What's In A Song?

Technically speaking, birds make two sounds: a call and a song. The call is relatively short and somewhat muted and is used for basic contact or in times of alarm, whereas the song  is a much elaborate and intricate affair and is associated with courtship and mating. Birdsong consists of sequences of smaller discrete units called elements. Groups of elements are combined into intermediate units called syllables, which in turn combine to make songs. If these units, elements and syllables, exist throughout an entire species they are called universal categories (1). 

Male (top) and female Chaffinch (Fringilla coelebs)

The song of the Chaffinch (Fringilla coelebs) is a wonderfully bubbly affair, especially when compared with the simple “pink” that is its call (2). Its song consists of an initial trill of several repeated syllable phrases, followed by a “flourish,” which typically consists of a short phrase of high-pitch elements and one long buzzy element (3). It has been shown that male Chaffinches assess songs differently from females based on the relative length of the trill and the flourish, showing that the differences in the two parts represents a communicative relevance (4). Analysis of Chaffinch song with a dynamic time-warping algorithm showed that the syllables were linked to certain positions within the song and were not randomly distributed (2). This lends further credence to the theory that birdsong has parallels with human language.

References:

1. Lachlan et al., 2010. Journal of Comparative Psychology  124 pp. 92-108
2. Sterry, 2004. Collins Guide to Irish Wildlife
3. Thorpe, 1954. Nature 173 p 465
4. Leitão et al., 2006.  Animal Behaviour 71 pp. 1289-1296.