Figure 1 |. Long range syntax rules in canary song.
a. Two example spectrograms of canary song. Colored bars indicate different phrases assembled from basic elements called syllables. Both examples contain a common phrase transition (orange to pink) but differ in the preceding and following phrases. b. A summary of all phrase sequences containing this common transition reveals that the choice of what to sing after the pink phrase depends on the phrases that were produced earlier. Lines represent phrase identity and duration. Song sequences are stacked (vertical axis) sorted by the identity of the 1st phrase, the last phrase and then the center phrases’ duration. Pie charts show the frequency of phrases that follow the pink phrase, calculated in the subset of songs that share a preceding sequence context (separated by dashed lines). In the pie chart, grey represents the song end, and other colors represent a phrase pictured in the first panel. The pink phrase precedes a 3rd order ‘complex transition’; the likelihood that a particular phrase will follow it is dependent on transitions three phrases in the past. c. Percent of phrases that precede complex transitions of different orders in N=5 birds (dots). Bars and error bars show mean and SE.