Quantifying wing wear in bumble bees using fractal geometry
Data files
Jul 10, 2026 version files 38.44 MB
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img.7z
38.24 MB
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msk.7z
167.88 KB
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README.md
1.51 KB
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specimen.csv
23.82 KB
Abstract
Wing wear in bees (Hymenoptera: Apidae) accumulates through flight activity and can serve as a proxy for foraging effort and age, yet methods for quantifying wear rely on coarse categorical scoring or simple geometric measurements that do not capture the complexity of wing edge degradation. We evaluate fractal dimension (FD) analysis as a quantitative morphometric for assessing wing wear and evaluate its relationship with visual scoring and body size. Unlike linear wing metrics, FD can capture subtle irregularities, yet no study has used FD to quantify wing wear in insects. We use forewing images collected from 263 workers of three North American bumble bee species (Bombus impatiens, B. bimaculatus, and B. rufocinctus) across meadows in Rouge National Urban Park (Toronto, Canada) to compare FD to traditional measures of wing condition, including wing wear scores and perimeter–area ratio. We found that FD of undamaged wings varied between species indicating interspecific variation in wing morphology. Furthermore, damaged wings correlated more strongly with visual wear scores than perimeter–area ratio, and unlike perimeter-area ratio, was not confounded by body size. Our findings highlight FD as a sensitive quantitative morphometric for wing wear and a promising tool for measurement of bee body condition, age, and foraging effort.
Dataset DOI: 10.5061/dryad.73n5tb39h
Description of the data and file structure
This repo contains (1) images (.png) of wings, (2) binary masks (.bmp) of imaged wings, (3) table (.csv) containing information on collected bumblebees.
Files and variables
File: msk.7z
Description: Binary masks of imaged wings. File names correspond to ‘specimen_id’ column in the ‘specimen’ CSV file.
File: specimen.csv
Description: information on collected bumblebee specimens.
Variables
- specimen_id: alphanumeric code unique to each specimen (unitless)
- site_id: alphanumeric code unique to each site (unitless)
- date: date of collection (YYYYMMDD)
- year: year of collection (2016 or 2017)
- month: month of collection (May - Sep)
- species: species of collected specimen (impatiens, bimaculatus, rufocinctus)
- sampling_method: collection method used (NETTING or PAN TRAP)
- thorax_width_mm: intertegular distance of specimen (millimetre)
- wing_wear: ordinal wing wear score based off visual assessment (0-6)
- pa: wing perimeter to area ratio (unitless)
- fd: wing fractal dimension measured using the box-count method (unitless)
File: img.7z
Description: Images (.png) of wings viewed under dissecting microscope of Bombus impatiens, B. bimaculatus and B. rufocintctus. File names correspond to ‘specimen_id’ column in the ‘specimen’ CSV file.
