Post-Construction Monitoring Report

The Post-Construction Follow-Up Plan (PCFP) for Wolfe Island is a state-of-the-art monitoring program, and is the most comprehensive program in Canada.

The PCFP requires bi-annual monitoring reports be prepared and submitted to Environment Canada, Ministry of Natural Resources, Natural Resources Canada and to Ducks Unlimited Canada for review and comment.

Data collected during the monitoring work is done professionally, objectively and without bias. The monitoring reports are prepared by third-party experts who have extensive experience in post-construction monitoring programs.

The PCFP ensures that any potentially significant unanticipated adverse environmental effects are identified if they occur. It also ensures the appropriate agencies are involved in the analysis of the monitoring results.

We proactively post the reports, along with Environment Canada and the Ministry of Natural Resources’ comments on the report, to our website for the public to view.

April 2014: Final report covering January-June 2012

Summary of Monitoring Results

This report, the seventh and final in a series, contains the results of the post-construction monitoring program for the period between January 1 and June 30, 2012. Consistent with the schedule for post-construction monitoring outlined in Section 5.1 of the Post-Construction Follow-Up Plan (PCFP) for Bird and Bat Resources for the Wolfe Island Wind Plant (revised February 2010), field surveys conducted during the Reporting Period included:

  • bird and bat mortality monitoring;
  • disturbance effects monitoring – wintering raptors; and
  • disturbance effects monitoring – breeding grassland birds

Mortality monitoring was carried out by employees of Wolfe Island Wind Monitoring, an independent consulting firm, according to a schedule and methods prepared by Stantec that were based on the PCFP. In addition to carcass searches, trials to determine various corrective factors for searcher efficiency and scavenging rates were conducted during the Reporting Period.

Bird Mortality Monitoring
A total of 20 carcasses of 13 bird species were collected during the Reporting Period. Bird fatalities were more commonly found later in the spring period (May and June), with no carcasses recorded in January or February.

Three Bobolink and 10 raptor fatalities were recorded within the search areas over the course of this Reporting Period. After applying correction factors for scavenger removal, searcher efficiency, and percent area searched, the three carcasses found represent an estimated 23.0 Bobolink fatalities over the Reporting Period. The number of fatalities is small relative to the estimated 1,000 to 1,500 that were observed in the Study Area during pre-construction surveys (Stantec, 2008) and the estimated Ontario population of 800,000 (Cadman et al., 2007).

The ten raptor carcasses recovered within the mapped search area, after applying correction factors, represent an estimated total raptor mortality rate of 0.36 raptors/turbine (0.16 raptors/MW) during the Reporting Period. When combined with the results of the July to December 2011 monitoring period, the annual raptor mortality rate is estimated to be 0.44 raptors/turbine (0.19 raptors/MW). The annual raptor mortality rate of 0.19 raptors/MW is within the annual mortality range observed at other facilities in North America outside California (0 to 0.49 raptors/MW; Strickland et al., 2011). However, the annual raptor mortality rate is higher than the notification threshold of 0.09 raptor/MW identified in the PCFP.

The estimated mortality rate (after applying correction factors) for all birds was 2.12 birds/turbine (0.93 birds/MW) for the Reporting Period. When combined with the results of the July to December 2011, the annual mortality rate can be estimated and was calculated to be 6.3 birds/turbine/year (2.54 birds/MW/year), well below the adaptive management threshold of 11.7 birds/MW identified in the PCFP.

The annual bird mortality rate (excluding raptors) of 0.77 birds/MW is lower than that observed at the Maple Ridge, New York facility (5.81 birds/MW) in 2006 (Jain et al., 2007), and in 2007 (3.82 birds/MW; Jain et al., 2009). The Maple Ridge facility is located approximately 75 km south of the Wolfe Island Wind Plant. The Wolfe Island mortality rates are within the mortality range of 0 to approximately 14 birds/MW reported by The National Wind Coordinating Collaborative (“NWCC”, Strickland et al., 2011) in their review of fatality rates at 63 North American wind facilities. When comparing numbers, it is important to note that most, if not all of the studies at Maple Ridge and those summarized in the NWCC report did not include winter mortality monitoring, and therefore any fatalities occurring over the winter months were not included in annual mortality rates. The data for the Wolfe Island Wind Plant includes winter fatalities.

Bat Mortality Monitoring
A total of eight carcasses of five bat species were collected during the Reporting Period.

Correcting for searcher efficiency, scavenger and other removal rates, and percent area searched, the eight recovered carcasses represent an estimated total bat mortality rate for the Reporting Period of 0.73 bats/turbine (0.32 bats/MW). When the results of the Reporting Period (January to June) are combined with the estimated mortality rate for the period July to December 2011 (3.19 bats/MW), the estimated annual mortality rate of 3.51 bats/MW is within the low end of the range of mortality reported by NWCC (Strickland et al., 2011) (0 to 39.7 bats/MW).
The annual bat mortality rate is below the adaptive management threshold of 12.5 bats/MW as identified in the PCFP.

Winter Raptor Surveys
Winter raptor surveys were completed in November and December 2011, the results of which were presented in Monitoring Report No. 6. This report addresses the entire winter raptor season (i.e., November 2011 to March 2012) which allowed for a full comparison to the preconstruction surveys conducted in 2006-2007, and the post-construction surveys conducted in 2009/2010 and 2010/2011. Maximum numbers of observations during any one survey in the 2011/2012 winter raptor surveys include 32 Rough-legged Hawks (March 6), 24 Northern Harriers (March 6), 20 Snowy Owls (January 18), 14 Red-tailed Hawks (January 18), and 6 American Kestrels (January 9). The largest number of Bald Eagles (3 observations) occurred on February 21, 2012.

Peak numbers of Short-eared Owls were observed in March 2012, with up to 67 individuals observed on a single survey (March 6). This high count coincided with the discovery of numerous Short-eared Owls (28) leaving an unknown roost on Wolfe Island and travelling over open water to nearby Simcoe Island, roughly 500 meters (m) away. One possible explanation for this behaviour is these birds showed roost site fidelity on Wolfe Island, yet higher prey densities on Simcoe encouraged the crossing to hunt. The abundance of Short-eared Owl observations suggests Wolfe Island remains an important and productive wintering area for this species.

The results of the multi-year studies demonstrate the annual variability of raptor abundance, with different species peaking in different years. Overall, the 2006/2007 season (0.72 raptors/kilometer (km)) appeared to have particularly high raptor abundance. Raptor numbers observed in 2009/2010 were significantly lower (0.25 raptors/km); however, some species such as Snowy Owl and Bald Eagle appeared to peak in abundance that year. The results from the 2010/2011 surveys (0.54 raptors/km) demonstrates that raptor abundance had increased from the 2009/2010 season, but numbers were lower than those observed in 2006/2007. Differences in raptor density observed within the Study Area between 2006/2007, 2009/2010, 2010/2011 and 2011/2012 seasons are reflective of observations throughout the Kingston area and across southern Ontario. Differences observed between the pre- and post-construction monitoring are attributed to natural variability.

Breeding Grassland Birds
Overall, the grassland surveys indicated that grassland breeding birds remained common throughout the wind plant area. The grassland point counts, repeated during pre and post-construction monitoring, recorded an apparent decrease in breeding density in some grassland species. However, decreases were not observed for the same species through paired point count surveys and grassland area searches. Results of the grassland area searches, which surveyed large portions of grassland habitat in the study area during both pre and post-construction, did not demonstrate a decrease in grassland bird density.

Species-specific results indicated that densities of Bobolink recorded in suitable breeding habitat (hay or pasture) in the Northwest Area of the Wolfe Island Wind Plant have shown a slight increase in post-construction monitoring in 2011 and 2012, when compared to 2007 and 2010. Bobolink in the Southeast Area experienced a notable increase in density in 2012 when compared to all previous years of monitoring. Interestingly, Savannah Sparrow showed a slight increase in the Southeast Area in 2012 compared to 2011 surveys, yet showed decline in the Northwest Area for the same years. A wind turbine avoidance effect was not observed for grassland species through paired point count data, as densities for most species were similar at 0 to 100m and 100 to 200m from wind turbine bases.

Disturbance effects monitoring surveys detailing raptor behaviour, staging and foraging migratory waterfowl, breeding waterfowl, as well as breeding woodland and marsh birds densities were not conducted in 2012. These surveys were discontinued based on the results from earlier in the Monitoring Program and through consultation with agencies that disturbance impact to these groups of birds was not a significant concern. Results of these surveys are provided in previous reports.

Overall, the Wolfe Island Wind Plant Post-Construction Follow-up Plan for Bird and Bat Resources, represents the most extensive post-construction monitoring program in Ontario to date. Results of this multi-year study indicate that the project area continues to support a healthy and vibrant bird community throughout the year, with levels of bird, raptor and bat mortality that are unlikely to have an impact at the local, regional or provincial population level.

To read the Executive Summary and the PCFP in its entirety, please click on the Current Report link below.

For more information about past research we’ve done relating to bat mortality, please click here.

Post-construction monitoring reports and related documents

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