Effects of Breeding Stage and Behavioral Context on Singing Behavior of Male Indigo Buntings

Abstract

Abstract We studied the effects of breeding stage and behavioral context on the singing behavior of male Indigo Buntings (Passerina cyanea; n = 15) during the 2004 breeding season in Madison County, Kentucky, USA, to better understand how males with a single-song repertoire vary the characteristics of their song to convey different information. Playback experiments were conducted in 2005 in territories of focal males (n = 14) to further examine the possible effect of male-male interactions on singing behavior. We analyzed 10,919 songs of 15 male Indigo Buntings with songs consisting of a series of figures that were usually paired (i.e., phrases). Mean song duration was 2.30 ± 0.13 (SE) sec (range = 1.44–3.40 sec) with males varying song duration by varying the number of figures and phrases in each song. Singing rates varied significantly (P < 0.0001) among breeding stages and were highest prior to pairing, suggesting singing has a role in mate attraction. Singing rates also differed (P = 0.013) du...