The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has caused a global panzootic among amphibians, but some skin microbes can provide protective effects against Bd. Ellison, Knapp and Vredenburg (2021) report on their study of longitudinal patterns in the skin microbiome of the endangered Sierra Nevada Yellow-legged frog (Rana sierrae) in two wild populations. Lower skin bacterial diversity was significantly correlated with greater microbiome stability over time. Amplicon sequence variants (ASV) with intermediate relative abundance were the most volatile over time, and ASVs with high relative abundance were the most transient. Their investigation suggests that efforts to develop probiotic treatments to combat Bd should focus on bacteria that are found at high relative abundances in some members of a population, as these strains are more likely to persist and remain stable in the long term.