DOI: 10.5061/dryad.q573n5tr5
title: Urbanization alters the song propagation of two human-commensal songbird species: Active space, amplitude, and attenuation code

description: Urban expansion has increased pollution including both physical (e.g.,
 exhaust, litter) and sensory (e.g., anthropogenic noise) components. Urban
 avian species tend to increase the frequency and/or amplitude of songs to
 reduce masking by low frequency noise. Nevertheless, song propagation to
 the receiver can also be constrained by the environment. We know
 relatively little about how this propagation may be altered across species
 that (1) vary in song complexity and (2) inhabit areas along an
 urbanization gradient. We investigated differences in song amplitude,
 attenuation, and active space, or the maximum distance a receiver can
 detect a signal, in two human-commensal species: the house sparrow (Passer
 domesticus) and house finch (Haemorhous mexicanus). We described
 urbanization both discretely and quantitatively to investigate the habitat
 characteristics most responsible for propagation changes. We found mixed
 support for our hypothesis of urban-specific degradation of songs. Urban
 songs propagated with higher amplitude; however, urban song fidelity was
 species-specific and showed lowered active space for urban house finch
 songs. Taken together, our results suggest that urban environments may
 constrain the propagation of vocal signals in species-specific manners.
 Ultimately this has implications for the ability of urban birds to
 communicate with potential mates or kin.
description: This data was collected for the manuscript titled
 "Urbanization alters the song propagation of two human-commensal
 songbird species." Data were originally .wav files
 collected during a propagation study. The .wav files were clipped so that
 each file contained a single exemplar with 0.1 seconds of silence before
 and after the exemplar. Each single-song .wav file was imported into Raven
 Pro to calculate active space using the "batch correlator"
 function. Within each site and exemplar, we cross correlated the song at
 1m to the song at each consecutive distance. We also corss correlated the
 song at 1m to the background noise at each site. To determine active space
 from the cross correlations, we created a linear line of best fit between
 the cross correlation value and distance (5m-100m) for each stimulus. We
 then determined the distance that the regression line intersected with the
 background noise (a horizontal line over distance). We defined the
 distance of the intersection point as active space. 
 The single-song .wav files were also imported into Praat to
 calculate amplitude. Before calculation, songs were filtered so that any
 sound more than 100 Hz below the minumum frequency of the song was
 removed. Then, amplitude was calculated in Praat using the "get
 intensity" function. We calculated attenuation in excel as the
 difference in amplitude at 1m (the reference signal) to each consecutive
 distance (5m, 10m-100m in 10m increments). 
description: # Urbanization alters the song propagation of two human-commensal songbird
 species: Active space, amplitude, and attenuation code
 [https://doi.org/10.5061/dryad.q573n5tr5](https://doi.org/10.5061/dryad.q573n5tr5) This dataset contains the active space, amplitude, and attenuation data, and the SAS code used to analyze them using general linear mixed models to model the independent effects of urbanization, species, and song exemplar (within a species) on our dependent variables. ## Description of the data and file structure The active space file and the amplitude/attenuation file are both in csv format. For active space (AS_withPCA.csv), the "Location" column refers to the site name. The habitat type (i.e., urban, suburban, or rural) is listed in the "Urban" column. The PCA data (PC1, PC2, PC3, and PC4) is also listed for each site. In the "Species" column, HOFI refers to house finch and HOSP refers to house sparrow. The "Exemplar" column refers to the specific song exemplar (1-15 for each species). In the last column, "AS" refers to active space and is listed in meters. For amplitude/attenuation (AmpAtten_withPCA.csv), the "Location" column refers to the site name. Site names are abbreviated codes for the names of each site (e.g., PC = Pigeon Creek). The habitat type (i.e., urban, suburban, or rural) is listed in the "Urban" column. The PCA data (PC1 and PC2) is also listed for each site. The "Distance" column refers to the distance between the speaker and recorder; this distance is in meters. In the "Species" column, HOFI refers to house finch and HOSP refers to house sparrow. The "Exemplar" column refers to the specific song exemplar (1-15 for each species). The last two columns are "Amplitude" (units dB SPL) and "Attenuation" (units dB SPL). ## Code/Software The code provided is for SAS software (SAS onDemand for Academics, SAS Institute Inc., Cary, NC, USA). The "ActiveSpaceCode.txt" is for analyzing the active space data. The "AmplitudeandAttenuationCode.txt" is for analyzing the amplitude and attenuation data.