“Junk” threatens re-establishment of California Condor
Of 13 breeding attempts by Critically Endangered California Condors Gymnogyps californianus in the wild in southern California between 2001 and 2005, only one resulted in successful fledging. A paper  published in Bird Conservation International finds that “ingested anthropogenic material” -swallowed junk -was directly responsible for the deaths of two condor nestlings, and is strongly implicated in the deaths of several more.
Four dead nestlings and two removed from the wild held substantial
quantities of junk such as glass fragments, metal bottle-tops, washers, cartridge cases, electrical wiring and plastic pipes.
By contrast, of nine chicks produced between 1980 and 1984, all but one fledged successfully. “Current levels of junk ingestion clearly surpass that found in the historical breeding population,” the authors assert. “The deleterious effects of junk ingestion on condor nest success now seriously threaten the long-term re-establishment of a viable, self-sustaining breeding population in southern California.”
The US Forest Service has tried to clean up sites used by condors, but because of the “growing and deeper human footprint on the environment of southern California”, the task is huge.
"Current levels of junk ingestion clearly surpass that found in the historical breeding population..."
The authors propose that as a matter of urgency, additional condor restaurants should be set up at multiple feeding sites away from problem areas. “However, an increase in the foraging ranges of condors is likely to result in increased exposure to lead. Removing the threat of lead poisoning from the condor range would allow greater flexibility for the management of condor populations.”
Bird Conservation International is the official journal of BirdLife International. It provides stimulating, up-to-date coverage of bird conservation topics important in today's world. For more information: BirdLife: Bird Conservation International
 Junk ingestion and nestling mortality in a reintroduced population of California Condors Gymnogyps californianus ALLAN MEE, BRUCE A RIDEOUT, JANET A. HAMBER, J. NICK TODD, GREG AUSTIN, MIKE CLARK and MICHAEL P. WALLACE Bird Conservation International (2007) 17:1-13.