DOI: 10.5061/dryad.qnk98sfvn
title: Data from: Correlated divergence of ecology, morphology, and fine-scale vocal motor performance among sparrow subspecies

description: Animal structures often evolve for multiple functions, such as limbs used
 for both climbing and fighting. Adaptations that optimize one function may
 limit performance of others. Here, we compare songs of inland (freshwater)
 and coastal (saltmarsh) subspecies of swamp sparrows (Melospiza georgiana)
 for which adaptation to distinct habitats has driven divergence in beak
 size and shape. Prior studies have shown that these subspecies’ songs
 differ in a broad-scale metric of vocal performance—vocal deviation—in a
 direction consistent with the hypothesis that vocal performance is
 disproportionately constrained in larger-beaked birds. We hypothesize that
 beak divergence has also driven divergence in additional, more fine-scale
 phonological and temporal measures of song including note types and the
 acoustic structure of notes and inter-note gaps. Consistent with
 expectations, coastal birds’ songs show greater proportions of
 low-performance notes and note transitions, notes and inter-note gaps that
 span narrower bandwidths, and notes situated farther from presumed
 performance maxima. Yet in contrast to expectations, coastal birds’ songs
 show shorter average inter-note gaps, suggesting a compensatory strategy
 to maintain baseline levels of vocal performance. We also find that, for
 each subspecies, males maximized performance of the parameters they sang
 with the least consistency, a finding that highlights a need to consider
 vocal consistency not in isolation, but rather in relation to other
 performance metrics. This study enhances our understanding of a previously
 developed example of how ecologically driven changes in morphology may
 cause divergence in display performance for sexually selected traits,
 which in theory could drive further divergence among lineages.
description: # Data from: Correlated divergence of ecology, morphology, and fine-scale
 vocal motor performance among sparrow subspecies Dataset DOI:
 [10.5061/dryad.qnk98sfvn](10.5061/dryad.qnk98sfvn) ## Description of the
 data and file structure Datasets and associated analysis code for a
 comparison of fine-scale song structure between two subspecies of swamp
 sparrow (*Melospiza georgiana*). ### Datasets and variables
 **multiphrasesongs.csv:** Summary sheet indicating syllables and notes
 within multiphrased swamp sparrow songs. *Variables:* * BirdID * SongID *
 MultiSyll: Essentially a syllableID indicating unique syllable types from
 each bird. The first syllable in the song is the same ID as the songID,
 and the second syllable is the songID followed by a 2. * Syllable.Number:
 Which syllable in sequence within a song the note is a part of. *
 Element.Number: Which note in sequence within a song. * ElementType: Note
 type as described by Marler and Pickert 1984. * Pop: Indicates which
 subspecies. **NoSyll.csv:** Summary sheet with the number of syllables in
 each song. *Variables:* * Pop: Indicates which subspecies. * SongID *
 NoSyll: Number of syllables in the song. **alldata3.csv**: Main dataset
 containing acoustic metrics for notes from swamp sparrow songs.
 *Variables:* * MultiSyll: Essentially a syllable ID indicating unique
 syllable types from each bird. * ElementID: Which note in sequence within
 a song. * SongID * Element.Number: Which note in sequence within a song. *
 Pop: Indicates which subspecies. * Syllable.Number: Which syllable in
 sequence within a song the note is a part of. * Echo.Tail: Dereverberation
 in ms (a spectrogram setting). * Start.time: Start time of the note in the
 original recording file in ms. * Length: Note duration in ms. * Gap.after:
 Duration of the silent gap following the note in ms. *
 Peak.frequency.Mean: Mean frequency of maximum intensity across all 5 ms
 time bins (includes overlapping time frames) in Hz. *
 Peak.frequency.Start: Frequency of maximum intensity of first 5 ms of a
 note in Hz. * Peak.frequency.End: Frequency of maximum intensity of last 5
 ms of a note in Hz. * Fundamental.frequency.Mean: Mean lowest frequency
 (first harmonic) across all 5 ms time bins (includes overlapping time
 frames) in Hz. * Fundamental.frequency.Start: Lowest frequency (first
 harmonic) of first 5 ms of a note in Hz. * Fundamental.frequency.End:
 Lowest frequency (first harmonic) of last 5 ms of a note in Hz. *
 Wiener.entropy.Mean: Mean Wiener entropy across all 5 ms time bins
 (includes overlapping time frames) in Hz. * Wiener.entropy.Start: Wiener
 entropy of first 5 ms of a note in Hz. * Wiener.entropy.End: Wiener
 entropy of last 5 ms of a note in Hz. * ElementType: Note type as
 described by Marler and Pickert 1984. * BirdID ## Code/software All
 analyses were completed in R. Required packages are indicated in the
 scripts below. **GapBWPerf_pub.R**: Code used for quantile regression
 analysis of gap bandwidth versus gap length for all note types combined.
 alldata3.csv is necessary as input. **GapLenPref_pub.R:** Code used for
 quantile regression analysis of note length versus gap length by note
 type. alldata3.csv is necessary as input. **LenBWPerf_pub.R**: Code used
 for quantile regression analysis of note length versus note bandwidth by
 note type. alldata3.csv is necessary as input. **SubspeciesDQR_pub.R**:
 Code for double quantile regression analysis of all tradeoffs.
 **SubspeciesAnalysis_pub.R**: Code used to perform statistical analysis
 for comparisons of descriptive stats across subspecies. All csv files in
 this folder are necessary as input.