Assessing environmental pollution in birds: a new methodological approach for interpreting bioaccumulation of trace elements in feather shafts using geochemical sediment data

Environmental trace element composition can have an important impact on ecosystem and population health as well individual fitness. Therefore, carefully assessing bioaccumulation of trace elements is central to studies investigating the ecological impact of pollution. Colonial birds are important bioindicators since non-invasive sampling can easily be achieved through sampling of chick feathers, which controls for some confounding factors of variability (age and environmental heterogeneity). However, an additional confounding factor, external contamination (ExCo), which remains even after washing feathers, has frequently been overlooked in the literature.
We developed a new method to reliably interpret bioaccumulation of 10 trace elements (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Sn and Zn) in feathers using chicks of a colonial species: the Greater Flamingo, Phoenicopterus roseus. First, only shafts were used to remove ExCo retained in vanes. Secondly, we applied a thorough washing procedure. ...