You can use it for research or reference. To access the current information, please visit NatureCounts - The State of Canada’s Birds (external link).
The Caspian Tern breeds in colonies scattered across Canada, from the Pacific coast of British Columbia to the Atlantic coast of Newfoundland, often in mixed colonies with other terns and gulls. Counts at several important colonies have documented moderate increases in the abundance of Caspian Terns in its core Canadian breeding area since about 1970, though smaller colonies breeding in Québec and Newfoundland appear to be declining. Although populations appear to be secure at present, Caspian Terns face a variety of threats from human disturbance, contaminants, and predators. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
Because they feed on fish, Caspian Terns are exposed to high levels of contaminants through the process of biomagnification. Harmful effects of this high exposure have been documented among terns breeding in industrialised regions of the Great Lakes (e.g., Grasman et al. 1996, Su et al. 2017). Terns are also sensitive to human disturbance at their breeding colonies, which are shared with other species of terns and gulls. This disturbance can lead to nest abandonment and predation by nearby gulls (Cuthbert and Wires 1999).
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.
