Dosing of adult pigeons with as little as one #9 lead pellet caused severe δ-ALAD depression, suggesting potential adverse effects in wild populations

Abstract

Avian wildlife species commonly ingest lead (Pb) spent shot or bullet fragments as grit or mistakenly as food. In previous studies in our laboratory and others, the toxicity varied based on the diet as well as type and quantity of Pb ingested. In the current study, domestic pigeons were gavaged with 1, 2, or 3 Pb pellets and then followed with weekly radiographs and blood physiologic endpoints for 28 days. Pellet retention decreased by roughly 50 % per week as pellets were either absorbed or excreted, except for week 4 where pellet number no longer was diminished. Size of retained pellets visually decreased over retention time. Birds dosed with a single #9 pellet showed mean blood Pb levels over 80 times higher than those of the controls, verifying Pb pellet absorption from the gut. A single Pb pellet also reduced plasma δ-aminolevulinic acid dehydratase (δ-ALAD) activity by over 80 % compared to controls, suggesting the potential for population injury in Pb pellet-exposed pigeons.

Lead poisoning and its in vivo biomarkers in Mallard and Coot from two hunting activity areas in Poland

“…Negative linear correlations were already observed in different specimens and level of exposure (e.g. Pain, 1989;Strom et al, 2002;Holladay et al, 2012;). The relationship found in birds from the Zator area is better fitted with a logarithmic model, especially in Coots (Figs.…”

Lead in terrestrial game birds from Spain

“…Birds may eliminate Pb pellets from their digestive tracts rapidly with little absorption, or they may be retained until they are eroded away, solubilised and absorbed, or may be processed in any intermediate stage (Pain et al 2019). Rates of Pb digestive absorption and particle transit times depend on the species (Holladay et al 2012).…”

“…The digestive retention time has been reported to be between two weeks and one month, approximately, in Japanese Quail (Coturnix japonica), Northern Bobwhite Quail (Colinus virginianus) and Domestic Pigeon (Yamamoto et al 1993;Kerr et al 2010;Holladay et al 2012). The Pb passes into the bloodstream and into soft tissues such as the liver and kidney, although a part may be excreted.…”

Relationship between blood test values and blood lead (Pb) levels in Black-headed gull (<i>Chroicocephalus ridibundus</i>: Laridae)

“…Although little is known about the transitions (changes) in blood concentrations following low lead accumulation, high lead accumulation has been reported in some avian species. For instance, some seagull species quickly develop many symptoms, such as anemia and neurological symptoms, following exposure to high lead concentrations [ 23 ]. On the other hand, regarding clinical symptoms related to low lead accumulation, Hollady et al [ 23 ] reported that domestic pigeons (Columbidae) exposed to low lead accumulation did not exhibit any clinical signs.…”

“…For instance, some seagull species quickly develop many symptoms, such as anemia and neurological symptoms, following exposure to high lead concentrations [ 23 ]. On the other hand, regarding clinical symptoms related to low lead accumulation, Hollady et al [ 23 ] reported that domestic pigeons (Columbidae) exposed to low lead accumulation did not exhibit any clinical signs. Therefore, we concluded that gulls were more likely to have been a steady, low lead accumulation since the beginning of exposure, than exposed to high and gradually decreasing from that levels.…”