| hepatic element concentrations of lesser scaup (aythya affinis) during spring migration in the upper midwest. | high concentrations of some hepatic elements might be contributing to the decline of the continental lesser scaup (aythya affinis) population. we evaluated hepatic element concentrations of male and female lesser scaup collected from the upper midwest (iowa, minnesota, north dakota, and south dakota) during the 2003 and 2004 spring migrations. we measured concentrations of 24 elements in livers of 117 lesser scaup. we found that only selenium concentrations were at levels (>3.0 μg/g wet weight [ ... | 2011 | 20803199 |