PRODUCTION OF EPP CANADA GEESE NEAR CAPE CHURCHILL IN 2004

Abstract

Nest searching for Eastern Prairie Population Canada geese was conducted on the Nestor One Study Area near Cape Churchill, Manitoba from 16-21 June 2004. A total of 6 nests was found in initial searches of 732 ha of wetlands in 14 primary sample areas, 11 nests were located in searches of 6 coastal sample areas, and 7 nests were located in 3 additional sample units south and east of the primary units. A total of 24 nests was located on the Nestor One study area in 2004. Nest density (unadjusted for observability) in the primary sample areas was 0.82 nests per 100 ha of wetland— the lowest nest density recorded on the Nestor One study site from 1976-2004, and 89% lower than that estimated in 2003. Clutch size in 21 nests with eggs present when located averaged 2.19—lower than the long-term mean of 3.87 (1976-2004) and the clutch size expected based on the established relationship between mean clutch size and median hatch date. Estimated median hatch date was 11 July, and ranged from 7 to 15 July, with no nests initiated on or before 23 May 2004 (the date used to define “bust” production). Nest success calculated as the average apparent success rate of nests active when first located during initial nest searching (0.15) and the 28-day survival of nests based on exposure days through nest location (0.33) was 0.24—considerably lower than the average nest success of 0.63 observed during the 1990s. Based on these estimates of nest density, clutch size, and nest success, gosling production at Nestor One was approximately 0.43 per 100 ha of wetland—the lowest productivity recorded from 1976-2004 and well below the average of 33.48 goslings per 100 ha of wetlands observed during that period.