Assessment of embryotoxicity, post-hatch development, and long-term effects on behavior and reproduction in zebra finches (Taeniopygia guttata) following in ovo methylmercury exposure

Mercury is an environmental contaminant that can bioaccumulate in terrestrial ecosystems as organic methylmercury (MeHg); however little is known on the effects of mercury exposure on terrestrial-feeding songbirds. The objectives of the current study were to 1) assess embryotoxic effects of in ovo exposure, via egg injection, to MeHg concentrations similar to those reported in free-living songbirds; and 2) investigate long term post-hatching effects of in ovo exposure to MeHg on offspring development, mating behavior, and reproduction in a model songbird species, the zebra finch (Taeniopygia guttata). In ovo MeHg decreased hatching success in a dose-dependent manner. However, it had no long-term post hatching effects on growth, hematological traits, male courtship song quality, mating behavior in either sex, or female reproductive performance. These findings would suggest that in ovo exposure to MeHg has acute effects on embryo survival, but no long-term effects on the behavioral endpoints measured or reproductive performance.