Spent lead shot availability and ingestion by ring-necked pheasants in South Dakota

摘要

Lead is toxic to all vertebrate species and ingestion of lead ammunition has been reported in >130 avian species. Research has primarily focused on the effects and exposure of spent lead shot on waterfowl with little information about effects on upland game species, such as ring-necked pheasant (Phasianus colchicus). We collected 1,450 soil samples to estimate the availability of lead shot on 2 licensed shooting preserves in South Dakota, USA, 2012–2013. We concurrently collected gizzards from 660 hunter-harvested wild male pheasants from the shooting preserves and compared lead ingestion rates with those of 1,301 gizzards collected from nonpreserve areas. Spatial modeling showed the distribution of spent lead shot was associated with the systematic hunting pattern of each study site and, to a lesser extent, land-use type. Prevalence of ingested lead shot was 4.9 times greater for birds harvested on shooting preserves (3.9%, 95% CI=2.7–5.7%) when compared with nonpreserve areas (0.8%, 95% CI=0.4-1.4%) where lead shot availability was presumed less. Wild pheasants inhabiting areas of artificially high hunting intensity and lead deposition are at elevated risk of lead exposure and poisoning, although the consequences of lead ingestion in wild pheasants are unknown.