One-day old American Kestrel (Falco sparverius) nestlings were dosed orally daily with 5 ?l/g of corn oil (controls), 25 mg/kg, 125 mg/kg, or 625 mg/kg of metallic lead in corn oil through day 10. Forty percent of the nestlings given 625 mg/kg died after six days. Growth rates became significantly different from controls in the 625 mg/kg group by day 3 and in the 125 mg/kg group by day 4. Crown-rump lengths and brain weights were significantly lower in both treatment groups. Liver and kidney weights were lower in the 625 mg/kg groups. Skeletal examination and measurement of alizarin red-S stained nestlings revealed reduced growth for the humerus, radius-ulna, femur, and tibiotarsus in the 125 mg/kg and 625 mg/kg groups. Skeletons were otherwise normal in appearance. Greater than 2 ppm (wet weight) lead in the liver or 6 ppm in the kidney was associated with suppressed growth, while more than 5 ppm in the liver and 15 ppm in the kidney occurred in survivors in the 625 mg/kg group. The order of accumulation of lead in tissues at the end of 10 days was kidney> liver> brain. These findings suggest that altricial nestlings may be considerably more sensitive to lead exposure than adults and also more sensitive than hatchlings of many precocial species.
Additional publication details
Survival, growth, and accumulation of ingested lead in nestling American kestrels (Falco sparverius)
Archives of Environmental Contamination and Toxicology