Great Shearwaters breed on a few remote islands in the central south Atlantic and migrate more than 15,000 km north along the east coasts of South and North America. It is thought that the vast majority of the world population spends the non-breeding season in the western North Atlantic, between Georges Bank and southern Greenland (Brooke 2004). In Canada, the species is regularly detected on pelagic surveys from spring through fall, capturing both overwintering and migrating birds. However, monitoring results from Canadian waters are too variable to determine any change in population status relative to about 1970. Canada’s conservation responsibility for the Great Shearwater is very high given the high percentage of the world’s population that use Canadian waters during the non-breeding season. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
Among seabird species globally, Great Shearwaters are within the top-20 largest consumers of marine biomass (Brooke 2004a), eating a wide variety of prey in Canadian waters including fish, squid, and krill (Ronconi et al. 2010). Great Shearwaters have been known to drown on long-lines off Tristan da Cunha and Brazil (Cuthbert 2005), and are reported as by-catch in American and Canadian fisheries (Hedd et al. 2015, Hatch 2018). These birds, like many other seabird species, have also been known to starve to death after ingesting plastics, which fill their stomachs (Pierce et al. 2004); in Provencher et al. 2014, Great Shearwaters had the highest prevalence of ingested plastics of all the species examined. The impact of these sources of mortality on the global population is unknown. The Eastern Canada Seabirds at Sea Monitoring Program provides current data and information on Great Shearwater abundance and distribution in Canadian waters during their non-breeding season. These data provide critical information for environmental assessments related to offshore developments, emergency response related to oil spills, risk assessments, marine protected area planning, and other management and conservation initiatives.
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.
