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(116) Environmental Contaminants and Deformities in the Endangered Southwestern Willow Flycatcher in Arizona, USA. Is There a Linkage? Mora, Miguel1, Rourke, Jay2, Sferra, Susan3, King, Kirke4, 1 2 3 4 ABSTRACT- The Lower San Pedro River in Arizona represents an important riparian corridor for nesting by many riparian birds, including the endangered southwestern willow flycatcher (Empidonax traillii extimus). This habitat, however, may be affected by agricultural, mining, and water treatment activities. Some environmental contaminants such as chlorinated hydrocarbons and metals have been associated with deformities (crossed bills, small or missing eyes, clubbed feet) in birds from diverse areas of the United States. Several deformed chicks of the southwestern willow flycatcher (WIFL) were reported during the last few years in Arizona. In this study, we attempted to establish if environmental contaminants could be linked to deformities of the WIFL in Arizona. We determined levels of selected inorganic and organic contaminants in potential insect prey of the WIFL and in avian surrogate species at selected sites within the San Pedro River and in Roosevelt Lake. DDE and PCBs were the only organochlorine compounds quantified above detection limits in all the samples. None of the mean concentrations of DDE and PCBs in eggs, fledglings, and adult birds were near or above the threshold for potential detrimental effects on the birds themselves or on predators that may feed on them. Except for Sr, all metals and metalloids in eggs and carcasses of three bird species were low and not of concern for biological effects such as deformities in birds. However, the unusually high concentrations of Sr in bird eggs may be of some concern for potential association with deformities of the WIFL, but more documentation is needed. Overall, it seems that DDE, PCBs, and most metals and metalloids analyzed in this study are not implicated in the deformities observed in WIFLs in the Lower San Pedro River and possibly other areas in Arizona. Key words: Monitoring, Contaminants, Endangered Species, Wildlife |
