Female signalling to male song in the domestic canary, Serinus canaria.

Gerard Leboucher,Mathieu Amy,Marc Naguib,Pauline Salvin

doi:10.1098/rsos.140196

Abstract

Most studies on sexual selection focus on male characteristics such as male song in songbirds. Yet female vocalizations in songbirds are growing in interest among behavioural and evolutionary biologists because these vocalizations can reveal the female's preferences for male traits and may affect male display. This study was designed to test whether male song performance influences the different female signals in the domestic canary (Serinus canaria). Female canaries were exposed to three types of song performance, differing in the repetition rate of sexy syllables. This experiment demonstrates that female birds are engaged in multimodal communication during sexual interaction. The results support the copulation solicitation hypothesis for female-specific trills: these trills were positively correlated and had a similar pattern to the copulation solicitation displays; responses were higher to the songs with higher performance and responses decreased with the repetition of the stimulation. Also, we observed a sensitization effect with the repetition of the song of the highest performance for the simple calls. Simple trills and other calls were more frequent during the broadcast of canary songs compared with the heterospecific control songs. The differential use of female signals in response to different song performance reveals a highly differentiated female signalling system which is discussed in light of the role of female traits to understand sexual selection in a broader perspective.

Highlights

Since Darwin [1], the development of the theory of sexual selection mainly focused on male secondary sexual characteristics
There was no correlation among female signals except that female-specific trills (FSTs) were significantly positively correlated with copulation solicitation display (CSD) (r = 0.69, p = 0.003, n = 16, Spearman’s rank-order correlation, table 1)
The occurrence of the CSDs was affected by song performance (GLMM; χ2 = 91.3; p < 0.0001) and the repetition of the stimulation (GLMM; χ 2 = 208.7; p < 0.0001) but there was no significant interaction between song performance and the repetition of the stimulation with the occurrence of the CSDs (GLMM; χ 2 = 2.8; p = 0.592)

Summary

Introduction

Since Darwin [1], the development of the theory of sexual selection mainly focused on male secondary sexual characteristics. Extravagant traits such as colourful plumages, courtships or vocalizations of males have been the object of a myriad studies [2]. Females express secondary sexual characteristics [4,5] and it is unlikely that it represents an artefact of the selection of male secondary sexual characteristics [6]. Females in many species compete for access to a reproduction territory, to other resources, or to a male [7]

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