The Iceland Gull is one of the least known gulls in North America, and has a contentious taxonomy. The species currently includes three subspecies: L. g. glaucoides, L. g. kumlieni (also known as "Kumlien’s Gull"), and L. g. thayeri (also known as "Thayer’s Gull"). Thayer’s Gull was, until recently, considered a full species, but was merged with Iceland Gull based on evidence of mating with L. g. kumlieni (Chesser et al. 2017). L. g. glaucoides breeds mainly in West Greenland, while L. g. kumlieni and L. g. thayeri breed only in the Canadian High Arctic (Gaston 2018). The subspecies also differ in where they winter: L. g. glaucoides remain at high latitudes in polynyas, ice leads, and among drifting pack ice, but sometimes move south into Europe; L. g. kumlieni remain in the Artic as well, but immature birds (which can be challening to differentiate among the subspecies) are commonly observed on the coast of Atlantic Canada and the north-eastern United States; and L. g. thayeri winter on the coast of the Pacific Northwest, only occasionally venturing east (Snell et al. 2018). Few long-term data are available to describe the gull’s status in Canada. Current data are limited in temporal scope and geography, and/or may be sampling too small a proportion of the population, so the status of the population in Canada remains unclear. The Iceland Gull is therefore considered to be data deficient until more information becomes available. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
The winter distribution for Canadian-breeding Iceland Gulls is not entirely understood, mainly due to the challenge of surveying the Artic in the winter, where the bulk of the population remains throughout the year (Snell et al. 2018). Consequently, the potential population-level effects of oil pollution in Atlantic Canada and Greenland, or hunting in Greenland, are difficult to assess. Some work has been done on L. g. thayeri along the Pacific coast; these birds often forage on lawns, agricultural areas, and garbage dumps, where they may be exposed to pesticides and other harmful contaminants (Snell 2002a). Others winter offshore and scavenge for fisheries discards, so changing fishing practices could affect feeding opportunities for wintering gulls. Like L. g. thayeri, L. g. kumlieni birds wintering in Newfoundland also forage in urban environments and may therefore be exposed to contaminants. Interestingly, recent work has shown that these gulls have some of the lowest concentrations of mercury found in Arctic gulls, suggesting that mercury contamination is not currently a threat to the species (Bond and Robertson 2015). Overall, an improved understanding of the species’ population size and trend, now that Thayer’s Gull and Iceland Gull are considered the same species, is needed.
Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:
Select any of the sub-regions below to view the BCR strategy for additional details.