More than 90% of the Horned Grebes in North America breed in ponds and lakes in western and northern Canada. A small isolated population also nests on the Magdalen Islands in the Gulf of St. Lawrence (COSEWIC 2009d). Results from the Breeding Bird Survey suggest a large decrease in the bulk of the population in Canada since 1970. However, limitations in coverage and contradictory results from the Christmas Bird Count, which suggest little change in the wintering population, mean the reliability of this assessment is considered to be low. Targeted surveys show large declines in the abundance of the tiny Magdalen Islands population. In 2009, the Committee on the Status of Endangered Wildlife in Canada designated the Western population as Special Concern because of ongoing declines and numerous threats throughout the year (COSEWIC), and the Magdalen Islands population as Endangered, given its very small and declining size (COSEWIC). Both populations are listed under the Species at Risk Act. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.
During migration and winter, Horned Grebes are vulnerable to oil spills and mortality from entanglement in commercial fishing nets, and significant mortality has also been linked to botulism and contaminant poisoning (Stedman 2000, COSEWIC 2009d, Princé et al. 2018). The Western population faces threats to breeding sites from agricultural development and degradation of wetlands, the loss of nesting sites through drought or rising water levels, increasing populations of predators, and possibly competition with other grebe species (Stedman 2000, COSEWIC 2009d). Given its very small size, the Magdalen Islands population is vulnerable to both demographic and environmental variation, as well as anthropogenic disturbance of breeders (COSEWIC 2009d). For information on the legal status of this species under the Species at Risk Act (SARA) and to view available recovery documents, see the SARA Registry.
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.