A Comparison of Blood Lead Levels in Bald Eagles From Two Regions on the Great Plains of North America

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

“…Of 66 blood samples analyzed, PbB concentrations ranged from not-detectable (Ͻ 0.05 g/ml) to 0.585 g/ml; 10% of eagles exhibited PbB concentrations suggestive of recent exposure (Ն0.200 g/ml) (Miller et al, 2001). A comparison between median and mean hematological variables of eagles exposed and not exposed to lead is presented in Table 2.…”

“…Grasman and Scanlon (1995) noted that the immunotoxic effects of lead were only observed in Japanese quail (Coturnix japonica) that exhibited other clinical signs of lead toxicosis. Since the maximum PbB concentration at GB was 0.585 g/ml (Miller et al, 2001), it appears that the threshold of immunotoxic effects was not reached and may explain the lack of detectable effects on most individual leucocyte species.…”

“…Blood samples were drawn and analyzed for lead content to determine the prevalence of lead exposure in a population of migrant bald eagles moving through an area of high hunting pressure at Galloway Bay (GB) (50Њ48ЈN, 108Њ27ЈW) located along the South Saskatchewan River, Saskatchewan (Canada) (Miller et al, 2001). Eagles were trapped using padded, weakened leg-hold traps with offset jaws following methods described by Harmata (1985).…”

“…To satisfy the assumption of independence, only data from the first capture of each bird was used. Blood samples (8 to 10 ml) were drawn from the brachial vein; analytical technique for detecting PbB in eagles at GB has been described previously (Miller et al, 1998). Elevated exposure to lead was indicated where PbB concentrations were Ն0.200 g/ml (Redig et al, 1983).…”

“…In addition, we attempted to relate these hematologic measures to blood lead (PbB) concentrations that were determined in a concurrent study (Miller et al, 2001). …”