Reviews of Environmental Contamination and Toxicology Volume 237

Golden, Nancy H, Warner, Sarah E, Coffey, Michael J, Nancy H. Golden, Sarah E. Warner, Michael J. Coffey, Golden, Nancy H., Warner, Sarah E., Coffey, Michael J.

There are multiple sources of lead in the environment. However, scientific evidence points to spent lead ammunition as the most frequent cause of lead exposure and poisoning in scavenging birds in the United States. Despite the ban on its use for waterfowl hunting, lead ammunition is still widely used for other hunting and shooting activities. Therefore, it can remain on the landscape in carcasses not retrieved and in discarded offal piles. Carcasses and gut piles can be attractive food sources to scavenging birds that can ingest bullet fragments or shot while feeding. Scavenging birds may be particularly vulnerable to exposure and effects of lead due to their foraging strategies and food preferences, physiological processes that facilitate the absorption of lead, and demographic traits. Numerous lines of evidence support ammunition as the source of exposure in the majority of lead poisoned scavenging birds and include the recovery of ingested lead fragments or shot from exposed birds, observations of birds feeding on contaminated carcasses, isotopic signatures of lead in tissue that match that found in ammunition, patterns of mortality coincident with hunting seasons, and the lack of abundant evidence for other lead sources. Lead can be replaced in ammunition by alternative metals that are currently available and present limited environmental threats.