(A) Song duration (seconds), (B) song energy (dB), (C) 3rd Quartile frequency (Hz) and (D) song average entropy (bits) at days +3, +10, +17 and +24 in 4 T-treated castrated male canaries that had started singing 3 days after the treatment. These song characteristics could obviously not be evaluated in control males that did not sing, with only one exception. The results of the repeated measure ANOVA are indicated in the insert. When the ANOVA is significant, significant differences with day +3 as determined by Tukey post hoc are shown. Statistical significance is indicated as follows: * p<0.05, ** p<0.01.