Imitation of bird song in folklore – onomatopoeia or not?

There are a number of expressions in Swedish and other languages, which describe the songs of different birds, e.g. the rose finch imitated as saying "Pleased to see you". These folk rhymes seem to both imitate the birds' songs and to describe some content connected to the bird. Swedish folk rhymes for the songs of different birds were analyzed in terms of sound structure and content. Imitation of the bird songs is reflected in both vowels and consonants of the folk rhymes, e.g. in speech sounds with energy on low frequencies, such as [m], [u], [o], or speech sounds with energy on high frequencies, such as [s], [t], [i]. Vibrant sounds are often transformed into [r]. Imitation also conserves the number of "syllables", i.e. the rhythmic structure of the bird songs. Intonation variation is also transformed into words like "falling", "down", "up". A special case of transformation of intonation variation is seen when the melody of the bird is interpreted as emotional or attitudinal, and transferred into words like "snälla" (please) and "fy" (shame on you). The creation of folk rhymes could be seen as a type of folk etymology. In folk etymologies an incomprehensible series of sounds is heard and interpreted in terms of already existing words that fit the context, in the language one knows. Folk etymologies can be seen as a productive force in language development. A nonarbitrary connection between sound and content can aid memory and facilitate language learning.