PARENT SESSION
PS1 - Wildlife Toxicology
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P033) Lead exposure in terrestrially foraging raptors in southern Ontario, Canada.
Martin, Pamela*,1, Campbell, Doug1, Scheuhammer, Tony3, 1 Canadian Wildlife Service, Burlington, ON, Canada3 National Wildlife Research Centre, Hull, PQ, Canada
ABSTRACT- Secondary poisoning of raptors with lead shot from waterfowl hunting has been well documented. In contrast, the degree of lead exposure and poisoning in terrestrially foraging raptors has received far less attention. Over 200 raptor carcasses received by the Canadian Cooperative Wildlife Health Centre between 1999 and 2001 were necropsied, and liver, kidney and bone were analyzed for Pb. Results indicated a low incidence of elevated Pb exposure in terrestrial raptors. For the two most common species, great-horned owls and red-tailed hawks, average Pb concentrations in liver and bone were very low (<3 ppm dry weight). No individuals exceeded the level of 6 ppm in liver considered to be indicative of elevated exposure in raptors. Similarly, individuals of other terrestrial raptor species also showed low soft tissue Pb levels. Nevertheless, 2/11 (18%) American kestrels, 3/9 (33%) of sharp-shinned hawks, 1/3 northern harriers and 4/4 turkey vultures had bone Pb concentrations indicating elevated lifetime exposure to Pb. The sources of Pb to these species is unknown; scavenging of hunter-shot carcasses is a possibility for harriers and vultures, but not suspected for kestrels and sharp-shinned hawks
Key words: raptors, Pb, subclinical exposure