In case you are unaware of the following, I draw this passage to your attention:
[Roy] Acuff began his recording career in 1936, when William R. Calaway of the American Radio Corporation heard him singing 'The Great Speckled Bird' (the original record labels, however, spelled it 'Speckle' and to many people it will always bear that title). Set to a melody reminiscent of 'I'm Thinking Tonight of My Blue Eyes', the song came to Acuff through the performances of another Knoxville radio group, Charlie Swain and the Black Shirts. The authorship of this famous song will probably always remain unknown, although it has been attributed to a Rev Gant and to Rev Guy Smith (Acuff also wrote four additional verses which became known as 'The Great Speckled Bird No 2'). The song, which pictures the church as a group of persecuted individuals who ultimately will gain eternal salvation as a reward for their earthly travail, is based upon the ninth verse of the twelfth chapter of Jeremia: 'Mine heritage is unto me as a speckled bird, the birds round about are against her'. The song was popular not only as a recording hit but as a favorite in some of the Pentecostal Holiness churches as well. Vance Randolph, for example, heard it sung in Pawhuska, Oklahoma, as an official Assembly of God hymn, and W.J. Cash claimed that it was 'the official hymn of the Church of God'.
[Bill C. Malone 'Country Music USA' University of Texas Press Revised Edition 1985 pp 189-190]
Shelton and Golblatt ('The Country Music Story) also refer to the Jeremiah passage, but suggest the title of the song is a symbol for the Bible.