Wolfe Island has been identified as a significant wintering area for a variety of species of raptors and owls, including one Species at Risk, the Short-eared Owl. Fieldwork and a review of several data sources confirmed the appropriateness of this designation. The endangered Bald Eagle is considered to be a regular, but uncommon winter visitor to Wolfe Island. Golden Eagles have been observed during the winter in the Kingston area, but are very uncommon visitors. Similar habitat conditions to those found on Wolfe Island are present on Simcoe Island.

Due to the concentration of raptors during the winter, there is some risk of potential negative effect, including direct mortality. Raptors appear to be more vulnerable to collision than other species groups (National Academy of Sciences, 2007). Some of the species present are known to hover while hunting, or fly erratically at dusk, potentially making them susceptible to collisions with the wind turbines. Because raptors have relatively low reproductive rates, population recovery from mortality effects can be slow (Kingsley and Whittam, 2007).

Key areas of raptor and owl use were located in the western (west of Concession 4) and southern (south of Reeds Bay Road) portion of the study area. Of the wintering birds, the Shorteared Owl, the Rough-legged Hawk, and the Horned Lark have the greatest potential to be directly affected through collision due to their species-specific behaviours.

Although the foraging habits of Short-eared Owls and Horned Larks would not usually bring them into the sweep area of the turbine blades, the Short-eared Owl avoids predators by quickly increasing its flight altitude, and both species have aerial flight displays. Four Short-eared Owl fatalities have been recorded at three western North American wind turbine facilities (Kingsley and Whittam, 2007). The hovering foraging behaviour of Rough-legged Hawks during the winter also has the potential to bring them into contact with the wind turbine blades. Direct mortality through collision is less likely, although still a potential effect, for the other species of raptors particularly as they engage in hunting activity.

Habitat characteristics will not change significantly as a result of the proposed wind plant, as the physical footprint of the project is relatively small. However, no information is available regarding the potential for disturbance effects arising from the operational turbines on raptor species (Kingsley and Whittam, 2007) or in raptor wintering areas. Disturbance effects during operation may include behavioural modification such as avoidance during flight or displacement from foraging areas as a result of noise or aversion to the turbine blade movement. The extent of disturbance effects has the potential to be more significant during winter than other times of the year, because an individual’s energy losses are more difficult to recoup in cold weather and when food sources are difficult to access (A. Sandilands, pers. comm., 2007).