Mercury is a toxic heavy metal that can cause obvious physiological and reproductive problems in animals. Very little is known, however, about its subtle behavioral effects. We examined whether birds that inhabited mercury-contaminated sites exhibited differences in singing behavior compared with birds at uncontaminated reference sites nearby. We recorded the songs of 3 oscines, the Carolina Wren (Thryothorus ludovicianus), House Wren (Troglodytes aedon), and Song Sparrow (Melospiza melodia), and 1 suboscine, the Eastern Phoebe (Sayornis phoebe). Spectrographic analysis revealed that songs of oscines living on contaminated sites contained a lower diversity of note types and were sung at lower tonal frequencies than songs of birds on reference sites. Read more…….