The reproductive status of both sexes affects the frequency of mating and the reproductive success of males in the ball roller beetle Canthon cyanellus cyanellus (Coleoptera: Scarabaeidae)

Behaviour ◽  
2009 ◽  
Vol 146 (11) ◽  
pp. 1499-1512 ◽  
Author(s):  
Mario Favila ◽  
Ivette Chamorro-Florescano
Keyword(s):  
Reproductive Success ◽  
Sperm Competition ◽  
Reproductive Status ◽  
Female Pair ◽  
Female Reproductive Status ◽  
Viable Sperm ◽  
Males And Females

AbstractSeveral studies have shown that males assess female reproductive status and use different mechanisms to increase their reproductive success. However, a male's reproductive status can also affect its own reproductive success. In Canthon cyanellus cyanellus, a male–female pair makes several brood balls during nesting and both care for the brood balls. However, in females that are transported to the nest by males, the spermatheca is often already filled with viable sperm from other males, such that sperm competition is strong. We analyze the effect of the reproductive status of males and females on the frequency of mating during brood ball construction, as well as the reproductive success of males that nest with previously mated females. Virgin and previously mated males copulated with the same frequency before the construction of each brood ball when they nested with virgin females. However, when both types of males nested with previously mated females, the frequency of mating increased before the construction of the first brood ball. The paternity of previously mated males was significantly higher (82%) than that of virgin males (62%). Therefore, the reproductive status of both sexes of C. c. cyanellus affects the frequency of mating and the reproductive success of males.

047. SPERM COMPETITION, INBREEDING AND THE EVOLUTION OF SUPERIOR EJACULATES

2009 ◽  
Vol 21 (9) ◽  
pp. 12 ◽  
Author(s):  
J. Fitzpatrick
Keyword(s):  
Reproductive Success ◽  
Sperm Competition ◽  
Sperm Morphology ◽  
Sperm Quality ◽  
Male Reproductive Success ◽  
High Quality ◽  
Genetic Quality ◽  
Viable Sperm ◽  
And Performance ◽  
Reproductive Consequences

The production of viable sperm is essential for male reproductive success. However, because females in many species mate with several males during a single reproductive episode, leading to sperm competition, a male's reproductive success also depends critically on the ability of his sperm to compete efficiently with those from rival males for fertilizations. Therefore, males who regularly encounter sperm competition are expected to produce high quality ejaculates. Here, I will provide an overview of how sperm morphology and performance are influenced by sperm competition, both within and between species, using recent empirical examples. Having established the importance of producing high quality ejaculates in males experiencing sperm competition, I will then examine the reproductive consequences of producing sub-optimal sperm. Given the well known role that inbreeding plays in reducing genetic quality and reproductive success, I will focus in particular on how inbreeding acts to reduce sperm quality. Finally, I will examine the consequences of inbreeding for male reproductive success in species where sperm competition is rampant. Together, these results highlight the evolutionary importance of sperm competition and inbreeding in shaping ejaculate traits.

scholarly journals The frequency of leg autotomy and its influence on survival in natural populations of the wolf spider Pardosa valens

2018 ◽  
Vol 96 (9) ◽  
pp. 973-979 ◽  
Author(s):  
Christopher A. Brown ◽  
Carlos C. Amaya ◽  
Daniel R. Formanowicz
Keyword(s):  
Riparian Zone ◽  
Natural Populations ◽  
Wolf Spider ◽  
Reproductive Status ◽  
Mark Recapture ◽  
Female Reproductive Status ◽  
Males And Females

Autotomy occurs when an animal intentionally sacrifices an appendage to escape predation or free a limb. While immediately beneficial, loss of an appendage can lead to a variety of future costs. In many spiders, leg autotomy is common; previous work has sometimes demonstrated autotomy costs in some behaviors, while other times, no costs of autotomy occur. We examined frequency of autotomy in two riparian zone populations of the wolf spider Pardosa valens Barnes, 1959 and then used both mark–recapture work at these sites and laboratory predation trials to determine whether autotomy affected survival. Autotomy occurred in 31% of spiders; males were more likely than females to have a missing leg, but female reproductive status (carrying an egg sac or not) was unrelated to leg loss status. At both sites, survival over 1 week in the field was significantly higher for intact spiders than for spiders missing a leg, for both sexes and both female reproductive states. Additionally, when we paired intact and autotomized spiders with a predator (the larger wolf spider Rabidosa santrita (Chamberlin & Ivie, 1942)), autotomized spiders were more likely to be attacked and eaten. Our results suggest that leg autotomy in P. valens leads to a significant future survival cost, and we discuss how this cost may affect males and females differently.

POLYGYNY, REPRODUCTIVE SUCCESS AND CHILD HEALTH IN RURAL ETHIOPIA: WHY MARRY A MARRIED MAN?

2006 ◽  
Vol 39 (2) ◽  
pp. 287-300 ◽  
Author(s):  
MHAIRI A. GIBSON ◽  
RUTH MACE
Keyword(s):  
Reproductive Success ◽  
Male Reproductive Success ◽  
Family Status ◽  
Rural Ethiopia ◽  
Younger Age ◽  
Married Individuals ◽  
Males And Females ◽  
Child Nutritional Status ◽  
And Child Health ◽  
Better Than

Summary.This study examines the reproductive success of men and women in rural Ethiopia as a function of their marital status, specifically by comparing polygamously and monogamously married individuals. In line with predictions from evolutionary theory, polygamy is beneficial to male reproductive success (i.e. producing larger numbers of surviving offspring). The success of polygamously married females depends on wife rank: the first wives of polygamous husbands do better than monogamously married women and much better than second or third wives. These effects are mirrored in child nutritional status: the children of second and third wives have lower weight for height. Due to potential, largely unmeasurable differences in marriageability (quality) between individuals, it was not possible to support a model of either resource-holding polygyny combined with female choice or female coercion into unwanted marriages. First wives of polygamously married men marry at a younger age and attract a higher brideprice, suggesting that both the males and females in the marriage are likely to be of higher quality (due to wealth, family status or some other factor such as beauty). Unions that end up monogamous are likely to be between slightly lower quality individuals; and second and third wives, who marry at the oldest ages and attract the lowest brideprice, may be ‘making the best of a bad job’. The relatively long gap between first and second marriages may mean that first wives of highly marriageable males can enjoy considerable reproductive success before their husbands marry again.

scholarly journals Safe sex: male–female coalitions and pre-copulatory mate-guarding in a fiddler crab

2009 ◽  
Vol 6 (2) ◽  
pp. 180-182 ◽  
Author(s):  
Richard N. C. Milner ◽  
Michael D. Jennions ◽  
Patricia R. Y. Backwell
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Success ◽  
Observational Data ◽  
Fiddler Crab ◽  
Lower Boundary ◽  
Mate Guarding ◽  
Maintenance Costs ◽  
Boundary Maintenance ◽  
Uca Annulipes ◽  
Males And Females

In fiddler crabs both males and females defend territories that are essential for survival. Given pronounced sexual dimorphism in weaponry, how do weaponless females defend their territory from well-armed males? Using observational data and two simple experiments, we test whether male Uca annulipes protect their female neighbours from conspecific intruders. We show that males defend their female neighbours against male but not female intruders. We also show that females sometimes mate with their immediate neighbours. Male defence of female neighbours appears to represent both pre-copulatory mate-guarding and a territorial coalition. Males who ensure that their neighbour remains female could benefit through increased opportunity for future reproductive success and lower boundary maintenance costs.

Variation in reproductive success of male and female Columbian ground squirrels (Urocitellus columbianus)

2012 ◽  
Vol 90 (6) ◽  
pp. 736-743 ◽  
Author(s):  
Philip H. Jones ◽  
Jeffrey L. Van Zant ◽  
F. Stephen Dobson
Keyword(s):  
Reproductive Success ◽  
Mating System ◽  
Multiple Paternity ◽  
Ground Squirrels ◽  
Male Reproductive Success ◽  
Offspring Production ◽  
Bateman Gradient ◽  
Coefficients Of Variation ◽  
Males And Females ◽  
Columbian Ground Squirrels

The imbalanced reproductive success of polygynous mammals results in sexual selection on male traits like body size. Males and females might have more balanced reproductive success under polygynandry, where both sexes mate multiply. Using 4 years of microsatellite DNA analyses of paternity and known maternity, we investigated variation in reproductive success of Columbian ground squirrels, Urocitellus columbianus (Ord, 1815); a species with multiple mating by both sexes and multiple paternity of litters. We asked whether male reproductive success was more variable than that of females under this mating system. The overall percentage of confirmed paternity was 61.4% of 339 offspring. The mean rate of multiple paternity in litters with known fathers was 72.4% (n = 29 litters). Estimated mean reproductive success of males (10.27 offspring) was about thrice that of females (3.11 offspring). Even after this difference was taken into account statistically, males were about three times as variable in reproductive success as females (coefficients of variation = 77.84% and 26.74%, respectively). The Bateman gradient (regression slope of offspring production on number of successful mates) was significantly greater for males (βM = 1.44) than females (βF = 0.28). Thus, under a polygynandrous mating system, males exhibited greater variation in reproductive success than females.

scholarly journals A LIFE-HISTORY PERSPECTIVE ON SEXUAL SELECTION IN A POLYGAMOUS SPECIES

2019 ◽  
Author(s):  
Gao Ke ◽  
Michiel van Wijk ◽  
Zoe Clement ◽  
Martijn Egas ◽  
Astrid Groot
Keyword(s):  
Sexual Selection ◽  
Life History ◽  
Sperm Competition ◽  
Reproductive Output ◽  
Relative Fitness ◽  
Quadratic Model ◽  
Costs And Benefits ◽  
Bateman Gradient ◽  
Multiple Matings ◽  
Males And Females

Abstract Background Ever since Darwin, evolutionary biologists have studied sexual selection driving differences in appearance and behaviour between males and females. An unchallenged paradigm in such studies is that one sex (usually the male) signals its quality as a mate to the other sex (usually the female), who is choosy in accepting a partner. Here, we argue that in polygamous species these roles may change dynamically with the mating status of males and females, depending on direct reproductive costs and benefits of multiple matings, and on sperm competition. We test this hypothesis using a polygamous moth species, as in moths not males but females are the signalers and males are the responders. Results We found that multiple matings are beneficial as well as costly for both sexes. Specifically, the number of matings did not affect the longevity of males or females, but when paired with a new virgin mate every night for five nights, only 67% of the males and 14% of the females mated successfully in all five nights. The female’s reproductive output increased with multiple matings, although when paired with a new virgin male every night, additional matings beyond 3 decreased her reproductive output, so that the Bateman gradient for females fit a quadratic model better than a linear model. The male’s reproductive success was positively affected by the number of matings and a linear regression line best fit the data. Simulations of the effect of sperm competition showed that increasing last-male paternity increases the steepness of the male Bateman gradient and thus the male’s relative fitness gain from additional mating. Irrespective of last-male paternity value, the female Bateman gradient is steeper than the male one for up to three matings. Conclusion Our results suggest that choosiness in moths may well change throughout the mating season, with males being more choosy early in the season and females being more choosy after having mated at least three times. This life-history perspective on the costs and benefits of multiple matings for both sexes sheds new light on sexual selection forces acting on sexual signals and responses.

scholarly journals Serial monogamy benefits both sexes in the biparental convict cichlid

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6535 ◽  
Author(s):  
Jennifer L. Snekser ◽  
Murray Itzkowitz
Keyword(s):  
Reproductive Success ◽  
Brood Size ◽  
Parental Behavior ◽  
Convict Cichlid ◽  
Costs And Benefits ◽  
Serial Monogamy ◽  
Convict Cichlids ◽  
Amatitlania Nigrofasciata ◽  
Males And Females

Monogamy can be either long-term or serial, with new pairs formed with each breeding bout. Costs and benefits are associated with each strategy. Because biparental convict cichlids (Amatitlania nigrofasciata) typically switch mates, exhibiting serial monogamy, we tested for the costs associated with forcing individuals to remain with the same mate. Convict cichlids were observed over two successive breeding bouts, either with the same or a new, equally experienced, mate. Parental behavior did not differ between breeding bouts, nor did brood size. Surprisingly, fish that remained with their original partner for a second bout took significantly longer to produce a brood compared to fish that paired with new partners. New partners were also more likely to successfully produce a second brood than re-mated partners. This is in contrast to the majority of bird studies that show many benefits to staying with the same partner for multiple broods. In convict cichlids, there seems to be no benefit associated with remaining with the same partner and switching mates reduces duration between broods for both males and females, potentially increasing overall reproductive success.

Sign in / Sign up

Export Citation Format

Share Document