DOI: 10.5061/dryad.2t53m
title: Data from: Benefits of polyandry: molecular evidence from field-caught dung beetles

description: When females mate with multiple males, they set the stage for
 post-copulatory sexual selection via sperm competition and/or cryptic
 female choice. Surprisingly little is known about the rates of multiple
 mating by females in the wild, despite the importance of this information
 in understanding the potential for post-copulatory sexual selection to
 drive the evolution of reproductive behavior, morphology, and physiology.
 Dung beetles in the genus Onthophagus have become a laboratory model for
 studying pre- and post-copulatory sexual selection, yet we still lack
 information about the reproductive behavior of female dung beetles in
 natural populations. Here, we develop microsatellite markers for
 Onthophagus taurus, and use them to genotype the offspring of wild-caught
 females, and to estimate natural rates of multiple mating and patterns of
 sperm utilization. We found that O. taurus females are highly polyandrous:
 88% of females produced clutches sired by at least two males, and 5%
 produced clutches with as many as five sires. Several females (23%)
 produced clutches with significant paternity skew, indicating the
 potential for strong post-copulatory sexual selection in natural
 populations. There were also strong positive correlations between the
 number of offspring produced and both number of fathers and paternity
 skew, which suggests that females benefit from mating polyandrously by
 inciting post-copulatory mechanisms that bias paternity towards males that
 can sire more viable offspring. This study evaluates the fitness
 consequences of polyandry for an insect in the wild, and provides strong
 evidence that female dung beetles benefit from multiple mating under
 natural conditions.
description: Benefits of polyandry
 dataThis Excel file contains
 data on the 40 field-collected Onthophagus taurus females that were used
 to estimate rates of multiple mating and patterns of sperm utilization.
 Column descriptions: PW = prothorax width (in mm); Larvae = number of
 larvae produced by each female; Min_sires = minimum number of sires (based
 on GERUD); Standardized_skew = standardized paternity skew, calculated as:
 (Corrected paternity skew – minimum skew) / (Range); Skew_average =
 Average paternity skew based on the 50 most likely minimum
 father-solutions generated by GERUD; Corrected_skew = Average paternity
 skew corrected for sampling error; Corr_max_skew = Maximum possible value
 of skew for that female (given the observed number of fathers and clutch
 size), corrected for sample size Corr_min_skew = Minimum possible value of
 skew for that female (given the observed number of fathers and clutch
 size), corrected for sample size; Range = range of possible values of
 skew, calculated as: Corr_max_skew – Corr_min_skew; Columns M-R are used
 to manually calculate maximum possible value of skew for that female
 (given the observed number of fathers and clutch size); Columns S-X are
 used to manually calculate minimum possible value of skew for that female
 (given the observed number of fathers and clutch size)Benefits_of_polyandry_data.xlsxSimulations for corrected paternity skewThis file contains the R code for generating hypothetical clutches in order to test whether our estimates of paternity skew were significantly different from a null distribution in which males have equal siring probability (accounting for sampling error in the number of offspring and sires). The script also reports P-values and null estimates of skew for each of the females used in this study (excluding the five females that produced offspring from a single sire).