Abstract
This report presents the results of a monitoring program at the Canadian National Exhibition (CNE) around the wind turbine installed there as a joint venture of Toronto Hydro and WindShare in December 2002. The purpose of the monitoring program was to estimate the bird mortality associated with the presence of this turbine. The program operated in the main migration seasons for small nocturnal migrants, both spring and autumn, when there was the greatest potential for avian mortality.
Monitoring
Direct visual searches covered a 50 m radius around the turbine except along the south edge as noted). The searches started just after dawn and lasted about one hour each time. The searcher (Coady) walked a pattern that covered the area at intervals of 5 m or less. The early start minimized the potential loss of any dead birds to diurnal scavengers such as gulls and squirrels, or avoided the possibility that people might find something.
Searches in spring were conducted twice a week from 27 April to 31 May (10 searches). In the autumn searches were three times a week from 18 August to 27 September (18 searches). Searches were spaced to get as even a coverage as possible (less even in spring), but were random with respect to weather conditions. Weather did not inhibit searches and many different conditions were encountered, from full sun to continuous light rain, from calm to strong winds. Notes were also made on birds seen in the area, and of any potential predators that might remove birds.
Predator Removal Study
This study was conducted to assess the potential for removal of dead birds by predators prior to their being found on searches. Dead birds were placed out within 50 m of the turbine on a variety of ground covers. A total of 50 birds was placed out, 17 in spring and 33 in autumn. Thirty one of the birds were small (warbler-sparrow size), 16 were medium size (jay-thrush size), and 3 were larger (woodcock-gull size). All birds were removed after a week or more, by the searcher, when no longer of much interest to a predator because of the state of decay.