EFFECTS OF LEAD SHOT INGESTION ON <i>δ</i>-AMINOLEVULINIC ACID DEHYDRATASE ACTIVITY, HEMOGLOBIN CONCENTRATION, AND SERUM CHEMISTRY IN BALD EAGLES

Self Cite

Lead-induced mortality appears to have been a major factor in the decline of the California condor (Gymnogyps californianus). We orally dosed turkey vultures (Cathartes aura) with BB-sized lead shot from January 1988 through July 1988 to determine physiologic response (delta-aminolevulinic acid dehydratase inhibition, erythrocyte protoporphyrin levels, anemia), diagnostic tissue lead concentrations (blood, liver, and kidney), and comparative sensitivity of this species. Two turkey vultures died and two became so intoxicated they were euthanized. Overall, responses of measured parameters were comparable to other species exposed to lead although there was considerable individual variation. Survival time (143-211 days), even with the large numbers of shot and constant redosing, was much longer than reported for other species of birds, suggesting considerable tolerance by turkey vultures to the deleterious effects of lead ingestion. Based on these observations, turkey vultures appear to be poor models for assessing the risk of lead poisoning to California condors or predicting their physiologic response.

Section: Discussionsupporting

confidence: 62%

Section: Discussionmentioning

confidence: 91%

Experimental Lead Poisoning in Turkey Vultures (Cathartes Aura)

Carpenter

Pattee²,

Fritts

et al. 2003

Self Cite

“…This is not surprising considering the wide range of effects of lead on plasma proteins reported in the literature. Hoffman et al (1985) reported that plasma protein levels for American kestrels (Falco sparverius) were not significantly affected by lead ingestion when compared with untreated birds. Redig et al (1983) noted that total protein in bald eagles exhibiting PbB concentration Ն 0.200 and Ͻ 0.600 g/ml was not significantly different from eagles not showing signs of lead exposure (Ͻ 0.200 g/ml), but found significantly depressed total proteins in eagles with PbB concentrations greater than 0.600 g/ml.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, at GB, Hct may be severely depressed only in conjunction with either extended retention of lead shot pellets or when PbB concentrations exceed levels considered indicative of clinical toxicosis. Nonetheless, depressed Hct in lead-exposed bald eagles has been report-ed where PbB concentrations have exceeded 0.600 g/ml (Hoffman et al, 1981;Redig et al, 1983).…”

Section: Discussionmentioning

confidence: 99%

Hemograms for and Nutritional Condition of Migrant Bald Eagles Tested for Exposure to Lead

Miller

Wayland

Bortolotti

2001

Plasma proteins, hematocrit, differential blood counts were examined and nutritional condition was estimated for bald eagles (Haliaeetus leucocephalus) trapped (n ϭ 66) during autumn migration, 1994-95 at Galloway Bay (Saskatchewan, Canada), for the purposes of estimating prevalence of exposure to lead. Sex and age differences in hematocrit and plasma proteins were not observed; however, female eagles exhibited larger median absolute heterophil counts than males. Hematologic values were similar to those previously reported from eagles in captivity. Departures from expected hematological values from a healthy population of eagles were not observed in birds with elevated levels of blood lead (Ն0.200 g/ml). Similarly, nutritional condition was not related to blood-lead concentrations. Therefore, it appears that lead exposure in this population was below a threshold required to indicate toxicological alteration in the hematological values and index of nutritional condition that we measured.

“…Birds ingest spent Pb shotgun pellets and fishing sinkers, which usually are retained in the gizzard where they are ground into small, easily absorbed particles (Kelley et al, 1998). Poisoning from Pb pellets has been implicated in many types of birds, from black ducks (Anas rubripes) and mallards (A. platyrhynchos) (Rattner et al, 1989), to Canada geese (Branta canadensis) and mute swans (Cygnus olor) (Simpson and Hunt, 1979;Windingstad and Hinds, 1987;O'Halloran et al, 1988), flamingos (Phoenicopterus ruber) (Mateo et al, 1997), bald eagles (Haliaeetus leucocephalus) (Jacobson et al, 1977;Hoffman et al, 1981) and spectacled and common eiders (Somateria fischeri and S. mollissima, respectively) (Franson et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Acute Toxicity of Lead, Steel, and an Iron-Tungsten-Nickel Shot to Mallard Ducks (Anas Platyrhynchos)

Brewer¹,

Fairbrother

Clark

et al. 2003

Twenty mallards (Anas platyrhynchos) of both sexes were dosed by oral gavage with Heavi-Shot (H-S; Environ-Metal, Inc., Sweet Home, Oregon, USA) pellets, 20 with steel shot, and 10 with lead (Pb) pellets, all of equal size. All pellets were fired from a shotgun into an absorbent material, retrieved, and weighed prior to introduction into the ducks. Birds were fed whole kernel corn and grit and observed for signs of toxicity for 30 days following dosing. HeviShot pellets lost an average of 6.2% of their mass and steel shot pellets lost 57% of their mass in the birds' gizzards. Almost all (90%) of the Pb shot dosed birds died before the end of the study, while no mortality was observed in the steel or H-S dosed groups. Even though total food consumption differed between the H-S and steel shot groups, mean bird weight change was not different. There were no significant morphologic or histopathologic abnormalities of the liver and kidney in the H-S and steel shot groups. Results indicated that mallards dosed orally with eight No. 4 H-S pellets were not adversely affected over a 30-day period, and that H-S provides another environmentally safe nontoxic shot for use in waterfowl hunting.