Sex ratio modulates reproductive output and dung burying behavior in dung beetle Gymnopleurus sturmi (Macleay, 1821) (Coleoptera: Scarabaeidae)
Data files
Oct 20, 2025 version files 883.42 KB
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Pair_experiment_F0_F1_Emergence_rate.xlsx
26.62 KB
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README.md
3.58 KB
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Script_AZamprogna_sex_ratio_article.html
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Abstract
Dung beetles are important ecosystem engineers as they play an important role in recycling dejections from animals. Dung beetles have evolved different behaviours, including dung ball rolling for their egg and developing offspring. Ball rolling is a complex behaviour that varies between species. In some species, males roll the dung ball and females choose partners based on this, while in other species, males and females work together to form the ball. Competition can be fierce, and fighting and ball stealing are common. Gymnopleurus sturmi is a ball rolling species that exhibit gregarious behaviours. In this study, assess sex-related roles in ball rolling as well and the impact of varying sex ratios on the number of balls produced either left at the surface, or buried and fertilized (pear-shaped), and emergence rates of the offspring. Results show that both males and females are capable of producing dung balls, and higher numbers were obtained when males and females were separated. Female-biased sex-ratio produced mostly buried and fertilized balls, while male-biased sex -ratio produced more unburied balls left on surface. When females were alone, they produced the maximum number of total dung balls compared to the rest of the treatment. On the other hand, emergence rate was found to be higher when more males were present When females were alone, emergence rate was extremely low, suggesting a lack or a scarce sperm storage. In a gregarious species like G. sturmi, finding a partner would be easier than for other dung beetle species, which could explain an increasing competition between males and reducing the need to store sperm on the longer term. This study highlights the diversity of behaviours present in this important type of animal.
Dataset DOI: 10.5061/dryad.8931zcs2k
Description of the data and file structure
Data were collected from artificial laboratory rearing of dung beetles.
File: Script_AZamprogna_sex_ratio_article.html
Description: This html file shows the script the author has run using the provided dataset in order to obtain the results described in the article. In HTML format.
File: Pair_experiment_F0_F1_Emergence_rate.xlsx
Description: All data from laboratory rearing. Each sheet represent a test that has been performed in the manuscript
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This dataset contains experimental data on dung beetle reproductive performance and emergence success under different treatments. The dataset is structured across four sheets:**
- F0 (Parental Generation) – Contains data on initial reproductive output, including the number of dung balls on the surface, pears (subterranean brood masses), and their ratio.
- F1 (Offspring Generation) – Includes data on the offspring generation, recording the number of dung balls, pears, total brood count, and log-transformed values.
- Emergence Rate – Documents the success rate of offspring emergence, with data on the number of pears hatched, emergence rates, and theoretical offspring production per female.
- Weight – Provides individual weight measurements of beetles, classified by treatment and sex.
Variable List and Descriptions for Each Sheet
1. F0 (Parental Generation)
- ID_container: Unique identifier for each experimental unit (container).
- Treatment: Experimental condition applied (e.g., different male-to-female ratios).
- Balls_on_surface: Number of dung balls observed on the surface.
- Pears: Number of subterranean brood masses.
- Sum_balls_pears: Total number of dung balls and pears combined.
- Pears_Sum_balls_ratio: Ratio of pears to the total number of balls and pears.
2. F1 (Offspring Generation)
- ID_container: Unique identifier for each experimental unit.
- Treatment: Experimental condition applied.
- Balls_on_surface: Number of dung balls observed on the surface.
- Pears: Number of subterranean brood masses.
- Total: Total brood count (Balls_on_surface + Pears).
- Ratio_pears_total: Proportion of pears relative to the total brood count.
- Balls_on_surface_log: Log-transformed values of Balls_on_surface.
- Pears_log: Log-transformed values of Pears.
3. Emergence Rate
- Id_container: Unique identifier for each experimental unit.
- Pears: Number of brood masses.
- Emergence_rate: Proportion of hatched offspring from total brood masses.
- Pears_hatched: Number of successfully hatched brood masses.
- Treatment: Experimental condition applied.
- Theoretical number of offspring per female: Expected offspring production per female based on experimental conditions.
4. Weight
- Treatment: Experimental condition applied.
- Weight: Individual weight of beetles (in grams).
- Sex: Sex of the beetle (M = Male, F = Female).
Code/software
All statistical analyses were conducted using R version 4.4.2 (2024-10-31 ucrt) -- "Pile of Leaves" in the RStudio 2024.12.0 Build 467, "Kousa Dogwood" Release (© © 2009-2024 Posit Software ). R. Packages that have been used are _dyplr (Wickham et al., 2023), _ggplot2 (Wickham, 2016) and _rstatix (Kassambara, 2019)