, when there was a spike in the number of species and individuals. The next recorded waves were on May 26 and May 29, with the May-26 wave recording the highest species diversity (16) and number of individuals (29). Given that 1.5 hours of sampling was conducted each day (15 minutes at each of six point counts), the maximum abundance of nocturnal migrants, recorded on May 26, was 19.3 birds/hour. Between sites, there was no significant difference in the number of individual night-migrating songbirds. In the vicinity of Fairport, 48 individuals were recorded in forest (F1), 31 in forest edge (E1), and 25 in grassland (G1). In the vicinity of Burnt Bluff, 56 individuals were recorded in forest (F2), 26 in forest edge (E2), and 24 in grassland (G2). This indicates that abundance was about the same in shoreline locations (F1) as in interior locations (F2) (see Figure 3). If significant migratory fallout had occurred, one might have expected greater abundances in lakeshore habitats, as night-migrating songbirds aloft over Lake Michigan at dawn would likely fly to them. Curry & Kerlinger, LLC September

31 4.0 Interpretation of Results/Risk Assessment 4.1 Migration Study The spring study confirmed that some northbound raptors use the Garden Peninsula on a migration track that departs Wisconsin s Door Peninsula. Raptor migration at Fairport (HW1) was measured at 7.3 birds/hour, with about one-half of the raptors appearing to have used an island-hopping route from the Door Peninsula. At Burnt Bluff (HW2), raptor traffic was measured at 10.7 birds/hour, with about one-fifth of raptors apparently arriving over water from Wisconsin or other points. The higher raptor traffic at Burnt Bluff was mostly attributable to resident Turkey Vultures, which were suspected to nest on the bluffs. Excluding vultures not judged to have originated from Wisconsin, the traffic rates would be similar 6.0 birds/hour at HW1 versus 6.5 birds/hour at HW2. Compared with Great Lakes raptor migration sites that are monitored annually in spring, the migration rates recorded in the Garden Peninsula study were low. From April 30 to May 31, 2008, the hawk watch at Whitefish Point, located 95 miles (150 km) northeast of the Project site (see Figure 1), recorded 9,770 raptors in 168 hours for a passage rate of 58.1 birds/hour 2. The most common raptors were Sharp-shinned Hawk (5,609 individuals) and Broad-winged Hawk (2,254). From April 30 to May 12, 2008, the hawk watch at the Straits of Mackinaw, located 85 miles (135 km) east of the Project site (see Figure 1), recorded 6,110 raptors in 82 hours for a passage rate of 74.5 birds/hour 3. The most common raptors were Broad-winged Hawk (4,570) and Red-tailed Hawk (993). Spring raptor traffic on the Garden Peninsula, therefore, was about one-tenth of that recorded at Whitefish Point and Straits of Mackinaw. There are various reasons for this. The Garden Peninsula is not a migrant trap or bottleneck to migration, as is the case at Whitefish Point and the Straits of Mackinaw. It appears, rather, that only a small percentage of the raptors migrating across Wisconsin in spring get funneled into the Door Peninsula and cross to the Garden Peninsula. It is also important to note that hawks counted at both Whitefish Point and the Straits of Mackinaw are at the northernmost points of land on these bodies of water, whereas the Garden Peninsula is at the southernmost point of land on a large lake. Thus, birds flying northward in spring are concentrated at both Whitefish Point and the Straits of Mackinaw, whereas they are not concentrated at the Garden Peninsula. The present study found that peak spring migration from the Door Peninsula to the Garden Peninsula occurred on southerly winds and involved mostly Broad-winged Hawks. There was also one instance of possible wind drift on northerly winds bringing Broad-wings to the Garden Peninsula perhaps from elsewhere. Regarding the fall raptor migration dynamic on the Garden Peninsula, a site visit conducted on September 8-10, 2007 for the Phase I Avian Risk Assessment (see Kerlinger and Guarnaccia 2007) noted that migrating raptors were quite numerous (nine species recorded, about For details, see 3 For details, see Curry & Kerlinger, LLC September