Great article in the San Francisco Chronicle today by Peter Fimrite:

The issue is not new. Wildlife officials have said 130 species are at risk of poisoning by spent lead ammunition left behind by hunters. The U.S. Fish and Wildlife Service outlawed the use of lead shot for duck and goose hunting in 1991 because of evidence that the heavy metal was contaminating waterways. It has been banned for use at national wildlife refuges and some state parks. Thirty-five states regulate the use of lead ammunition on specific species or seasons.

California condors, which were down to only 22 individuals 25 years ago, and other scavenging birds like golden eagles and turkey vultures, are especially susceptible to lead poisoning. Wildlife biologists traced a good many of the deaths and poisonings to bullet fragments in the entrails and carcasses left by hunters that the birds regularly scavenge.