Evolution of female song and duetting in the chaffinch (Fringilla) species complex

Female song is ancestral to songbirds and shows considerable phylogenetic signal, but its presence also appears to be labile and correlated with life-history and ecology. While previous studies have examined the evolution of female song across species-rich families, here we studied female song in island populations of a recently diverged species-complex, the chaffinches (genus Fringilla). We show this behaviour has recently evolved in these populations, and probably on two independent occasions. In F. teydea, female song is performed in loose duets with males, while in F. coelebs, female song is produced solo. Populations with singing females showed year-round territoriality and were found in regions with low seasonality – both factors previously connected with high rates of female singing. To determine the relative saliency of female songs to conspecifics, and the degree to which they instigate territorial defence behaviours, we performed a series of speaker playback experiments. In F. c. canariensis, female song could induce comparable responses to male song, whilst duetting F. teydea playback produced similar responses to solo songs, and therefore may relate to within-pair communication instead. Our results suggest female song can be a highly labile trait that can evolve over short evolutionary timescales.

Methods
This is the data repository for the 2023 paper: Evolution of female song and duetting in the chaffinch (Fringilla) species complex.

Data were collected between February 2016 – May 2018. 

##### Acoustic Analysis ######

The Luscinia database (Dryad_JAB_Female) containing the recordings used in the bioacoustics analysis. Luscinia is an open-source biaocoustics software freely available, here:

https://github.com/rflachlan/Luscinia/releases:

To read the database following Luscinia installation, create a folder named JAB_female_Fringilla.luscdb, and place the JAB_female_Fringilla.h2.db file in it. 

Next open Luscinia, and locate the Folder. Press the log in button (without changing username or adding password) and you should be able to access the database.

The Luscinia database contains the song recordings used for the analysis. Follow instructions found here: https://rflachlan.github.io/Luscinia/ to derive the acoustic properties of each song. 

The acoustic measures for the exemplar songs (F.c.canariensis) are reported in raw_acoustics.csv.  Analysis of these measures are reported in the R script FemaleSong.R. Other song outputs (used in the figures) are produced directly from Luscinia (NMDS plots, DTW song comparison), following different types of analysis as instructed in the paper.

Female_Song_Data.xlsx contains 4 sheets of additional data to aid analysis of recordings and add further context

Recordings: Contains information regarding which song-files were analysed

Population - The species/population recorded
Individual - Unique individual ID
Exemplar - The sound recording file analysed
Sex - The sex of the individual
Syllables - The number of syllables in the song
Songs recorded (F.coelebs only), The number of songs recorded per bird
Syllables: The average amount of syllables produced per song 
Sex - Male or Females of the species
Population - The species/population recorded
Average per - Average number of syllables from exemplar recordings
SD per - Standard deviation of the syllables in exemplar recordings 

Timesheet: The dates of sampling female songs in different populations:

Date- Day of fieldwork
Population - The species/population recorded
Mins - Minutes of sampling taken
Start - Time (local) when sampling started 
End - Time (local) when sampling ended
Hours - Conversion of minutes to hours 

Songs Recorded: Contains further song recorded dates (primarily from 2017 & 2018 data collection)

Population - The species/population recorded
Individual - Unique individual ID
Songs recorded - The number of songs recorded per bird

F.c.canariensis F_vs_Sunrise: The time relative to sunrise when females were recorded

Name - Unique individual ID
Sunrise - Sunrise time that day (local time)
Time - Time of recording
Time difference - Difference between sunrise and time of recording
Date - Date of recording

##### Playback ######

Data derived from playback experiments are recorded in duet_playback.csv & f_c_c_playback. Analysis of the playback experiments are reported in the R script code/FemaleSong.R

f_c_c_playback.csv: Playback data from trials involving Fringilla coelebs canariensis

Individual - The individual bird responding to the trial
Experiment - The type of experiment being performed (FcoeMF = Male vs Female, FcoeSF = Swamp Sparrow vs Female)
Sex - The sex of the individual responding
Pair - A unique number for the territory on which the experiment is performed
FLatency - The latency (seconds) to approach the speaker broadcasting female song
FClosest - The closest distance approached to the speaker broadcasting female song
FTimein2m - The time (seconds) spent within 2m of the speaker broadcasting female song
FTimein2to4 - The latency (seconds) to approach the speaker broadcasting female song
FPlaybackScore - The score attributed to the speaker broadcasting female song (see score calculations in the paper)
FProportional - The proportion of the score attributed to the speaker broadcasting female song
OLatency - The latency (seconds) to approach the speaker broadcasting non-female song
Oclosest - The closest distance approached to the speaker broadcasting non-female song
OTimein2m - The time (seconds) spent within 2m of the speaker broadcasting non-female song
OTimein2to4 - The latency (seconds) to approach the speaker broadcasting non-female song
OPlaybackScore - The score attributed to the speaker broadcasting non-female song (see score calculations in the paper)
OProportional - The proportion of the score attributed to the speaker broadcasting non-female song

duet_playback.csv: Playback data from trials involving Fringilla teydea

Individual - The individual bird responding to the trial
Sex - The sex of the individual responding
Stim - The type of stimuli heard (male only, female only or duet)
Order - Whether the trial is the 1st 2nd or 3rd presented at this territory
Pair - Unique territory identifying number
Time - The time of the experiment
Latency - The time taken to approach the speaker (x 6 seconds)
Approach - The closest distance a bird approached the speaker
Time_2  - The time spent within 2m of the speaker (x 6 seconds)
Time_2_4 - The time spent within 2-4m of the speaker