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 birds, 5%), but did not differ between sexes or collection methods. Prevalences of ingested steel shot did not differ between sexes, but were higher for hunter shot (10 of 39 birds, 26%) than for randomly collected birds (2 of 54 birds, 4%), and tended to be higher for immatures (8 of 32 birds, 25%) than for adults (4 of 61 birds, 7%). We recommend continued monitoring of lead exposure in ring-necked ducks at Catahoula Lake to evaluate management techniques used there to reduce lead poisoning.
