Cadmium, the white metal used in rechargeable batteries, is poisoning the white ptarmigan, a species of grouse, in Colorado. Stretching from Denver to Durango, the state's ore belt is rich in the toxic metal. Although cadmium concentrations in soil and water are highest downstream from commercial mining operations, it's not mining activities in this region that endanger the birds, researchers say.
Seeking to discover why the Colorado Lagopus leucurus has fragile bones, a team of ecologists led by James R. Larison of Oregon State University in Corvallis undertook a 2-year study of the foods that the ptarmigan consumes. The researchers also analyzed tissues from 39 birds. "The studies that took us through the food web clearly indicated that we were dealing with cadmium problems," Larison says.