Polychlorinated biphenyls, dioxins, furans, and organochlorine pesticides in belted kingfisher eggs from the upper Hudson River basin, New York, USA

Nesting belted kingfishers (hereafter kingfishers, Ceryle alcyon) were studied on the Hudson River near Fort Edward south to New Baltimore (NY, USA) and three nearby river drainages in 2004. Concentrations of 28 organochlorine pesticides, 160 polychlorinated biphenyl (PCB) congeners, and 17 dioxin and furan (PCDD‐F) congeners were quantified in kingfisher eggs. The pattern of organochlorine pesticides and PCDD‐F congeners did not differ significantly between 14 eggs collected from individual nests on the Hudson River and five eggs similarly collected on three other nearby rivers. In contrast, the pattern of PCB congeners in eggs collected on the Hudson River differed significantly from the other rivers. The differences in patterns of PCB congeners were associated with a higher representation of lower‐numbered congeners on the Hudson River than the other rivers. The higher prevalence of the lower‐numbered congeners and lower prevalence of the higher‐numbered congeners is consistent with Aroclor 1016 and 1242 being the source of the PCBs on the Hudson River. Concentrations in a sample egg collected at each nest were compared to nest survival and egg success (the proportion of eggs hatching in a clutch if at least one egg hatched) of the remaining eggs in the clutch. Models that predicted nest survival and egg success as functions of contaminant levels were poorly distinguished from models that presumed no such associations. Small sample sizes could have contributed to the inability to distinguish among contaminant and no toxicant models. However, we cannot rule out the possibility that contaminant concentrations on the Hudson River were not sufficiently high to demonstrate a relationship between contaminant concentrations and reproductive success in kingfishers.