Data for: Variation in nestling feather mercury concentrations at individual, brood, and breeding colony levels: implications for sampling mercury in birds.

Data on [Hg] at different aggregation levels in great egret nestling scapular feathers collects in the Florida Everglades in 2018. Data include [Hg] values and deviation from average concentrations in feathers of the same individual (individual replicates, intra-individual variation), siblings (nestlings from the same nest, intra-brood variation), and breeding colony (inter-brood variation).