Skip to main content
U.S. flag

An official website of the United States government

Mercury and other element exposure in tree swallows nesting at low pH and neutral pH lakes in northern Wisconsin USA

May 31, 2012

The primary objective of this study was to determine whether tree swallows (Tachycineta bicolor) demonstrate similar responses to lake pH and mercury (Hg) contamination in northern Wisconsin as do common loons (Gavia immer). Similar to common loons, Hg concentrations in the blood of tree swallow nestlings were higher, Hg concentrations in eggs tended to be higher, and egg size tended to be smaller at low (<6.2) pH lakes. In contrast to common loons, tree swallow nestling production was not lower at low pH lakes. Based on modeling associations, Hg concentrations in tree swallow eggs and nestling blood can be used to predict Hg concentrations in common loons without the invasive or destructive sampling of loons. Mean concentrations of cadmium, manganese, and mercury in nestling livers were higher at low pH lakes than neutral pH lakes. Concentrations of cadmium, chromium, mercury, selenium, and zinc were not at toxic levels.

Publication Year 2012
Title Mercury and other element exposure in tree swallows nesting at low pH and neutral pH lakes in northern Wisconsin USA
DOI 10.1016/j.envpol.2011.12.017
Authors Thomas W. Custer, Christine M. Custer, Wayne E. Thogmartin, Paul M. Dummer, Ronald Rossmann, Kevin P. Kenow, Michael W. Meyer
Publication Type Article
Publication Subtype Journal Article
Series Title Environmental Pollution
Index ID 70037930
Record Source USGS Publications Warehouse
USGS Organization Upper Midwest Environmental Sciences Center