Fig. 6
From: Volatiles of symbiotic bacterial origin explain ectoparasitism and fledging success of hoopoes
Statistically significant partial associations between scores from Principal Component (PC) axes summarizing relative abundance of detected volatile of hoopoe nest-box environments (dependent variables) and those summarizing volatiles of the uropygial secretion of females (green dots, a, b, c and d) and of nestlings (blue dots, e, f, g, h, i). Each PC-axis was named by a composition of letters that indicate the type of samples. The first letter indicates whether the sample corresponds to bacteria (B) or volatiles (V), the second letter indicates whether the sample is from secretions of females (SF), secretions of nestlings (SN) or nest material (M). Finally, for distinguishing between types of samples that were collected at the beginning (1) and at the end (2) of the nestling period, the name finished with a number. Lines are regression lines