Form and function of song in a population of <i>Amphispiza bilineata</i> (Cassin)

TitleForm and function of song in a population of Amphispiza bilineata (Cassin)
Publication TypeThesis
Year of Publication1965
AuthorsHeckenlively DBruce
Date Published1965
UniversityNew Mexico State University
CityLas Cruces, New Mexico
Thesis TypeM.S. Thesis
Call Number00109
KeywordsAves, also SEE <BIRD>, Aves, Amphispiza, bird, Black-throated sparrow, song, dissertation, dissertations, theses, thesis
AbstractStructure and function of song were studied in a population of twenty-two Black-throated Sparrows. Audiospectograms were made of eighty songs found in the population; seventy of the songs were used in most of the analyses. Song duration, duration and structure of the parts, frequency limits, and temporal ordering within the song were studied. Nine song types were the most recorded in an individual; the same individual had less variable song duration than the population as a whole. Black-throated Sparrows are highly variable singers, both as individuals and as a population. They are more variable than other emberizines in song duration and minimum frequency and less variable in detailed syllable characteristics. Factors apparently important in the song variation are the lack of closely related sympatric species and reduced numbers of bird species in desert scrub habitat. Large territories appear to encourage selection for overall pattern variation and for vocal versus visual communication maintaining territoriality. Experiments substantiated that territories are defended primarily by vocalization. Individual recognition appears to be through variation in the fine structure of the song, including duration; while species recognition is postulated as being through the overall format of the song and the presence of trills.