Table 2. Factors affecting variation in primate vaginal microbiota.

Factor	R2 a	ANOSIM Rb
Species	42.7	0.95
Sample origin	21.56±0.75	0.49
Sexual swelling	10.58±0.99	0.408
Promiscuity	10.56±0.41	0.33
Social structure	9.37±1.16	0.6
Testes mass	6.14±0.37	0.22
Body weight	6.1±0.28	0.22
Neonatal weight	6.04±0.29	0.22
Gestation duration	5.86±0.24	0.56
Mating group size	5.45±0.37	0.32
Baculum length	5.53±0.22	0.33
Group size	5.52±0.22	0.71

Abbreviation: ANOSIM, analysis of similarities.

^aPermutational multivariate analysis of variance using distance matrices. Values represent the average percent R² variation explained by the factor after all potential factor-ordered combinations were tested to account for shared R². Values are presented with their 95% confidence intervals and all were significant based on F-tests of sequential sums of squares from permutations of the raw data (P<0.001).

^bANOSIM values based on groupings of high, medium and low thresholds for continuous variables (Supplementary Table S2) or otherwise their discrete variables. Analyses were based on 10 000 permutations and all values were significant (P<0.001).