Journal ArticleDOI
Semen Quality, Female Choice and Multiple Mating in Domestic Sheep: a Test of Trivers' Sexual Competence Hypothesis
R.M. Gibson,P.A. Jewell +1 more
Reads0
Chats0
TLDR
Repeated mating, rather than a preference for sexually competent males, might function to ensure fertilisation in female sheep and perhaps in other ruminants.Abstract:
TRIVERS (1972) proposed that females may choose to mate with males of high sexual competence (the ability to supply sufficient sperm for fertilisation). This hypothesis was tested by allowing ewes in oestrus to choose between four tethered adult rams, two of high and two of low semen quality. Contrary to the hypothesis, ewes did not prefer rams of higher semen quality and, even though frequent mating can depress the fertilising ability of ram semen, the attractiveness of each ram to oestrous ewes was not lowered by frequent ejaculation. Also, in contrast to TRIVERS' suggestion, semen quality and male courtship vigour were not consistently related either between or within individual rams. Ewes mated repeatedly during oestrus, receiving nearly six ejaculates each on average, and over two thirds of ewes mated with more than one ram. Repeated mating, rather than a preference for sexually competent males, might function to ensure fertilisation in female sheep and perhaps in other ruminants.read more
Citations
More filters
Journal ArticleDOI
Female fitness in Drosophila melanogaster: an interaction between the effect of nutrition and of encounter rate with males.
Tracey Chapman,Linda Partridge +1 more
TL;DR: The data suggest that remating frequencies in laboratory cultures may evolve to a low enough level for the cost of mating to be only weakly expressed, if at all, and further data are required to assess the importance of thecost of mating in natural populations.
Journal ArticleDOI
Male phenotype, fertility, and the pursuit of extra-pair copulations by female birds
TL;DR: A simple model is described, in which functional fertility (the success of ejaculates in fertilizing eggs) covaries with male phenotype, which can explain the observed associations equally well and several alternative approaches are discussed which may allow their resolution.
Book ChapterDOI
Sperm morphological diversity
TL;DR: This chapter reviews the current knowledge of variation in sperm morphology over several levels of biological organization: variation within males (both within and across ejaculates), among males, among populations, and among species, along with prevailing hypotheses addressing the adaptive significance of such variation.
Journal ArticleDOI
Multiple mating by females: a perspective from quantitative genetics
TL;DR: This chapter discusses the breeding activities of the little redfish, a landlocked form of the sockeye salmon, Oneorhynchus nerka, and the spawning behaviour of chum salmon and rainbow trout.
Journal ArticleDOI
Do females promote sperm competition? Data for humans
Mark A. Bellis,R. Robin Baker +1 more
References
More filters
Book
Nonparametric statistics for the behavioral sciences
TL;DR: This is the revision of the classic text in the field, adding two new chapters and thoroughly updating all others as discussed by the authors, and the original structure is retained, and the book continues to serve as a combined text/reference.
Book
Biometry: The Principles and Practice of Statistics in Biological Research
Robert R. Sokal,F. James Rohlf +1 more
TL;DR: In this paper, the authors present a model for the analysis of variance in a single-classification and two-way and multiway analysis of Variance with the assumption of correlation.
Journal ArticleDOI
Sperm competition and its evolutionary consequences in the insects
TL;DR: In this article, Simpson et al. describe a method to solve the problem of homonymity in Bee W l d 34, 14) and show that it works well in beekeeping.
Book
The Evolution of Sex
TL;DR: In this paper, the authors compared the short-term advantages of sex and recombination in a finite population with the long-term consequences of recombination and sex and showed that recombination has shortterm advantages for both sexes.