Male and female song structure and singing behaviour in the duetting eastern whipbird, Psophodes olivaceus

Abstract

In many tropical bird species, partners combine their songs to form precise duets, of which the function is imperfectly understood. Duet structure and sex differences in vocal strategies may be important indicators of different selective pressures that have led to the evolution and maintenance of these complex acoustic displays. This study examines the singing behaviour of a population of the eastern whipbird, a bird that forms antiphonal duets initiated exclusively by the male. In all, 7% of duets recorded were between a paired female and a male other than her social partner. Males sang more often than females, their songs were longer and moved through a wider frequency range, and they had a larger song repertoire. Females sang two types of song: response songs, used primarily in a duet context, and structurally distinct solo songs, typically used during interactions with other females. Eastern whipbirds lacked unique song types among the repertoires of individual males and females. Males and females combined songs non-randomly to produce specific duets that were shared across the population. Results suggested that song and duet type matching might play an important role in intrasex interactions, such as defence of a territory, or a partner, from same-sex intruders.

Typical Males and Unconventional Females: Songs and Singing Behaviors of a Tropical, Duetting Oriole in the Breeding and Non-Breeding Season

“…Overall, troupial songs are remarkable for their relative lack of sexual dimorphism. Some species, including some monochromatic species, exhibit distinctive sex-specific songs or structural features (Mennill et al, 2005;Rogers, 2005;Logue et al, 2007). However, in other species, males and females have similar overall structure, but differ in a few, continuous parameters, such as frequency or number of syllables (Mennill et al, 2005;Brunton and Li, 2006;Illes and Yunes-Jimenez, 2009).…”

“…Most studies that have directly compared male and female songs have compared structural variation (Logue and Gammon, 2004;Mennill et al, 2005;Rogers, 2005;Brunton and Li, 2006;Hall, 2006;Molles et al, 2006;Dowling and Webster, 2013;Hahn et al, 2013;exceptions: Price et al, 2008;Topp and Mennill, 2008;Illes and Yunes-Jimenez, 2009). Comparing structure of male and female song has revealed interesting trends in the overall complexity or repertoire sizes of male vs. female song.…”

“…This has been used to assess the relative role of sexual selection in shaping elaboration of male vs. female traits (Mennill et al, 2005;Brunton and Li, 2006). Similarly, structural similarity and sex-specific song features have been useful for evaluating sex-role similarity and individual motivation, especially in duetting species (Logue and Gammon, 2004;Rogers, 2005;Hall, 2006).…”

Duetting as a Collective Behavior

“…Duet-type is a pair-level property that is generated by individual-level answering rules. Duet-type is a useful term for species with highly stereotyped duets (e.g., Sonnenschein and Reyer, 1983;Rogers, 2005).…”

On the natural history of duetting in White-browed Coucals: sex- and body-size-dependent differences in a collective vocal display

“…Duet styles vary considerably between species, ranging from rather loose temporal associations such as in Stripe-headed Sparrows (Aimophila ruficauda), in which the female and male simply overlap their parts with no further coordination (Illes and Yunes-Jimenez 2009), to cases of a stimulus response type, where the phrase of one partner is answered by the phrase of the other [e.g. in the Whipbird Psophodes olivaceus (Rogers 2005)], to rapid antiphonal cycles where female and male fit their song elements precisely in the brief pauses between the elements of their partner [e.g. in the Happy Wren, Pheugopedius felix (Templeton et al 2013)].…”