Condors not damned by dams
The article about David Moen (a research associate of the Oregon Zoo) and his search for evidence that condors once nested in the Columbia River Gorge states that "scientists blame its decline largely on deforestation and the impact of dams on salmon" (HCN, 10/12/09). For clarity, we would like to point out that this is not the position of the Oregon Zoo. We are not aware of any scientific evidence linking either of these things to the condor's decline in the region. Indeed, by the time most of the major dams were built (1930s to 1960s), condors were already extremely rare or absent from the Pacific Northwest. We cannot be certain what caused the condor's decline in the Pacific Northwest, but likely candidates include lead poisoning from the ingestion of spent ammunition, egg collecting, intentional shooting, and poisoned carcasses intended to kill livestock predators. As we work with stakeholders to investigate the feasibility of returning condors to the skies of the Pacific Northwest, we believe it is important to use the most accurate scientific information available.
David Shepherdson, Ph.D.
Deputy Conservation Division Manager, Oregon Zoo