The Mew Gull winters along the Pacific coast from Alaska to Mexico, and is abundant on Christmas Bird Counts (CBC) in appropriate habitats. The CBC results for North America suggest that the abundance of Mew Gulls has decreased by over 50% relative to 1970. Although much of the breeding range of the Mew Gull lies outside of areas covered regularly by the Breeding Bird Survey (BBS) and the trend estimates' precision is only medium, the BBS provides corroborating evidence specific to the Canadian population; the BBS suggests declines of approximately 75% both in Canada and continentally. The British Columbia Coastal waterbird Survey showed little overall change in the population between 1999 and 2016, suggesting that some portions of the population may not be decreasing, but the area covered by this survey is small. Overall, the population appears to have shown a large decrease in Canada since 1970. The lack of coverage during the breeding season and the unknown proportion of Canadian birds represented by the continental CBC results means that the reliability of this assessment is considered medium. The Mew Gull is currently is below the lowest acceptable level relative to its national population goal (see CBC graph below).
Additional information on: Christmas Bird Count (CBC)
Additional information on: Breeding Bird Survey (BBS) - Canadian analysis
Additional information on: British Columbia Coastal Waterbird Survey
