Data and code from: Uncovering the calls of data-deficient masked owls using morphology and environmental gradients
Data files
Sep 11, 2026 version files 133.59 KB
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calls.csv
50.74 KB
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Figure_3_Environmental_correlates_of_morphology_and_vocal_traits_in_masked_owls.R
6.32 KB
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morph_r2.csv
12.50 KB
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README.md
5.38 KB
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t-test_data.csv
44.84 KB
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Table-2_Linear_model_performance_metrics.R
5.97 KB
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Table-3_Silhouette_widths_for_duration_and_meandom.R
3.39 KB
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Table-4_Figure-4_predict-calculations.R
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Abstract
'Lost' and data-deficient species pose a major challenge for conservation because we often know too little about them to guide detection or monitoring efforts. We used the well-studied Australian Masked Owl (Tyto novaehollandiae) as a model system to test whether vocal traits of poorly known relatives can be predicted from environmentally driven morphological and vocal relationships. We measured wing length from 196 Australian Masked Owl museum specimens and extracted call duration and mean dominant frequency from 700 screech calls recorded through passive acoustic monitoring at 33 sites across Australia, then fit linear models relating these traits to latitude, temperature, and elevation. Wing length was longer in females than males and increased with cooler temperatures and higher latitudes, consistent with Bergmann's rule, while calls were shorter and higher-pitched at lower latitudes and warmer temperatures, and mean dominant frequency declined with elevation. We used these latitude-based relationships, together with museum wing measurements, to predict the call duration and mean dominant frequency of four data-deficient Papuo-Moluccan masked owl taxa (Tyto aurantia, Tyto manusi, Tyto sororcula and Tyto novaehollandiae calabyi), including the 'lost' Manus Masked Owl, unrecorded since 1934. Predicted values closely matched measured values for Australian taxa, supporting the reliability of this trait-transfer approach. This dataset includes wing measurements, sex, and collection locality and environmental data (latitude, longitude, temperature, elevation) for nine masked owl taxa held across eight museum collections, along with call duration and mean dominant frequency measurements from 700 Australian Masked Owl screech calls and their associated recording locations and environmental variables. These data can support future work testing predictive frameworks linking morphology, environment, and vocalisations across birds, and can help guide acoustic monitoring and rediscovery efforts for poorly known masked owl taxa.
Dataset DOI: 10.5061/dryad.73n5tb390
Description of the data and file structure
This dataset was compiled to investigate whether vocal characteristics of data-deficient masked owl taxa can be inferred from environmental and morphological correlates in the Australian Masked Owl (Tyto novaehollandiae). Morphological measurements were obtained from 196 museum specimens collected across Australia between 1870 and 2023. Acoustic data were derived from 700 calls recorded via passive acoustic monitoring between 2010 and 2023. The dataset supports predictive modelling of call characteristics (call duration and mean dominant frequency) for the Papuo-Moluccan masked owl taxa (T. aurantia, T. manusi, T. sororcula, T. n. calabyi) based on environmental gradients and trait correlations.
Files and variables
File: calls.csv
Description: Australian Masked Owl (Tyto novaehollandiae) call measurements dataset
Variables
- taxon: Taxonomic label
- latitude: Latitude of acoustic recording location in decimal degrees
- longitude: Longitude of acoustic recording location in decimal degrees
- duration: Call duration (seconds)
- meandom: Mean dominant frequency of the call (kHz)
- temperature: Mean annual temperature at acoustic recording location (°C)
- elevation: Elevation at acoustic recording location (masl)
File: Figure_3_Environmental_correlates_of_morphology_and_vocal_traits_in_masked_owls.R
Description: R code for generating data for Figure 3 of the manuscript. This script examines how latitude, temperature, and elevation relate to masked owl wing length and vocal traits using linear regression, reporting R² and p-values. It then combines nine regression plots into a 3 × 3 figure to visualize these environmental relationships.
File: morph_r2.csv
Description: Australian Masked Owl (Tyto novaehollandiae) morphological measurements dataset
Variables
- taxon: Taxonomic label
- latitude: Latitude of specimen collection location in decimal degrees
- longitude: Longitude of specimen collection location in decimal degrees
- sex: Sex of the specimen (male, female, undetermined)
- wing: Wing length (mm)
- temp: Mean annual temperature at specimen collection location (°C)
- elevation: Elevation at specimen collection location (masl)
Missing values: 42 specimens lack latitude, longitude, temperature, and elevation values because collection locality could not be determined from specimen tags or database records; these specimens were excluded from environmental regression models in the associated manuscript. An additional 19 specimens have latitude/longitude but lack temperature/elevation values, as their coordinates fell outside the extent of the climate and elevation raster layers used. Empty cells are left blank (rather than coded as "NA" or "0") to preserve compatibility with the accompanying R scripts, which handle missing values using R's native NA parsing on import.
File: Table-2_Linear_model_performance_metrics.R
Description: R code for Linear model performance metrics for absolute wing length, call duration, and mean dominant frequency
File: Table-3_Silhouette_widths_for_duration_and_meandom.R
Description: R code for Silhouette widths for duration and mean dominant frequency from k-means clustering (K = 2).
File: Table-4_Figure-4_predict-calculations.R
Description: R code for Table 4. Measured (M) and wing-length – predicted (P) call duration and mean dominant frequency (± SD) for all masked owls; Figure 4. Comparison of measured and predicted vocal traits across masked owl taxa.
File: t-test_data.csv
Description: Comparison of measured versus wing-length-predicted call duration and mean dominant frequency across Australian Masked Owl taxa
Variables
- taxon: Taxonomic label
- duration: Call duration (seconds)
- meandom: Mean dominant frequency of the call (kHz)
- method: Origin of measurement (measured, predicted)
Code/software
All analyses were conducted in R version 4.4.3 using RStudio 2024.12.1 Build 563. The packages used to run the files are listed within each script.
Access information
Other publicly accessible locations of the data:
- This dataset is hosted exclusively on Dryad.
Data were derived from the following sources:
- Morphological data were obtained from museum specimens held in publicly accessible ornithological collections, including:
- Australian Museum, Australian National Wildlife Collection, American Museum of Natural History, Museums Victoria, Natural History Museum (London), Queensland Museum, Western Australian Museum, and South Australian Museum.
- Additional wing measurements for Tyto sororcula taxa were sourced from Jønsson et al. (2013).
- Acoustic data were collected from 33 sites across Australia between 2010 and 2024, primarily via passive acoustic monitoring using autonomous recording units, with supplementary handheld recorder data.
- Environmental data:
- Mean annual temperature: Bureau of Meteorology (2024)
- Elevation: SRTM-derived DEM (Gallant et al., 2009), Version 1.0
- Environmental rasters were processed in ArcGIS and matched to specimen or call locations.