Suboscine song development. In contrast to oscines, suboscine passerines typically develop normal songs without learning or experience. For example, (A) Alder Flycatchers (Empidonax alnorum) and (B) Willow Flycatchers (Empidonax traillii) develop songs typical of their species even when exclusively exposed to songs of a different species as young birds. Although the two species look very similar, their songs are quite distinct.
(A) Alder Flycatcher
Michael J. Andersen, Macaulay Library
(B) Willow Flycatcher
Some suboscines may learn their songs. Long‐lived Three‐wattled Bellbirds (Procnias tricarunculatus) modify their songs from year to year. These changes occur in concert among all birds in a population, strongly suggesting that the birds are imitating one another. Bellbird songs contain some incredibly loud elements.
David L. Ross, Jr., Macaulay Library
Dual syringeal control. Australasian Magpie (Gymnorhina tibicen) songs include sounds produced using both sides of the syrinx together (B), as well as by the left (L) or right (R) syrinx alone. The high variability in each of the song syllables (labeled 1–4) relates to changes in the thoracic air‐sac pressure before and after syllable production, as new air passes through the thoracic sac before reaching the lungs.
F. N. Robinson, Macaulay Library
Individual variety. An Eastern Phoebe (Sayornis phoebe) sings two song forms: (A) “phoe‐be” and (B) “phoe‐bree.”
Medium‐sized song repertoires. The song repertoire of an Eastern Towhee (Pipilo erythrophthalmus) provides an opportunity to practice your song discrimination skills. See if you can hear the differences apparent in the spectrograms.
Estimating repertoire size. A Wood Thrush (Hylocichla mustelina) typically sings several song types, which differ in the phrases they contain. Pay particular attention to the middle portion of each song. How many different versions of the middle portion do you hear?
Large song repertoires. Baltimore Orioles (Icterus galbula) often switch rapidly between the songs in their repertoires. Listen for a song type you can remember and count how many songs are uttered before your memorized type is repeated.
(A) Baltimore Oriole Song Variation 1
(B) Baltimore Oriole Song Variation 2
(C) Baltimore Oriole Song Variation 3