DOI: 10.5061/dryad.8931zcs2k
title: Sex ratio modulates reproductive output and dung burying behavior in dung beetle <em>Gymnopleurus sturmi</em> (Macleay, 1821) (Coleoptera: Scarabaeidae)

description: 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.   
description: # Sex ratio article - Gymnopleurus sturmi Dataset DOI:
 [10.5061/dryad.8931zcs2k](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 ** This dataset contains experimental data on dung beetle
 reproductive performance and emergence success under different treatments.
 The dataset is structured across four sheets:** 1. **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. 2. **F1 (Offspring Generation)** – Includes data
 on the offspring generation, recording the number of dung balls, pears,
 total brood count, and log-transformed values. 3. **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. 4. **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)