Population status

Ring-billed Gull
(Larus delawarensis)

The species breeds widely across Canada, where a large portion of its breeding population is well covered by the Breeding Bird Surveys(BBS). Results from the BBS suggest that the population in Canada has exhibited a large increase in abundance since about 1970. 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, recent censuses of colonies in the Great Lakes report a 26% decline in the abundance of Ring-billed Gulls between 1999 and 2009. This decline is partly attributable to direct management of populations considered over-abundant at several locations (Morris et al. 2011; see Conservation and Management).

 

Breeding Bird Survey (BBS) - Canadian analysis

Additional information on: Breeding Bird Survey (BBS) - Canadian analysis

Table 1: Population trends by geographic area
Geographic areaTime Period Table 1 - footnote 1 Annual trend Table 1 - footnote 2 Intervals Table 1 - footnote3
LowerUpper
Canada Select to view graph of the geographic area: Canada 1970-2012; Breeding Bird Survey (BBS) - Canadian analysis1970-20123.31.27.8
 

Great Lakes Decadal Colonial Waterbird Census

Additional information on: Great Lakes Decadal Colonial Waterbird Census

Trend of number of nests observed

View numerical data of the graph.

References