Relationship between blood lead concentrations in common ravens and date in 2011 and 2012.

<p>Dot size is proportional to the log of the sample size. Error bars represents SE. Dotted lines represent the 95%CI. The light blue barplot illustrates the cumulative number of rifle-shot moose in the hunting area selected for the study. Ravens with no sign of clinical contamination were reported to have lead concentration <100 µg.L⁻¹ (horizontal red dashed line) according to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0111546#pone.0111546-Craighead1" target="_blank">[28]</a>.