Fig 1. Spectrogram representations of various bird species showing some of the typical appearances of sounds.

(a) A fox sparrow (Passerella iliaca) song illustrating its syllables, phrases, and elements (S = syllable and E = element). (b)-(e) show representations of lines: (b) tui (Prosthemadera novaeseelandiae); (c) the more-pork sound of ruru (Ninox novaeseelandiae); (d) kakapo (Strigops habroptilus) booming; (e) brewer’s sparrow (Spizella breweri). (f)-(h) demonstrate blocks: (f) (long billed) marsh wren (Cistothorus palustris); (g) female North Island brown kiwi (Apteryx mantelli) call; (h) kakapo chinging. (i)-(j) show stacked harmonics: (i) male North Island brown kiwi whistles; (j) ruru trill. (k) oscillations: North Island saddleback (Philesturnus rufusater).