Causes of Mortality in Bald Eagles (Haliaeetus leucocephalus) in The Canadian Maritime Provinces, 1991-2016

Posted on Nov 30, 2020


by Amélie MATHIEU, E. Jane PARMLEY, Scott MCBURNEY, Colin ROBERTSON, Helene VAN DONINCK, and Pierre-Yves DAOUST
CWBM 9 (2): 159-173.

Correspondence: Pierre-Yves Daoust, Canadian Wildlife Health Cooperative, Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, C1A 4P3, Canada.



This article summarizes the results of necropsy findings on 420 bald eagles (Haliaeetus leucocephalus) from the 3 Canadian Maritime provinces over a 26-yr period. It shows that, as in other regions of North America, anthropogenic factors dominate the diagnosed causes of mortality in this species, representing close to 50% of the cases. These factors included vehicular collision (n=57; 14%), electrocution (n=47; 11%), poisoning (n=38; 9%), snares and other trapping devices (n=35; 8%), gunshot (n=20; 5%), and other (n=5; 1%). At least some cases of trauma of unknown cause (n=79; 19%) and some unknown causes of death (n=53; 13%) may have also involved anthropogenic factors. As in several other regions of North America, lead continued to be the most common source of poisoning in this species. Other causes of mortality identified, such as conspecific fights (n=11; 3%) and drowning / hypothermia (n=4; 1%), are natural challenges faced by these birds. Although bald eagles are not considered a species at risk in Canada, results of this study indicate that human-related causes of death are an ongoing issue in the Maritime region as elsewhere. Therefore, mitigating measures aimed at their reduction, for example those in relation to lead-based ammunition and fishing tackle, pesticide use and trapping, should continue to be implemented and expanded.

Key Words: Anthropogenic factors, Bald Eagle, Canada, Haliaeetus leucocephalus, Maritimes, Mortality

10 - Mathieu et al


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