Relative abundance of bacteria detected in fecal microbiota of red junglefowl selected for high fear and low fear towards humans. Relative abundance of order‐level bacterial in 16S rRNA amplicon sequence variants detected in 23 high fear and 27 low fear red junglefowl fecal samples: A) Top 10 most abundant bacteria orders and differentially abundant. B) Clostridiales (Wald test, t value = 3.1, p value = 0.003) and C) Lactobacillales (Wald test, t value = –3.7, p value = 0.0006) orders between the high and low fear selection lines. D) Differential abundance of the class Clostridia (Wald test, t value = 3.3, p value = 0.002) observed in the metagenome‐assembled‐genomes (MAGs) detected in 22 high fear and 23 low fear red junglefowl fecal samples. Microbial community composition was modeled at the order and class level for B,C) the 16S and D) shotgun sequence data respectively by fitting the beta‐binomial regression model implemented in the “corncob” package in R. Differentially abundant taxa were considered significant using the parametric Wald test with a controlled false discovery rate (p value cutoff <0.05) ** p ≤ 0.01, *** p ≤ 0.001.