DOI: 10.5061/dryad.k3j9kd5pj
title: Data from: Asymmetry in responsiveness to playback of geographic song variation after a recent range expansion

description: Birdsong variation among populations within species has been regarded as a
 possible precursor for variation between species and may play a role in
 speciation. However, acoustic variation between two populations of the
 same or different species can have a variable impact on mutual
 responsiveness, and we currently lack sufficient insight into the
 underlying reasons. We report here on geographic song variation and
 responsiveness to playback for the light-vented bulbul (Pycnonotus
 sinensis), a species with recent range expansion in China. We recorded
 songs in four historical populations in the south and six newly
 established populations in the north. We tested responsiveness in two
 southern and two northern locations to songs from southern and northern
 birds. Besides songs from the other distribution range (south to north and
 north to south), we used recordings for playback from local, nearby, and
 faraway dialects from within their own distribution range. We confirmed
 distinct dialectal differentiation in the south and a more gradual pattern
 of geographic song divergence in the north. Birds in the south showed very
 little response to almost all non-local songs. In contrast, birds in the
 north showed a strong response to a wide range of stimuli, just gradually
 fading from local, nearby, to far-away northern dialects, which may be
 related to song type sharing or individual mobility and aggression
 associated with the recent range expansion. We hereby add an asymmetric
 response pattern in response to the literature and review the current
 insights about the potential impact of song variation on avian speciation.
description: We recorded songs in six northern populations: Beijing (BJ),
 Dalian (DL), Beidaihe (BDH), Xian (XA), Zhengzhou (ZZ), and Jinan (JN),
 and four southern populations: Nanchong (NC), Changsha (CS),
 Yaan (YA), and Wuhan (WH). We recorded the spontaneous songs (not
 playback-triggered) of 10 males from each population. All these songs were
 recorded during the early phase of the breeding season and were
 subsequently used to create playback stimuli. We conducted playback
 experiments from 9 April to 30 May during the early breeding seasons in
 both southern and northern populations. We selected NC
 and CS for the southern populations and BJ and DL for the northern
 populations to test local responsiveness to geographic variation in song
 via playback experiments. We compared response strength to songs of the
 local population, a nearby and far-away population of the same region
 (historical source or recently expanded range), and a far-away population
 from the other region. The song of a particular male was used twice per
 playback population, which means that we used four sets (own, nearby,
 far-away, other) of ten unique song stimuli from different males per
 population of origin (thus forty unique songs) to test the responsiveness
 of twenty unique males in twenty different territories per site (thus
 eighty playback trials per site). In this way, we reduced problems of
 pseudo-replication by restricting the repeated use of the same stimuli in
 the same population more than twice. We started each
 series of playback with a heterospecific great tit (<em>Parus
 major</em>) song to get an experimental control of baseline behavior
 during playback set-up, sound playback, and observer presence. After the
 great tit song control, we played the four bulbul song treatments of
 different origins in random order. We therefore had a playback sequence of
 five different song stimuli, with each song played five times for 11
 minutes, resulting in a total trial duration of 55 minutes per bird
 territory. Every playback trial consisted of three periods per song
 stimulus (Fig. 3): pre-playback (5 min, the time before or in between
 subsequent playbacks), during-playback (3 min), post-playback (3 min). The
 heterospecific control never elicited any obvious response, and the
 quantification of the relatively low level of excitement during this
 playback period thereby adequately served as baseline behaviour for the
 evaluation of any responsiveness during the following bulbul song
 stimuli. 
description: # Data from: Asymmetry in responsiveness to playback of geographic song
 variation after a recent range expansion Dataset DOI:
 [10.5061/dryad.k3j9kd5pj](https://doi.org/10.5061/dryad.k3j9kd5pj) Paper
 Citation Xing XY, Yang XJ, Xu XJ, Fu CJ, Song G, Lei FM, Slabbekoorn H.
 2026. Asymmetry in responsiveness to playback of geographic song variation
 after a recent range expansion. *Behavioral Ecology*, *in press*.
 Originators and contact information Xiaoying Xing,
 e-mail: [ab71588@163.com](mailto:ab71588@163.com) Xiaojing Yang,
 e-mail: [jogxoyang@cug.edu.cn](mailto:jogxoyang@cug.edu.cn) Xiajuan Xu,
 e-mail: [2024020134@nefu.edu.cn](mailto:2024020134@nefu.edu.cn) Changjian
 Fu,
 e-mail: [602022300007@smail.nju.edu.cn](mailto:602022300007@smail.nju.edu.cn) Gang Song, e-mail: [songgang@ioz.ac.cn](mailto:songgang@ioz.ac.cn) Fumin Lei, e-mail: [leifm@ioz.ac.cn](mailto:leifm@ioz.ac.cn)  Hans Slabbekoorn, e-mail: [h.w.slabbekoorn@biology.leidenuniv.nl](mailto:h.w.slabbekoorn@biology.leidenuniv.nl) #### Description of the data and file structure #### Files and variables Files: date-local_and_nonlocal_table.csv and  data-result_of_great_tit_playback.csv **Description:**  date-local and nonlocal table: The responses of the four populations — DL (Dalian), BJ (Beijing), CS (Changsha), and NC (Nanchong) — to playback stimuli of songs from different geographical origins. data-result of great tit playback:  The response of great tits to playback stimuli of songs from different geographical origins. ##### Variables The variables of the table named “date-local and nonlocal” in the Raw_date dataset： * Localities (the four playback-exposed populations): DL (Dalian); BJ (Beijing); CS (Changsha); NC (Nanchong) * Individual: the playback-exposed individuals * Stimuli (The playback source population: DL (Dalian); BJ (Beijing); BDH (Beidaihe); XA (Xian), ZZ (Zhengzhou); JN (Jinan); NC (Nanchong); CS (Changsha); YA (Yaan); WH (Wuhan) * SS: search for speaker * LA: latency to first approach, measured in seconds * DR: duration of response, measured in seconds * AD: approach distances 0 = &lt; 1 m, 1 = 1-5 m, 2 = 5-10 m, 3 = &gt; 10 m: the minimum distance of the focal bird to the speaker * NOC: number of perch changes, * LS: latency to first song, , measured in seconds * NOS: number of response songs (NOS), measured in seconds * LM: mean song length, measured in seconds The meaning of the variables in the table named "data-result of great tit playback" within the Raw_date dataset is the same as those in the "date-local and nonlocal" table. #### Code/software To view the raw data files (in xlsx.format), Microsoft Excel version 2019 or later is sufficient. Principal component analysis (PCA), Kaiser–Meyer–Olkin test (KMO) and Bartlett’s test were performed using the ‘psych’ package (version 2.0.9) in R. Linear mixed models (LMM) was performed using the ‘lme4’ package (version 1.1-27.1) in R. Tukey’s test for post-hoc comparisons was performed using the ‘multcomp’ package (version R 1.4-17) in R. Figures were created using the ‘ggplot2’ package (version 3.3.2) in R.