Influence of operational sex ratio and density on the copulatory behaviour and mating system of Brandt’s voleMicrotus brandti

2003 ◽  
Vol 48 (3) ◽  
pp. 335-346 ◽  
Author(s):  
Jianjun Zhang ◽  
Zhibin Zhang
Keyword(s):  
Sex Ratio ◽  
Mating System ◽  
Operational Sex Ratio ◽  
Copulatory Behaviour

Modeling Mating Patterns Given Mutual Mate Choice: The Importance of Individual Mating Preferences and Mating System

2003 ◽  
Vol 11 (03) ◽  
pp. 205-219 ◽  
Author(s):  
Carmen Bessa-Gomes ◽  
Jean Clobert ◽  
Stéphane Legendre ◽  
Anders Pape Møller
Keyword(s):  
Mate Choice ◽  
Sex Ratio ◽  
Mating System ◽  
Population Biology ◽  
Structured Populations ◽  
Operational Sex Ratio ◽  
Mating Preferences ◽  
Mating Patterns ◽  
Single Sex ◽  
Individual Mating

When we consider structured populations with sexual reproduction, the distribution of characters among mating pairs may influence the population biology, namely its dynamics and genetics. In the present paper, we propose a general framework to estimate the population mating patterns taking into account individual mating preferences and mating system, thus taking into account the inter- and intra-sexual interactions such as mate competition and mate choice. According to our results, mating patterns are not a direct reflection of mating preferences, but also depend upon the average sex ratio between individuals that are ready to mate at any given time (i.e., the Operational Sex Ratio, OSR). Therefore, mating patterns should be assessed not only in function of preferences, but also of OSR. It is then possible to distinguish three OSR regions: (1) the equilibrium OSR, where there is a predominance of assortative mating patterns due to differential access to mates (inter-sexual interactions); (2) the slightly biased OSR, where there is a high diversity of mating patterns and no clear predominance of inter- or intra-sexual interactions; and (3) the highly biased OSR where there is a predominance of mating patterns corresponding to single-sex uniform preferences and an increased influence of intra-sexual interactions. We hope that this approach may allow to further explore the interaction between OSR and mate choice, namely how such interaction may affect sexual selection and mate choice tactics.

Mating Tactics in the Tropical Millipede Alloporus Uncinatus (Diplopoda: Spirostreptidae)

Behaviour ◽  
1993 ◽  
Vol 124 (1-2) ◽  
pp. 45-56 ◽  
Author(s):  
Steven R. Telford ◽  
J. Mark Dangerfield
Keyword(s):  
Sex Ratio ◽  
Mating System ◽  
Sperm Competition ◽  
Breeding Season ◽  
Female Choice ◽  
Laboratory Experiments ◽  
Mating Behaviour ◽  
Operational Sex Ratio ◽  
Mating Tactics ◽  
Mate Acquisition

AbstractField and laboratory observations of mating behaviour in a population of the tropical millipede Alloporus uncinatus were carried out over one breeding season. Males obtained mates through random encounters and by forming triplet associations with copula pairs. The occurrence of triplet associations in the field was coincident with a highly male biased operational sex ratio. Mate acquisition by males was apparently stochastic and direct physical competition did not occur. In laboratory experiments mating was size-selective probably as a consequence of female choice. We consider the possibility that sperm competition has contributed to the evolution of the mating system in this species.

scholarly journals How Many Females Are There? Cheating and Female Dispersion Can Explain Mating Behavior Evolution

2017 ◽  
Author(s):  
B. V. Gomes ◽  
D. M. Guimarães ◽  
D. Szczupak ◽  
K. Neves
Keyword(s):  
Sex Ratio ◽  
Mating System ◽  
Mating Behavior ◽  
Mammalian Species ◽  
Operational Sex Ratio ◽  
Social Monogamy ◽  
Single Factor ◽  
Agent Based ◽  
Computational Environment ◽  
Socially Monogamous

AbstractOnly around 3% of all mammalian species are socially monogamous and the conditions that favor the evolution of this mating system in mammals are not well understood. With several approaches, studies have proposed different hypotheses relating female dispersion and infanticide as drivers for the evolution of social monogamy. Here, we used an agent-based model, that allowed us to examine how different mating behaviors affect populations in a controlled computational environment. We found that the evolution of social monogamy does not rely on a single factor. Rather, our experimental results support an interplay of different factors in the evolution of social monogamy – female dispersion and availability and breeding season duration – and suggests that polygamy will only evolve in populations with a female-biased operational sex ratio or one where cheating is common. These results can explain why social monogamy is so uncommon in mammals and points to new lines for ethological investigation of mammalian behavior.

scholarly journals Sex Chromosome Meiotic Drive in Stalk-Eyed Flies

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1169-1180 ◽  
Author(s):  
Daven C Presgraves ◽  
Emily Severance ◽  
Gerald S Willrinson
Keyword(s):  
Sex Ratio ◽  
Sex Chromosome ◽  
Sex Ratios ◽  
Natural Populations ◽  
Meiotic Drive ◽  
Operational Sex Ratio ◽  
Genetic Modifiers ◽  
Ratio Distortion ◽  
The Impact ◽  
Sex Ratio Distortion

Meiotically driven sex chromosomes can quickly spread to fixation and cause population extinction unless balanced by selection or suppressed by genetic modifiers. We report results of genetic analyses that demonstrate that extreme female-biased sex ratios in two sister species of stalk-eyed flies, Cyrtodiopsis dalmanni and C. whitei, are due to a meiotic drive element on the X chromosome (Xd). Relatively high frequencies of Xd in C. dalmanni and C. whitei (13–17% and 29%, respectively) cause female-biased sex ratios in natural populations of both species. Sex ratio distortion is associated with spermatid degeneration in male carriers of Xd. Variation in sex ratios is caused by Y-linked and autosomal factors that decrease the intensity of meiotic drive. Y-linked polymorphism for resistance to drive exists in C. dalmanni in which a resistant Y chromosome reduces the intensity and reverses the direction of meiotic drive. When paired with Xd, modifying Y chromosomes (Ym) cause the transmission of predominantly Y-bearing sperm, and on average, production of 63% male progeny. The absence of sex ratio distortion in closely related monomorphic outgroup species suggests that this meiotic drive system may predate the origin of C. whitei and C. dalmanni. We discuss factors likely to be involved in the persistence of these sex-linked polymorphisms and consider the impact of Xd on the operational sex ratio and the intensity of sexual selection in these extremely sexually dimorphic flies.

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