Figure S1 from Loss of cultural song diversity and the convergence of songs in a declining Hawaiian forest bird community

Representative ‘akeke‘e song spectrogram displaying the 11 measured acoustic variables : 1) song length (seconds), 2) total number of syllables (n=11), 3) number of unique syllable types (n=2), 4) trill rate (total syllables/song length), 5) average number of notes per syllable (n=1.5), 6) average number of frequency changes within a syllable (n=1.6), 7) number of frequency changes between syllables within the song (n=2), 8) peak frequency (kHz), 9) low (kHz) and 10) high (kHz) frequencies at which the amplitude exceeded -24dB relative to the peak, and 11)frequency bandwidth (kHz).