Biological and Societal Dimensions of Lead Poisoning of Birds in the USA

Friend, Milton
Franson, J Christian
Anderson, William L.
U.S. Geological Survey
National Wildlife Health Center
Publication Date: 

ABSTRACT.—The ingestion of spent lead shot was known to cause mortality in wild waterfowl in the US a
century before the implementation of nontoxic shot regulations began in 1972. The biological foundation
for this transition was strongly supported by both field observations and structured scientific investigations.
Despite the overwhelming evidence, various societal factors forestalled the full transition to nontoxic shot
for waterfowl hunting until 1991. Now, nearly 20 years later, these same factors weigh heavily in current
debates about nontoxic shot requirements for hunting other game birds, requiring nontoxic bullets for big
game hunting in California Condor range and for restricting the use of small lead sinkers and jig heads for
sport-fishing. As with waterfowl, a strong science-based foundation is requisite for further transitions to
nontoxic ammunition and fishing weights. Our experiences have taught us that the societal aspects of this
transition are as important as the biological components and must be adequately addressed before
alternatives to toxic lead ammunition, fishing weights, and other materials will be accepted as an
investment in wildlife conservation. Received 16 May 2008, accepted 8 July 2008.