Rainfall structures the gelada gut microbiome. a Partial residual plot of Shannon alpha diversity index according to cumulative rainfall (in mm). Black dots represent the partial residuals from the LMM (i.e., showing the association between cumulative rainfall and alpha diversity, while controlling for all other predictors). The blue line and confidence intervals come from a linear regression (for representation only). Seven outlier samples (with a particularly low Shannon index) were omitted for clarity of representation. b Visualization of between-sample dissimilarity (based on Aitchison distance) on the first principal component (PC1) according to cumulative rainfall. c Compositional barplot of the five most abundant phyla in the dry (< 100 mm of rain in the past month, N = 362) and wet (> 200 mm of rain in the past month, N = 282) samples (cumulative rainfall was converted to a categorical variable for representation purposes). d Loading scores of each amplicon sequence variant (ASV) on the first principal component. ASVs with a loading score > 0.4 (characteristics of the wet season) and < −0.4 (characteristic of the dry season) are colored.