Accumulation of cadmium, copper and zinc in the liver of some passerine species wintering in Central Norway

The concentration (mg kg−1 dry weight) of cadmium (Cd), copper (Cu) and zinc (Zn) in the liver of Parus palustris, P. montanus, P. major, Carduelis chloris and Pyrrhula pyrrhula was determined in birds collected in October–March, 1992–1995, in Central Norway. This study is especially focused on interspecific and age-dependent variations. The metal concentrations in liver are generally higher for adults than for juveniles, and there is an accumulation of Cd in the Parus species during winter. There is a positive correlation between Cd-Cu and Cu-Zn, but not for Cd-Zn. Juvenile P. montanus and P. major from a subalpine area had a higher accumulation of Cd and Cu than juvenile P. palustris from lowland areas, probably as an effect of a higher consumption of willow (Salix spp., known to have a high level of cadmium) seeds and insects living on willows, and a relatively high copper level in the ground of the subalpine area.