The Causes of Eagle Mortality in Saskatchewan, 1992-2012

Posted on Feb 1, 2015


Steven J. SCOTT and Trent K. BOLLINGER

Correspondence: Steven Scott, Canadian Wildlife Health Cooperative, Western College of Veterinary Medicine, 52 Campus Drive, Saskatoon, Saskatchewan, S7N 5B4, Canada. Email:

Submitted 7 December 2014 – Accepted 1 February 2015


Diagnostic records of 227 bald eagles (Haliaeetus leucocephalus) and 78 golden eagles (Aquila chrysaetos) collected in Saskatchewan, during 1992 to 2012, were reviewed to identify common causes of mortality. The most frequent cause of death in bald eagles was toxicosis (53%), followed by trauma (22%), electrocution (6%), infectious disease (4%), malnutrition (3%), and idiopathic disease (2%). Trauma and toxicosis were equally responsible for the majority of golden eagle mortalities (28%). Overall, 77% of toxicosis cases were attributed to organophosphate and carbamate pesticides, and 22% were attributed to lead. Automobile collision was responsible for the majority (18%) of traumarelated mortalities in which a cause was known. Pasteurella multocida and Aspergillus fumigatus were the most common cause of infectious disease in bald eagles and golden eagles, respectively. One golden eagle infected with A. fumigatus was also diagnosed with osteosarcoma. This study shows that anthropogenic factors are the most significant cause of eagle mortality in Saskatchewan, and that organophosphate and carbamate insecticides pose a significant risk to resident and migrant eagle populations.

Key Words: Aquila chrysaetos, Bald eagle, Golden eagle, Haliaeetus leucocephalus, Saskatchewan, Insecticides.



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