St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings

Transcription

1 5309 Shilshole Avenue NW Suite 200 Seattle, WA phone fax memorandum date August 31, 2017 to from subject Debbie Bent, City of Kenmore Ilon Logan and Christina Hersum, ESA St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings At the request of Perteet, Inc. and the City of Kenmore (City), Environmental Science Associates (ESA) performed field surveys to provide continued environmental permit support for a planned ballfield development site at St. Edward State Park in Kenmore, Washington (Figure 1). The site is located at an existing ballfield, due east of the main parking lot at St. Edward State Park and south of NE 145th Street (the main entrance road into the park). ESA performed four surveys for bird species using the site during twilight hours in August The purpose of the surveys is to provide the City with baseline information on the bird species present when the ballfield would be illuminated by the proposed lighting, typically during the early evening. This memorandum describes the methods and results of each survey, as well as existing information related to nocturnal bird presence in the park and an evaluation of the literature review developed by Washington State Parks and Recreation Commission (State Parks) titled Potential Environmental Impacts of Artificial Lighting at St. Edward State Park: A Literature Review (Kunze, 2017). Existing Information Several local sources of information document the presence of owls at St. Edward State Park. A 2015 report written by the Eastside Audubon Society documents their results of a yearlong (2014 to 2015) bird survey of the park and includes the recorded presence of barred owls during their survey (McCormick, 2015). The online checklist program, ebird, launched by the Cornell Lab of Ornithology and National Audubon Society, has generated a checklist for the park based on data gathered from participant observations of birds at the park. The ebird checklist for the park includes the following owl species on the checklist: great horned owl (Bubo virginianus), barred owl (Strix varia), western screech-owl (Megascops kennicottii), and northern saw-whet owl (Aegolius acadicus) (ebird, 2017). There are also local news reports of incidents of great horned owl attacks on hikers using trails in the park (Johnston, 2000; Mapes, 2000). Washington State Parks and Recreation Commission Literature Review The purpose of the literature review written by State Parks was to provide information from a number of research articles on the potential impacts of artificial lighting on native wildlife species, including invertebrates, bats, mammals, amphibians, and birds, as well as plants. While State Parks found several studies about the effects of artificial lighting on migratory birds, bats, and invertebrates, little to no literature was found regarding artificial lighting effects on other species, including owls. However, we acknowledge that a limited amount of scientific 1

2 St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings literature is currently available about the effects of artificial lighting on owls and that most literature is concentrated on migrating birds and collisions with tall, lighted towers. The review cites numerous studies regarding how certain factors can determine the extent of artificial lighting effects on migratory birds, including the following: wavelength, height, and orientation of the light source, and current weather conditions. In general, these studies found that downward directed, short wavelength lights at a height common to artificial lighting structures at recreational ballfields were unlikely to negatively impact migratory birds. This discussion of the literature review also provides information about the role of light in the life history of birds (physiology, behavior, and hormone production) and includes an anecdotal account of pileated woodpecker presence in the project area (Kunze, 2017). Methods ESA surveyed for crepuscular and nocturnal bird species in the vicinity of the existing ballfield site using established protocols outlined by Ralph and Scott (1998), and Takats et al. (2001). The protocol involves walking the study area, conducting passive visual and aural observations of bird activity, and documenting individual species, activity, and abundance. Surveys also included active acoustic playback methods to elicit territorial behavior from individuals. The protocol notes that evening surveys should commence between a half-hour after sunset and midnight, and morning surveys commence 2 hours before and a half-hour after sunrise. Five survey stations were established in the study area, as shown on Figure 1. The study area is comprised of an existing mowed grass ballfield surrounded by mature forest and wetlands to the east and south. The mature forest contains an overstory of big-leaf maple, black cottonwood, red alder, western red cedar, and Douglas fir. Understory shrubs are predominantly salmonberry, Indian plum, and Himalayan blackberry. Immediately west of the ballfield is a picnic area with mature evergreen trees, a gravel parking lot, and restroom facilities. This area is regularly used by recreationists. The ballfield is relatively flat, and the topography slopes upward from the ballfield to the east and west. Surveys were led by Ilon Logan, a senior ecologist with ESA experienced in the identification of crepuscular and nocturnal birds by song, call, and visual observation and in active acoustic playback methods. Ilon was supported by other ESA biologists with experience in wildlife identification and bird survey. Survey Results ESA performed four crepuscular and nocturnal bird surveys (two at dusk and two at dawn) between August 9 and August 22, 2017 in the study area. At each survey station, up to three different pre-recorded owl species calls (western screech owl, barred owl, and great horned owl) were broadcast at separate times to elicit owl responses. Vocalizations from two barred owl individuals were detected during one survey at a survey station on the western border of the ballfield. A barred owl and great horned owl were also detected during separate surveys, but from far-off distances. It was only during Survey #4 that surveyors elicited a response within the study area: two barred owl individuals responded to a broadcasted call by flying and perching in coniferous trees above Survey Station #3, and subsequently vocalizing agitated calls. Both individuals continued to vocalize for 10 minutes after the call was first broadcast and then moved to the west away from the survey station. During Surveys #1 and #3, surveyors detected barred owl and great horned owl responses to broadcasted calls, but at far distances from the study area. No other nocturnal or crepuscular species were observed during any of the surveys. The following tables summarize the results from each survey. 2

3 St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings Date and Survey Time: Weather: Observers: Table 1. St. Edward Ballfield Twilight Bird Survey Summary for Survey #1 8/9/2017 9:01PM to 11:20PM 0% cloud cover; haze and smoke from B.C. wildfires; no wind; o F Ilon Logan, Peter Carr Site Conditions and Activity: Cars, music activity in parking lot at 11:00PM. Crepuscular & Nocturnal Species Observed: Other Species Observed: Survey Notes: Two series of BADO* hoots heard from NE at very far distance. No other species observed. Birds using St. Edward State Park: AMCR*, BEWR* heard before 9:00PM. Other Wildlife: 1 2 bats observed in South Canyon trail and 1 2 over ballfield. Deer and rabbit observed west of the seminary building. Concluded survey at 11:20PM due to noise. *Four-letter codes used by The Institute for Bird Populations (Pyle and DeSante, 2017); BADO = Barred owl, AMCR = American crow, BEWR = Bewick s wren. Date and Survey Time: Weather: Observers: Table 2. St. Edward Ballfield Twilight Bird Survey Summary for Survey #2 8/15/2017 8:50PM to 11:10PM 0% cloud cover; light breeze; o F Ilon Logan, Christina Hersum Site Conditions and Activity: Some activity in adjacent parking areas to ballfield, cars leaving park. Crepuscular & Nocturnal Species Observed: Other Species Observed: Survey Notes: None Birds using St. Edward State Park: None observed. Other Wildlife: About 4 bats observed over ballfield at dusk. Cooler temperatures than Survey #1. May have heard TYAL* near seminary building but did not observe visually. Concluded survey at 11:10PM due to absence of activity. *Four-letter code used by The Institute for Bird Populations (Pyle and DeSante, 2017); TYAL = Barn owl. 3

4 St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings Date and Survey Time: Weather: Observers: Table 3. St. Edward Ballfield Twilight Bird Survey Summary for Survey #3 8/17/2017 4:08AM to 6:20AM 100% cloud cover; no precipitation; light breeze; o F Ilon Logan, Christina Hersum Site Conditions and Activity: No activity in park; very calm and quiet. Crepuscular & Nocturnal Species Observed: Other Species Observed: Survey Notes: Three low and faint GHOW* hoots heard from far distance to the east. No other species observed. Birds using St. Edward State Park: None observed. Other Wildlife: None observed. Concluded survey at 6:20AM due to daylight. *Four-letter code used by The Institute for Bird Populations (Pyle and DeSante, 2017); GHOW = Great horned owl. Date and Survey Time: Weather: Observers: Table 4. St. Edward Ballfield Twilight Bird Survey Summary for Survey #4 8/22/2017 4:00AM to 6:00AM 0% cloud cover; light breeze; o F Ilon Logan, Peter Carr Site Conditions and Activity: No activity in park; very quiet. Crepuscular & Nocturnal Species Observed: Other Species Observed: Survey Notes: Two BADO* individuals flew in to Survey Station #3 after broadcast of BADO and began calling. One of the BADO individuals moved toward the other and then into an adjacent tree. Both continued vocalizing for 10+ minutes before moving away to west. No other species observed. Birds using St. Edward State Park: None. Other Wildlife: None. Concluded survey at 6:00AM due to daylight. *Four-letter codes used by The Institute for Bird Populations (Pyle and DeSante, 2017); BADO = Barred owl. 4

5 St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings Under existing conditions and based on our observations, the ballfield and surrounding forest edge provide habitat that is used by nocturnal bird species (owls). ESA surveyors observed that portions of the ballfield area are partially illuminated from dusk until dawn by floodlights affixed to the seminary building and adjacent gymnasium building. While some areas of forest edge are shaded from the floodlights by shadows cast by mature evergreen trees in the picnic area, the majority of the ballfield and surrounding forest is well-lit from the floodlights. Attached to this memo is a set of completed survey datasheets for each survey and figure of the survey station locations. Limitations ESA s scope-of-work included surveys for nocturnal birds only, and did not include surveys for daytime bird use or bat presence/absence. The survey study area was limited to the vicinity of the ballfield and did not include the entire park property. The surveys occurred outside of the preferred window for nocturnal bird use (late winter early spring) due to schedule constraints. Within the limitations of the schedule, budget, and scope-of-work, we warrant that this study was conducted in accordance with generally accepted environmental science practices, including the technical guidelines and criteria in effect at the time this study was performed. The results and conclusions of this memo represent the authors best professional judgment, based on information provided by the project proponent in addition to that obtained during the course of this study. No other warranty, expressed or implied, is made. Attachments Figure 1 Survey Stations Completed Survey Datasheets Literature Cited ebird Online field checklist for Saint Edward SP King County, Washington, US. Available at: Accessed July Johnston, G Hikers warned after owl attack at St. Edward. Seattle PI. November 1, Kunze, L Potential Environmental Impacts of Artificial Lighting at St. Edward State Park: A Literature Review. Washington State Parks and Recreation Commission. Mapes, L.V Owl attacks on hikers prompt warnings. Seattle Times. November 3, McCormick, A Bird Survey at St Edward State Park: Report With Comparison with Report. Eastside Audubon Society. September 14, Pyle, P., and D.F. DeSante Four-letter (English name) and Six-letter (Scientific Name) Alpha Codes for 2143 Bird Species (and 99 Non-Species Taxa) Checklist. The Institute for Bird Populations. Available at: Ralph, C.J., and J.M. Scott Estimating Numbers of Terrestrial Birds. Cooper Ornithological Society: Studies in Avian Biology No. 6. October 1, Takats, L.D., C.M. Francis, G.L. Holroyd, J.R. Duncan, K.M. Mazur, R.J. Cannings, W. Harris, and D. Holt Guidelines for Nocturnal Owl Monitoring in North America. Beaverhill Bird Observatory and Bird Studies Canada. Available at: 5

6 St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings FIGURE 1 6

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8 St. Edward State Park Field Improvements: Nocturnal Bird Survey Findings COMPLETED SURVEY DATASHEETS 7

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