Blood Lead Concentrations and Ingested Shot in Ring-necked Ducks at Catahoula Lake, Louisiana
We analyzed blood lead concentrations and prevalences of ingested lead and steel shot in 93 ring-necked ducks (Aythya collaris) at Catahoula Lake, Louisiana. Blood lead concentrations were higher for immatures than for adults, but did not differ between sexes or between randomly collected and hunter-shot birds. Blood lead concentrations were elevated (≥ 0.20 ppm) in 18 of 31 immatures (58%) and 13 of 61 adults (21%), and were toxic (≥ 0.50 ppm) in 11 immatures (35%) and 5 adults (8%). Prevalences of ingested lead shot were higher for immatures (7 of 32 birds, 22%) than for adults (3 of 61...