The study of vocal mimicry in birds has been largely dominated by male-focused sexual selection theory. Despite this, females of many species demonstrate remarkable mimetic abilities that cannot be explained by these conventional male-centric frameworks. We analysed vocal recordings from nesting female superb lyrebirds (Menura novaehollandiae) to examine age-related patterns in mimetic behaviour during a female specific ecological context: nest defence. Our dataset includes annotations from the 10-minute recordings from individual females of known age, with a subset of six females recorded across multiple years. We classified vocal elements into three categories: mimicry of heterospecific sounds, conspecific vocalisations, and ambiguous elements which were assumed to be mimicry production errors. For mimetic elements, we identified the model species and sound type and categorised models as predators versus non-predators. We constructed repertoire accumulation curves to validate our 10-minute sampling protocol. We used linear mixed models (LMM) and generalised linear mixed models (GLMM) to analyse relationships between female age and various aspects of vocal behaviour, including total element production, mimetic diversity, time spent vocalising, and predator mimicry proportions. Additional analyses examined potential confounding factors including testing for habituation and the effects of time of breeding. Our data reveals high individual variation in mimetic behaviour, with no age effects on overall mimicry propensity or diversity. However, older females are more likely to mimic predators during nest defence than younger females. There are two main implications of these findings. First, age-related factors are unlikely to account for individual variation in female mimetic repertoires. Second, females may refine their vocal mimicry with age, selectively retaining models that offer the greatest defensive advantage during nest defence.

Paper title: The effect of age on vocal mimicry in female superb lyrebirds

Submitted Journal: Avian Biology DOI 10.1002/jav.03520

About: This file pertains to the data associated with the above paper.

The master data for this project is “song_2025_final.csv”. All data and analysis derives from these data

Due to the length of code, there are five separate R files with analysis code. They and the associated data are labelled as follows:

1. File One_The effect of age on vocal mimicry in female superb lyrebirds_female quality: data = 2025_Banding exposure summary data_final.csv

2. File two_The effect of age on vocal mimicry in female superb lyrebirds_Repertoire accumulation curve: data = FSB_mim_final

3. File three_The effect of age on vocal mimicry in female superb lyrebirds_Predators: data = song_2025_final.csv

4. File four_The effect of age on mimicry in female superb lyrebirds_Mimicry and age: data = three_element_count_final.csv

5. File five_The effect of age on vocal mimicry in female superb lyrebirds_Time singing and element duration: data = song_2025_final.csv

Data structure “song_2025_final.csv”

Each line corresponds to a single element that was measured. Quality of recordings was not sufficient to measure accuracy of mimicry.

bird.id (colour bands) = unique colour code of bands of individual birds. Each capital letter corresponds to a unique colour using the first letter of that colour. Lower case letters further differentiate between colours e.g., Dg = Dark green (See end of read me file for complete list)
bird.age (years) = age of birds at time of recording in years
year.recorded = the calendar year the recording was taken
Begin.Time..s.: begin time of element in seconds
End.Time..s.: end time of element in seconds
Begin.File: Recording name for which data is derived
Delta.Time..s.: Delta time in seconds
Dur.90…s.: 90% of the duration of an element in seconds
vocalisation = the vocalisation type, either “l” for lyrebird or “m” for mimicry
vocalisation_three_categories = the vocalisation type broken down further into three categories, either conspecific, mimicry or ambiguous
mimicry.id = the species being mimicked. Where NA is present, no species is recorded e.g., corresponds with conspecific vocals
call.type = the category of vocalisation e.g., one species may have multiple call types such magpie A, magpie B etc. “Unknown” means the vocalisation could not be identified.
confidence = confidence in ID of mimicry, “c” = confident, “nc” = non confident and translates to ambiguous elements
vocal.type = simplified version of call type e.g., all lyrebird vocalisations are listed as lyrebird instead of subcategories
predator_non predator = category of mimicked model as either a predator (p) or non predator (n) (converted to 0 and 1 in r). Blank spaces in this column correspond to conspecific vocalisations meaning they were not categorised

Data structure “FSB_mim_final.csv”

each line corresponds to a single element that was measured

Selection: spectrogram selection number
Begin.Time..s.: begin time of element in seconds
End.Time..s.: end time of element in seconds
Low.Freq..Hz: lowest frequency measurement of the element in Hz
High.Freq..Hz.: highest frequency measurement of the element in Hz
Begin.File: Recording name for which data is derived
Species: the species mimicked
Vocalisation: the type of vocalisation mimicked e.g., one species may have multiple call types such magpie A, magpie B etc
bird.id (colour bands) = unique colour band code of individual birds. Each capital letter corresponds to a unique colour using the first letter of that colour. Lower case letters further differentiate between colours e.g., Dg = Dark green (See end of read me file for complete list)

Data structure “2025_Banding exposure summary data_final.csv”

each line corresponds to a single banding/recording event for each female

bird.id (colour bands) = unique colour band code of individual birds. Each capital letter corresponds to a unique colour using the first letter of that colour. Lower case letters further differentiate between colours e.g., Dg = Dark green (See end of read me file for complete list)
bird.age (years) = age of birds at time of recording in years
year.recorded = the calendar year the female’s chick was banded and recorded
Length (seconds) = total time spent vocalising in recording in seconds (based on element length)
Total.Sound.duration (seconds) = total time spent mimicking in recording in seconds (based on element length)
Ave.duration (seconds) = average duration of each individual element of mimicry in seconds
banded = whether the bird had experienced banding of chick before - y = yes, n = no
num.species.mim = number of species mimicked
call.diversity = number of different kinds of mimetic elements e.g., a female may mimic multiple calls from one species e.g., magpie A and magpie B
chicks.banded = number of chicks the female had had banded in her lifetime (1 corresponds with “n” in the “banded” column)
julian.day = year and day of the year that the chick was banded (proxy for chick age as all chicks were banded at approximately the same time)
julian.singular = Julian date just by day of year (proxy for chick age as all chicks were banded at approximately the same time)

Data structure “three_element_count_final.csv”

three.categories = the vocalisation type broken down further into three categories, either conspecific, mimicry or ambiguous
bird.age (years) = age of birds at time of recording in years
bird.id (colour bands)= unique colour band code of individual birds. Each capital letter corresponds to a unique colour using the first letter of that colour. Lower case letters further differentiate between colours e.g., Dg = Dark green (See end of read me file for complete list
year.recorded = the calendar year the recording was taken
elementcount = a count of the number of elements produced for each category (corresponding to the three.categories column)

Notes

Where NA is present, no species is recorded e.g., corresponds with conspecific vocals

Where columns are blank, no data is recorded

Bird ID: colour bands labels for each individual female

BWW = Blue White White
DgBR = Dark green, Blue, Red
DgDgY = Dark green, Dark green, Yellow
DgWW = Dark green, White, White
DgYDg = Dark green, Yellow, Dark green
DgYR = Dark green, Yellow, Red
GGW = Green, Green, White
LbYLb = Light blue, Yellow, Light blue
RRR = Red, Red, Red
RYDg = Red, Yellow, Dark green
YYY = Yellow, Yellow, Yellow
YBB = Yellow, Blue, Blue
YBR = Yellow, Blue, Red
YbYLb = Yellow brown, Yellow, Light blue
YDgB = Yellow, Dark green, Blue
YYR = Yellow, Yellow, Red

Data from: The effects of age on vocal mimicry in female superb lyrebirds

Data files

Abstract

Data structure “song_2025_final.csv”

Data structure “FSB_mim_final.csv”

Data structure “2025_Banding exposure summary data_final.csv”

Data structure “three_element_count_final.csv”

Data from: The effects of age on vocal mimicry in female superb lyrebirds

Data files

Abstract

README: Read Me

Data structure “song_2025_final.csv”

Data structure “FSB_mim_final.csv”

Data structure “2025_Banding exposure summary data_final.csv”

Data structure “three_element_count_final.csv”