Data from: Giant mice on small islands: Biogeographic and ecological differences contribute to gigantism in island populations
Data files
Jun 25, 2025 version files 440.65 KB
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gigantism_final_analysis.csv
19.60 KB
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gigantism_script.R
17.08 KB
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gigantism.fasta
253.77 KB
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gigantism.sh
4.35 KB
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island_predators.csv
4.71 KB
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mean_depths_cytB.txt
4.04 KB
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museum_mice.csv
131.92 KB
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README.md
5.17 KB
Abstract
Island populations of small land vertebrates frequently exhibit insular gigantism, presenting with larger body sizes compared to their mainland counterparts. While insular gigantism has been observed globally, the effects of biogeographic and ecological factors on body size in island systems are not well understood. Here we examine the biogeographic and ecological associations of insular gigantism. Deer Mice (Peromyscus maniculatus) were live-trapped, and body mass was measured on six of the Gulf Islands and the mainland of British Columbia, Canada. In addition to field sampling, body mass measurements were also recovered from museum specimens from the Gulf Islands area via the VertNet database. Biogeographic measures of land area and island distance from the mainland were estimated using ArcMap. The ecological measure of predator species richness was estimated from iNaturalist observations. These data were used in piecewise structural equation modeling to identify associations with insular gigantism. We found evidence of insular gigantism in the Gulf Islands system, with island mice having a larger mean body mass than mainland populations. Land area was positively associated with predator species richness, and predator species richness had a strong negative effect on Deer Mouse body mass, resulting in the observed pattern of insular gigantism. The concurrent analysis of biogeographic and ecological factors contributes to a better understanding of the evolution of insular gigantism in small vertebrates and its juxtaposition to the phenomenon of insular dwarfism of large vertebrates.
Dataset DOI: 10.5061/dryad.s7h44j1k6
Description of the data and file structure
Data was collected as part of a master's thesis aimed to understand island gigantism in deer mice. Field data and tissue samples were collected from live trapped mice in the Canadian Gulf Islands in British Columbia. Museum data was generated from datasets publicly available on VertNet.org.
Files and variables
File: island_predators.csv
Description: Information about the predator species found on each island
Variables
- island: Name of the island location (or mainland "Vancouver")
- unique_species: List of unique species derived from iNaturalist data. No individual records or copyrighted materials are included.
- n_species: Count of unique species
File: mean_depths_cytB.txt
Description: Mean sequencing depths of the cytB region for samples used in species confirmation analysis
Variables
- Column 1: Sample name file path
- Column 2: Mean sequencing depth
File: gigantism.fasta
Description: Fasta file of mitochondrial cytB sequences - used to generate phylogenetic tree
File: gigantism.sh
Description: Outlines code used to generate gigantism.fasta
File: gigantism_final_analysis.csv
Description: Dataset generated from field sampled deer mice
Variables
- row_field_id: Unique identifier of order samples were collected
- trapping_code: Unique identifier for each sample (first two letters designate sampling location)
- sampling_site: Island or mainland location where sample was collected
- site: Specific site within the sampling_site
- weight_animal: Mass of animal in grams
- distance: Distance of the sampling_site from the "mainland" (Vancouver Island) in kilometers
- islandsize: Area of the sampling_site in square kilometers
- predation: Predator species richness for sampling_site
- location: Designation of "mainland" or "island"
- X_BCAlbers: Longitude coordinate data in BC Albers
- Y_BCAlbers: Latitude coordinate data in BC Albers
- X_UTM10: Longitude coordinate data in UTM10
- Y_UTM10: Latitude coordinate data in UTM10
File: museum_mice.csv
Description: Data collected from museum specimens generated from VertNet.org - Note: Samples from Lopez Island are not included here as they are part of the University of Alaska Museum database designated by a CC BY-NC 4.0 license. These data can be found at https://doi.org/10.15468/lbixob.
Variables
- site: Location within the sampling_site where the specimen was collected
- sampling_site: Island or mainland location where the specimen was collected
- lengthinmm: Length of specimen in mm
- lengthtype: How the length was measured
- country: Country where specimen was collected
- verbatimlocality: Detailed locality information
- decimallatitude: Latitude in decimals
- decimallongitude: Longitude in decimals
- geodeticdatum: Datum for latitude and longitude data
- dynamicproperties: Notes on several body measurements of the specimen
- catalognumber: Dataset catalog number within the institutions dataset
- sex: Sex of the specimen
- lifestage: Lifestage of the specimen
- eventdate: Date when the specimen was collected
- scientificname: Scientific Name of the specimen
- institutioncode: Institution code corresponding to the dataset the observation is from
- location: Designation of "mainland" or "island"
- weight_animal: Mass of animal in grams
- islandsize: Area of the sampling_site in square kilometers
- distance: Distance of the sampling_site from the closest "mainland" in kilometers
- predation: Predator species richness for sampling_site
File: gigantism_script.R
Description: Code used to run all statistical analyses and generate corresponding figures for publication
Code/software
I have included the code for the species confirmation analysis which was run on a HPC system. The *.sh file runs through the commands used and the corresponding software and versions needed.
The code for statistical analysis and graph making is also included. Run this code in R and make sure the gigantism_final_analysis.csv and museum_mice.csv files are in the working directory.
Access information
Other publicly accessible locations of the data:
- None
Data was derived from the following sources:
- Dataset citation information:
Cowan Tetrapod Collection at the University of British Columbia Beaty Biodiversity Museum (UBCBBM). University of British Columbia. https://www.gbif.org/dataset/3ad882bb-cd21-4201-8b83-3684bfc6d830 (accessed on 2024-12-02)
UWBM Mammalogy Collection (Arctos). University of Washington Burke Museum.https://www.gbif.org/dataset/830eb5d0-f762-11e1-a439-00145eb45e9a (accessed on 2024-12-02) - iNaturalist.org. Available from https://www.inaturalist.org