The Ring-billed Gull breeds widely across Canada, where a large portion of its population is well covered by the Breeding Bird Survey (BBS). Results from the BBS suggest that both the Canadian and continental populations have exhibited large increases in abundance since about 1970. However, there is regional variation in the results, with the central and western Bird Conservation Regions (BCRs) showing smaller increases or even declines, and the eastern BCRs showing strong increases (all BCRs for which there are reasonably reliable BBS results in Canada are shown below). The species has also expanded its range to the north and west (Sirois et al. 1995, Pollet et al. 2012). However, although the abundance in Canada remains well above 1970s levels, censuses of colonies in the Great Lakes report a 26% decline in the abundance of Ring-billed Gulls between 1999 and 2009. Declines have also been observed in the large St. Lawrence River and Estuary population (Cotter et al. 2012). These declines are partly attributable to direct management of populations due to conflicts with humans at several locations (Morris et al. 2011, Cotter et al. 2012); see Conservation and Management). The Ring-billed Gull is currently at an acceptable level relative to its national population goal (see BBS Canada graph below).
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
Additional information on: British Columbia Coastal Waterbird Survey
Additional information on: Great Lakes Decadal Colonial Waterbird Census