Birding Archives

Primary song. Phillips County, Arkansas; 27 March 2006. This song type consists of alternating sharply downslurred whistles (A), which are rather unmusical, and lower, slowly upslurred whistles (B), which are very musical. This song is mostly whistled, but several harmonics are faintly visible; these may be responsible for the "rich" quality of the whistles. Figure by © Nathan Pieplow.

Primary song. Larimer County, Colorado; 24 June 2005. For the most part, this is a clear whistled song, although faint traces of the first harmonics can be seen above most of the notes. Notes B and D are monotone; A and C are downslurred. Note C, as it is higher and more sharply downslurred than the others, is the least musical of the bunch. Figure by © Nathan Pieplow.

Adult calls and juvenile begging calls. Fremont County, Colorado; 18 May 2005. The juvenile begging calls are labeled A; they are in strict monotone series, each upslurred and nasal at the beginning, noisy at the end. Notes B are typical of adult calls; the "zebra stripe" pattern of many strong harmonics indicates strong nasality, and the arched shape indicates an overslurred intonation. Figure by © Nathan Pieplow.

Primary song. Weld County, Colorado; 21 May 2006. Notes A are the "stick-breaking" noises typical of eastern populations; the strong vertical lines represent popping or clicking sounds, and the "mess" in between is noise similar to that of static. Part B of the song starts out noisy, but develops a voice with fast beats that rises in pitch. In part C, the highly nasal voice with beats has lost its noise content. Note that because the harmonics are multiples of the fundamental frequency, the rate of any change in the fundamental frequency is also multiplied; this is why the beats appear progressively more exaggerated with each higher harmonic. Figure by © Nathan Pieplow.

Primary song. Mesa County, Colorado; 7 April 2007. Although this song pattern fits the definition of variable variety, note the strong tendency toward alternating variety. This tendency usually distinguishes Black-throated Sparrow's song from that of Bewick'sWren, which can sound very similar in western Colorado, but which typically repeats song types dozens of times before switching. Figure by © Nathan Pieplow.