Territorial responses of male Bermuda White‐eyed Vireos (<i>Vireo griseus</i>subsp.<i>bermudianus</i>) reflect phylogenetic similarity of intruders and acoustic similarity of their songs

For signal divergence to drive speciation, receivers should perceive structural differences in divergent signals; similar-structured signals from closer relatives are expected to elicit stronger responses than dissimilar signals from distant relatives. Two mechanisms can affect receiver responses to passerine song: (1) sympatric song familiarity and (2) an innate auditory template used to assess acoustic similarity. We examined the role of acoustic similarity by comparing behavioral responses of male Bermuda White-eyed Vireos (Vireo griseus bermudianus) to playback of the songs of allopatric species from across the family Vireonidae. Phylogenetic distance between the focal and stimulus species predicted response strength. Males uttered fewer vocalizations, had fewer speaker flyovers, and remained farther from the speaker during playback of the songs of more distantly related vireos. We then tested whether structural similarity of playback songs, as defined by three phylogenetically conserved song traits, explained these relationships. As predicted, males uttered fewer vocalizations, had fewer speaker flyovers, and remained farther from the speaker in response to more dissimilar songs. Collectively, our results suggest that male Bermuda Vireos perceive and respond to interspecies variation in the phylogenetically conserved song traits of allopatric species of vireos. This suggests that song divergence, and the ability to distinguish divergent songs, reinforces reproductive isolation and competitor exclusion. Las respuestas territoriales de los machos del vireo Vireo griseus subsp. bermudianus reflejan la similitud filogenética de los intrusos y la similitud acústica de sus cantos Para que la divergencia de señales conduzca a la especiación, los receptores deben percibir las diferencias estructurales de señales divergentes. Se espera que las señales de estructuras similares de parientes más cercanos provoquen respuestas más fuertes que las señales disimilares de parientes distantes. Dos mecanismos pueden afectar las respuestas de los receptores al canto de paserinas: (1) familiaridad de canto simpátrico y (2) una plantilla auditiva innata que se usa para determinar la similitud acústica. Examinamos el papel de la similitud acústica por medio de comparaciones de respuestas de comportamiento en machos del vireo Vireo griseus bermudianus a grabaciones de cantos de especies alopátricas de la familia Vireonidae. La distancia filogenética entre las especies focal y estímulo predicen la fuerza de la respuesta. Los machos completaron menos vocalizaciones, tuvieron menos sobrevuelos a la bocina y permanecieron más lejos durante el tiempo en que se tocó la grabación de los vireos más distantemente emparentados. Cuando sometimos a prueba la similitud estructural de los cantos grabados, tal y como lo definen tres características filogenéticamente conservadas de los cantos, éstas explicaron esas relaciones. Como lo predecimos, los machos completaron menos vocalizaciones, tuvieron menos sobrevuelos a la bocina y permanecieron más lejos en respuesta a los cantos más disímiles. En conjunto, nuestros resultados sugieren que los machos de este vireo perciben y responden a variación interespecífica en las características del canto filogenéticamente conservadas de las especies de vireos alopátricos. Esto sugiere que la divergencia del canto, y la capacidad de distinguir cantos divergentes, refuerza el aislamiento reproductivo y la exclusión competitiva. Table S1. Song measurements from 137 individuals from 38 species of male vireonids. Songs were collected from Macaulay (ML) and Xeno-canto (XC) libraries; songs from V. griseus bermudianus were recorded in the field by MM for this study. We viewed each recording as a waveform and spectrogram (Hamming window, FFT size = 512 samples, 87.5% overlap) using Raven Pro v1.5 sound analysis software (Charif et al., 2010). Table S2. Song structure of 38 vireonid species and Bermuda Vireo subspecies used as stimuli in 165 playback trials to 15 male Bermuda Vireos. Also shown are the phylogenetic distances between each species and Bermuda Vireos. Table S3. Relationships between the strength of response of 15 male Bermuda Vireos to playbacks and the phylogenetic distance between Bermuda Vireos and the playback stimulus species. Model results for trial order are also presented. Trials involving consubspecific stimuli have been excluded (N = 15). Statistically significant P-values, relative to an adjusted alpha of 0.0167, are in bold. All variance inflation factors (VIFs) were < 5, indicating low collinearity among model predictor variables. Table S4. Relationships between the strength of response of 15 male Bermuda Vireos to playbacks and the acoustic distance between Bermuda Vireos and the playback species. Model results for trial order are also presented. Trials involving consubspecific stimuli have been excluded (N = 15). Statistically significant P-values, relative to an adjusted alpha of 0.0167, are in bold. All variance inflation factors (VIFs) were < 5, indicating low collinearity among model predictor variables. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.