PW01 Wildlife Toxicology
Exhibit Hall
8:00 AM - Wednesday, 12 November 2003
(PW029) Secondary lead poisoning in birds of prey from scavenging shot black-tailed prairie dogs.
Stephens, R.1, Johnson, A.1, Plumb, R.1, Dickerson, K.2, McKinstry, M.1, Anderson, S.1, 1 Wyoming Cooperative Fish and Wildlife Research Unit, Laramie, WY, USA2 U.S. Fish and Wildlife Service, Cheyenne, WY, USA
ABSTRACT- Raptors are susceptible to lead (Pb) poisoning if they consume Pb bullet fragments when scavenging shot prey items. Recreational black-tailed prairie dog shooting is a common activity at Thunder Basin National Grasslands (TBNG), Wyoming. The three objectives we developed to determine if (Pb) poisoning was occurring in raptors scavenging shot prairie dogs from TBNG were: 1) monitor raptor use of prairie dog colonies, 2) X-ray and dissect carcasses of shot prairie dogs to determine content of Pb bullet fragments, and 3) compare hematological parameters of raptors at the treatment site to the reference site. We observed raptors foraging at prairie dog colonies but raptor use did not correlate with shooter intensity. We detected metal fragments in prairie dog carcasses but levels of blood Pb and feather Pb were below sub-clinical levels in raptors from TBNG and the reference site. Our analysis of red blood cell delta-aminolevulinic acid dehydratase activity (ALAD), hemoglobin levels, and protoporphyrin levels also did not indicate Pb poisoning in raptors at TBNG. While we know that raptors scavenge on carcasses of shot prairie dogs and that the carcasses may contain Pb bullet fragments, we did not detect Pb poisoning in any of the birds. Lead poisoning may become important if the availability of alternate food sources decreases or shooter intensity increases.
Key words: raptors, lead poisoning, prairie dogs, blood chemistry