Comparative bioacoustics of multiple eastern versus western songbird pairs in North America reveals a gradient of song divergence: Raw acoutic measurements
Data files
Aug 16, 2024 version files 150.76 KB
Abstract
Vocalizations are one of the key premating reproductive barriers that could affect species formation. In song-learning birds, vocal traits are sometimes overlooked in species delimitation, as compared to morphological or plumage-based differences. In this study, we assessed geographic variation in songs of eight pairs of oscines on two scales: (1) comparing primary songs of species/subspecies pairs whose breeding grounds are eastern and western counterparts of each other in the continental North America, and (2) for each counterpart, identifying and comparing possible variation among their populations. We found that there were strong differences in the songs between eastern and western taxa, though the magnitude of that difference was not correlated to a mitochondrial DNA-based estimates of divergence. Additionally, we found that within-taxa geographic variation was not common in our focal taxa, beyond a single species (Townsend’s warbler, Setophaga townsendi). The result of this study provides a standardized, quantitative comparison of eastern and western songbirds, and implies the possible effectiveness of vocalizations as a reproductive barrier as this geographic scale may not be as strong as has been previously suggested.
README: Comparative bioacoustics of multiple eastern versus western songbird pairs in North America reveals a gradient of song divergence: Raw acoutic measurements
https://doi.org/10.5061/dryad.w6m905qxx
We extracted acoustic measurements from thousands of bird songs for a systematic comparative analysis of song divergence between eastern and western regions of continental North America. We used eight pairs of eastern and western closely related taxa. All song recordings are provided by The Macaulay Library at the Cornell Lab of Ornithology.
Description of the data and file structure
There are 9 .csv files, each contains acoustic measurement of each pair.
- combined_btnwar_towwar_A.csv: Acoustic measurements of Black-throated Green Warbler song type A (n=25) and Townsend's Warbler song type A (n=38)
- combined_btnwar_towwar_B.csv: Acoustic measurements of Black-throated Green Warbler song type B (n=52) and Townsend's Warbler song type B (n=32)
- combined_mouwar_macwar.csv: Acoustic measurements of Mourning Warbler (n=50) and MacGillivray's Warbler (n=50)
- combined_easmea_wesmea.csv: Acoustic measurements of Eastern Meadowlark (n=43) and Western Meadowlark (n=54)
- combined_nawa.csv: Acoustic measurements of eastern Nashville Warbler subspecies (n=50) and western Nashville Warbler subspecies (n=50)
- combined_buhvir_casvir.csv: Acoustic measurements of Blue-headed Vireo (n=73) and Cassin's Vireo (n=60)
- combined_balori_bulori.csv: Acoustic measurements of Baltimore Oriole (n=69) and Bullock's Oriole (n=65)
- combined_wlswar.csv: Acoustic measurements of Wilson's Warbler east of the Rocky Mountains (n=75) and west of the Rocky Mountains (n=74)
- combined_myrwar_audwar.csv: Acoustic measurements of eastern Yellow-rumped Warbler (Myrtle's, n=73), and western Yellow-rumped Warbler (Audubon's, n=74)
Generally, each file contains these variables for each acoustic unit, such as note, syllable, phrase, or the whole song. See more details in Table 1 in the primary article, and the Raven Pro Manual. All empty cells in the data spreadsheets are not applicable (n/a), due to the variable nature of song types.
- StateID: Unique identification of the individual
- Duration, Duration_Song, or Duration_Phrase: Duration of the selected acoustic unit, measured in seconds (s)
- PeakFreq: Frequency at which max power (measured in decibel, dB) of the selected acoustic unit, measured in Hertz (Hz)
- PFC Max Frequency: Maximum frequency of the selected acoustic unit, measured in Hertz (Hz)
- PFC Min Frequency: Minimum frequency of the selected acoustic unit, measured in Hertz (Hz)
- Note_rep or Syl_rep: Number of repeats of the selected acoustic unit, measured as a total count
- Syl_note: Number of notes in the selected syllable, measured as a total count
- N0_Syl: Number of syllable in the whole song, measured as a total count
Sharing/Access information
All raw data is provided. Please contact the corresponding author with any question.
Methods
The bioacoustic data was collected using the bioacoustic software RavenPro (https://www.ravensoundsoftware.com/). All measurements are raw measurements of sound frequency and duration exported from RavenPro. The details of collection method are described in the primary article.