Correcting seasonally for searcher efficiency, scavenger and other removal rates, and the percent area searched, the 12 raptor/vulture and 88 other bird carcasses recovered represent approximately 602 bird fatalities over the course of this [six month] Reporting Period.
WOLFE ISLAND ECOPOWER® CENTRE, POST-CONSTRUCTION FOLLOW-UP PLAN – BIRD AND BAT RESOURCES, MONITORING REPORT NO. 2, JULY-DECEMBER 2009
Executive Summary May 2010
(FATALITIES) Seven of the species have been identified as species of conservation priority by Ontario Partners in Flight (2006):
- American Kestrel (one on each of July 1 and August 31),
- Northern Flicker (one on October 8),
- Black-billed Cuckoo (one on July 14),
- Eastern Kingbird (one on each of July 28 and August 17),
- Bank Swallow (one on August 17),
- Savannah Sparrow (one on September 10),
- and Bobolink (eight fatalities between July 27 and September 10). In late summer and fall, young Bobolinks have left the nest and have joined mobile flocks of fledglings and adults that move about the breeding habitat.
- Over the Reporting Period, a total of 28 Tree Swallow fatalities were recorded at 22 different WTGs. Sixteen of 28 (57%) Tree Swallow fatalities were juvenile birds. Together with Bank Swallow (one fatality), Barn Swallow (two fatalities), and Purple Martin (seven fatalities), swallows and martins represented 38 (38%) of the 100 recorded bird fatalities during the course of the Reporting Period.
Two WTGs were each responsible for three swallow/martin fatalities, and five turbines were each responsible for two swallow/martin fatalities. There was no apparent clustering of swallow/martin fatalities.
Twelve raptor and vulture fatalities were recorded over the course of this Reporting Period:
- six Turkey Vultures,
- three Red-tailed Hawks,
- two American Kestrels, and
- one Merlin.
Correcting seasonally for searcher efficiency, scavenger and other removal rates, and the percent area searched, the 12 raptor/vulture and 88 other bird carcasses recovered represent approximately 602 bird fatalities over the course of this Reporting Period.
The estimated total bird mortality for the Reporting Period is 6.99 birds/turbine (3.04 birds/MW). The mortality rate for the six-month Reporting Period at the EcoPower® Centre, at 3.04 birds per MW, is consistent with the results in nearby New York and other studies summarized by Arnett et al. (2007).
The Reporting Period (July-December) covered slightly different seasons than other studies (e.g., in New York, late April to mid-October or November). Direct comparison of mortality at the EcoPower® Centre and the other wind power facilities will be possible following a full year of field studies in 2010.
The 12 raptor/vulture carcasses recovered, when corrected for scavenger removal, represent approximately 13 raptor/vulture fatalities, over the course of this Reporting Period. The resultant total raptor/vulture mortality for the Reporting Period is 0.15 raptors and vultures/turbine (0.07 raptors and vultures/MW). The raptor mortality rate, excluding vultures, of 0.04 raptors per MW is at the mid-point of the range observed at other facilities in North America (0 – 0.09 raptors per MW; Arnett et al., 2007) and is consistent with rates observed elsewhere in Ontario (Stantec, unpublished data).
It is well below the threshold for notification identified in the Follow-up Plan of 0.09 raptors per MW, which is the highest rate of raptor mortality recorded in North American, outside California, at the Stateline, Oregon facility (Arnett et al., 2007).