National Survey on Loon Mortality
Assessing the health of a wildlife species that is near the top of the food chain is known to be useful for monitoring environmental quality. Bio-accumulation of some environmental contaminants frequently results in toxic effects at higher levels in the food chain. Monitoring and diagnosing causes of mortality in predatory and scavenger species can often detect exposure and mortality caused by pollutants. Loons are proving to be a useful species in this regard. Over the past few years in Atlantic and Ontario regions, special effort has been made to secure specimens of loons found dead in the wild. Close to 100 loons have been necropsied in the two regions combined. Among birds in good body condition, causes of mortality included trauma, possibly from impact with motor boats, and drowning in gill nets. Birds in poor body condition had a variety of disease problems, often two to three in the same individual. The most important problems included chronic lead poisoning form ingestion of lead sinkers, repiratory aspergillosis ( a fungal infection of the lungs), oil contamination of the plumage (particularly in birds at sea in the Atlantic region), marked intestinal parasitism, and high level of mercury in tissues. More work is needed to determine how these various disease problems interact in an individual bird to cause debilitation and death.
A national survey of loon mortatlity has been implemented to better understand causes of mortality in loons and to assess the relative importance of lead poisoning associated with the ingestion of lead sinkers. This survey depends on the willingness of the public to report and submit dead loons to appropriate diagnostic laboratories for examination.
Carcasses that cannot be submitted within 36 hours of being found should be kept frozen. Please do NOT send eggs – call the Canadian Lakes Loon Survey (toll free 1 – 888 – 448 – 2473) and they will let you know where to ship them.
To submit specimens in our region contact:
Ted Leighton, Gary Wobeser or Trent Bollinger at (306 – 966 – 5099)
CCWHC (Canadian Cooperative Wildlife Health Centre)
Western College of Veterinary Medicine
Saskatoon, Saskatchewan
This survey is being implemented in cooperation with Environment Canada and is being supported by several provincial resource agencies and the Canadian Lakes Loon Survey (a Bird Studies Canada program).
Visit the CCWHC Web Page at: wildlife.usask.ca (no www required).