Songs of the Fox Sparrow. II. Intra- and Interpopulation Variation

Abstract

Little intra- or interpopulation variation in songs of fox sparrows was found in Utah and Idaho [USA]. Variations in the geographic distribution of syllable-types and song-types were mutually dependent due to uniformity in the syllable-types used to form song-types. One population tended to form a unique grouping due to the high incidence of song-type D and the absence of song-type E. Individuals of another population displayed the greatest diversity of song-types. Cluster analyses based on syllable-types and song-types emphasized and supported the contention that the incidence of syllable-types and song-types was very uniform within and among all populations. The song structure in populations of fox sparrows appears intermediate between those species that exhibit no intrapopulation structuring of song and those that maintain well-structured dialects. Fox sparrows may learn their song repertoires early in life, and probably do not change the structure of their repertoires after the 1st autumn. Song in this species appears well-adapted for encoding messages of sexual, individual, population (or geographic) and species identity