DOI: 10.5061/dryad.6djh9w19w
title: Sound spectra from study of Great Bowerbird bower male sound arrival in bower avenue

description: Sexual selection can result in extreme development of multimodal
 mate-attracting traits, including complex constructions.  Male
 great bowerbirds build bowers for attracting females.  Bowers
 contain a thatched twig tunnel (avenue) opening onto two courts covered
 with decorations.  Males displaying on a court are seen by a
 female from within the avenue.  She sees and hears displays
 through the avenue entrance but can only see the male's head and
 objects in his bill as it passes repeatedly across the entrance. 
 Because the bower may affect the auditory as well as the visual parts of
 the multimodal male display we investigated bower acoustic properties by
 playing standard sounds from multiple court positions, recording the
 resulting sounds at the female's head position within the
 avenue.  Bower geometry results in a limited zone at the avenue
 entrance where his vocalisations can be heard with maximum intensity; this
 corresponds to his typical display position.  Experiments show
 that court decorations increase the intensity of some frequencies and
 reduce the intensity of others. Bower structure simultaneously affects
 both visual and auditory male display components and could be important in
 sexual selection.  It is important to consider more than one
 sensory mode, especially in the context of built signalling structures.
 This is the data, corrected for position 1, used in the analysis. It also
 includes a sample R script to run an analysis to show how the GAM was
 done.  The original article has been accepted to Behavioural
 Ecology: Acoustic effects complement visual displays of Great Bowerbird
 bowers, by John A. Endler, Selina Meehan, Aida Rodrigues, and Vicki
 Hallett, Behavioral Ecology (in press 2024).
description: We played spectrally flat standard sounds from various positions
 on the bower court, where the male displays visually and auditorally, with
 a microphone at the female's head position within the bower avenue. 
 This yielded sound spectra and total intensity as a function of direction
 and distance from the bower avenue entrance as well as what was on the
 bower court, with locations with no bower as controls.
 The standard sounds were either white noise or a spectral sweep,
 bandwidth 2 to 20 kHz, both generated in MATLAB.  The bandwidth includes
 all frequencies recorded in natural male soundss recorded by us and by
 others.  These sounds were played back from a Marantz PMD661 digital
 recorder. For bowers the speaker (Second Marantz PMD661
 experiments 1,3, and Bose Revolve II SoundLink experiments 2,4) was placed
 at the avenue entrance (position 1) and at two more distant positions on
 the court (25 and 50 cm from position 1) at 0 degrees (avenue axis), 45
 degrees left and right and 90 degrees left and right.  Males call just in
 front of the avenue entrance, mostly at the ends of the walls so the
 speaker was also placed in those two positions.  The Marantz speaker shows
 less than 0.5db change when within ±20° of perpendicular to the microphone
 (Fig. S2), and our avenue entrance aiming error was less than 5°.  The
 Bose was omnidirectional within our measurement error.
 Recordings were made inside the bower avenue at the female's
 head position and height.  In experiment 1 recordings of the played sounds
 were made with an AudioTechnica AT8035 directional microphone connected to
 a second Marantz PMD661 recorder set to record 16 bits/sample at 44.1
 kHz.  The input gain was set to 4.5 for clipping at maximum -8dB.  In
 experiment 2,  We placed a matched pair of FEL Communications Clippy XLR
 EM272 Stereo Microphones back-to-back within a 5 cm diameter Styrofoam
 ball with their faces flush with the ball surface, with close to 360°
 solid angle reception.  This is larger than a bowerbird head but the
 microphone lengths set the minimum width and the ball diameter is smaller
 than the female head excursions whilst watching the male.  We oriented the
 ball at female head height with its left and right microphones facing the
 left and right avenue walls.  The microphone pair was connected to both
 channels of a Marantz PMD661 digital recorder with the same settings as in
 experiment 1. Both channels were converted from dB to power, added, and
 converted back to dB before further analysis. This configuration accounts
 for sound entering the avenue from the entrance, but also through the
 roof, through the avenue walls and the opposite entrance.  The Clippy pair
 sound spectrum was similar to but slightly flatter than the AudioTechnica
 microphone.  Experiment 1 looks at the effects of sound arriving at the
 female from the entrance next to the calling male and experiment 2 also
 includes sound coming around the back to the second avenue entrance and
 through the top of the avenue. For all experiments we
 also recorded with the same geometry but a short distance away where there
 was no bower--this servs as a control for enviromental structure and also
 microphone receptive geometry.  Recordings were
 converted from power to frequency spectra (dB vs sound frequency), using
 the MATLAB 2021b functions <em>audioread</em>,<em>
 pspectrum</em>, and <em>db</em>.  All recordings were
 converted to relative spectra by subtracting the spectrum from position 1,
 and this was done for all bowers and controls.  This eliminates variation
 and the need for absolute microphone calibation.  This is analagous to our
 use of a white standard in visual spectrum analysis.
 For more details see methods section of paper Acoustic effects
 complement visual displays of Great Bowerbird bowers, by John A. Endler,
 Selina Meehan, Aida Rodrigues, and Vicki Hallett, DOI:
 10.1093/beheco/arae070.
description: # Sound Spectra used in the analysis
 [https://doi.org/10.5061/dryad.6djh9w19w](https://doi.org/10.5061/dryad.6djh9w19w) ## Description of the data and file structure The data are in the form of spectra and totals corrected for position 1 (bower avenue entrance) in .csv format. ## **List of files and experiments** **Geo2021StDirectionalSpectralData.csv**:  EXPERIMENT 1, directional geometry (spectra) **Geo2021StDirectionalIntensityData.csv**:  EXPERIMENT 1, directional geometry as intensity **Geo2023StSpectraBwrOrCt.csv**:   EXPERIMENT 2, omnidirectional geometry **CtSeqRm2017ObjectExperiment25-50St.csv**:  EXPERIMENT 3, directional progressive object removal **CtRm2023-StSpectraBeforeAfter25and50cm.csv**: EXPERIMENT 4, omnidirectional gesso removal **Variables in each file:** **Geo2021StDirectionalSpectralData.csv** Site: bower number BorC: bower or open (no bower) Position: position relative to avenue entrance x,y: cartesian location of each position relative to position 1 angle,distance: angle and distance from position 1 Frequency: sound frequency kHz Amplitude: sound amplitude at given frequency and location relative to position 1 **Geo2021StDirectionalIntensityData.csv** Site: bower number BorO: bower or open (no bower) Position: position relative to avenue entrance x,y: cartesian location of each position relative to position 1 angle,distance: angle and distance from position 1 TotInten: total intensity at each position relative to position 1 **Geo2023StSpectraBwrOrCt.csv** Bower: bower number BwOrCt: bower or control (no bower) Distance,angle: distance and angle from position 1 Stones: number of stones in court Shells: number of shells in court Bones: number of bones in court Frequency: sound frequency kHz Amplitude: sound amplitude at given frequency and location relative to position 1 **CtSeqRm2017ObjectExperiment25-50St.csv** Bower: bower number Exper: natural or which objects remaining: Anat= intact: undisturbed bower Ct0 = court only CD0 = central depression only FSS = clay-filled snail shells WSS = empy Distance: distance from position 1 (avenue entrance) Frequency: (kHz) Amlitude: (db) **CtRm2023-StSpectraBeforeAfter25and50cm.csv** Bower: bower number BfAf: before (intact) and after all gesso removed Distance: distance from position 1 Stones: number of stones on court (before removal) Shells: number of shells on court (before removal) Bones: number of bones on court (before removal) Frequency: sound frequency (kHz) Amplitude: sound amplitude at given frequency relative to position 1 \======================================================================= The data were analysed in R ver 4.3.2 using these packages: nlme, mgcv, itsadug (latter for the plot_smooth() function, which gives response curves and their 95% CI ## Code/software This is a sample of how we did the GAM analysis of the sound spectral data after loading nlme, mgcv, and itsadug, and reading in the appropriate .csv file: this one compares spectra from bowers from open areas (controls), similarly for before and after court removal. mdl&lt;-gam(Amplitude~s(Frequency)+s(Frequency,BwOrCt,bs="fs",m=1)+s(Frequency,Angle,bs="fs",m=1)+s(Frequency,Distance,bs="fs",m=1)+s(Bower,bs="re"),data=dta,method="REML") summary(mdl) dev.new() pC&lt;-plot_smooth(mdl, view = "Frequency", rm.ranef = FALSE, ``` cond = list(BwOrCt="C"), main = "Bowers Vs. OpenAreas 2023", col = 'black', lwd=2, ylab='Standard Amplitude & 95% CL',ylim=c(0.1,0.45)) ``` pB&lt;-plot_smooth(mdl, view = "Frequency", rm.ranef = FALSE, ``` cond = list(BwOrCt="B"), add = TRUE, col = 'blue') ``` legend("top",legend=c("No Bower","Bowers"),fill=(col=c("black","blue")))