Performing Department
Environmental & Forest Biology
Non Technical Summary
Wind power development is rapidly increasing in the United States, and the potential for avian mortality due to collisions with turbine blades, towers, power lines, and associated structures is well-documented (Orloff and Flannery 1992, Williams 2006, de Lucas et al. 2008). In the eastern United States, wind resources are found primarily along mountain ridges and in the coastal zone, including along the shoreline and in the offshore environment (U.S. Department of Energy 2011). A high proportion of avian coastal species are considered to be of conservation concern, as the innately low numbers, low annual reproductive rate, and rare nesting habitat of shorebirds and seabirds makes them vulnerable to negative effects of human activity. The U.S. Endangered Species Act (ESA) prohibits "take" (a term that includes killing, wounding, harming, harassing, and capturing) of endangered and threatened wildlife species (87 Stat 884, 16 U.S.C. § 1531 et seq., 50 CFR Part 17.31(a)). However, the primary purpose of the ESA is to provide a framework for planning species recovery (typically, population increase) and for identifying and ameliorating threats to long-term persistence of species at risk. Section 7 of the ESA requires all federal agencies, in consultation with the U.S. Fish and Wildlife Service, to evaluate effects of activities they conduct, authorize, or fund on listed species. Such consultations provide a process to identify potential adverse effects, recommend measures to avoid or reduce them, and authorize incidental take if it is determined that the proposed activity will not jeopardize the continued existence of the species (50 CFR Part 402). Determinations of jeopardy are based on best available science. Section 10 of the ESA provides procedures for issuing permits for take related to research, conservation, and otherwise lawful activities not involving federal actions (50 CFR Part 17.22 and 17.32). Despite several decades of data on wind-power related mortality in birds, the science of assessing risk of wind development at the population level is still in development (Morrison and Pollock 1998, de Lucas et al. 2007). Given the current interest in coastal wind resources, however, the need to understand avian mortality risks associated with wind turbines is likely to become a pressing need for endangered species permit reviews. This may include large-scale offshore wind farms and smaller onshore construction, including single-turbine projects. The Piping Plover is federally-threatened on the Atlantic Coast of the U. S. and Canada under the U.S. ESA, and as endangered by the Canadian Species at Risk Act. The Atlantic population has increased since listing by 234% (Hecht and Melvin 2009, U.S. Fish and Wildlife Service 2011), and is approaching the recovery goal of 2,000 nesting pairs due in large part to habitat protection and predation management with attendant intensive monitoring. Population viability models predict that small decreases in adult or juvenile survival of Piping Plovers can lead to declining population trends (Melvin and Gibbs 1994, Plissner and Haig 2000). Low numbers of collision mortalities occurring at many sites with small wind projects could reverse recent gains in recovery for Atlantic Coast Piping Plovers (Watts 2010). Our goal is to provide data needed for collision models that can be used to assess the risk of small onshore wind projects to Piping Plovers. During the breeding season, Piping Plovers are territorial, and may use space including flight paths in a nonrandom fashion. Hence risk assessment should take into account the specifics of the movement paths and behavior of birds at particular sites. To date no study has quantified movement patterns, flight heights, flight speeds, and obstruction avoidance behavior on the breeding grounds. Our goal is to address these data gaps.
Animal Health Component
0%
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Goals / Objectives
The Piping Plover is federally-threatened on the Atlantic Coast of the U. S. and Canada under the U.S. ESA, and as endangered by the Canadian Species at Risk Act. The Atlantic population has increased since listing by 234% (Hecht and Melvin 2009, U.S. Fish and Wildlife Service 2011), and is approaching the recovery goal of 2,000 nesting pairs due in large part to habitat protection and predation management with attendant intensive monitoring. Population viability models predict that small decreases in adult or juvenile survival of Piping Plovers can lead to declining population trends (Melvin and Gibbs 1994, Plissner and Haig 2000). Low numbers of collision mortalities occurring at many sites with small wind projects could reverse recent gains in recovery for Atlantic Coast Piping Plovers (Watts 2010). Our goal is to provide data needed for collision models that can be used to assess the risk of small onshore wind projects to Piping Plovers. During the breeding season, Piping Plovers are territorial, and may use space including flight paths in a nonrandom fashion. Hence risk assessment should take into account the specifics of the movement paths and behavior of birds at particular sites. To date no study has quantified movement patterns, flight heights, flight speeds, and obstruction avoidance behavior on the breeding grounds. Our goal is to address these data gaps.
Project Methods
Flight paths and heights Prior to the nesting period (i.e., March to late April), unmarked birds will be studied to record flight heights and frequency for courtship displays and non-courtship flight distances and pathways. Once the nesting period commences, radio-tracking of a subsample of birds will be used to estimate flight paths (Hull et al. 2001) and heights of female Piping Plovers. In the first week of the study at both sites, rangefinders with height functions will be used for height estimation exercises by all crew members, and a 120' tether marked in 10' increments will be raised with a 6' diameter helium balloon to aid in height estimation. Up to 10 adult female Piping Plovers and 8 fledglings will be radio-tagged in each state and followed until 15 August. Radio-tags will be applied to chicks close to fledging (20+ days of age) and to adults when captured on the nest. Radio-tags (1.3-g) will be applied to the intrascapular region using 5-minute epoxy (Drake et al. 2001). Up to four radio-tagged birds per day will be randomly selected without replacement for sampling, by each of 2 observers. Untagged males (March - April) will be selected for sampling as they are encountered, from a different 200-m segment of beach each day. After nesting birds are marked, radio-tagged birds will be relocated at the start of a survey, and observed with a 60x spotting scope for 2 hours. When a bird under observation moves, the observer will follow from 50 to 100 m away, using radio-telemetry to assist if applicable. Locations of the birds will be recorded every minute using a GPS unit. If a bird flies more than 100 m over land but remains in view, the observer will attempt to record the flight path using a GPS unit and will estimate the height of the flight, then relocate the bird. If the bird flies out of view over land, the observer will walk along the path used by the bird until the vanishing point if possible, recording the track using the GPS unit. The observer will also attempt to estimate flight height. If the path cannot be followed, the observer will attempt to record the start and end points of the path, before proceeding to attempt to relocate the bird's new location. Position and height of the path, and distance and height of nearest human structures, if any, will be recorded. If the bird flies over water, the observer will record the point of departure from land using a GPS unit, and estimate the bearing and distance of the path taken over water until vanishing. Weekly or biweekly boat surveys will be used to locate difficult-to-access foraging sites (e.g., saltmarsh islands and tidal flats) via radio-tracking and visual observation. Data-logging Automated Telemetry Receiving Stations (ARTS) will be placed in such spots for the duration of the study after the first birds are tagged, and data will be downloaded from them one to two times per week, to allow for estimation of frequency of use by Piping Plovers. These data will be used in a GIS to calculate probabilities and heights for different movement paths, for different phases of the breeding cycle (incubation, brood-rearing, post brood rearing) for adult females and for fledglings. We will attempt to record the paths of at least 25 100-m or commuting flights per bird per phase of the breeding season.Weather and lighting effectsOnce typical flight paths have been established with initial "follows" of tagged Piping Plovers, ARTS will be placed by often-used paths and programmed with the frequencies for 1-2 birds most likely to traverse the area, to keep scan times low to capture ephemeral events such as fly-bys. ARTS will be left for 24 hours. Data will be retrieved each day and used to estimate the probability of movement at night relative to day, and poor-weather days relative to fair weather days. Known fly-bys and walk-bys from daytime "follows" will be noted, to aid interpretation of logged data from the ARTS.Object avoidance and flight speed experimentsDuring daytime follows, we will identify places where Piping Plovers fly across dune fields or other landscapes that have been proposed for wind turbine or other human structures, or where such structures have been built in other places. Avoidance experiments will be conducted at least once per month for 6 day periods. Every day if the weather is clear, two potential crossing sites (A and B) separated by at least 100 m will be selected for 2-hour behavioral observations, conducted in random order the first day. A reference point where crossings seem to occur most will be recorded with a GPS unit at each site. Stakes will be placed at two points in the field of view, so that an observer with a stopwatch can record the time flying and walking birds take to pass between them, and hence calculate passage speed. Two observers will set up portable chair blinds in positions that give a clear field of view. Piping Plovers walking or flying through the site will be recorded. Flight height will be visually estimated, and flight or walking path will be marked with a GPS unit once birds have left the area. Orientation, location, and heights of flight paths relative to the reference point will be calculated later using GIS. After three days of such measurements taken at the same time relative to tidal stage, a 6-foot diameter helium balloon attached to a set of 120-foot flagged tethers will be placed in one of sites (either A or B, chosen at random), anchored to the reference point. Flagging will be bright and obvious, to prevent collisions by birds with the tethers. Flight paths and heights of birds will be recorded, and position and orientation and height relative to the balloon will be calculated. Behavior of walking and flying Piping Plovers entering within 10 m of the balloon will be recorded, including changes in flight behavior (Savereno et al. 1996). Identity of individual birds will be determined by bands or radio-tracking where possible. Balloons will be taken down at the end of each observation period, and the experiment will continue for three days. The second crossing point will serve as a control, and will continue to be observed without a balloon for the same three days. We will use generalized linear models in a before-after control-impact framework to examine the effect of the balloon presence on passage probability, and passage distance, orientation, and height relative to the reference point (i.e., balloon anchor point). Disturbance responses by Piping Plovers or other beach nesting species to the balloon will be monitored, and the experiment will be modified or if need be discontinued where problems are noted. The experiment will be repeated at another pair of sites if such can be identified. Otherwise, it will be repeated at the same sites after at least one week has passed, with the objective of replicates during different parts of the breeding season. We will place stakes at fixed points at least 20 m apart, along the length of typical flight paths. During pre-treatment phases of the avoidance experiment, we will use videocameras to record flights of Piping Plovers past the observation positions. Videos will be analyzed frame by frame to determine passage time between the stakes, and hence flight speed (Hilton et al. 1999).