Comparative study of the vocalizations and singing behavior of four Aimophila sparrows

TR Number

Date

1983

Journal Title

Journal ISSN

Volume Title

Publisher

Virginia Polytechnic Institute and State University

Abstract

Vocalizations and singing behaviors of Rufous-crowned Sparrows, Rufous-winged Sparrows, and Cassin's Sparrows were analyzed, described, and compared. For comparative purposes, data from previously studied Five-striped Sparrows were also included.

Ten, 5, 3, and 6 types of calls were present in the repertoires of Rufous-crowns, Rufous-wings, Cassin's, and Five-stripes, respectively.

Songs were sung from the ground, or from a variety of perch heights. Only Cassin's and Rufous-crowns regularly sang flight songs. Cassin's Sparrows sang a higher percentage of flight songs before nesting than after, but time of day did not affect the occurrence of flight songs.

A Discriminant Function Analysis performed on six song parameters showed that the species differed significantly in the parameters measured. Song length proved to be of primary importance for discriminating the species' songs.

From 8 male Rufous-crowns, 3320 songs were recorded. Fifty-one different song types composed of 259 different note complexes were found in this species' repertoire. The average song repertoire size for an individual was 12. Nine songs and 84 note complexes were shared among individuals. From 14 male Rufous-winged Sparrows, 3593 songs were recorded. Fourteen different song types were found; all individuals potentially may sing all fourteen song types. Nine hundred sixty-nine songs were recorded from 18 Cassin's Sparrows, of which 15 different songs were recognized. Individual repertoires consisted of an average of 3 song types, thus some sharing did occur, but no individuals shared the same repertoire.

Rufous-crowns varied their singing rate regardless of the song type used, and singing rate was not related to time of day. Rufous-wings frequently engaged in counter-singing bouts with males alternating and matching song types. Singing rate appeared to be affected by the song type being sung. Singing rates of Cassin's Sparrow songs delivered from perches were sung at a faster rate than those sung only in flight, but there was no relation between singing rate and variation in number of different song types employed in a bout or the proportion of flight versus perch songs.

The vocalizations and singing behavior of the four Aimophila species were dissimilar in many respects, and suggested possible functions of the diverse singing behaviors exhibited by these species were discussed.

Description

Keywords

Citation