Fig. 5

a and b Principal component analysis of BC dissimilarity between gut bacterial compositions of adult female Assamese macaques. Dissimilarity was influenced by a season (classified by food abundance) but not b age categorized into young adult (6–10), mid-aged (> 10 and < 18), and old (≥ 18). Boxes represent the interquartile range (IQ), which contains the middle 50% of the records, and a line across the box indicates the median. Vertical lines extend from the upper and lower edges of the box to the highest and lowest values which are no greater than 1.5 times the IQ range. Circles represent outliers. One outlier was excluded to improve displays. c Personalization of gut bacterial communities increased with age. Personalization is expressed per sample as the minimum dissimilarity to any sample from another female in the same group and season. d The older females were the less often they groomed with their closest female partner. Regression lines and confidence intervals are derived from c a generalized linear mixed model with beta error distribution and controlling for gestation status, social group, and season of sampling or d from multiple linear regressions with Gaussian distribution, controlling for social group