PARENT SESSION
PS1 - Wildlife Toxicology
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P020) Blood lead and ALAD activity levels of migratory Cooper's Hawks in the southern Rocky Mountains.
McBride, Tobias*,1, Gross, Howard2, Smith, Jeff2, Smith, Ruthie3, Hooper, Michael1, 1 Texas Tech University, Lubbock, TX2 HawkWatch International, Salt Lake City, UT3 University of New Mexico, Albuquerque, NM
ABSTRACT- Predatory or scavenging raptors can be exposed to lead contamination through the ingestion of hunter injured or killed game species that contain residual lead bullets or pellets, or fragments thereof. We studied the potential for lead exposure in the northern and southern ranges of migratory Cooper's Hawks (Accipiter cooperii) by sampling their southward and northward migrating populations, respectively. Cooper's Hawks have been regularly captured for a variety of research purposes at 2 long term HawkWatch International monitoring and banding stations in north central New Mexico. Blood samples were collected from 60 individuals during the 2001 fall migration, and 38 individuals during the spring 2002 migration. Blood lead levels during fall migration ranged from 0.027 (one half detection limit; n = 53) to 0.112 ppm (ww) with a mean (± SE) of 0.033 ± 0.003 ppm. Lead concentrations from the spring northward migration were significantly increased (P = 0.040), ranging from 0.0169 (one half detection limit; n = 13) to 0.356 ppm with a mean (± SE) of 0.063 ± 0.011 ppm. Erythrocyte ALAD activity during the fall season had a mean (± SE) of 66.69 ± 2.34 units (nmoles ALA / min × ml RBC), which was significantly greater (P = 0.002) than spring migration ALAD activity which had a mean (± SE) of 53.98 ± 3.09 units, indicating a 19% reduction in mean ALAD activity. No significant differences between sexes or between age classes were detected for any of the measured endpoints. The findings suggest that Cooper's Hawks are exposed to greater levels of lead in their southern range than they are in the north.
Key words: Accipiter cooperii, raptor, lead , alad