Avian mercury concentration can be measured using feathers, which are easily collected and analyzed. Feather collection has resulted in archives of samples spanning decades. Mercury concentrations (henceforth [Hg]) in breast tissue is of interest; it is most often consumed by hunters and is less variable than feathers, so may better represent the effect of mercury on avian survival and reproduction. The relationship between feather and breast [Hg] is relatively unknown. Understanding this relationship may permit using feathers to predict breast [Hg]. We collected 39 wood ducks harvested by hunters on the Carson River, NV, an area highly contaminated with mercury. We measured [Hg] in axillary and flank feathers and liver and breast tissue using a Milestone DMA-80 mercury analyzer. We examined the relationship between these tissues using a multivariate log-normal regression model within a Bayesian framework. We found a positive correlation between flank feathers (Beta = 0.82; 95% CRI = 0.64—0.99) and breast [Hg], although there was considerable variability. We developed a predictive tool to estimate the 95% credible interval of breast [Hg] using flank feathers, permitting us to use flank feathers to determine if hunter consumption advisories are warranted and estimate historical breast [Hg] from archived feather samples.

Morgan is a Master’s student in the Department of Natural Resources and Environmental Science at the University of Nevada, Reno looking at demographic data to analyze survival in wood duck populations in Nevada in relation to methylmercury loading. She received a B. S. in Biology from Gonzaga University where she studied wood duck eggs for use as a biomonitoring tool for lead in northern Idaho. Her research interests include ecotoxicology, restoration of contaminated habitats, and quantitative ecology.