Fig. 1

Comparison of Shannon diversity (alpha diversity) of the skin microbiota of wild living zebra finches. No effect of a bird age [n = 4 fully replicated families consisting of two adults (female, male) and two nestlings (offspring)], b sex (n = 5 families consisting of two adults and at least one nestling) and c family (n = 12 families with three to four individuals consisting of one or two adults and one or two nestlings) on Shannon diversity. X-axis labelling is representing the number of the families’ nest boxes. In the boxplots, the median is the bold horizontal line, the boxes refer to the interquartile range, and whiskers extend to max. 1.5 times the interquartile range, whereas dots are outliers