DOI: 10.5061/dryad.dc335
title: Data from: Long sperm fertilize more eggs in a bird

description: Sperm competition, in which the ejaculates of multiple males compete to
 fertilize a female's ova, results in strong selection on sperm
 traits. Although sperm size and swimming velocity are known to
 independently affect fertilization success in certain species, exploring
 the relationship between sperm length, swimming velocity and fertilization
 success still remains a challenge. Here, we use the zebra finch
 (Taeniopygia guttata), where sperm size influences sperm swimming
 velocity, to determine the effect of sperm total length on fertilization
 success. Sperm competition experiments, in which pairs of males whose
 sperm differed only in length and swimming speed, revealed that males
 producing long sperm were more successful in terms of (i) the number of
 sperm reaching the ova and (ii) fertilizing those ova. Our results reveal
 that although sperm length is the main factor determining the outcome of
 sperm competition, complex interactions between male and female
 reproductive traits may also be important. The mechanisms underlying these
 interactions are poorly understood, but we suggest that differences in
 sperm storage and utilization by females may contribute to the outcome of
 sperm competition.
description: Sperm competition
 experimental dataThe file contains the
 data collected during a sperm competition experiment conducted on captive
 bred zebra finches. Using a mate switching experimental design, we
 investigated whether sperm length (either long or short) influenced the
 number of sperm from each competing male that reached the ovum, and the
 number of embryos sired by each male.Summary
 paternityThe file contains the
 summary paternity data for each individual trio of birds (one female and
 one pair of males) used in the sperm competition experiment. This file was
 required to calculate summary statistics for the
 manuscript.Sperm length and
 competitive successThis R script contains
 the code that was used to carry out the statistical tests and summary data
 in the manuscript and for table S5 in the electronic supplementary
 materialSperm quality comparison
 sperm competiton malesThis data file contains
 the results of the sperm quality analyses carried out on all male zebra
 finches that were used in the sperm competition experiments. Data are
 arranged side by side for each pair of competing males, and analysed by
 comparing the sperm quality long and short sperm males, using a paired
 design.sperm quality comparison sperm
 competiton males.txtTestes mass sperm
 competition malesThis file contains the
 left testes mass data from the males used in sperm competition
 experimentSeminal glomera
 massThis file contains the
 left and right seminal glomera mass data from a small number of male zebra
 finches producing either long or short sperm. These males were not used in
 the sperm competition experiments.Copulation
 rateThis file contains the
 data from a study investigating whether male zebra finches with different
 sperm lengths (long or short) copulated with females at the same rate.
 These males were not used in the sperm competition
 experiments.Sperm quality
 comparisonsThis R script contains
 the code to investigate whether sperm quality varies with sperm length
 (long or short), and whether left testes mass is related to sperm length.
 Code is also provided for additional studies investigating whether sperm
 length is related to seminal glomera mass and copulation rate (not that
 these final two studies did not use the males from the sperm competition
 experiments. The results of all statistical tests were used to make tables
 S1 - S4 in electronic supplementary material 2.Relatedness
 scoresThis file contains the
 relatedness scores for all males and females used in the sperm competition
 experiments. Data were obtained from the detailed zebra finch pedigree and
 estimated using the R package Pedantics.Relatedness scores_male
 x female_ male x maleThe data file contains
 relatedness scores for the males and females arranged so the male x female
 and male x male mean scores can be calculatedRelatedness
 scoresThis R script contains
 code to calculate the mean relatedness scores between pairs of males and
 females, and between the pairs of competing males.relatedness
 scores.RReadme