Figure 1.

Modifications of begging call acoustic structure over the development of zebra finches reared either by zebra finches (ZFR, N=24, 13 females and 11 males) or by Bengalese finches (BFR, N=21, 12 females and nine males). PC1 is the first principal component from a PCA on acoustic parameters. Points are mean (±s.e.) when the corresponding subset of data contains several chicks, and mean only (without error bar) when the data point represents only one chick. The dataset for one chick at a given age still represents multiple calls, so the corresponding data point is the mean of all these calls. Grey shades are 95% CIs of the linear regression. Because the three-way interaction was significant (cross-fostering group: sex: age; table 1), post hoc tests were performed for each sex. Significance of the interaction between cross-fostering group and age as a covariate is indicated in insert: *p≤0.05.