Behavioural data and R code to reproduce analyses of the paper "Differences in plumage coloration predict female but not male territorial responses in three antbird sister species pairs" published in Animal Behaviour by Gabriel Macedo, Gustavo A. Bravo, Rafael Sobral Marcondes , Elizabeth P. Derryberry , and Cibele Biondo. Introduction: In this study, we hypothesized that the eumelanin concentration in the plumage of antbirds (a family of Neotropical birds) function as ornaments that evolve under social selection, signaling quality or competitive ability of females and males. We tested the prediction that conspicuous eumelanic dark plumage patches are positively associated with territorial responses of females and males of three antbird sister species pairs: Drymophila ochropyga and D. genei; Myrmoderus loricatus and M. squamosus; Thamnophilus torquatus and T. ruficapillus. We compared responses of between sexes and sister species. Females of Drymophila ochropyga bear more conspicuous dark plumage patches than females of D. genei. Males of these species are similarly coloured. Females of Myrmoderus loricatus bear more conspicuous dark plumage patches than females of M. squamosus. Males of these species are similarly coloured. Males of Thamnophilus torquatus bear more conspicuous dark plumage patches than males of T. ruficapillus. Females of these species are similarly coloured. Methods: Using playback experiments in the field, we assessed the strength of territorial responses by measuring number of songs, latency to approach and interaction time of females and males that were forming social pairs. Strong territorial responses correspond to higher values of these variables. We simulated territorial intrusions by a solitary female (female solo song), a solitary male (male solo song), and a social pair (duetting social pair). Results: We found that females of Drymophila ochropyga and Mymoderus loricatus – which bear more conspicuous dark plumage patches – showed stronger territorial responses than females of D. genei and M. squamosus, respectively. Stronger responses occurred against simulated female and/or male intruders, but not against simulated social pairs. Males of Drymophila and Mymorderus species – which are similarly colored – showed similar territorial responses. However, contrary to out predictions, males of Thamnophilus torquatus – which bear more conspicuous dark plumage patches – did not show stronger territorial responses than males of T. ruficapillus. Females of the Thamnophilus species – which are similarly colored – showed weak, similar territorial responses. Discussion: Our results suggest that eumelanic patches in antbirds may function as ornaments in intra- and intersexual contexts in females. In contrast, in species pairs with greater interspecific differences in male ornamentation, territorial competition may occur predominantly among males and female mate choice may drive the evolution of male ornamentation.
Steps to reproduce
Macedo_etal_AnimBehav_data.xlsx: The spreadsheet contains three sheets named “Drymophila”, “Myrmoderus”, and “Thamnophilus” corresponding to genera of sister species pairs analyzed in the paper. Columns names correspond to: Species: specific epithet. Treatment: playback treatment; female solo, male solo, or duet. Rec.ID: identification of the recording used in the experiment. Sex: female or male of a social pair. Social.Pair.ID: identification of social pairs; e.g., female 1 is paired with male 1 and so on. n_songs_control: number of songs during the control phase. interaction_time_control: interaction time during the control phase. n_songs_silence: number of songs during the silent phase. interaction_time_silence: interaction time during the silent phase. n_songs_post_pb: number of songs during the after-playback phase. interaction_time_post_pb: interaction time during the after-playback phase. latency: latency to approach the loudspeaker Macedo_etal_AnimBehav_code.R: The R code contains instructions to run the analyses. The code was initially written in R version 3.6.3 (2019), but was also tested and is working on R version 4.0.3 (2020) and 4.0.5 (2021).