Wild bird mass mortalities in eastern Canada associated with the Highly Pathogenic Avian Influenza A(H5N1) virus, 2022
Stephanie Avery‐Gomm,
Tatsiana Barychka,
Matthew English,
Robert A. Ronconi,
Sabina I. Wilhelm,
Jean‐François Rail,
Tabatha Cormier,
Matthieu Beaumont,
Campbell Bowser,
Tori V. Burt,
Sydney M. Collins,
Steven Duffy,
Jolene A. Giacinti,
Scott Gilliland,
Jean‐François Giroux,
Carina Gjerdrum,
Magella Guillemette,
Kathryn E. Hargan,
Megan Jones,
Andrew Kennedy,
Liam Kusalik,
Stéphane Lair,
Andrew Lang,
Raphael A. Lavoie,
Christine Lepage,
Gretchen McPhail,
William A. Montevecchi,
Glen J. Parsons,
Jennifer F. Provencher,
Ishraq Rahman,
Gregory J. Robertson,
Yannick Seyer,
Catherine Soos,
Christopher R. E. Ward,
Regina Wells,
Jordan Wight
Affiliations
Stephanie Avery‐Gomm
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Ottawa Ontario Canada
Tatsiana Barychka
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Ottawa Ontario Canada
Matthew English
Environment and Climate Change Canada Canadian Wildlife Service Dartmouth Nova Scotia Canada
Robert A. Ronconi
Environment and Climate Change Canada Canadian Wildlife Service Dartmouth Nova Scotia Canada
Sabina I. Wilhelm
Environment and Climate Change Canada Canadian Wildlife Service Mount Pearl Newfoundland and Labrador Canada
Jean‐François Rail
Environment and Climate Change Canada Canadian Wildlife Service Québec Quebec Canada
Tabatha Cormier
Environment and Climate Change Canada Canadian Wildlife Service Sackville New Brunswick Canada
Matthieu Beaumont
Environment and Climate Change Canada Canadian Wildlife Service Québec Quebec Canada
Campbell Bowser
Environment and Climate Change Canada Canadian Wildlife Service Sackville New Brunswick Canada
Tori V. Burt
Department of Psychology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
Sydney M. Collins
Department of Psychology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
Steven Duffy
Environment and Climate Change Canada Canadian Wildlife Service Mount Pearl Newfoundland and Labrador Canada
Jolene A. Giacinti
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Ottawa Ontario Canada
Scott Gilliland
Environment and Climate Change Canada Canadian Wildlife Service Sackville New Brunswick Canada
Jean‐François Giroux
Département des Sciences Biologiques Université du Québec à Montréal Montréal Quebec Canada
Carina Gjerdrum
Environment and Climate Change Canada Canadian Wildlife Service Dartmouth Nova Scotia Canada
Magella Guillemette
Department of Biology, Chemistry and Geography Université du Québec à Rimouski Rimouski Quebec Canada
Kathryn E. Hargan
Department of Biology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
Megan Jones
Canadian Wildlife Health Cooperative, Department of Pathology and Microbiology, Atlantic Veterinary College University of Prince Edward Island Charlottetown Prince Edward Island Canada
Andrew Kennedy
Environment and Climate Change Canada Canadian Wildlife Service Sackville New Brunswick Canada
Liam Kusalik
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Ottawa Ontario Canada
Stéphane Lair
Canadian Wildlife Health Cooperative, Faculté de médecine vétérinaire, Centre québécois sur la santé des animaux sauvages Université de Montréal St‐Hyacinthe Quebec Canada
Andrew Lang
Department of Biology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
Raphael A. Lavoie
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Québec Quebec Canada
Christine Lepage
Environment and Climate Change Canada Canadian Wildlife Service Québec Quebec Canada
Gretchen McPhail
Department of Psychology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
William A. Montevecchi
Department of Psychology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
Glen J. Parsons
Nova Scotia Department of Natural Resources and Renewables Halifax Nova Scotia Canada
Jennifer F. Provencher
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Ottawa Ontario Canada
Ishraq Rahman
Department of Biology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
Gregory J. Robertson
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Mount Pearl Newfoundland and Labrador Canada
Yannick Seyer
Environment and Climate Change Canada Canadian Wildlife Service Québec Quebec Canada
Catherine Soos
Environment and Climate Change Canada Wildlife and Landscape Science Directorate Saskatoon Saskatchewan Canada
Christopher R. E. Ward
Environment and Climate Change Canada Canadian Wildlife Service Mount Pearl Newfoundland and Labrador Canada
Regina Wells
Environment and Climate Change Canada Canadian Wildlife Service Happy‐Valley Goose Bay Newfoundland and Labrador Canada
Jordan Wight
Department of Biology Memorial University of Newfoundland St. John's Newfoundland and Labrador Canada
Abstract In 2022, a severe outbreak of disease caused by clade 2.3.4.4b Highly Pathogenic Avian Influenza (HPAI) H5N1 virus resulted in unprecedented mortality among wild birds in eastern Canada. Tens of thousands of birds were reported sick or dead, prompting a comprehensive assessment of mortality spanning the breeding season between April 1 and September 30, 2022. Mortality reports were collated from federal, Indigenous, provincial, and municipal agencies, the Canadian Wildlife Health Cooperative, and other nongovernmental organizations, universities, and citizen science platforms. A scenario analysis was conducted to refine mortality estimates, accounting for potential double counts from multiple sources under a range of spatial and temporal overlaps. Correcting for double counting, HPAI is estimated to have caused 40,391 wild bird mortalities in eastern Canada during the spring and summer of 2022; however, this figure underestimates total mortality as it excludes unreported deaths on land and at sea. Seabirds and sea ducks, long‐lived species that are slow to recover from perturbations, accounted for 98.7% of estimated mortalities. Our study provides estimates of bird mortality, with Northern Gannets (Morus bassanus; 25,669), Common Murres (Uria aalge; 8133), and American Common Eiders (Somateria mollissima dresseri; 1894) exhibiting the highest mortality figures. We then compare these mortality estimates with recent population estimates and trends and make an initial assessment of whether biologically meaningful population‐level impacts are possible. Specifically, we focus on the Northern Gannet, a species that has suffered significant global mortality, and two harvested species, Common Murre and American Common Eider, to inform management decisions. Our analysis suggests population‐level impacts in eastern Canada are possible for Northern Gannets and American Common Eiders, but are unlikely for Common Murres. This study demonstrates a comprehensive approach to assessing mortality and underscores the urgent need for further research to understand the broader ecological ramifications of the HPAI outbreak on wild bird populations.
