Effects of diet and cold exposure on captive female mourning doves dosed with lead shot

Abstract

The effects of diet and cold exposure on captive female mourning doves (Zenaida macroura) dosed with lead (Pb) shot were investigated from 12 December 1985 to 2 January 1986. Doves were screened for Pb exposure using a blood delta-aminolevulinic acid dehydratase assay. A 2×2× 2 factorial design was employed with Pb (1 #8 Pb shot {70±0.5 mg} or seed), temperature (5°C or 22°C), and diet (commercial pelleted ration or mixed seed) as the three factors of interest. Ninetysix doves were assigned randomly to 1 of the 8 treatments, confined individually, and acclimated to their respective diets 3 weeks prior to dosing.

No mortality occurred during the experiment. Changes in body weight after 2 and 3 weeks did not differ between Pb-treated doves and controls. Tissue Pb concentrations were higher in Pb-dosed birds than controls. Partially eroded Pb shot were recovered from feces in 89% (39/44) of the Pb-dosed doves. Doves on the pelleted diet retained Pb shot longer and eroded more Pb than did doves on the mixed seed diet. Tissue Pb concentrations, especially in the kidney, were higher in Pb-treated birds on the mixed seed diet. There were no differences in tissue Pb concentrations due to temperature although there was a diet × temperature interaction in kidney Pb concentrations of Pb-treated doves. The increased likelihood of shot expulsion on the mixed seed diet was apparently offset by nutritional and/or other factors which increased Pb absorption and/or retention in body tissues.