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Sample records for male mating strategy

  1. Polygyny, mate-guarding, and posthumous fertilization as alternative male mating strategies.

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    Zamudio, K R; Sinervo, B

    2000-12-19

    Alternative male mating strategies within populations are thought to be evolutionarily stable because different behaviors allow each male type to successfully gain access to females. Although alternative male strategies are widespread among animals, quantitative evidence for the success of discrete male strategies is available for only a few systems. We use nuclear microsatellites to estimate the paternity rates of three male lizard strategies previously modeled as a rock-paper-scissors game. Each strategy has strengths that allow it to outcompete one morph, and weaknesses that leave it vulnerable to the strategy of another. Blue-throated males mate-guard their females and avoid cuckoldry by yellow-throated "sneaker" males, but mate-guarding is ineffective against aggressive orange-throated neighbors. The ultradominant orange-throated males are highly polygynous and maintain large territories; they overpower blue-throated neighbors and cosire offspring with their females, but are often cuckolded by yellow-throated males. Finally, yellow-throated sneaker males sire offspring via secretive copulations and often share paternity of offspring within a female's clutch. Sneaker males sire more offspring posthumously, indicating that sperm competition may be an important component of their strategy.

  2. Trading or coercion? Variation in male mating strategies between two communities of East African chimpanzees.

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    Kaburu, Stefano S K; Newton-Fisher, Nicholas E

    2015-06-01

    Across taxa, males employ a variety of mating strategies, including sexual coercion and the provision, or trading, of resources. Biological market theory (BMT) predicts that trading of commodities for mating opportunities should exist only when males cannot monopolize access to females and/or obtain mating by force, in situations where power differentials between males are low; both coercion and trading have been reported for chimpanzees (Pan troglodytes). Here, we investigate whether the choice of strategy depends on the variation in male power differentials, using data from two wild communities of East African chimpanzees (Pan troglodytes schweinfurthii): the structurally despotic Sonso community (Budongo, Uganda) and the structurally egalitarian M-group (Mahale, Tanzania). We found evidence of sexual coercion by male Sonso chimpanzees, and of trading-of grooming for mating-by M-group males; females traded sex for neither meat nor protection from male aggression. Our results suggest that the despotism-egalitarian axis influences strategy choice: male chimpanzees appear to pursue sexual coercion when power differentials are large and trading when power differentials are small and coercion consequently ineffective. Our findings demonstrate that trading and coercive strategies are not restricted to particular chimpanzee subspecies; instead, their occurrence is consistent with BMT predictions. Our study raises interesting, and as yet unanswered, questions regarding female chimpanzees' willingness to trade sex for grooming, if doing so represents a compromise to their fundamentally promiscuous mating strategy. It highlights the importance of within-species cross-group comparisons and the need for further study of the relationship between mating strategy and dominance steepness.

  3. Paternity in wild ring-tailed lemurs (Lemur catta): Implications for male mating strategies.

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    Parga, Joyce A; Sauther, Michelle L; Cuozzo, Frank P; Youssouf Jacky, Ibrahim Antho; Lawler, Richard R; Sussman, Robert W; Gould, Lisa; Pastorini, Jennifer

    2016-12-01

    In group-living species with male dominance hierarchies where receptive periods of females do not overlap, high male reproductive skew would be predicted. However, the existence of female multiple mating and alternative male mating strategies can call into question single-male monopolization of paternity in groups. Ring-tailed lemurs (Lemur catta) are seasonally breeding primates that live in multi-male, multi-female groups. Although established groups show male dominance hierarchies, male dominance relationships can break down during mating periods. In addition, females are the dominant sex and mate with multiple males during estrus, including group residents, and extra-group males-posing the question of whether there is high or low male paternity skew in groups. In this study, we analyzed paternity in a population of wild L. catta from the Bezà Mahafaly Special Reserve in southwestern Madagascar. Paternity was determined with 80-95% confidence for 39 offspring born to nine different groups. We calculated male reproductive skew indices for six groups, and our results showed a range of values corresponding to both high and low reproductive skew. Between 21% and 33% of offspring (3 of 14 or three of nine, counting paternity assignments at the 80% or 95% confidence levels, respectively) were sired by extra-troop males. Males siring offspring within the same group during the same year appear to be unrelated. Our study provides evidence of varying male reproductive skew in different L. catta groups. A single male may monopolize paternity across one or more years, while in other groups, >1 male can sire offspring within the same group, even within a single year. Extra-group mating is a viable strategy that can result in extra-group paternity for L. catta males. © 2016 The Authors. American Journal of Primatology Published by Wiley Periodicals, Inc.

  4. Paternity in wild ring‐tailed lemurs (Lemur catta): Implications for male mating strategies

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    Sauther, Michelle L.; Cuozzo, Frank P.; Youssouf Jacky, Ibrahim Antho; Lawler, Richard R.; Sussman, Robert W.; Gould, Lisa; Pastorini, Jennifer

    2016-01-01

    1 In group‐living species with male dominance hierarchies where receptive periods of females do not overlap, high male reproductive skew would be predicted. However, the existence of female multiple mating and alternative male mating strategies can call into question single‐male monopolization of paternity in groups. Ring‐tailed lemurs (Lemur catta) are seasonally breeding primates that live in multi‐male, multi‐female groups. Although established groups show male dominance hierarchies, male dominance relationships can break down during mating periods. In addition, females are the dominant sex and mate with multiple males during estrus, including group residents, and extra‐group males—posing the question of whether there is high or low male paternity skew in groups. In this study, we analyzed paternity in a population of wild L. catta from the Bezà Mahafaly Special Reserve in southwestern Madagascar. Paternity was determined with 80–95% confidence for 39 offspring born to nine different groups. We calculated male reproductive skew indices for six groups, and our results showed a range of values corresponding to both high and low reproductive skew. Between 21% and 33% of offspring (3 of 14 or three of nine, counting paternity assignments at the 80% or 95% confidence levels, respectively) were sired by extra‐troop males. Males siring offspring within the same group during the same year appear to be unrelated. Our study provides evidence of varying male reproductive skew in different L. catta groups. A single male may monopolize paternity across one or more years, while in other groups, >1 male can sire offspring within the same group, even within a single year. Extra‐group mating is a viable strategy that can result in extra‐group paternity for L. catta males. PMID:27391113

  5. Thanatosis as an adaptive male mating strategy in the nuptial gift-giving spider Pisaura mirabilis

    DEFF Research Database (Denmark)

    Hansen, Line S.; Gonzalez, Sofía F.; Toft, Søren;

    2008-01-01

    (death feigning). Thanatosis in a sexual context is exceptional and was suggested to function as an antipredation strategy toward potentially cannibalistic females. If thanatosis serves as a protection strategy, males should death feign in response to female aggression or when they are more vulnerable...... to attack. We tested these predictions in a factorial design: males that were handicapped (1 leg removed) and hence vulnerable and control males were paired with females that were more or less aggressive intrinsically (measured toward prey). In mating trials, we recorded the tendency of males to death feign......, copulation success, and copulation duration. In addition, we investigated the effect of female mating status (virgin or mated) on these male mating components. Intrinsically aggressive females showed increased mating aggression toward males. Neither female aggressiveness, mating status, nor male...

  6. Male mating strategy and the introgression of a growth hormone transgene.

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    Valosaari, Kata-Riina; Aikio, Sami; Kaitala, Veijo

    2008-11-01

    Escaped transgenic organisms (GMO's) may threaten the populations of their wild relatives if able to hybridize with each other. The introgression of a growth enhancement transgene into a wild Atlantic salmon population may be affected by the transgene's effects not only on fitness parameters, but also on mating behaviour. Large anadromous GMO males are most preferred in mating, but a transgene can also give the large sneakers a reproductive advantage over the smaller wild individuals. With a simulation model, we studied whether the increase in the proportion and mating success of sneakers in transgenic and hybrid genotypes could facilitate the introgression of a transgene into wild population after the release of GMOs. The model combines population dynamics and Mendelian inheritance of a transgenic trait. We found that the introgression of the transgene is strongly affected by the greater mating preference of large GMO males. Furthermore, the difference in reproductive success between the anadromous versus sneaker strategy defines how much GMO's have to be preferred to be able to invade. These results emphasize the importance of detailed knowledge of reproductive systems and the effect of a transgene on the phenotype and behaviour of GMOs when assessing the consequences of their release or escape to the wild.

  7. Strategies of Human Mating

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    David M. Buss

    2006-12-01

    Full Text Available Modern humans have inherited the mating strategies that led to the success of their ancestors. These strategies include long-term mating, short-term mating, extra-pair mating, mate poaching, and mate guarding. This article presents empirical evidence supporting evolution-based hypotheses about the complexities of these mating strategies. Since men and women historically confronted different adaptive problems in the mating domain, the sexes differ profoundly in evolved strategic solutions. These differences include possessing different mate preferences, different desires for short-term mating, and differences in the triggers that evoke sexual jealousy. The study of human mating is one of the “success stories” of evolutionary psychology.

  8. Male Texas Horned Lizards increase daily movements and area covered in spring: A mate searching strategy?

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    Stark, Richard C.; Fox, S. F.; David, M.L.

    2005-01-01

    Texas Horned Lizards, Phrynosoma cornutum, were tracked using fluorescent powder to determine exact daily movements. Daily linear movements and daily space use were compared between adult males and females. Lizards that traveled the greatest linear distances also covered the largest areas. In Oklahoma, adults emerge from hibernation in late April and early May and mate soon afterward. Males traveled significantly greater distances (and covered significantly larger areas in a day) than females in May but not after May. We propose that males move more and cover more area than females early in the mating season to intercept receptive females. Copyright 2005 Society for the Study of Amphibians and Reptiles.

  9. Male rock sparrows adjust their breeding strategy according to female ornamentation: parental or mating investment?

    DEFF Research Database (Denmark)

    Pilastro, Andrea; Griggio, Matteo; Matessi, Giuliano

    2003-01-01

    mass and breeding status; double-brooding and primary females of polygynous males had a larger patch, and patch size could therefore be an indicator of female phenotypic quality. We conducted a field experiment to test whether males allocate their parental effort in relation to female quality...... (song output) and sexual activity (courtship and copulation). The reduction in sexual activity suggests that males may have changed their nest attendance in response to their mate's renesting probability. Whatever the interpretation, these results provide some of the first evidence that not only female...

  10. Contrasting reproductive strategies of triploid hybrid males in vertebrate mating systems.

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    Pruvost, N B M; Mikulíček, P; Choleva, L; Reyer, H-U

    2015-01-01

    The scarcity of parthenogenetic vertebrates is often attributed to their 'inferior' mode of clonal reproduction, which restricts them to self-reproduce their own genotype lineage and leaves little evolutionary potential with regard to speciation and evolution of sexual reproduction. Here, we show that for some taxa, such uniformity does not hold. Using hybridogenetic water frogs (Pelophylax esculentus) as a model system, we demonstrate that triploid hybrid males from two geographic regions exhibit very different reproductive modes. With an integrative data set combining field studies, crossing experiments, flow cytometry and microsatellite analyses, we found that triploid hybrids from Central Europe are rare, occur in male sex only and form diploid gametes of a single clonal lineage. In contrast, triploid hybrids from north-western Europe are widespread, occur in both sexes and produce recombined haploid gametes. These differences translate into contrasting reproductive roles between regions. In Central Europe, triploid hybrid males sexually parasitize diploid hybrids and just perpetuate their own genotype--which is the usual pattern in parthenogens. In north-western Europe, on the other hand, the triploid males are gamete donors for diploid hybrids, thereby stabilizing the mixed 2n-3n hybrid populations. By demonstrating these contrasting roles in male reproduction, we draw attention to a new significant evolutionary potential for animals with nonsexual reproduction, namely reproductive plasticity. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  11. The variability of male quality and female mate choice decisions: second-order stochastic dominance and the behavior of searchers under a sequential search strategy.

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    Seubert, Steven M; Wade, Gordon A; Wiegmann, Daniel D

    2011-12-01

    The strategy employed by a female to sample prospective mates determines the likelihood that a high-quality male is encountered in the search process. In general, the choosiness of females is expected to depend on the variability of quality amongst the males that are sampled. The sequential search strategy is a prominent model of search behavior that involves the use of a threshold criterion to evaluate encountered individuals. In this paper, we show that the stochastic dominance of one distribution of male quality over another at the second order is necessary and sufficient for the optimal threshold criterion to differ under two distributions of male quality when the cost to sample males is held constant and the mean quality of males under each of the distributions is identical. A difference of the variance of male quality between two distributions does not imply that one distribution stochastically dominates the other at the second order and, hence, should not, in general, be used to assess the relative variability of quality amongst prospective mates. The adjustment of the threshold criterion in response to experimental manipulations of the distribution of male quality has been inferred from induced differences of the duration of search or the number of males sampled in the search process. Here we show that such inferences are unjustified. In particular, the difference of the threshold criterion imposed by second-order stochastic dominance does not determine the distribution under which females are expected to sample a larger number of males in the search process.

  12. Sexual experience enhances Drosophila melanogaster male mating behavior and success.

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    Sehresh Saleem

    Full Text Available Competition for mates is a wide-spread phenomenon affecting individual reproductive success. The ability of animals to adjust their behaviors in response to changing social environment is important and well documented. Drosophila melanogaster males compete with one another for matings with females and modify their reproductive behaviors based on prior social interactions. However, it remains to be determined how male social experience that culminates in mating with a female impacts subsequent male reproductive behaviors and mating success. Here we show that sexual experience enhances future mating success. Previously mated D. melanogaster males adjust their courtship behaviors and out-compete sexually inexperienced males for copulations. Interestingly, courtship experience alone is not sufficient in providing this competitive advantage, indicating that copulation plays a role in reinforcing this social learning. We also show that females use their sense of hearing to preferentially mate with experienced males when given a choice. Our results demonstrate the ability of previously mated males to learn from their positive sexual experiences and adjust their behaviors to gain a mating advantage. These experienced-based changes in behavior reveal strategies that animals likely use to increase their fecundity in natural competitive environments.

  13. Sperm economy between female mating frequency and male ejaculate allocation.

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    Abe, Jun; Kamimura, Yoshitaka

    2015-03-01

    Why females of many species mate multiply is a major question in evolutionary biology. Furthermore, if females accept matings more than once, ejaculates from different males compete for fertilization (sperm competition), which confronts males with the decision of how to allocate their reproductive resources to each mating event. Although most existing models have examined either female mating frequency or male ejaculate allocation while assuming fixed levels of the opposite sex's strategies, these strategies are likely to coevolve. To investigate how the interaction of the two sexes' strategies is influenced by the level of sperm limitation in the population, we developed models in which females adjust their number of allowable matings and males allocate their ejaculate in each mating. Our model predicts that females mate only once or less than once at an even sex ratio or in an extremely female-biased condition, because of female resistance and sperm limitation in the population, respectively. However, in a moderately female-biased condition, males favor partitioning their reproductive budgets across many females, whereas females favor multiple matings to obtain sufficient sperm, which contradicts the predictions of most existing models. We discuss our model's predictions and relationships with the existing models and demonstrate applications for empirical findings.

  14. Drosophila melanogaster females restore their attractiveness after mating by removing male anti-aphrodisiac pheromones

    NARCIS (Netherlands)

    Laturney, Meghan; Billeter, Jean-Christophe

    2016-01-01

    Males from many species ensure paternity by preventing their mates from copulating with other males. One mate-guarding strategy involves marking females with anti-aphrodisiac pheromones (AAPs), which reduces the females' attractiveness and dissuades other males from courting. Since females benefit

  15. Drosophila melanogaster females restore their attractiveness after mating by removing male anti-aphrodisiac pheromones

    NARCIS (Netherlands)

    Laturney, Meghan; Billeter, Jean-Christophe

    2016-01-01

    Males from many species ensure paternity by preventing their mates from copulating with other males. One mate-guarding strategy involves marking females with anti-aphrodisiac pheromones (AAPs), which reduces the females' attractiveness and dissuades other males from courting. Since females benefit f

  16. Variation in male mate choice in Drosophila melanogaster.

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    Edward, Dominic A; Chapman, Tracey

    2013-01-01

    Male mate choice has been reported in the fruit fly, Drosophila melanogaster, even though males of this species were previously thought to maximise their fitness by mating with all available females. To understand the evolution of male mate choice it is important to understand variation in male mating preferences. Two studies, using different stock populations and different methods, have reported contrasting patterns of variation in male mate choice in D. melanogaster. Two possible explanations are that there are evolved differences in each stock population or that the methods used to measure choice could have biased the results. We investigated these hypotheses here by repeating the methods used in one study in which variable male mate choice was found, using the stock population from the other study in which choice was not variable. The results showed a significant resource-independent male preference for less fecund, smaller females, which contrasts with previous observations of male mate choice. This indicates that different selection pressures between populations have resulted in evolved differences in the expression of male mate choice. It also reveals phenotypic plasticity in male mate choice in response to cues encountered in each choice environment. The results highlight the importance of variation in male mate choice, and of identifying mechanisms in order to understand the evolution of mate choice under varying ecological conditions.

  17. Variation in male mate choice in Drosophila melanogaster.

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    Dominic A Edward

    Full Text Available Male mate choice has been reported in the fruit fly, Drosophila melanogaster, even though males of this species were previously thought to maximise their fitness by mating with all available females. To understand the evolution of male mate choice it is important to understand variation in male mating preferences. Two studies, using different stock populations and different methods, have reported contrasting patterns of variation in male mate choice in D. melanogaster. Two possible explanations are that there are evolved differences in each stock population or that the methods used to measure choice could have biased the results. We investigated these hypotheses here by repeating the methods used in one study in which variable male mate choice was found, using the stock population from the other study in which choice was not variable. The results showed a significant resource-independent male preference for less fecund, smaller females, which contrasts with previous observations of male mate choice. This indicates that different selection pressures between populations have resulted in evolved differences in the expression of male mate choice. It also reveals phenotypic plasticity in male mate choice in response to cues encountered in each choice environment. The results highlight the importance of variation in male mate choice, and of identifying mechanisms in order to understand the evolution of mate choice under varying ecological conditions.

  18. Male mate choice in Tibetan macaques Macaca thibetana at Mt. Huangshan, China

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    Min ZHANG, Jinhua LI, Yong ZHU, Xi WANG, Su WANG

    2010-04-01

    Full Text Available Though females are generally more selective in mate choice, males may also benefit from mate choice if male reproductive success is limited by factors other than simply the number of female mates, and if females differ in short-term reproductive potential. We studied male mate choice in a free-ranging troop of Tibetan macaques Macaca thibetana at Mt. Huangshan, China, from August 2007 to April 2008. We employed focal animal sampling and all occurrence sampling to record sexual related behaviors. Eight adult females were divided into three female quality categories according to the females’ age, rank and parity. Using male mating effort as a proxy for male mate choice, we found that males do distinguish female quality and show time-variant mating strategies. Specifically, females with dominant rank, high fecundity, and middle age attracted significantly more males. Our results suggest that female short-term reproductive potential appears to be an important variable in determining male mating effort. Male Tibetan macaques do exercise mate choice for higher quality females as well as reduce useless reproductive cost, which is consistent with the direct benefits theory of mate choice [Current Zoology 56 (2: 213–221, 2010].

  19. A comparison of two methods to assess audience-induced changes in male mate choice

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    Madlen ZIEGE; Carmen HENNIGE-SCHULZ; Frauke MUECKSCH; David BIERBACH; Ralph TIEDEMANN; Bruno STREIT; Martin PLATH

    2012-01-01

    Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior.Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented.This could be a male strategy to reduce sperm competition risk:interacting more equally with different females may be advantageous because rivals might copy mate choice decisions.In line with this hypothesis,a previous study found males to show a strong audience effect when being observed while exercising mate choice,but not when the rival was presented only before the choice tests.Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs,but it remains unknown if patterns found from measuring association times translate into actual mating behavior.Thus,we createl five audience treatments simulating different forms of perceived sperm competition risk and determined focal males' mating preferences by scoring pre-mating (nipping) and mating behavior (gonopodial thrusting).Nipping did not reflect the pattern that was found when association preferences were measured,while a very similar pattern was uncovered in thrusting behavior.The strongest response was observed when the audience could eavesdrop on the focal male's behavior.A reduction in the strength of focal males' preferences was also seen after the rival male had an opportunity to mate with the focal male's preferred mate.In comparison,the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior.While measuring direct sexual interactions between the focal male and both stimulus females not only the male's motivational state is reflected but also females' behavior such as avoidance of male sexual harassment [Current Zoology 58 (1):84-94,2012].

  20. The evolution and significance of male mate choice.

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    Edward, Dominic A; Chapman, Tracey

    2011-12-01

    The distinct reproductive roles of males and females, which for many years were characterised in terms of competitive males and choosy females, have remained a central focus of sexual selection since Darwin's time. Increasing evidence now shows that males can be choosy too, even in apparently unexpected situations, such as under polygyny or in the absence of male parental care. Here, we provide a synthesis of the theory on male mate choice and examine the factors that promote or constrain its evolution. We also discuss the evolutionary significance of male mate choice and the contrasts in male versus female mate choice. We conclude that mate choice by males is potentially widespread and has a distinct role in how mating systems evolve.

  1. Sequential male mate choice under sperm competition risk.

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    Ramm, Steven A; Stockley, Paula

    2014-05-01

    Male eagerness to mate is a central paradigm of sexual selection theory. However, limited sperm supplies mean that male sexual restraint might sometimes be favored under promiscuous mating. Here, we demonstrate dynamic plasticity in male mating effort when females are encountered sequentially under varying sperm competition risk. Rather than showing consistent eagerness to mate, male house mice (Mus musculus domesticus) instead tailor their mating effort according to likely reproductive payoffs. They are significantly less likely to mate when sperm competition is certain and potential reproductive payoffs low, but dramatically increase investment if they do choose to mate under such circumstances. By contrast, male mice are significantly more likely to mate in situations simulating extra-territorial copulations, where future risk of competition is high but so too are potential reproductive rewards. Differential mating propensity appears to be the primary mechanism by which male house mice allocate sperm adaptively under sperm competition risk because we find no evidence for facultative adjustment of sperm numbers per ejaculate or ejaculation frequency in response to female-related cues. We conclude that sequential male mate choice under sperm competition risk could be a widespread but often unappreciated mechanism of strategic sperm allocation.

  2. Female and male moths display different reproductive behavior when facing new versus previous mates.

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    Yan-Ying Li

    Full Text Available Multiple mating allows females to obtain material (more sperm and nutrient and/or genetic benefits. The genetic benefit models require sperm from different males to fertilize eggs competitively or the offspring be fathered by multiple males. To maximize genetic benefits from multiple mating, females have evolved strategies to prefer novel versus previous mates in their subsequent matings. However, the reproductive behavior during mate encounter, mate choice and egg laying in relation to discrimination and preference between sexes has been largely neglected. In the present study, we used novel and previous mate treatments and studied male and female behavior and reproductive output in Spodoptera litura. The results of this study do not support the sperm and nutrient replenishment hypotheses because neither the number of mates nor the number of copulations achieved by females significantly increased female fecundity, fertility and longevity. However, females showed different oviposition patterns when facing new versus previous mates by slowing down oviposition, which allows the last male has opportunities to fertilize her eggs and the female to promote offspring diversity. Moreover, females that have novel males present called earlier and more than females that have their previous mates present, whereas no significant differences were found on male courtship between treatments. These results suggest that S. litura females can distinguish novel from previous mates and prefer the former, whereas males generally remate regardless of whether the female is a previous mate or not. In S. litura, eggs are laid in large clusters and offspring competition, inbreeding and disease transfer risks are thus increased. Therefore, offspring diversity should be valuable for S. litura, and genetic benefits should be the main force behind the evolution of female behavioral strategies found in the present study.

  3. A comparison of two methods to assess audience-induced changes in male mate choice

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    Madlen ZIEGE, Carmen HENNIGE-SCHULZ, Frauke MUECKSCH,David BIERBACH, Ralph TIEDEMANN, Bruno STREIT, Martin PLATH

    2012-02-01

    Full Text Available Multidirectional communicative interactions in social networks can have a profound effect on mate choice behavior. Male Atlantic molly Poecilia mexicana exhibit weaker mating preferences when an audience male is presented. This could be a male strategy to reduce sperm competition risk: interacting more equally with different females may be advantageous because rivals might copy mate choice decisions. In line with this hypothesis, a previous study found males to show a strong audience effect when being observed while exercising mate choice, but not when the rival was presented only before the choice tests. Audience effects on mate choice decisions have been quantified in poeciliid fishes using association preference designs, but it remains unknown if patterns found from measuring association times translate into actual mating behavior. Thus, we created five audience treatments simulating different forms of perceived sperm competition risk and determined focal males’ mating preferences by scoring pre-mating (nipping and mating behavior (gonopodial thrusting. Nipping did not reflect the pattern that was found when association preferences were measured, while a very similar pattern was uncovered in thrusting behavior. The strongest response was observed when the audience could eavesdrop on the focal male’s behavior. A reduction in the strength of focal males’ preferences was also seen after the rival male had an opportunity to mate with the focal male’s preferred mate. In comparison, the reduction of mating preferences in response to an audience was greater when measuring association times than actual mating behavior. While measuring direct sexual interactions between the focal male and both stimulus females not only the male’s motivational state is reflected but also females’ behavior such as avoidance of male sexual harassment [Current Zoology 58 (1: 84–94, 2012].

  4. Mating alters gene expression patterns in Drosophila melanogaster male heads

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    Ellis Lisa L

    2010-10-01

    Full Text Available Abstract Background Behavior is a complex process resulting from the integration of genetic and environmental information. Drosophila melanogaster rely on multiple sensory modalities for reproductive success, and mating causes physiological changes in both sexes that affect reproductive output or behavior. Some of these effects are likely mediated by changes in gene expression. Courtship and mating alter female transcript profiles, but it is not known how mating affects male gene expression. Results We used Drosophila genome arrays to identify changes in gene expression profiles that occur in mated male heads. Forty-seven genes differed between mated and control heads 2 hrs post mating. Many mating-responsive genes are highly expressed in non-neural head tissues, including an adipose tissue called the fat body. One fat body-enriched gene, female-specific independent of transformer (fit, is a downstream target of the somatic sex-determination hierarchy, a genetic pathway that regulates Drosophila reproductive behaviors as well as expression of some fat-expressed genes; three other mating-responsive loci are also downstream components of this pathway. Another mating-responsive gene expressed in fat, Juvenile hormone esterase (Jhe, is necessary for robust male courtship behavior and mating success. Conclusions Our study demonstrates that mating causes changes in male head gene expression profiles and supports an increasing body of work implicating adipose signaling in behavior modulation. Since several mating-induced genes are sex-determination hierarchy target genes, additional mating-responsive loci may be downstream components of this pathway as well.

  5. Mating with stressed males increases the fitness of ant queens.

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    Alexandra Schrempf

    Full Text Available BACKGROUND: According to sexual conflict theory, males can increase their own fitness by transferring substances during copulation that increase the short-term fecundity of their mating partners at the cost of the future life expectancy and re-mating capability of the latter. In contrast, sexual cooperation is expected in social insects. Mating indeed positively affects life span and fecundity of young queens of the male-polymorphic ant Cardiocondyla obscurior, even though males neither provide nuptial gifts nor any other care but leave their mates immediately after copulation and die shortly thereafter. PRINCIPAL FINDINGS: Here, we show that mating with winged disperser males has a significantly stronger impact on life span and reproductive success of young queens of C. obscurior than mating with wingless fighter males. CONCLUSIONS: Winged males are reared mostly under stressful environmental conditions, which force young queens to disperse and found their own societies independently. In contrast, queens that mate with wingless males under favourable conditions usually start reproducing in the safety of the established maternal nest. Our study suggests that males of C. obscurior have evolved mechanisms to posthumously assist young queens during colony founding under adverse ecological conditions.

  6. Associations between body morphology, mating success and mate preferences among Slovak males and females.

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    Prokop, Pavol; Fedor, Peter

    2013-01-01

    Human body morphology is thought to be correlated with sexual behaviour and sociosexuality (defined as an increased willingness to engage in sex without commitment) influences the perception of certain cues of physical attractiveness. Based on a sample of Slovak university students, we investigated relationships between 1) male and female mating success and reported body morphology (body mass index, BMI and waist-to-hip ratio, WHR) and 2) mate preference characteristics and mating success. Both males and females reported a similar number of long-term sexual partners and frequency of engaging in extra-pair copulation (EPC). The mating success of both sexes was positively mediated by self-perceived attractiveness. However, female BMI was inversely associated with mating success whereas increasing BMI was positively associated with male mating success (the total number of lifetime sexual partners) as well as with the likelihood of engaging in EPC. Unrestricted sociosexuality positively correlated with direct and indirect benefits from mating and negatively with the religious/political background of a potential mate and with the desire for a home/ children. These results confirm the hypothesis that human body morphology is associated with sexual behaviour and that cues of direct/indirect benefits in a potential mate positively correlate with sociosexuality.

  7. Optimal swimming strategies in mate searching pelagic copepods

    DEFF Research Database (Denmark)

    Kiørboe, Thomas

    2008-01-01

    Male copepods must swim to find females, but swimming increases the risk of meeting predators and is expensive in terms of energy expenditure. Here I address the trade-offs between gains and risks and the question of how much and how fast to swim using simple models that optimise the number...... of lifetime mate encounters. Radically different swimming strategies are predicted for different feeding behaviours, and these predictions are tested experimentally using representative species. In general, male swimming speeds and the difference in swimming speeds between the genders are predicted...... and observed to increase with increasing conflict between mate searching and feeding. It is high in ambush feeders, where searching (swimming) and feeding are mutually exclusive and low in species, where the matured males do not feed at all. Ambush feeding males alternate between stationary ambush feeding...

  8. An experimental test of condition-dependent male and female mate choice in zebra finches.

    Directory of Open Access Journals (Sweden)

    Marie-Jeanne Holveck

    Full Text Available In mating systems with social monogamy and obligatory bi-parental care, such as found in many songbird species, male and female fitness depends on the combined parental investment. Hence, both sexes should gain from choosing mates in high rather than low condition. However, theory also predicts that an individual's phenotypic quality can constrain choice, if low condition individuals cannot afford prolonged search efforts and/or face higher risk of rejection. In systems with mutual mate choice, the interaction between male and female condition should thus be a better predictor of choice than either factor in isolation. To address this prediction experimentally, we manipulated male and female condition and subsequently tested male and female mating preferences in zebra finches Taeniopygia guttata, a songbird species with mutual mate choice and obligatory bi-parental care. We experimentally altered phenotypic quality by manipulating the brood size in which the birds were reared. Patterns of association for high- or low-condition individuals of the opposite sex differed for male and female focal birds when tested in an 8-way choice arena. Females showed repeatable condition-assortative preferences for males matching their own rearing background. Male preferences were also repeatable, but not predicted by their own or females' rearing background. In combination with a brief review of the literature on condition-dependent mate choice in the zebra finch we discuss whether the observed sex differences and between-studies differences arise because males and females differ in context sensitivity (e.g. male-male competition suppressing male mating preferences, sampling strategies or susceptibility to rearing conditions (e.g. sex-specific effect on physiology. While a picture emerges that juvenile and current state indeed affect preferences, the development and context-dependency of mutual state-dependent mate choice warrants further study.

  9. Lifetime mating opportunities and male mating behaviour in sexually cannibalistic praying mantids.

    Science.gov (United States)

    Maxwell

    1998-04-01

    I examined the number of lifetime mating opportunities and mating behaviour of males in two sexually cannibalistic species, the Mediterranean, Iris oratoria, and bordered, Stagmomantis limbata, praying mantids (Mantodea: Mantidae). Two approaches estimated the number of lifetime mating opportunities: direct observations of intersexual encounters in the field, and an encounter model. I collected behavioural observations, together with ecological data for use in the model, over three field seasons. The ecological data included an assessment of the feeding condition of S. limbata females in nature; the females fed at a level comparable to females maintained on an abundant diet in the laboratory. As for the number of mating opportunities, individual males of both species encountered two or more females, as predicted by the model. I observed no male, however, in more than one copulation. This result could reflect individual variation in the times and places of sexual activity or an actual low number of mating opportunities in the field. Furthermore, a higher percentage of I. oratoria males encountered two or more females than S. limbata males, as the model indicates. Fewer mating opportunities could lead to greater selection upon S. limbata males to ensure paternity at each mating, which can explain the longer copulation times observed for S. limbata males. I considered two hypotheses about male behaviour in light of the number of lifetime encounters with females: male suicide and male reduction of the risk of cannibalism. Behavioural observations do not strongly support male suicide in either species. Certain male behaviours, such as the nature of copulatory position and, in captivity, mounting females from the rear, are consistent with the idea that males behave so as to reduce the probability that they are cannibalized during intersexual encounters. Moreover, male I. oratoria preferentially mount well-fed, fecund females in captivity. Taken together, these results

  10. Spermless males elicit large-scale female responses to mating in the malaria mosquito Anopheles gambiae

    Science.gov (United States)

    Thailayil, Janis; Magnusson, Kalle; Godfray, H. Charles J.; Crisanti, Andrea; Catteruccia, Flaminia

    2011-01-01

    Anopheles gambiae sensu stricto is the major vector of malaria, a disease with devastating consequences for human health. Given the constant spread of the disease, alternative approaches to the use of insecticides are urgently needed to control vector populations. Females of this species undergo large behavioral changes after mating, which include a life-long refractoriness to further insemination and the induction of egg laying in blood-fed individuals. Genetic control strategies aimed at impacting Anopheles fertility through the release of sterile males are being advocated to reduce the size of mosquito field populations. Such strategies depend on the ability of the released sterile males to mate successfully with wild females and to switch off the female receptivity to further copulation. Here we evaluate the role of sperm in regulating female behavioral responses after mating in An. gambiae. We developed spermless males by RNAi silencing of a germ cell differentiation gene. These males mated successfully and preserved standard accessory gland functions. Females mated to spermless males exhibited normal postcopulatory responses, which included laying large numbers of eggs upon blood feeding and becoming refractory to subsequent insemination. Moreover, spermless males induced transcriptional changes in female reproductive genes comparable to those elicited by fertile males. Our data demonstrate that, in contrast to Drosophila, targeting sperm in An. gambiae preserves normal male and female reproductive behavior for the traits and time frame analyzed and validate the use of approaches based on incapacitation or elimination of sperm for genetic control of vector populations to block malaria transmission. PMID:21825136

  11. The role of male contest competition over mates in speciation

    Directory of Open Access Journals (Sweden)

    Anna QVARNSTRÖM, Niclas VALLIN, Andreas RUDH

    2012-06-01

    Full Text Available Research on the role of sexual selection in the speciation process largely focuses on the diversifying role of mate choice. In particular, much attention has been drawn to the fact that population divergence in mate choice and in the male traits subject to choice directly can lead to assortative mating. However, male contest competition over mates also constitutes an important mechanism of sexual selection. We review recent empirical studies and argue that sexual selection through male contest competition can affect speciation in ways other than mate choice. For example, biases in aggression towards similar competitors can lead to disruptive and negative frequency-dependent selection on the traits used in contest competition in a similar way as competition for other types of limited resources. Moreover, male contest abilities often trade-off against other abilities such as parasite resistance, protection against predators and general stress tolerance. Populations experiencing different ecological conditions should therefore quickly diverge non-randomly in a number of traits including male contest abilities. In resource based breeding systems, a feedback loop between competitive ability and habitat use may lead to further population divergence. We discuss how population divergence in traits used in male contest competition can lead to the build up of reproductive isolation through a number of different pathways. Our main conclusion is that the role of male contest competition in speciation remains largely scientifically unexplored [Current Zoology 58 (3: 490–506, 2012].

  12. The role of male contest competition over mates in speciation

    Institute of Scientific and Technical Information of China (English)

    Anna QVARNSTR(O)M; Niclas VALLIN; Andreas RUDH

    2012-01-01

    Research on the role of sexual selection in the speciation process largely focuses on the diversifying role of mate choice.In particular,much attention has been drawn to the fact that population divergence in mate choice and in the male traits subject to choice directly can lead to assortative mating.However,male contest competition over mates also constitutes an important mechanism of sexual selection.We review recent empirical studies and argue that sexual selection through male contest competition can affect speciation in ways other than mate choice.For example,biases in aggression towards similar competitors can lead to disruptive and negative frequency-dependent selection on the traits used in contest competition in a similar way as competition for other types of limited resources.Moreover,male contest abilities often trade-off against other abilities such as parasite resistance,protection against predators and general stress tolerance.Populations experiencing different ecological conditions should therefore quickly diverge non-randomly in a number of traits including male contest abilities.In resource based breeding systems,a feedback loop between competitive ability and habitat use may lead to further population divergence.We discuss how population divergence in traits used in male contest competition can lead to the build up of reproductive isolation through a number of different pathways.Our main conclusion is that the role of male contest competition in speciation remains largely scientifically unexplored.

  13. Strategic male mating effort and cryptic male choice in a scorpionfly.

    Science.gov (United States)

    Engqvist, L; Sauer, K P

    2001-04-07

    In animal species with high male mating effort, males often find themselves in a dilemma: by increasing their mating effort, the gain from each copulation increases but simultaneously reduces available resources and, thus, the opportunity for future copulations. Therefore, we expect males to spend less reproductive resources on matings that provide low reproductive potential, thereby saving resources for future copulations, possibly with high-quality females, a sort of cryptic male choice. However, the strength of the trade-off between investment in a current mating and resources available for future matings must not be the same for all males. Males with relatively high mating costs should allocate their limited resources more cautiously than males with more plentiful resources. Here, we examine this prediction in the scorpionfly Panorpa cognata. Prior to copulation, males produce a large salivary mass on which females feed during copulation. We show that the production of larger salivary masses leads to longer copulations. Moreover, the size of the salivary gland and salivary mass increases with increasing male condition. However, males in poor condition make a relatively higher mating investment than males in good condition. We therefore expect male condition to influence cryptic male choice. In accordance with our hypothesis, only males in poor condition choose cryptically, producing larger salivary masses in copulations with females of high fecundity.

  14. Indiscriminate males: mating behaviour of a marine snail compromised by a sexual conflict?

    Directory of Open Access Journals (Sweden)

    Kerstin Johannesson

    Full Text Available BACKGROUND: In promiscuous species, male fitness is expected to increase with repeated matings in an open-ended fashion (thereby increasing number of partners or probability of paternity whereas female fitness should level out at some optimal number of copulations when direct and indirect benefits still outweigh the costs of courtship and copulation. After this fitness peak, additional copulations would incur female fitness costs and be under opposing selection. Hence, a sexual conflict over mating frequency may evolve in species where females are forced to engage in costly matings. Under such circumstance, if females could avoid male detection, significant fitness benefits from such avoidance strategies would be predicted. METHODOLOGY/PRINCIPAL FINDINGS: Among four Littorina species, one lives at very much higher densities and has a longer mating season than the other three species. Using video records of snail behaviour in a laboratory arena we show that males of the low-density species discriminate among male and female mucous trails, trailing females for copulations. In the high-density species, however, males fail to discriminate between male and female trails, not because males are unable to identify female trails (which we show using heterospecific females, but because females do not, as the other species, add a gender-specific cue to their trail. CONCLUSIONS/SIGNIFICANCE: We conclude that there is likely a sexual conflict over mating frequency in the high-density species (L. saxatilis owing to females most likely being less sperm-limited in this species. This has favoured the evolution of females that permanently or optionally do not release a cue in the mucus to decrease excessive and costly matings resulting in unusually high frequencies of male-male copulating attempts in the wild. This is one of few examples of masking gender identity to obtain fewer matings.

  15. Why Are Males Bad for Females? Models for the Evolution of Damaging Male Mating Behavior

    NARCIS (Netherlands)

    Lessells, C.M.

    2005-01-01

    One explanation for the cost to mating for females caused by damaging male mating behavior is that this causes the females to adaptively modify their subsequent life histories in a way that also increases male fitness. This might occur because the reduction in residual reproductive value of the fema

  16. Male-male competition, female mate choice and their interaction: determining total sexual selection

    National Research Council Canada - National Science Library

    Hunt, John; Breuker, Casper J; Sadowski, Jennifer A; Moore, Allen J

    2009-01-01

    .... We first show how a quantitative partitioning and examination of sexual selection mechanisms can inform by identifying illustrative studies that describe both male-male competition and female mate...

  17. Mating strategy, disgust, and food neophobia.

    Science.gov (United States)

    Al-Shawaf, Laith; Lewis, David M G; Alley, Thomas R; Buss, David M

    2015-02-01

    Food neophobia and disgust are commonly thought to be linked, but this hypothesis is typically implicitly assumed rather than directly tested. Evidence for the connection has been based on conceptually and empirically unsound measures of disgust, unpublished research, and indirect findings. This study (N = 283) provides the first direct evidence of a relationship between trait-level food neophobia and trait-level pathogen disgust. Unexpectedly, we also found that food neophobia varies as a function of sexual disgust and is linked to mating strategy. Using an evolutionary framework, we propose a novel hypothesis that may account for these previously undiscovered findings: the food neophilia as mating display hypothesis. Our discussion centers on future research directions for discriminatively testing this novel hypothesis.

  18. Male Mating Signaling in Social Dilemma Games

    DEFF Research Database (Denmark)

    Jensen, Niels Holm

    2013-01-01

    According to sexual selection theory and costly signaling theory, men benefit from signaling costly mate qualities to attractive women. To date, several studies have investigated whether men use conspicuous altruism to attract women, but the findings are mixed. This study investigated whether men...... being observed by an attractive woman engage in competitive economic altruism in three social dilemma games — the Dictator Game, Trust Game (2nd mover), and Public Goods Game — in comparison to men being observed by a non-attractive woman. Results showed that altruistic contributions in the games were...... not significantly larger in the attractive observer group than in the non-attractive observer group. Exploratory analyses did reveal, however, that amongst participants with an attractive observer only, dispositional generosity had a strongly positive effect on altruism while dispositional dominance had a negative...

  19. Sexual behavior across ovarian cycles in wild black howler monkeys (Alouatta pigra): male mate guarding and female mate choice.

    Science.gov (United States)

    Van Belle, Sarie; Estrada, Alejandro; Ziegler, Toni E; Strier, Karen B

    2009-02-01

    We studied two multimale-multifemale groups of black howler monkeys (Alouatta pigra) during a 14-month study (June 2006-July 2007) in Palenque National Park, Mexico to evaluate the ways in which their sexual behavior changes across ovarian cycles. We analyzed 231 fecal samples, collected every 2.2+/-1.4 days from five females. For four females, estradiol and progesterone profiles revealed an average (+/-SE) cycle length of 18.3+/-1.4 days. Copulations occurred significantly more frequently during the periovulatory period (POP), defined as the estimated day of ovulation +/-3 days (N=18). This was largely the result of cycling females soliciting sexual interactions during their POPs. Females directed their solicitations significantly more often toward "central" males of their group, who had close spatial associations with females at other times, compared with "noncentral" males, who did not associate closely with females. Central males rarely solicited sexual interactions, but instead monitored the females' reproductive status by sniffing their genitals, and maintained significantly closer proximity to females during their POPs, suggesting male mate guarding when conceptions are most likely to occur. Our findings indicate that the reproductive strategies of black howler central males and females coincide, highly skewing mating opportunities toward central males. Black howler females, however, occasionally choose to copulate with noncentral resident males or extra-group males during their POPs, undermining the ability of central males to monopolize all reproductive opportunities. (c) 2008 Wiley-Liss, Inc.

  20. Sexual conflict and the evolution of female mate choice and male social dominance.

    Science.gov (United States)

    Moore, A J; Gowaty, P A; Wallin, W G; Moore, P J

    2001-03-07

    Conflicts between the sexes over control of reproduction are thought to lead to a cost of sexual selection through the evolution of male traits that manipulate female reproductive physiology and behaviour, and female traits that resist this manipulation. Although studies have begun to document negative fitness effects of sexual conflict, studies showing the expected association between sexual conflict and the specific behavioural mechanisms of sexual selection are lacking. Here we experimentally manipulated the opportunity for sexual conflict in the cockroach. Nauphoeta cinerea and showed that, for this species, odour cues in the social environment influence the behavioural strategies and fitness of males and females during sexual selection. Females provided with the opportunity for discriminating between males but not necessarily mating with preferred males produced fewer male offspring than females mated at random. The number of female offspring produced was not affected, nor was the viability of the offspring. Experimental modification of the composition of the males' pheromone showed that the fecundity effects were caused by exposure to the pheromone component that makes males attractive to females but also makes males less likely to be dominant. Female mate choice therefore carries a demographic cost but functions to avoid male manipulation and aggression. Male-male competition appears to function to circumvent mate choice rather than directly manipulating females, as the mate choice can be cryptic. The dynamic struggle between the sexes for control of mating opportunities and outcomes in N. cinerea therefore reveals a unique role for sexual conflict in the evolution of the behavioural components of sexual selection.

  1. No evidence for learned mating discrimination in male Drosophila pseudoobscura

    Directory of Open Access Journals (Sweden)

    Kandul Ekaterina V

    2006-07-01

    Full Text Available Abstract Background Since females often pay a higher cost for heterospecific matings, mate discrimination and species recognition are driven primarily by female choice. In contrast, frequent indiscriminate matings are hypothesized to maximize male fitness. However, recent studies show that previously indiscriminate males (e.g., Drosophila melanogaster and Poecilia reticulata can learn to avoid heterospecific courtship. This ability of males to discriminate against heterospecific courtship may be advantageous in populations where two species co-occur if courtship or mating is costly. Results Here, we tested whether Drosophila pseudoobscura males learn to discriminate against heterospecific females after being exposed to and rejected by D. persimilis females. In most of our assays, we failed to observe differences in D. pseudoobscura courtship intensity of heterospecific females by males that had previously courted heterospecific females vs. males that had been maintained in isolation. Conclusion We conclude that learning to avoid heterospecific courtship may not be universal, even within the genus Drosophila, and may possibly be dependent on the natural history of the species.

  2. Mating competitiveness of sterile male Anopheles coluzzii in large cages.

    Science.gov (United States)

    Maïga, Hamidou; Damiens, David; Niang, Abdoulaye; Sawadogo, Simon P; Fatherhaman, Omnia; Lees, Rosemary S; Roux, Olivier; Dabiré, Roch K; Ouédraogo, Georges A; Tripet, Fréderic; Diabaté, Abdoulaye; Gilles, Jeremie R L

    2014-11-26

    Understanding the factors that account for male mating competitiveness is critical to the development of the sterile insect technique (SIT). Here, the effects of partial sterilization with 90 Gy of radiation on sexual competitiveness of Anopheles coluzzii allowed to mate in different ratios of sterile to untreated males have been assessed. Moreover, competitiveness was compared between males allowed one versus two days of contact with females. Sterile and untreated males four to six days of age were released in large cages (~1.75 sq m) with females of similar age at the following ratios of sterile males: untreated males: untreated virgin females: 100:100:100, 300:100:100, 500:100:100 (three replicates of each) and left for two days. Competitiveness was determined by assessing the egg hatch rate and the insemination rate, determined by dissecting recaptured females. An additional experiment was conducted with a ratio of 500:100:100 and a mating period of either one or two days. Two controls of 0:100:100 (untreated control) and 100:0:100 (sterile control) were used in each experiment. When males and females consort for two days with different ratios, a significant difference in insemination rate was observed between ratio treatments. The competitiveness index (C) of sterile males compared to controls was 0.53. The number of days of exposure to mates significantly increased the insemination rate, as did the increased number of males present in the untreated: sterile male ratio treatments, but the number of days of exposure did not have any effect on the hatch rate. The comparability of the hatch rates between experiments suggest that An. coluzzii mating competitiveness experiments in large cages could be run for one instead of two days, shortening the required length of the experiment. Sterilized males were half as competitive as untreated males, but an effective release ratio of at least five sterile for one untreated male has the potential to impact the fertility of

  3. Male-male and male-female aggression may influence mating associations in wild octopuses (Abdopus aculeatus).

    Science.gov (United States)

    Huffard, Christine L; Caldwell, Roy L; Boneka, Farnis

    2010-02-01

    Abdopus aculeatus engages in frequent aggression and copulation, exhibits male mate-choice, and employs multiple mating tactics. Here we draw upon established hypotheses to compare male-male aggression (MMA) and male-female aggression (MFA), as they relate to their mating behavior in the wild. When contesting for females, males appear to balance mate preference (resource value) with perceived chances of winning contests (resource holding potential). Although males spent more time mating with and contesting for large "Adjacent Guarded" females (those occupying a den within arm's reach of a large "Adjacent Guarding" male), they exhibited higher rates of aggression over nonadjacent "Temporarily Guarded" females that may be more accessible. The major determinant of male-male aggressive success was size, and this factor may dictate the expression of conditional mating tactics in males. "Adjacent Guarding" males were the largest and most aggressively successful males, earning the most time copulating with females. They are considered to have the highest resource holding potential (RHP) in MMA. By contrast, in MFA, some larger individuals fled from smaller individuals, indicating that RHP appears to be a function of both size and sex in intersexual aggression. This result suggests variation in aggressiveness, or potential for severe injury-even sexual cannibalism during MFA. Male-female aggression may also be influenced by the sexual nonreceptivity of some individuals, or attempts by both sexes to increase foraging behavior by delaying mate-guarding activity.

  4. Age Variation in Mating Strategies and Mate Preferences: Beliefs versus Reality

    Directory of Open Access Journals (Sweden)

    April Bleske-Rechek

    2009-04-01

    Full Text Available We conducted three studies to (1 investigate individuals' beliefs about change in mating desires over the course of emerging adulthood and (2 determine whether those beliefs reflect actual variation in mating desires among emerging adults of varied ages (late teens through twenties. In Study 1, 103 men and women gave their thoughts on how college students change, if at all, in what they most desire in a relationship and relationship partner as they move from being incoming freshmen to graduating seniors. In Studies 2 and 3, using a college sample and then an internet sample (n s = 288 and 307, men and women between the ages of 18 and 26 completed mating strategies inventories and allotted a limited number of “mate dollars” to 10 mate characteristics. Findings suggest that although emerging adults believe that their peers' mating desires change systematically over time, emerging adults' self-reported mating desires vary little with age.

  5. Temporal variation in size-assortative mating and male mate choice in a spider with amphisexual care

    Science.gov (United States)

    Moura, Rafael R.; Gonzaga, Marcelo O.

    2017-04-01

    Males should be more selective when they have a high investment in reproduction, especially in species with biparental or paternal care. In this context, male mate choice can promote size-assortative mating (SAM) when (1) large males win intrasexual disputes, (2) large females are more fecund, and (3) males prefer larger females to smaller ones. In the spider Manogea porracea, males exhibit high reproductive investment by building their webs above those of females and exhibiting extended care of offspring in the absence of females. Under these circumstances, we expect the occurrence of SAM and male preference for large females. Herein, we performed observations and experiments in the field to evaluate the hypotheses that (1) M. porracea mates assortatively by size and (2) SAM is influenced by male mate choice. Furthermore, we measured variables that could affect mating patterns, the sex ratios, and densities of both sexes. Pairing in M. porracea was positively size-assortative in 2012, but not in 2013. Large males won most disputes for mates and preferred larger females, which produced more eggs. The inconsistency in detection of SAM was due to population dynamics, namely variations in sex ratio and population density across the breeding season. Furthermore, we found that the significance of male mate choice on sexual selection of body size in M. porracea strongly depends on the competition intensity for mating opportunities. The traditional sexual selection hypothesis of SAM needs to be reviewed and must include measures of competition intensity.

  6. Mating strategies in primates: a game theoretical approach to infanticide.

    Science.gov (United States)

    Lyon, James E; Pandit, Sagar A; van Schaik, Carel P; Pradhan, Gauri R

    2011-04-07

    Infanticide by newly immigrated or newly dominant males is reported among a variety of taxa, such as birds, rodents, carnivores and primates. Here we present a game theoretical model to explain the presence and prevalence of infanticide in primate groups. We have formulated a three-player game involving two males and one female and show that the strategies of infanticide on the males' part and polyandrous mating on the females' part emerge as Nash equilibria that are stable under certain conditions. Moreover, we have identified all the Nash equilibria of the game and arranged them in a novel hierarchical scheme. Only in the subspace spanned by the males are the Nash equilibria found to be strict, and hence evolutionarily stable. We have therefore proposed a selection mechanism informed by adaptive dynamics to permit the females to transition to, and remain in, optimal equilibria after successive generations. Our model concludes that polyandrous mating by females is an optimal strategy for the females that minimizes infanticide and that infanticide confers advantage to the males only in certain regions of parameter space. We have shown that infanticide occurs during turbulent changes accompanying male immigration into the group. For changes in the dominance hierarchy within the group, we have shown that infanticide occurs only in primate groups where the chance for the killer to sire the next infant is high. These conclusions are confirmed by observations in the wild. This model thus has enabled us to pinpoint the fundamental processes behind the reproductive decisions of the players involved, which was not possible using earlier theoretical studies.

  7. Assortative mating and differential male mating success in an ash hybrid zone population

    Directory of Open Access Journals (Sweden)

    Frascaria-Lacoste Nathalie

    2006-11-01

    Full Text Available Abstract Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash and F. angustifolia Vahl (narrow-leaved ash, which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears

  8. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish

    Science.gov (United States)

    Magalhaes, I. S.; Smith, A. M.; Joyce, D. A.

    2017-01-01

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle “bowers” several times their size. We tested the idea that a less costly “sneaking” strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females’ mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders. PMID:28128313

  9. Quantifying mating success of territorial males and sneakers in a bower-building cichlid fish.

    Science.gov (United States)

    Magalhaes, I S; Smith, A M; Joyce, D A

    2017-01-27

    The strategies and traits males evolve to mate with females are incredible in their diversity. Theory on the evolution of secondary sexual characters suggests that evolving any costly trait or strategy will pay off and stabilise in the population if it is advantageous compared to the alternative less costly strategy, but quantifying the relative success of the two can be difficult. In Lake Malawi, Africa, there are >200 species of cichlid fish in which the males form leks and spend several weeks per year building sand-castle "bowers" several times their size. We tested the idea that a less costly "sneaking" strategy could be successful by quantifying the mating success of bower-holding versus non-bower-holding males. We PIT-tagged every fish in a semi-natural experimental set-up and placed tag-readers on the side of bowers to determine which fish held a bower. We then genotyped the eggs removed from females' mouths to assign paternity of each egg. Broods were fathered by up to 3 different males. Although paternity was mostly assigned to males that held a bower, a small number of males who did not own a bower were more successful than some of those that did, indicating a role for an alternative strategy in these bower builders.

  10. Intrasexual competition facilitates the evolution of alternative mating strategies in a colour polymorphic fish

    Directory of Open Access Journals (Sweden)

    Uy J Albert C

    2010-12-01

    Full Text Available Abstract Background Intense competition for access to females can lead to males exploiting different components of sexual selection, and result in the evolution of alternative mating strategies (AMSs. Males of Poecilia parae, a colour polymorphic fish, exhibit five distinct phenotypes: drab-coloured (immaculata, striped (parae, structural-coloured (blue and carotenoid-based red and yellow morphs. Previous work indicates that immaculata males employ a sneaker strategy, whereas the red and yellow morphs exploit female preferences for carotenoid-based colours. Mating strategies favouring the maintenance of the other morphs remain to be determined. Here, we report the role of agonistic male-male interactions in influencing female mating preferences and male mating success, and in facilitating the evolution of AMSs. Results Our study reveals variation in aggressiveness among P. parae morphs during indirect and direct interactions with sexually receptive females. Two morphs, parae and yellow, use aggression to enhance their mating success (i.e., number of copulations by 1 directly monopolizing access to females, and 2 modifying female preferences after winning agonistic encounters. Conversely, we found that the success of the drab-coloured immaculata morph, which specializes in a sneak copulation strategy, relies in its ability to circumvent both male aggression and female choice when facing all but yellow males. Conclusions Strong directional selection is expected to deplete genetic variation, yet many species show striking genetically-based polymorphisms. Most studies evoke frequency dependent selection to explain the persistence of such variation. Consistent with a growing body of evidence, our findings suggest that a complex form of balancing selection may alternatively explain the evolution and maintenance of AMSs in a colour polymorphic fish. In particular, this study demonstrates that intrasexual competition results in phenotypically distinct

  11. Ontogenetic shifts in male mating preference and morph-specific polyandry in a female colour polymorphic insect.

    Science.gov (United States)

    Sánchez-Guillén, Rosa Ana; Hammers, Martijn; Hansson, Bengt; Van Gossum, Hans; Cordero-Rivera, Adolfo; Galicia Mendoza, Dalia Ivette; Wellenreuther, Maren

    2013-06-06

    Sexual conflict over mating rates may favour the origin and maintenance of phenotypes with contrasting reproductive strategies. The damselfly Ischnura elegans is characterised by a female colour polymorphism that consists of one androchrome and two gynochrome female morphs. Previous studies have shown that the polymorphism is genetic and to a high extent maintained by negative frequency-dependent mating success that varies temporally and spatially. However, the role of learning in male mating preferences has received little attention. We used molecular markers to investigate differences in polyandry between female morphs. In addition, we experimentally investigated innate male mating preferences and experience-dependent shifts in male mating preferences for female morphs. Field and molecular data show that androchrome females were less polyandrous than gynochrome females. Interestingly, we found that naïve males showed significantly higher sexual preferences to androchrome than to gynochrome females in experimental trials. In contrast, experienced males showed no preference for androchrome females. The ontogenetic change in male mate preferences occurs most likely because of learned mate recognition after experience with females, which in this case does not result in a preference for one of the morphs, but rather in the loss of an innate preference for androchrome females.

  12. Drosophila melanogaster females restore their attractiveness after mating by removing male anti-aphrodisiac pheromones.

    Science.gov (United States)

    Laturney, Meghan; Billeter, Jean-Christophe

    2016-08-03

    Males from many species ensure paternity by preventing their mates from copulating with other males. One mate-guarding strategy involves marking females with anti-aphrodisiac pheromones (AAPs), which reduces the females' attractiveness and dissuades other males from courting. Since females benefit from polyandry, sexual conflict theory predicts that females should develop mechanisms to counteract AAPs to achieve additional copulations, but no such mechanisms have been documented. Here we show that during copulation Drosophila melanogaster males transfer two AAPs: cis-Vaccenyl Acetate (cVA) to the females' reproductive tract, and 7-Tricosene (7-T) to the females' cuticle. A few hours after copulation, females actively eject cVA from their reproductive tract, which results in increased attractiveness and re-mating. Although 7-T remains on those females, we show that it is the combination of the two chemicals that reduces attractiveness. To our knowledge, female AAP ejection provides the first example of a female mechanism that counter-acts chemical mate-guarding.

  13. Female mate choice across spatial scales: influence of lek and male attributes on mating success of blue-crowned manakins.

    Science.gov (United States)

    Durães, Renata; Loiselle, Bette A; Parker, Patricia G; Blake, John G

    2009-05-22

    Lekking males compete for females within and among leks, yet female choice is expected to work differently at each of these spatial scales. We used paternity analyses to examine how lek versus male attributes influence mate choice in the blue-crowned manakin Lepidothrix coronata. We tested the hypotheses that females prefer (i) to mate at larger leks where a larger number of potential mates can be assessed, (ii) to mate with unrelated or highly heterozygous males expected to produce high-quality offspring, (iii) to mate with males that display at higher rates, and that (iv) display honestly reflects male genetic quality. Our results show that (i) males at larger leks are not more likely to sire young, although females nesting close to small leks travel further to reach larger leks, (ii) siring males are not less related to females or more heterozygous than expected, (iii) within a lek, high-display males are more likely to sire young, and (iv) both male heterozygosity and display rate increased with lek size, and as a result display does not reliably reflect male genetic quality across leks. We suggest that female mate choice in this species is probably driven by a Fisherian process rather than adaptive genetic benefits.

  14. Mating with large males decreases the immune defence of females in Drosophila melanogaster

    Indian Academy of Sciences (India)

    K. Imroze; N. G. Prasad

    2011-12-01

    Mating has been widely reported to be a costly event for females. Studies indicate that female cost of mating in terms of fecundity and survivorship can be affected by their mates, leading to antagonistic coevolution between the sexes. However, as of now, there is no evidence that the female cost of mating in terms of immune defence is affected by their mates. We assess the effect of different sized males on antibacterial immune defence and reproductive fitness of their mates. We used a large outbred population of Drososphila melanogaster as the host and Serratia marcescens as the pathogen. We generated three different male phenotypes: small, medium and large, by manipulating larval densities. Compared to females mating with small males, those mating with large males had higher bacterial loads and lower fecundity. There was no significant effect of male phenotype on the fraction of females mated or copulation duration (an indicator of ejaculate investment). Thus, our study is the first clear demonstration that male phenotype can affect the cost of mating to females in terms of their antibacterial immune defence. Mating with large males imposes an additional cost of mating to females in terms of reduced immune defence. The observed results are very likely due to qualitative/quantitative differences in the ejaculates of the three different types of males. If the phenotypic variation that we observed in males in our study is mirrored by genetic variation, then, it can potentially lead to antagonistic coevolution of the sexes over immune defence.

  15. Caenorhabditis elegans glutamylating enzymes function redundantly in male mating.

    Science.gov (United States)

    Chawla, Daniel G; Shah, Ruchi V; Barth, Zachary K; Lee, Jessica D; Badecker, Katherine E; Naik, Anar; Brewster, Megan M; Salmon, Timothy P; Peel, Nina

    2016-09-15

    Microtubule glutamylation is an important modulator of microtubule function and has been implicated in the regulation of centriole stability, neuronal outgrowth and cilia motility. Glutamylation of the microtubules is catalyzed by a family of tubulin tyrosine ligase-like (TTLL) enzymes. Analysis of individual TTLL enzymes has led to an understanding of their specific functions, but how activities of the TTLL enzymes are coordinated to spatially and temporally regulate glutamylation remains relatively unexplored. We have undertaken an analysis of the glutamylating TTLL enzymes in C. elegans We find that although all five TTLL enzymes are expressed in the embryo and adult worm, loss of individual enzymes does not perturb microtubule function in embryonic cell divisions. Moreover, normal dye-filling, osmotic avoidance and male mating behavior indicate the presence of functional amphid cilia and male-specific neurons. A ttll-4(tm3310); ttll-11(tm4059); ttll-5(tm3360) triple mutant, however, shows reduced male mating efficiency due to a defect in the response step, suggesting that these three enzymes function redundantly, and that glutamylation is required for proper function of the male-specific neurons.

  16. Mate choice and optimal search behavior: fitness returns under the fixed sample and sequential search strategies.

    Science.gov (United States)

    Wiegmann, Daniel D; Seubert, Steven M; Wade, Gordon A

    2010-02-21

    The behavior of a female in search of a mate determines the likelihood that she encounters a high-quality male in the search process. The fixed sample (best-of-n) search strategy and the sequential search (fixed threshold) strategy are two prominent models of search behavior. The sequential search strategy dominates the former strategy--yields an equal or higher expected net fitness return to searchers--when search costs are nontrivial and the distribution of quality among prospective mates is uniform or truncated normal. In this paper our objective is to determine whether there are any search costs or distributions of male quality for which the sequential search strategy is inferior to the fixed sample search strategy. The two search strategies are derived under general conditions in which females evaluate encountered males by inspection of an indicator character that has some functional relationship to male quality. The solutions are identical to the original models when the inspected male attribute is itself male quality. The sequential search strategy is shown to dominate the fixed sample search strategy for all search costs and distributions of male quality. Low search costs have been implicated to explain empirical observations that are consistent with the use of a fixed sample search strategy, but under conditions in which the original models were derived there is no search cost or distribution of male quality that favors the fixed sample search strategy. Plausible alternative explanations for the apparent use of this search strategy are discussed.

  17. Male moth songs tempt females to accept mating: the role of acoustic and pheromonal communication in the reproductive behaviour of Aphomia sociella.

    Science.gov (United States)

    Kindl, Jiří; Kalinová, Blanka; Červenka, Milan; Jílek, Milan; Valterová, Irena

    2011-01-01

    Members of the subfamily Galleriinae have adapted to different selective environmental pressures by devising a unique mating process. Galleriinae males initiate mating by attracting females with either chemical or acoustic signals (or a combination of both modalities). Six compounds considered candidates for the sex pheromone have recently been identified in the wing gland extracts of Aphomia sociella males. Prior to the present study, acoustic communication had not been investigated. Signals mediating female attraction were likewise unknown. Observations of A. sociella mating behaviour and recordings of male acoustic signals confirmed that males initiate the mating process. During calling behaviour (stationary wing fanning and pheromone release), males disperse pheromone from their wing glands. When a female approaches, males cease calling and begin to produce ultrasonic songs as part of the courtship behaviour. Replaying of recorded courting songs to virgin females and a comparison of the mating efficiency of intact males with males lacking tegullae proved that male ultrasonic signals stimulate females to accept mating. Greenhouse experiments with isolated pheromone glands confirmed that the male sex pheromone mediates long-range female attraction. Female attraction in A. sociella is chemically mediated, but ultrasonic communication is also employed during courtship. Male ultrasonic songs stimulate female sexual display and significantly affect mating efficiency. Considerable inter-individual differences in song structure exist. These could play a role in female mate selection provided that the female's ear is able to discern them. The A. sociella mating strategy described above is unique within the subfamily Galleriinae.

  18. Condition dependence varies with mating success in male Drosophila bunnanda.

    Science.gov (United States)

    McGuigan, K

    2009-09-01

    Although key to sexual selection theories, condition dependence has proven a challenging area of empirical research. It is expected that availability of resources will affect both mean and variation of sexual trait expression, with lower mean and greater variation in harsher environments. Here, I manipulated the environment in a laboratory population of Drosophila bunnanda to test for condition dependence of sexually selected traits. Sexually successful and unsuccessful males differed in how the environment affected sexual trait expression. Specifically, sexual trait attractiveness declined more rapidly with declining resources in sexually unsuccessful males, consistent with the expectation that low quality males were less able to meet the greater signalling costs associated with harsher environments. This study illustrates the potential insights into condition dependence that might be gained through considering sexual trait expression and mating success within the same manipulative experimental design.

  19. On the evolutionary stability of male harassment in a coercive mating game

    Directory of Open Access Journals (Sweden)

    Oyita Udiani

    2016-03-01

    Full Text Available In many animals, males employ coercive mating strategies to help them maximize their expected number of offspring. In such systems, selection will favor behavioral adaptations in females that help them mitigate harassment costs and maximize their reproductive fitness. Previously, Bokides et al. [1] presented a model showing how male harassment strategies can co-evolve with female habitat preferences in a mating game. Their results indicated that if females dispersed freely between habitats where males were present and where males were excluded, selection could favor males who strategically harassed at high (or low levels, depending on the proximity of their phenotype to a threshold level $h^*$. This article is a continuation of that work addressing the questions of stability at equilibria where males harass at the threshold level (i.e., $h^*$. We show these states are both locally and globally asymptotically stable. Further, we argue based on these results that $h^*$ is an evolutionary stable male harassment level at which females will be ideally distributed to match the resource quality and social environments of their alternative habitats.

  20. Crayfish females eavesdrop on fighting males before choosing the dominant mate.

    OpenAIRE

    L. AQUILONI; M. Buřič; F. GHERARDI

    2008-01-01

    Identifying the traits that influence mate choice is a major challenge in behavioural ecology and evolutionary biology. Male dominance often conditions mating decisions by females but how the hierarchical status of potential mates is assessed remains poorly understood. In crustacean decapods, chemical signals convey information about male sexual responsiveness and quality. However, at least in the red swamp crayfish Procambarus clarkii, females appeared unable to recognize dominant mates usin...

  1. The evolution of male mate choice in insects: a synthesis of ideas and evidence.

    Science.gov (United States)

    Bonduriansky, R

    2001-08-01

    Mate choice by males has been recognized at least since Darwin's time, but its phylogenetic distribution and effect on the evolution of female phenotypes remain poorly known. Moreover, the relative importance of factors thought to underlie the evolution of male mate choice (especially parental investment and mate quality variance) is still unresolved. Here I synthesize the empirical evidence and theory pertaining to the evolution of male mate choice and sex role reversal in insects, and examine the potential for male mating preferences to generate sexual selection on female phenotypes. Although male mate choice has received relatively little empirical study, the available evidence suggests that it is widespread among insects (and other animals). In addition to 'precopulatory' male mate choice, some insects exhibit 'cryptic' male mate choice, varying the amount of resources allocated to mating on the basis of female mate quality. As predicted by theory, the most commonly observed male mating preferences are those that tend to maximize a male's expected fertilization success from each mating. Such preferences tend to favour female phenotypes associated with high fecundity or reduced sperm competition intensity. Among insect species there is wide variation in mechanisms used by males to assess female mate quality, some of which (e.g. probing, antennating or repeatedly mounting the female) may be difficult to distinguish from copulatory courtship. According to theory, selection for male choosiness is an increasing function of mate quality variance and those reproductive costs that reduce, with each mating, the number of subsequent matings that a male can perform ('mating investment') Conversely, choosiness is constrained by the costs of mate search and assessment, in combination with the accuracy of assessment of potential mates and of the distribution of mate qualities. Stronger selection for male choosiness may also be expected in systems where female fitness

  2. The dance of male Anopheles gambiae in wild mating swarms.

    Science.gov (United States)

    Butail, Sachit; Manoukis, Nicholas C; Diallo, Moussa; Ribeiro, José M C; Paley, Derek A

    2013-05-01

    An important element of mating in the malaria vector Anopheles gambiae Giles in nature is the crepuscular mating aggregation (swarm) composed almost entirely of males, where most coupling and insemination is generally believed to occur. In this study, we mathematically characterize the oscillatory movement of male An. gambiae in terms of an established individual-based mechanistic model that parameterizes the attraction of a mosquito toward the center of the swarm using the natural frequency of oscillation and the resistance to its motion, characterized by the damping ratio. Using three-dimensional trajectory data of ten wild mosquito swarms filmed in Mali, Africa, we show two new results for low and moderate wind conditions, and indicate how these results may vary in high wind. First, we show that in low and moderate wind the vertical component of the mosquito motion has a lower frequency of oscillation and higher damping ratio than horizontal motion. In high wind, the vertical and horizontal motions are similar to one another and the natural frequencies are higher than in low and moderate wind. Second, we show that the predicted average disagreement in the direction of motion of swarming mosquitoes moving randomly is greater than the average disagreement we observed between each mosquito and its three closest neighbors, with the smallest level of disagreement occurring for the nearest neighbor in seven out of 10 swarms. The alignment of the direction of motion between nearest neighbors is the highest in high wind. This result provides evidence for flight-path coordination between swarming male mosquitoes.

  3. Prenatal exposure to low doses of atrazine affects mating behaviors in male guppies.

    Science.gov (United States)

    Shenoy, Kausalya

    2014-07-01

    Performing appropriate mating behaviors is crucial to male reproductive success, especially in species where mating is predominantly via female mate choice. Mating behaviors are hormonally regulated and may be sexually selected traits: courtship displays are selected via mate choice, while forced copulations and aggressive behaviors are selected for via intrasexual competition. Endocrine disrupting compounds interfere with proper hormonal functioning in exposed animals. Exposures during developmentally crucial life stages can have irreversible effects lasting through adulthood. I tested the effects of prenatal exposure to environmentally relevant doses of a commonly used herbicide, atrazine (1 and 13.5μg/L) on mating behaviors in male guppies. Guppies were used as a model organism to test the effects of atrazine exposure on wildlife reproductive health. Adult female guppies were mated and exposed to the treatments throughout the gestation period, and offspring born to them were raised without further treatment. At adulthood, the males were tested for the effects of prenatal exposure on their mating behaviors such as courtship displays, gonopodium swings, forced copulatory attempts, and competitive and aggressive behaviors towards rivals who were not exposed to atrazine. I also tested female preference for treated males compared to control males. Atrazine-exposed males were less likely to perform the mating behaviors, and performed them less frequently, than control males. Atrazine exposure also made males less aggressive towards rivals. Females preferred untreated males over atrazine-treated males. In all cases, a non-monotonic pattern was seen, highlighting the significance of low-dose exposures.

  4. Large male mating advantage in natterjack toads, Bufo calamita: Sexual selection or energetic constraints?

    OpenAIRE

    1992-01-01

    Variation in the effect of male body size on mating success was studied in natterjack toads during two breeding seasons with different temporal patterns of reproductive activity. Larger males were more likely to mate than small males in the season with a single peak and continuous breeding activity, whereas random mating by size was found when reproduction occurred during several peaks separated by periods of inactivity. Playback tests did not reveal any consistent preference by females for c...

  5. Male traits, mating tactics and reproductive success in the buff-breasted sandpiper, Tryngites subruficollis

    Science.gov (United States)

    Lanctot, Richard B.; Weatherhead, Patrick J.; Kempenaers, Bart; Scribner, Kim T.

    1998-01-01

    Buff-breasted sandpipers use a variety of mating tactics to acquire mates, including remaining at a single lek for most of the breeding season, attending multiple leks during the season, displaying solitarily or displaying both on leks and solitarily. We found that differences in body size, body condition, fluctuating asymmetry scores, wing coloration, territory location and behaviour (attraction, solicitation and agonistic) did not explain the observed variation in mating tactics used by males. Which males abandoned versus returned to leks was also not related to morphology or behaviour, and there was no tendency for males to join leks that were larger or smaller than the lek they abandoned. These results suggest that male desertion of leks was not dependent on a male's characteristics nor on the size of the lek he was presently attending. Males did join leks with larger males than their previous lek, perhaps to mate with females attracted to these larger 'hotshot' males. Males at both leks and solitary sites successfully mated. Lek tenure did not affect mating success, although lekking males appeared to mate more frequently than solitary males. Courtship disruption and to a lesser extent, female mimicry, were effective at preventing females from mating at leks, and may offer a partial explanation for female mating off leks. Our analysis that combined all males together within a year (regardless of mating tactic) indicated that males that attended leks for longer periods of time and that had fewer wing spots were significantly more likely to mate. Given some evidence that wing spotting declines with age, and that females inspect male underwings during courtship, the latter result suggests that female choice may play some role in determining male success. We suggest that male buff-breasted sandpipers may use alternative mating tactics more readily than males in other 'classic' lek-breeding species because: (1) unpredictable breeding conditions in this species' high

  6. Male traits, mating tactics and reproductive success in the buff-breasted sandpiper, Tryngites subruficollis.

    Science.gov (United States)

    Lanctot; Weatherhead; Kempenaers; Scribner

    1998-08-01

    Buff-breasted sandpipers use a variety of mating tactics to acquire mates, including remaining at a single lek for most of the breeding season, attending multiple leks during the season, displaying solitarily or displaying both on leks and solitarily. We found that differences in body size, body condition, fluctuating asymmetry scores, wing coloration, territory location and behaviour (attraction, solicitation and agonistic) did not explain the observed variation in mating tactics used by males. Which males abandoned versus returned to leks was also not related to morphology or behaviour, and there was no tendency for males to join leks that were larger or smaller than the lek they abandoned. These results suggest that male desertion of leks was not dependent on a male's characteristics nor on the size of the lek he was presently attending. Males did join leks with larger males than their previous lek, perhaps to mate with females attracted to these larger 'hotshot' males. Males at both leks and solitary sites successfully mated. Lek tenure did not affect mating success, although lekking males appeared to mate more frequently than solitary males. Courtship disruption and to a lesser extent, female mimicry, were effective at preventing females from mating at leks, and may offer a partial explanation for female mating off leks. Our analysis that combined all males together within a year (regardless of mating tactic) indicated that males that attended leks for longer periods of time and that had fewer wing spots were significantly more likely to mate. Given some evidence that wing spotting declines with age, and that females inspect male underwings during courtship, the latter result suggests that female choice may play some role in determining male success. We suggest that male buff-breasted sandpipers may use alternative mating tactics more readily than males in other 'classic' lek-breeding species because: (1) unpredictable breeding conditions in this species' high

  7. Female sticklebacks use male coloration in mate choice and hence avoid parasitized males

    Science.gov (United States)

    Milinski, Manfred; Bakker, Theo C. M.

    1990-03-01

    AN important problem in evolutionary biology since the time of Darwin has been to understand why females preferentially mate with males handicapped by secondary sexual ornaments1-3. One hypothesis of sexual selection theory is that these ornaments reliably reveal the male's condition4-6, which can be affected for example by parasites4,7-13. Here we show that in the three-spined stickleback (Gasterosteus aculeatus) the intensity of male red breeding coloration positively correlates with physical condition. Gravid females base their active mate choice on the intensity of the male's red coloration. Choice experiments under green light prevent the use of red colour cues by females, and males that were previously preferred are now chosen no more than randomly, although the courtship behaviour of the males remains unchanged. Parasitieation causes a deterioration in the males' condition and a decrease in the intensity of their red coloration. Tests under both lighting conditions reveal that the females recognize the formerly parasitized males by the lower intensity of their breeding coloration. Female sticklebacks possibly select a male with a good capacity for paternal care14 but if there is additive genetic variation for parasite resistance, then they might also select for resistance genes, as proposed by Hamilton and Zuk4.

  8. Olfactory contribution to Fos expression during mating in inexperienced male hamsters.

    Science.gov (United States)

    Fernandez-Fewell, G D; Meredith, M

    1998-06-01

    Male hamsters are very dependent on chemosensory cues for normal mating behavior. We have previously reported that central, vomeronasal pathways are intensely and selectively activated during mating or pheromonal stimulation. The contribution of main olfactory sensory input to the patterns of c-fos activation was investigated in this study. Sexually inexperienced male hamsters were either made anosmic by intranasal infusion of zinc sulfate or remained intact. Fos protein immunoreactivity was analyzed in main olfactory and vomeronasal pathways of the zinc sulfate-treated, anosmic animals after mating with receptive females for 45 min, and compared with Fos patterns seen in intact mating animals, some of which have been described in a previous publication. The zinc sulfate-treated anosmic males described here all mated when given access to receptive females. Whether mated or unstimulated, anosmic males had little or no Fos expression in main olfactory pathways; significantly less even than in unstimulated intact animals. Mating did not increase Fos expression in main olfactory pathways of intact animals over that of unstimulated intact controls. However, Fos expression in central vomeronasal pathways was significantly higher in mating anosmic males, as in intact males, compared with appropriate non-mating controls. Fos expression was significantly different between intact and zinc sulfate-treated anosmic mating males in only one area studied. The rostral anterior medial amygdala, known to receive a small olfactory terminal field, had significantly lower Fos expression in zinc sulfate-treated anosmic males that mated when compared with intact-mating animals. Thus, functional main olfactory input to the rostral vomeronasal amygdala can be demonstrated but does not appear to be critical for mating behavior in previously inexperienced male hamsters with intact vomeronasal organs. Other main olfactory input appears to have a negligible contribution to Fos-patterns in such

  9. The effects of perceived mating opportunities on patterns of reproductive investment by male guppies.

    Directory of Open Access Journals (Sweden)

    Luke T Barrett

    Full Text Available Males pay considerable reproductive costs in acquiring mates (precopulatory sexual selection and in producing ejaculates that are effective at fertilising eggs in the presence of competing ejaculates (postcopulatory sexual selection. Given these costs, males must balance their reproductive investment in a given mating to optimise their future reproductive potential. Males are therefore expected to invest in reproduction prudently according to the likelihood of obtaining future matings. In this study we tested this prediction by determining whether male reproductive investment varies with expected future mating opportunities, which were experimentally manipulated by visually exposing male guppies (Poecilia reticulata to high or low numbers of females in the absence of competing males. Our experiment did not reveal consistent effects of perceived future mating opportunity on either precopulatory (male mate choice and mating behaviour or postcopulatory (sperm quality and quantity investment. However, we did find that male size and female availability interacted to influence mating behaviour; large males visually deprived of females during the treatment phase became more choosy and showed greater interest in their preferred female than those given continuous visual access to females. Overall, our results suggest males tailor pre- rather than postcopulatory traits according to local female availability, but critically, these effects depend on male size.

  10. Male mating history and body size influence female fecundity and longevity of the dengue vector Aedes aegypti.

    Science.gov (United States)

    Helinski, Michelle E H; Harrington, Laura C

    2011-03-01

    Male reproductive success is dependent on insemination success and reproductive output. During mating, male mosquitoes transfer not just sperm, but also seminal fluid proteins that may have profound effects on mated female biology and behavior. In this study, we investigated the role of male body size and mating history on semen depletion, female longevity, and reproductive success in Aedes aegypti L. Small and large males were mated in rapid succession with up to five females. Our results indicate that large males had greater mating capacity than small males. A reduction in fecundity by >50% was observed in females that were fourth to mate with small males in comparison with females that mated earlier in sequence. For females mated to large males, this reduction became evident for females that mated fifth in sequence. No loss of fertility (measured as hatch rate) was observed in females that were third-fifth in mating sequence compared with females mated to virgin males. When females were maintained on a low-quality (5% sucrose) diet, those mated to virgin males had a greater longevity compared with females mated third in sequence. We conclude that small males experience more rapid seminal depletion than large males, and discuss the role of semen depletion in the mated female. Our results contribute toward a better understanding of the complexity of Ae. aegypti mating biology and provide refined estimates of mating capacity for genetic control efforts.

  11. Oxytocin receptor density is associated with male mating tactics and social monogamy.

    Science.gov (United States)

    Ophir, Alexander G; Gessel, Ana; Zheng, Da-Jiang; Phelps, Steven M

    2012-03-01

    Despite its well-described role in female affiliation, the influence of oxytocin on male pairbonding is largely unknown. However, recent human studies indicate that this nonapeptide has a potent influence on male behaviors commonly associated with monogamy. Here we investigated the distribution of oxytocin receptors (OTR) throughout the forebrain of the socially monogamous male prairie vole (Microtus ochrogaster). Because males vary in both sexual and spatial fidelity, we explored the extent to which OTR predicted monogamous or non-monogamous patterns of space use, mating success and sexual fidelity in free-living males. We found that monogamous males expressed higher OTR density in the nucleus accumbens than non-monogamous males, a result that mirrors species differences in voles with different mating systems. OTR density in the posterior portion of the insula predicted mating success. Finally, OTR in the hippocampus and septohippocampal nucleus, which are nuclei associated with spatial memory, predicted patterns of space use and reproductive success within mating tactics. Our data highlight the importance of oxytocin receptor in neural structures associated with pairbonding and socio-spatial memory in male mating tactics. The role of memory in mating systems is often neglected, despite the fact that mating tactics impose an inherently spatial challenge for animals. Identifying mechanisms responsible for relating information about the social world with mechanisms mediating pairbonding and mating tactics is crucial to fully appreciate the suite of factors driving mating systems. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.

  12. Sex and the public: Social eavesdropping, sperm competition risk and male mate choice.

    Science.gov (United States)

    Plath, Martin; Bierbach, David

    2011-05-01

    Mate choice can be sensitive to social cues from neighboring individuals, e.g., animals can copy mate choice decisions. Males that are at risk of being copied by others may respond to this with reduced preference expression ("audience effects"). We review the various pathways by which sperm competition risk affects (1) male mate copying behavior and (2) audience effects. For example, a recent study suggests that males gather complex social information on rivals' sexual competitiveness (sexual activity and attractiveness to females) and respond with reduced expression of mating preferences only "when it matters," i.e., when a sexually competitive rival is present.

  13. The cost of mating: influences of life history traits and mating strategies on lifespan in two closely related Yponomeuta species

    NARCIS (Netherlands)

    Bakker, A.C.; Campos Louçã, J.; Roessingh, P.; Menken, S.B.J.

    2011-01-01

    Theory predicts that in monandrous butterfly species males should not invest in a long lifespan because receptive females quickly disappear from the mating population. In polyandrous species, however, it pays for males to invest in longevity, which increases the number of mating opportunities and

  14. Do female Nicrophorus vespilloides reduce direct costs by choosing males that mate less frequently?

    Science.gov (United States)

    Mazué, G. P. F.; Carter, M. J.; Head, M. L.; Moore, A. J.; Royle, N. J.

    2016-01-01

    Sexual conflict occurs when selection to maximize fitness in one sex does so at the expense of the other sex. In the burying beetle Nicrophorus vespilloides, repeated mating provides assurance of paternity at a direct cost to female reproductive productivity. To reduce this cost, females could choose males with low repeated mating rates or smaller, servile males. We tested this by offering females a dichotomous choice between males from lines selected for high or low mating rate. Each female was then allocated her preferred or non-preferred male to breed. Females showed no preference for males based on whether they came from lines selected for high or low mating rates. Pairs containing males from high mating rate lines copulated more often than those with low line males but there was a negative relationship between female size and number of times she mated with a non-preferred male. When females bred with their preferred male the number of offspring reared increased with female size but there was no such increase when breeding with non-preferred males. Females thus benefited from being choosy, but this was not directly attributable to avoidance of costly male repeated mating. PMID:26979560

  15. Flying the nest: male dispersal and multiple paternity enables extrafamilial matings for the invasive bark beetle Dendroctonus micans.

    Science.gov (United States)

    Fraser, C I; Brahy, O; Mardulyn, P; Dohet, L; Mayer, F; Grégoire, J-C

    2014-10-01

    There is an evolutionary trade-off between the resources that a species invests in dispersal versus those invested in reproduction. For many insects, reproductive success in patchily-distributed species can be improved by sibling-mating. In many cases, such strategies correspond to sexual dimorphism, with males-whose reproductive activities can take place without dispersal-investing less energy in development of dispersive resources such as large body size and wings. This dimorphism is particularly likely when males have little or no chance of mating outside their place of birth, such as when sperm competition precludes successful fertilisation in females that have already mated. The economically important bark beetle pest species Dendroctonus micans (Coleoptera: Curculionidae, Scolytinae) has been considered to be exclusively sibling-mating, with 90% of females having already mated with their brothers by emergence. The species does not, however, show strong sexual dimorphism; males closely resemble females, and have been observed flying through forests. We hypothesised that this lack of sexual dimorphism indicates that male D. micans are able to mate with unrelated females, and to sire some or all of their offspring, permitting extrafamilial reproduction. Using novel microsatellite markers, we carried out cross-breeding laboratory experiments and conducted paternity analyses of resulting offspring. Our results demonstrate that a second mating with a less-related male can indeed lead to some offspring being sired by the latecomer, but that most are sired by the first, sibling male. We discuss these findings in the context of sperm competition versus possible outbreeding depression.

  16. Quantitative Trait Locus Analysis of Mating Behavior and Male Sex Pheromones in Nasonia Wasps

    Directory of Open Access Journals (Sweden)

    Wenwen Diao

    2016-06-01

    Full Text Available A major focus in speciation genetics is to identify the chromosomal regions and genes that reduce hybridization and gene flow. We investigated the genetic architecture of mating behavior in the parasitoid wasp species pair Nasonia giraulti and Nasonia oneida that exhibit strong prezygotic isolation. Behavioral analysis showed that N. oneida females had consistently higher latency times, and broke off the mating sequence more often in the mounting stage when confronted with N. giraulti males compared with males of their own species. N. oneida males produce a lower quantity of the long-range male sex pheromone (4R,5S-5-hydroxy-4-decanolide (RS-HDL. Crosses between the two species yielded hybrid males with various pheromone quantities, and these males were used in mating trials with females of either species to measure female mate discrimination rates. A quantitative trait locus (QTL analysis involving 475 recombinant hybrid males (F2, 2148 reciprocally backcrossed females (F3, and a linkage map of 52 equally spaced neutral single nucleotide polymorphism (SNP markers plus SNPs in 40 candidate mating behavior genes revealed four QTL for male pheromone amount, depending on partner species. Our results demonstrate that the RS-HDL pheromone plays a role in the mating system of N. giraulti and N. oneida, but also that additional communication cues are involved in mate choice. No QTL were found for female mate discrimination, which points at a polygenic architecture of female choice with strong environmental influences.

  17. Effects of a parasitic nematode on male mate choice in a livebearing fish with a coercive mating system (western mosquitofish, Gambusia affinis).

    Science.gov (United States)

    Deaton, Raelynn

    2009-01-01

    I examined the effects of the parasitic larval nematode, Eustrongylides ignotus, on male mate choice in the western mosquitofish, Gambusia affinis. I hypothesized that parasite presence influences male mate choice either directly (via reduction in male mating behavior due to presence of parasite in females) or indirectly (via reduction in male mating behavior due to reduced condition of infected females). Specifically, I tested the predictions that (1) males would mate preferentially with uninfected over infected females (scoring both mating attempts and association time with females); (2) parasitized females would be in poorer condition than non-parasitized females (measured as soluble fat stores); and (3) parasitized females would have reduced fecundity (measured as number of developing embryos). Males preferred to mate with non-parasitized over parasitized females, but showed no differences in association time between females. The nematode did not decrease female body condition, but did decrease female mass, and appeared to decrease female fecundity via reduction in broods (# embryos). Results support that parasites affect male mate choice in mosquitofish; however, the mechanisms used by males to differentiate between parasitized and non-parasitized females remain untested. This study provides the first empirical evidence of parasite affects on male mate choice in livebearing fishes, and suggest a potentially important role for parasite-mediated sexual selection in organisms that use coercive mating as the primary mechanism of obtaining mates.

  18. A high aggression strategy for smaller males.

    Directory of Open Access Journals (Sweden)

    P Andreas Svensson

    Full Text Available Male-male conflict is common among animals, but questions remain as to when, how and by whom aggression should be initiated. Factors that affect agonistic strategies include residency, the value of the contested resource and the fighting ability of the two contestants. We quantified initiation of aggression in a fish, the desert goby, Chlamydogobius eremius, by exposing nest-holding males to a male intruder. The perceived value of the resource (the nest was manipulated by exposing half of the residents to sexually receptive females for two days before the trial. Resident male aggression, however, was unaffected by perceived mating opportunities. It was also unaffected by the absolute and relative size of the intruder. Instead resident aggression was negatively related to resident male size. In particular, smaller residents attacked sooner and with greater intensity compared to larger residents. These results suggest that resident desert goby males used set, rather than conditional, strategies for initiating aggression. If intruders are more likely to flee than retaliate, small males may benefit from attacking intruders before these have had an opportunity to assess the resident and/or the resource.

  19. Assortative mating among Lake Malawi cichlid fish populations is not simply predictable from male nuptial colour

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    Taylor Martin I

    2009-03-01

    Full Text Available Abstract Background Research on the evolution of reproductive isolation in African cichlid fishes has largely focussed on the role of male colours and female mate choice. Here, we tested predictions from the hypothesis that allopatric divergence in male colour is associated with corresponding divergence in preference. Methods We studied four populations of the Lake Malawi Pseudotropheus zebra complex. We predicted that more distantly-related populations that independently evolved similar colours would interbreed freely while more closely-related populations with different colours mate assortatively. We used microsatellite genotypes or mesh false-floors to assign paternity. Fisher's exact tests as well as Binomial and Wilcoxon tests were used to detect if mating departed from random expectations. Results Surprisingly, laboratory mate choice experiments revealed significant assortative mating not only between population pairs with differently coloured males, but between population pairs with similarly-coloured males too. This suggested that assortative mating could be based on non-visual cues, so we further examined the sensory basis of assortative mating between two populations with different male colour. Conducting trials under monochromatic (orange light, intended to mask the distinctive male dorsal fin hues (blue v orange of these populations, did not significantly affect the assortative mating by female P. emmiltos observed under control conditions. By contrast, assortative mating broke down when direct contact between female and male was prevented. Conclusion We suggest that non-visual cues, such as olfactory signals, may play an important role in mate choice and behavioural isolation in these and perhaps other African cichlid fish. Future speciation models aimed at explaining African cichlid radiations may therefore consider incorporating such mating cues in mate choice scenarios.

  20. Females' sampling strategy to comparatively evaluate prospective mates in the peacock blenny Salaria pavo

    Science.gov (United States)

    Locatello, Lisa; Rasotto, Maria B.

    2017-08-01

    Emerging evidence suggests the occurrence of comparative decision-making processes in mate choice, questioning the traditional idea of female choice based on rules of absolute preference. In such a scenario, females are expected to use a typical best-of- n sampling strategy, being able to recall previous sampled males based on memory of their quality and location. Accordingly, the quality of preferred mate is expected to be unrelated to both the number and the sequence of female visits. We found support for these predictions in the peacock blenny, Salaria pavo, a fish where females have the opportunity to evaluate the attractiveness of many males in a short time period and in a restricted spatial range. Indeed, even considering the variability in preference among females, most of them returned to previous sampled males for further evaluations; thus, the preferred male did not represent the last one in the sequence of visited males. Moreover, there was no relationship between the attractiveness of the preferred male and the number of further visits assigned to the other males. Our results suggest the occurrence of a best-of- n mate sampling strategy in the peacock blenny.

  1. The Cost of Mating: Influences of Life History Traits and Mating Strategies on Lifespan in Two Closely Related Yponomeuta Species

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    A. C. Bakker

    2011-01-01

    Full Text Available Theory predicts that in monandrous butterfly species males should not invest in a long lifespan because receptive females quickly disappear from the mating population. In polyandrous species, however, it pays for males to invest in longevity, which increases the number of mating opportunities and thus reproductive fitness. We tested an extension of this idea and compared male and female lifespan of two closely related Yponomeuta species with different degree of polyandry. Our results confirmed the theoretical prediction that male lifespan is fine-tuned to female receptive lifespan; once-mated males and females of both polyandrous species had an equal lifespan. However, the degree of polyandry was not reflected in male relative to female lifespan. The observed similar female and male lifespan could largely be attributed to a dramatic reduction of female lifespan after mating.

  2. Overt female mate competition and preference for central males in a lekking antelope.

    Science.gov (United States)

    Bro-Jørgensen, Jakob

    2002-07-01

    In mammals, there exists only scant evidence of female mate choice in species mating on arenas, so-called leks. This has led to hypotheses of lek evolution that are based on benefits to females from reduced harassment by males, low predation risk, or improved availability of scarce nutrients. Here I report that female topi antelopes (Damaliscus lunatus) compete aggressively for matings with preferred males on central lek territories. Females fight at higher rates and more likely disrupt mating attempts of others in the lek center than elsewhere. Contrary to the predictions of the alternative hypotheses, food resources were insignificant, and harassment levels and estimated predation risk were higher on than off lek. These results clearly demonstrate female competition for mates in a lekking mammal in which a female chooses between males for the sole purpose of mating. The finding suggests that the forces leading to lek evolution in mammals and birds may be more similar than previously acknowledged.

  3. Male coercion and the costs of promiscuous mating for female chimpanzees

    OpenAIRE

    2007-01-01

    For reasons that are not yet clear, male aggression against females occurs frequently among primates with promiscuous mating systems. Here, we test the sexual coercion hypothesis that male aggression functions to constrain female mate choice. We use 10 years of behavioural and endocrine data from a community of wild chimpanzees (Pan troglodytes schweinfurthii) to show that sexual coercion is the probable primary function of male aggression against females. Specifically, we show that male aggr...

  4. Male Mating Competitiveness of a Wolbachia-Introgressed Aedes polynesiensis Strain under Semi-Field Conditions

    Science.gov (United States)

    Bossin, Hervé; Dobson, Stephen L.

    2011-01-01

    Background Lymphatic filariasis (LF), a global public health problem affecting approximately 120 million people worldwide, is a leading cause of disability in the developing world including the South Pacific. Despite decades of ongoing mass drug administration (MDA) in the region, some island nations have not yet achieved the threshold levels of microfilaremia established by the World Health Organization for eliminating transmission. Previously, the generation of a novel Aedes polynesiensis strain (CP) infected with an exogenous type of Wolbachia has been described. The CP mosquito is cytoplasmically incompatible (i.e., effectively sterile) when mated with wildtype mosquitoes, and a strategy was proposed for the control of A. polynesiensis populations by repeated, inundative releases of CP males to disrupt fertility of wild females. Such a strategy could lead to suppression of the vector population and subsequently lead to a reduction in the transmission of filarial worms. Methodology/Principal Findings CP males and F1 male offspring from wild-caught A. polynesiensis females exhibit near equal mating competitiveness with F1 females under semi-field conditions. Conclusions/Significance While laboratory experiments are important, prior projects have demonstrated the need for additional testing under semi-field conditions in order to recognize problems before field implementation. The results reported here from semi-field experiments encourage forward progression toward small-scale field releases. PMID:21829750

  5. Male mating behaviour in relation to female sexual swellings, socio-sexual behaviour and hormonal changes in wild Barbary macaques.

    Science.gov (United States)

    Young, Christopher; Majolo, Bonaventura; Heistermann, Michael; Schülke, Oliver; Ostner, Julia

    2013-01-01

    In many cercopithecine primates females display probabilistic cues of fertility to indicate the periovulatory period to males. These cues may include female behaviour, acoustic signals, and morphological signs such as the anogenital swelling. However, the extent to which males can utilise this information varies between species. We describe male sexual behaviour in relation to changes in anogenital swelling size, timing of ovulation and female socio-sexual behaviour in wild Barbary macaques (Macaca sylvanus). We further compare male sexual behaviour during conception and post-conception cycles to evaluate if males differentiate between these qualitatively different cycle types. Our results show that during conception cycles male mating behaviour was concentrated around the fertile phase implying that males inferred information from more than swelling size alone. Male mating frequency increased in line with female socio-sexual behaviour, namely female presenting and the frequency of copulations with copulation calls. Most strikingly our results show that males invested equally in mating during fertile and non-fertile, i.e. post-conception, maximum swelling phases. Whether post-conception swellings were merely a result of changes in hormone concentrations during pregnancy or part of a female reproductive strategy remains elusive. In sum, this study adds to the body of research on the evolution of female sexual signals and how males may infer information from these cues.

  6. Scented males and choosy females: does male odor influence female mate choice in the Mediterranean fruit fly?

    Science.gov (United States)

    Shelly, Todd E; Edu, James; Pahio, Elaine; Nishimoto, Jon

    2007-12-01

    The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), displays a lek mating system characterized by a high level of female discrimination among potential mates. The basis of female choice is not understood, but recent studies indicate that male exposure to the aroma of certain plant structures or essential oils may increase mating success. In particular, exposure to the aroma of ginger root oil (GRO) enhances male mating frequency, and several sterile-male release programs against C. capitata have incorporated 'aromatherapy' (large-scale exposure of pre-release insects to GRO) to increase the effectiveness of control efforts. We investigated the mechanism underlying female preference for GRO-exposed males. Two sets of experiments were conducted. In the first, we monitored female attraction to (1) freshly killed flies, or (2) paper discs that contained hexane extracts from varying treatments. In these tests, females were sighted more often (1) near GRO-exposed than non-exposed males (even when the males were visually concealed) and (2) near extracts from GRO-exposed than non-exposed males. These findings suggest a 'perfume effect', whereby female mate choice is mediated by olfactory differences. In the second set, we compared (1) mate choice between intact females and females from which both antennae had been surgically removed, and (2) mating success between intact males and males from which both antennae had been surgically removed before GRO exposure. Intact females preferred GRO-exposed males, whereas females lacking both antennae rarely mated and showed no preference between GRO-exposed and non-exposed males. In the opposite treatment (intact females but surgically altered males), GRO-exposed males lacking both antennae mated as frequently as GRO-exposed intact males. These data suggest that female choice was dependent on olfactory perception of male odor but that male mating success did not depend on olfactory perception of GRO aroma, suggesting, in

  7. Male Drosophila melanogaster learn to prefer an arbitrary trait associated with female mating status

    DEFF Research Database (Denmark)

    Verzijden, Machteld Nicolette; Abbott, Jessica K.; Philipsborn, Anne von

    2015-01-01

    Although males are generally less discriminating than females when it comes to choosing a mate, they still benefit from distinguishing between mates that are receptive to courtship and those that are not, in order to avoid wasting time and energy. It is known that males of Drosophila melanogaster...... of the experiment was carried out in darkness.This is, to our knowledge 1) the first evidence that male D. melanogaster can use more arbitrary cues and 2) the first evidence that males use visual cues during mate choice learning. Our findings suggest that that D. melanogaster has untapped potential as a model...

  8. Mating strategy of Oecophylla smaragdina (Hymenoptera: Formicidae) in northern Australia

    DEFF Research Database (Denmark)

    Nielsen, Mogens Gissel; Peng, Renkang; Offenberg, Hans Joachim

    2016-01-01

    The aim of this study was to elucidate the mating strategy of Oecophylla smaragdina (Fabricius, 1775) and to clarify the factors that related to the nuptial flight. The nuptial flight was investigated over three seasons in the Darwin area, Australia, in which a total of 19 swarmings were observed...

  9. Methyl eugenol aromatherapy enhances the mating competitiveness of male Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae).

    Science.gov (United States)

    Haq, Ihsan; Vreysen, Marc J B; Cacéres, Carlos; Shelly, Todd E; Hendrichs, Jorge

    2014-09-01

    Males of Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae) are strongly attracted to methyl eugenol (ME) (1,2-dimethoxy-4-(2-propenyl)benzene), a natural compound occurring in variety of plant species. ME-feeding is known to enhance male B. carambolae mating competitiveness 3 days after feeding. Enhanced male mating competitiveness due to ME-feeding can increase the effectiveness of sterile insect technique (SIT) manifolds. However, the common methods for emergence and holding fruit flies prior to field releases do not allow the inclusion of any ME feeding treatment after fly emergence. Therefore this study was planned to assess the effects of ME-aromatherapy in comparison with ME feeding on male B. carambolae mating competitiveness as aromatherapy is pragmatic for fruit flies emergence and holding facilities. Effects of ME application by feeding or by aromatherapy for enhanced mating competitiveness were evaluated 3d after treatments in field cages. ME feeding and ME aromatherapy enhanced male mating competitiveness as compared to untreated males. Males treated with ME either by feeding or by aromatherapy showed similar mating success but mating success was significantly higher than that of untreated males. The results are discussed in the context of application of ME by aromatherapy as a pragmatic approach in a mass-rearing facility and its implications for effectiveness of SIT. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Feminization of pheromone-sensing neurons affects mating decisions in Drosophila males

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    Beika Lu

    2014-01-01

    The response of individual animals to mating signals depends on the sexual identity of the individual and the genetics of the mating targets, which represent the mating social context (social environment. However, how social signals are sensed and integrated during mating decisions remains a mystery. One of the models for understanding mating behaviors in molecular and cellular terms is the male courtship ritual in the fruit fly (Drosophila melanogaster. We have recently shown that a subset of gustatory receptor neurons (GRNs that are enriched in the male appendages and express the ion channel ppk23 play a major role in the initiation and maintenance of male courtship via the perception of cuticular contact pheromones, and are likely to represent the main chemosensory pathway that influences mating decisions by males. Here we show that genetic feminization of ppk23-expressing GRNs in male flies resulted in a significant increase in male–male sexual attraction without an apparent impact on sexual attraction to females. Furthermore, we show that this increase in male–male sexual attraction is sensory specific, which can be modulated by variable social contexts. Finally, we show that feminization of ppk23-expressing sensory neurons lead to major transcriptional shifts, which may explain the altered interpretation of the social environment by feminized males. Together, these data indicate that the sexual cellular identity of pheromone sensing GRNs plays a major role in how individual flies interpret their social environment in the context of mating decisions.

  11. Male moth songs tempt females to accept mating: the role of acoustic and pheromonal communication in the reproductive behaviour of Aphomia sociella.

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    Jiří Kindl

    Full Text Available BACKGROUND: Members of the subfamily Galleriinae have adapted to different selective environmental pressures by devising a unique mating process. Galleriinae males initiate mating by attracting females with either chemical or acoustic signals (or a combination of both modalities. Six compounds considered candidates for the sex pheromone have recently been identified in the wing gland extracts of Aphomia sociella males. Prior to the present study, acoustic communication had not been investigated. Signals mediating female attraction were likewise unknown. METHODOLOGY/PRINCIPAL FINDINGS: Observations of A. sociella mating behaviour and recordings of male acoustic signals confirmed that males initiate the mating process. During calling behaviour (stationary wing fanning and pheromone release, males disperse pheromone from their wing glands. When a female approaches, males cease calling and begin to produce ultrasonic songs as part of the courtship behaviour. Replaying of recorded courting songs to virgin females and a comparison of the mating efficiency of intact males with males lacking tegullae proved that male ultrasonic signals stimulate females to accept mating. Greenhouse experiments with isolated pheromone glands confirmed that the male sex pheromone mediates long-range female attraction. CONCLUSION/SIGNIFICANCE: Female attraction in A. sociella is chemically mediated, but ultrasonic communication is also employed during courtship. Male ultrasonic songs stimulate female sexual display and significantly affect mating efficiency. Considerable inter-individual differences in song structure exist. These could play a role in female mate selection provided that the female's ear is able to discern them. The A. sociella mating strategy described above is unique within the subfamily Galleriinae.

  12. The urethral glands of male mice in relation to depletion of secretory granules upon mating.

    Science.gov (United States)

    Parr, M B; de França, L R; Kepple, L; Ying, L; Parr, E L; Russell, L D

    1994-08-01

    The present study describes the effects of mating on urethral gland acinar cells in male mice. Histological and morphometric analysis demonstrated that there was a depletion of secretory granules in the urethral glands during mating. However, no change occurred in the rough endoplasmic reticulum containing tubular elements. The results indicate that the urethral glands are functional during mating. The timing of their granule depletion suggests that urethral gland secretions may contribute to the formation of semen or the copulation plug.

  13. Determinants of male reproductive health disorders: the Men in Australia Telephone Survey (MATeS)

    OpenAIRE

    Wittert Gary; Cumming Robert; Pitts Marian; McLachlan Robert I; Holden Carol A; Ehsani Johnathon P; de Kretser David M; Handelsman David J

    2010-01-01

    Abstract Background The relationship between reproductive health disorders and lifestyle factors in middle-aged and older men is not clear. The aim of this study is to describe lifestyle and biomedical associations as possible causes of erectile dysfunction (ED), prostate disease (PD), lower urinary tract symptoms (LUTS) and perceived symptoms of androgen deficiency (pAD) in a representative population of middle-aged and older men, using the Men in Australia Telephone Survey (MATeS). Methods ...

  14. Male mating costs in a polygynous mosquito with ornaments expressed in both sexes.

    Science.gov (United States)

    South, Sandra H; Steiner, Dianna; Arnqvist, Göran

    2009-10-22

    Male mate choice in species with conventional sex roles is difficult to explain and has, therefore, been the focus of many recent theoretical models. These models have focused on variance in female quality and, to a lesser extent, male investments/costs associated with mating. In this study, we investigate the costs of courtship and copulation in the polygynous mosquito Sabethes cyaneus. In this species, both males and females possess elaborate ornaments. Previous studies suggest that the most likely explanation for the presence of these ornaments is mutual mate choice. Thus, this system provides an excellent model for exploring the evolution of mutual mate choice in polygynous species. We disentangle the costs of courtship and copulation by monitoring male survival in three groups of males: housed alone (group 1); able only to court females (group 2); or able to court and copulate with females (group 3). We show that males incur a cost of courtship and copulation and that courtship intensity is negatively related to male longevity. Our results suggest that courtship and copulation carry additive costs to males. We discuss the implications of these results in the context of current mutual mate choice theory and suggest that courtship costs may be an unappreciated key factor in the evolution of male mate choice.

  15. Effect of mating activity and dominance rank on male masturbation among free-ranging male rhesus macaques.

    Science.gov (United States)

    Dubuc, Constance; Coyne, Sean P; Maestripieri, Dario

    2013-11-01

    The adaptive function of male masturbation is still poorly understood, despite its high prevalence in humans and other animals. In non-human primates, male masturbation is most frequent among anthropoid monkeys and apes living in multimale-multifemale groups with a promiscuous mating system. In these species, male masturbation may be a non-functional by-product of high sexual arousal or be adaptive by providing advantages in terms of sperm competition or by decreasing the risk of sexually transmitted infections. We investigated the possible functional significance of male masturbation using behavioral data collected on 21 free-ranging male rhesus macaques (Macaca mulatta) at the peak of the mating season. We found some evidence that masturbation is linked to low mating opportunities: regardless of rank, males were most likely to be observed masturbating on days in which they were not observed mating, and lower-ranking males mated less and tended to masturbate more frequently than higher-ranking males. These results echo the findings obtained for two other species of macaques, but contrast those obtained in red colobus monkeys (Procolobus badius) and Cape ground squirrels (Xerus inauris). Interestingly, however, male masturbation events ended with ejaculation in only 15% of the observed masturbation time, suggesting that new hypotheses are needed to explain masturbation in this species. More studies are needed to establish whether male masturbation is adaptive and whether it serves similar or different functions in different sexually promiscuous species.

  16. Mating structure and male production in the giant hornet Vespa mandarinia (Hymenoptera: Vespidae)

    OpenAIRE

    Takahashi, Jun-Ichi; Akimoto, Shin'Ichi; Martin, Stephen J.; Tamukae, Masato; Hasegawa, Eisuke

    2004-01-01

    Queen mating frequency, genetic relatedness between workers and worker reproduction were estimated in Vespa mandarinia by microsatellite DNA markers. Of 20 colonies examined, eighteen contained queens inseminated by a single male and two colonies contained queens inseminated by two males. The estimated effective number of matings was 1.03±0.023 (mean±SE) with 85% of the offspring of the two multiply-mated queens being sired by one of the two males. The genetic relatedness between workers was ...

  17. Male Drosophila melanogaster learn to prefer an arbitrary trait associated with female mating status

    DEFF Research Database (Denmark)

    Verzijden, Machteld Nicolette; Abbott, Jessica K.; Philipsborn, Anne von;

    2015-01-01

    are able to learn to associate olfactory and gustatory cues with female receptivity, but the role of more arbitrary, visual cues in mate choice learning has been overlooked to date in this species. We therefore carried out a series of experiments to determine: 1) whether males had a baseline preference...... of the experiment was carried out in darkness.This is, to our knowledge 1) the first evidence that male D. melanogaster can use more arbitrary cues and 2) the first evidence that males use visual cues during mate choice learning. Our findings suggest that that D. melanogaster has untapped potential as a model...... system for mate choice learning...

  18. Motile male gametes of the araphid diatom Tabularia fasciculata search randomly for mates.

    Directory of Open Access Journals (Sweden)

    Robyn Edgar

    Full Text Available Sexuality in the marine araphid diatom Tabularia involves an unusual type of gamete, not only among diatoms but possibly in all of nature. The non-flagellated male gamete is free and vigorously motile, propelled by pseudopodia. However, the cues (if any in their search for compatible female gametes and the general search patterns to locate them are unknown. We tracked and compared male gamete movements in the presence and absence of receptive female gametes. Path linearity of male movement was not affected by presence of female gametes. Male gametes did not move towards female gametes regardless of their proximity to each other, suggesting that the detection range for a compatible mate is very small compared to known algal examples (mostly spermatozoids and that mate recognition requires (near contact with a female gamete. We therefore investigated how male gametes move to bring insight into their search strategy and found that it was consistent with the predictions of a random-walk model with changes in direction coming from an even distribution. We further investigated the type of random walk by determining the best-fit distribution on the tail of the move length distribution and found it to be consistent with a truncated power law distribution with an exponent of 2.34. Although consistent with a Lévy walk search pattern, the range of move lengths in the tail was too narrow for Lévy properties to emerge and so would be best described as Brownian motion. This is somewhat surprising because female gametes were often outnumbered by male gametes, thus contrary to the assumption that a Brownian search mode may be most optimal with an abundant target resource. This is also the first mathematically analysed search pattern of a non-flagellated protistan gamete, supporting the notion that principles of Brownian motion have wide application in biology.

  19. Pest management programmes in vineyards using male mating disruption.

    Science.gov (United States)

    Harari, Ally R; Zahavi, Tirtza; Gordon, Dvora; Anshelevich, Leonid; Harel, Miriam; Ovadia, Shmulik; Dunkelblum, Ezra

    2007-08-01

    Israeli vine growers have been reluctant to adopt the mating disruption technique for control of the European vine moth, Lobesia botrana Den. & Schiff. Since the chemically controlled honeydew moth, Cryptoblabes gnidiella Mill., coexists with the European vine moth, growers have maintained that the use of mating disruption would fail to bring about a significant reduction in pesticide use. In this study, the efficacy of mating disruption techniques against C. gnidiella was tested, as well as the effect of these methods on pesticide use and damage to clusters when the method was employed against both of the pests in wine grapes. Comparisons were made between plots treated with (1) L. botrana mating disruption pheromone, (2) L. botrana and C. gnidiella mating disruption pheromones and (3) control plots. A significant difference in the number of clusters infested with the developmental stages of the moths was seen between pheromone-treated plots and controls, while no such difference was observed between plots treated with one versus two pheromones. A similar pattern was observed in the number of insecticide applications; the greatest number of applications was used in control plots, followed by plots treated with L. botrana mating disruption pheromone and by plots treated with pheromones against both pests, in which no pesticides were applied.

  20. Mating enhances the probability of winning aggressive encounters in male lobster cockroaches.

    Science.gov (United States)

    Kou, Rong; Hsu, Chu-Chun

    2013-08-01

    In the present study, we report that contact with isolated female antenna significantly increases both the pheromone 3-hydroxy-2-butanone (3H-2B) release and the hemolymph JH III level in all examined aggressive posture-adopting (AP) and NP (non-AP-adopting) socially naïve males, with significantly faster concomitant pre-mating wing-raising behavior in AP as compared to NP males. 3H-2B release and JH III level were significantly increased after mating in both AP and NP males. A positive correlation was observed between mating experience and dominant status. Furthermore, mated-AP males initiated fights more rapidly and fought for a significantly longer duration than mated-NP males; retention with the paired female for 24h did not affect this increase. JH III level and 3H-2B release were significantly increased in dominant males as compared to subordinates. These results suggest that prior mating experience in invertebrates may enhance aggression in subsequent male-male encounters, with accompanying physiological (hormone and pheromone) responses. © 2013. Published by Elsevier Inc. All rights reserved.

  1. Multi-attribute mate choice decisions and uncertainty in the decision process: a generalized sequential search strategy.

    Science.gov (United States)

    Wiegmann, Daniel D; Weinersmith, Kelly L; Seubert, Steven M

    2010-04-01

    The behavior of females in search of a mate determines the likelihood that high quality males are encountered and adaptive search strategies rely on the effective use of available information on the quality of prospective mates. The sequential search strategy was formulated, like most models of search behavior, on the assumption that females obtain perfect information on the quality of encountered males. In this paper, we modify the strategy to allow for uncertainty of male quality and we determine how the magnitude of this uncertainty and the ability of females to inspect multiple male attributes to reduce uncertainty influence mate choice decisions. In general, searchers are sensitive to search costs and higher costs lower acceptance criteria under all versions of the model. The choosiness of searchers increases with the variability of the quality of prospective mates under conditions of the original model, but under conditions of uncertainty the choosiness of searchers may increase or decrease with the variability of inspected male attributes. The behavioral response depends on the functional relationship between observed male attributes and the fitness return to searchers and on costs associated with the search process. Higher uncertainty often induces searchers to pay more for information and under conditions of uncertainty the fitness return to searchers is never higher than under conditions of the original model. Further studies of the performance of alternative search strategies under conditions of uncertainty may consequently be necessary to identify search strategies likely to be used under natural conditions.

  2. No Evidence for Significant Effect of Body Size and Age on Male Mating Success in the Spot-legged Treefrog

    Institute of Scientific and Technical Information of China (English)

    Jianping YU; Cheng CHEN; Long JIN; Li ZHAO; Wenbo LIAO

    2016-01-01

    In anurans, body size and age of individuals generally affect male mating success. To test whether body size and age have effects on male mating success in the foam-nesting treefrog Polypedates megacephalus, a species widely distributed in China, we analyzed differences in body size and age between mated and unmated males for three populations using a Generalized Linear Mixed Model (GLMM). The results showed that mated males did not exhibit larger body size and older age than unmated males, suggesting that large and/or old male individuals did not have greater mating success than small and/or young males. Moreover, we also found a non-significant size-assortative mating pattern for all populations. Our findings suggest that body size and age of the foam-nesting treefrog do not affect male mating success.

  3. When not to copy: female fruit flies use sophisticated public information to avoid mated males

    Science.gov (United States)

    Loyau, Adeline; Blanchet, Simon; van Laere, Pauline; Clobert, Jean; Danchin, Etienne

    2012-10-01

    Semen limitation (lack of semen to fertilize all of a female's eggs) imposes high fitness costs to female partners. Females should therefore avoid mating with semen-limited males. This can be achieved by using public information extracted from watching individual males' previous copulating activities. This adaptive preference should be flexible given that semen limitation is temporary. We first demonstrate that the number of offspring produced by males Drosophila melanogaster gradually decreases over successive copulations. We then show that females avoid mating with males they just watched copulating and that visual public cues are sufficient to elicit this response. Finally, after males were given the time to replenish their sperm reserves, females did not avoid the males they previously saw copulating anymore. These results suggest that female fruit flies may have evolved sophisticated behavioural processes of resistance to semen-limited males, and demonstrate unsuspected adaptive context-dependent mate choice in an invertebrate.

  4. Coordination of opposing sex-specific and core muscle groups regulates male tail posture during Caenorhabditis elegans male mating behavior

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    Sternberg Paul W

    2009-06-01

    Full Text Available Abstract Background To survive and reproduce, animals must be able to modify their motor behavior in response to changes in the environment. We studied a complex behavior of Caenorhabditis elegans, male mating behavior, which provided a model for understanding motor behaviors at the genetic, molecular as well as circuit level. C. elegans male mating behavior consists of a series of six sub-steps: response to contact, backing, turning, vulva location, spicule insertion, and sperm transfer. The male tail contains most of the sensory structures required for mating, in addition to the copulatory structures, and thus to carry out the steps of mating behavior, the male must keep his tail in contact with the hermaphrodite. However, because the hermaphrodite does not play an active role in mating and continues moving, the male must modify his tail posture to maintain contact. We provide a better understanding of the molecular and neuro-muscular pathways that regulate male tail posture during mating. Results Genetic and laser ablation analysis, in conjunction with behavioral assays were used to determine neurotransmitters, receptors, neurons and muscles required for the regulation of male tail posture. We showed that proper male tail posture is maintained by the coordinated activity of opposing muscle groups that curl the tail ventrally and dorsally. Specifically, acetylcholine regulates both ventral and dorsal curling of the male tail, partially through anthelmintic levamisole-sensitive, nicotinic receptor subunits. Male-specific muscles are required for acetylcholine-driven ventral curling of the male tail but dorsal curling requires the dorsal body wall muscles shared by males and hermaphrodites. Gamma-aminobutyric acid activity is required for both dorsal and ventral acetylcholine-induced curling of the male tail and an inhibitory gamma-aminobutyric acid receptor, UNC-49, prevents over-curling of the male tail during mating, suggesting that cross

  5. Incestuous sisters: mate preference for brothers over unrelated males in Drosophila melanogaster.

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    Adeline Loyau

    Full Text Available The literature is full of examples of inbreeding avoidance, while recent mathematical models predict that inbreeding tolerance or even inbreeding preference should be expected under several realistic conditions like e.g. polygyny. We investigated male and female mate preferences with respect to relatedness in the fruit fly D. melanogaster. Experiments offered the choice between a first order relative (full-sibling or parent and an unrelated individual with the same age and mating history. We found that females significantly preferred mating with their brothers, thus supporting inbreeding preference. Moreover, females did not avoid mating with their fathers, and males did not avoid mating with their sisters, thus supporting inbreeding tolerance. Our experiments therefore add empirical evidence for inbreeding preference, which strengthens the prediction that inbreeding tolerance and preference can evolve under specific circumstances through the positive effects on inclusive fitness.

  6. Mass Rearing History and Irradiation Affect Mating Performance of the Male Fruit Fly, Anastrepha obliqua

    Science.gov (United States)

    Rull, Juan; Encarnación, Nery; Birke, Andrea

    2012-01-01

    As an initial step to improve the efficiency of the sterile insect technique applied to eradicate, suppress, and control wild Anastrepha obliqua (Macquart) (Diptera: Tephritidae) in mango producing areas of Mexico, the effect of radiation dose and mass rearing history on male mating performance was examined. Field cage tests in which both male and female laboratory flies were irradiated at different doses (0, 40, and 80 Gy) were released with cohorts of wild flies of both sexes, revealing that both mass rearing history and irradiation affected male mating performance. Laboratory males were accepted for copulation by wild females less frequently than wild males. Copulations involving laboratory males were shorter than those involving wild males. Irradiated males mated less frequently with wild females than wild males, and irradiated females appeared to be less able to reject courting males of both origins. High levels of fertility for untreated laboratory females crossed with males irradiated at different doses may reflect problems in mass rearing affecting homogeneity of pupal age before irradiation, and possibly masked a dose effect. Proposed remedial measures to improve male mating performance are discussed. PMID:22957485

  7. The influence of male parr body size and mate competition on fertilization success and effective population size in Atlantic salmon.

    Science.gov (United States)

    Jones, M W; Hutchings, J A

    2001-06-01

    Alternative mating strategies in male Atlantic salmon, Salmo salar, are characterized by variability in body size and mate competition. Controlling breeding numbers of larger, older anadromous males, we examined whether body size of mature male parr influenced fertilization success and whether such an association was affected by mate competition among parr. Variation at three to four hypervariable microsatellite loci was used to determine individual paternity of 53-60 offspring from two or three nests from each experimental treatment. Although individual and total parr reproductive success differed significantly among nests within treatments, there was no relationship between parr size and individual reproductive success at any level of competition when anadromous males were involved. However, in a single treatment having no anadromous male, the influence of body size on parr fertilization success was highly significant. Combining data from all treatments, parr body size was an important predictor of the probability of an individual being involved in spawning. We found a negative relationship between total parr reproductive success and intensity of anadromous male competition. To our knowledge, the present study is the first to estimate the effective number of males from individual fertilization success in fish. Our estimates of Ne should not be taken as absolute and may have a downward bias because we did not sample all nests and we used a proxy for lifetime reproductive success. They do, however, illustrate how mature male parr can greatly increase the effective number of males when the latter is estimated from anadromous individuals alone. Although reproductive success by mature male parr increases the effective number of males, this increase seems likely to be most pronounced in natural populations when the number of anadromous males is low.

  8. Mating success and body condition not related to foraging specializations in male fur seals.

    Science.gov (United States)

    Kernaléguen, L; Cherel, Y; Guinet, C; Arnould, J P Y

    2016-07-01

    Individual specialization is widespread among wild populations. While its fitness consequences are central in predicting the ecological and evolutionary trajectories of populations, they remain poorly understood. Long-term individual foraging specializations occur in male Antarctic (Arctocephalus gazella) and Australian (A. pusillus doriferus) fur seals. Strong selective pressure is expected in these highly dimorphic and polygynous species, raising the question of the fitness payoffs associated with different foraging strategies. We investigated the relationship between individual isotopic niche (a proxy of foraging specialization), body size and condition, and an index of reproductive success (harem size) in territorial males. Individuals varied greatly in their skin and fur isotopic values reflecting a range of foraging strategies within the two populations. However, in both species, isotopic niche was not correlated to body size, condition or mating success (R (2)/ρ < 0.06). Furthermore, no foraging niche was predominant in either species, which would have indicated a substantial long-term fitness benefit of a particular strategy via a higher survival rate. These results suggest that the fitness consequences of a foraging strategy depend not only on the quality of prey and feeding habitat but also on an individual's hunting efficiency and skills.

  9. Genotype-by-environment interactions for female mate choice of male cuticular hydrocarbons in Drosophila simulans.

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    Fiona C Ingleby

    Full Text Available Recent research has highlighted the potential importance of environmental and genotype-by-environment (G×E variation in sexual selection, but most studies have focussed on the expression of male sexual traits. Consequently, our understanding of genetic variation for plasticity in female mate choice is extremely poor. In this study we examine the genetics of female mate choice in Drosophila simulans using isolines reared across two post-eclosion temperatures. There was evidence for G×Es in female choosiness and preference, which suggests that the evolution of female mate choice behaviour could differ across environments. However, the ranked order of preferred males was consistent across females and environments, so the same males are favoured by mate choice in spite of G×Es. Our study highlights the importance of taking cross-environment perspectives in order to gain a more comprehensive understanding of the operation of sexual selection.

  10. From resource to female defence: the impact of roosting ecology on a bat's mating strategy.

    Science.gov (United States)

    Günther, Linus; Lopez, Marlena D; Knörnschild, Mirjam; Reid, Kyle; Nagy, Martina; Mayer, Frieder

    2016-11-01

    With their extraordinary species richness and diversity in ecological traits and social systems, bats are a promising taxon for testing socio-ecological hypotheses in order to get new insights into the evolution of animal social systems. Regarding its roosting habits, proboscis bats form an extreme by occupying sites which are usually completely exposed to daylight (e.g. tree trunks, vines or rocks). This is accompanied by morphological and behavioural adaptations to remain cryptic in exposed day roosts. With long-term behavioural observations and genetic parentage analyses of individually marked proboscis bats, we assessed its social dispersion and male mating strategy during day and night. Our results reveal nocturnal male territoriality-a strategy which most closely resembles a resource-defence polygyny that is frequent also in other tropical bats. Its contrasting clumped social dispersion during the day is likely to be the result of strong selection for crypsis in exposed roosts and is accompanied by direct female defence in addition to male territoriality. To the best of our knowledge, such contrasting male mating strategies within a single day-night cycle have not been described in a vertebrate species so far and illustrate a possible evolutionary trajectory from resource-defence to female-defence strategy by small ecologically driven evolutionary steps.

  11. Male mating rate is constrained by seminal fluid availability in bedbugs, Cimex lectularius.

    Science.gov (United States)

    Reinhardt, Klaus; Naylor, Richard; Siva-Jothy, Michael T

    2011-01-01

    Sexual selection, differences in reproductive success between individuals, continues beyond acquiring a mating partner and affects ejaculate size and composition (sperm competition). Sperm and seminal fluid have very different roles in sperm competition but both components encompass production costs for the male. Theoretical models predict that males should spend ejaculate components prudently and differently for sperm and seminal fluid but empirical evidence for independent variation of sperm number and seminal fluid volume is scarce. It is also largely unknown how sperm and seminal fluid variation affect future mating rate. In bedbugs we developed a protocol to examine the role of seminal fluids in ejaculate allocation and its effect on future male mating rate. Using age-related changes in sperm and seminal fluid volume we estimated the lowest capacity at which mating activity started. We then showed that sexually active males allocate 12% of their sperm and 19% of their seminal fluid volume per mating and predicted that males would be depleted of seminal fluid but not of sperm. We tested (and confirmed) this prediction empirically. Finally, the slightly faster replenishment of seminal fluid compared to sperm did not outweigh the faster decrease during mating. Our results suggest that male mating rate can be constrained by the availability of seminal fluids. Our protocol might be applicable to a range of other organisms. We discuss the idea that economic considerations in sexual conflict research might benefit from distinguishing between costs and benefits that are ejaculate dose-dependent and those that are frequency-dependent on the mating rate per se.

  12. Male mating rate is constrained by seminal fluid availability in bedbugs, Cimex lectularius.

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    Klaus Reinhardt

    Full Text Available Sexual selection, differences in reproductive success between individuals, continues beyond acquiring a mating partner and affects ejaculate size and composition (sperm competition. Sperm and seminal fluid have very different roles in sperm competition but both components encompass production costs for the male. Theoretical models predict that males should spend ejaculate components prudently and differently for sperm and seminal fluid but empirical evidence for independent variation of sperm number and seminal fluid volume is scarce. It is also largely unknown how sperm and seminal fluid variation affect future mating rate. In bedbugs we developed a protocol to examine the role of seminal fluids in ejaculate allocation and its effect on future male mating rate. Using age-related changes in sperm and seminal fluid volume we estimated the lowest capacity at which mating activity started. We then showed that sexually active males allocate 12% of their sperm and 19% of their seminal fluid volume per mating and predicted that males would be depleted of seminal fluid but not of sperm. We tested (and confirmed this prediction empirically. Finally, the slightly faster replenishment of seminal fluid compared to sperm did not outweigh the faster decrease during mating. Our results suggest that male mating rate can be constrained by the availability of seminal fluids. Our protocol might be applicable to a range of other organisms. We discuss the idea that economic considerations in sexual conflict research might benefit from distinguishing between costs and benefits that are ejaculate dose-dependent and those that are frequency-dependent on the mating rate per se.

  13. Courtship raises male fertilization success through post-mating sexual selection in a spider.

    Science.gov (United States)

    Schneider, Jutta M; Lesmono, Kristiani

    2009-09-07

    Courtship is well known for its positive effects on mating success. However, in polyandrous species, sexual selection continues to operate after copulation. Cryptic female choice is expected under unpredictable mating rates in combination with sequential mate encounters. However, there are very few accounts of the effects of courtship on cryptic female choice, and the available evidence is often correlative. Mature Argiope bruennichi females are always receptive and never attack or reject males before mating, although sexual cannibalism after mating occurs regularly. Still, males usually perform an energetic vibratory display prior to copulation. We tested the hypothesis that beneficial effects of courtship arise cryptically, during or after mating, resulting in increased paternity success under polyandry. Manipulating courtship duration experimentally, we found that males that mated without display had a reduced paternity share even though no differences in post-copulatory cannibalism or copulation duration were detected. This suggests that the paternity advantage associated with courtship arose through female-mediated processes after intromission, meeting the definition of cryptic female choice.

  14. No evidence for the effect of MHC on male mating success in the brown bear.

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    Katarzyna Kuduk

    Full Text Available Mate choice is thought to contribute to the maintenance of the spectacularly high polymorphism of the Major Histocompatibility Complex (MHC genes, along with balancing selection from parasites, but the relative contribution of the former mechanism is debated. Here, we investigated the association between male MHC genotype and mating success in the brown bear. We analysed fragments of sequences coding for the peptide-binding region of the highly polymorphic MHC class I and class II DRB genes, while controlling for genome-wide effects using a panel of 18 microsatellite markers. Male mating success did not depend on the number of alleles shared with the female or amino-acid distance between potential mates at either locus. Furthermore, we found no indication of female mating preferences for MHC similarity being contingent on the number of alleles the females carried. Finally, we found no significant association between the number of MHC alleles a male carried and his mating success. Thus, our results provided no support for the role of mate choice in shaping MHC polymorphism in the brown bear.

  15. Female crickets assess relatedness during mate guarding and bias storage of sperm towards unrelated males.

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    Tuni, C; Beveridge, M; Simmons, L W

    2013-06-01

    Recent evidence shows that females exert a post-copulatory fertilization bias in favour of unrelated males to avoid the genetic incompatibilities derived from inbreeding. One of the mechanisms suggested for fertilization biases in insects is female control over transport of sperm to the sperm-storage organs. We investigated post-copulatory inbreeding-avoidance mechanisms in females of the cricket Teleogryllus oceanicus. We assessed the relative contribution of related and unrelated males to the sperm stores of double-mated females. To demonstrate unequivocally that biased sperm storage results from female control rather than cryptic male choice, we manipulated the relatedness of mated males and of males performing post-copulatory mate guarding. Our results show that when guarded by a related male, females store less sperm from their actual mate, irrespective of the relatedness of the mating male. Our data support the notion that inhibition of sperm storage by female crickets can act as a form of cryptic female choice to avoid the severe negative effects of inbreeding.

  16. The population dynamical implications of male-biased parasitism in different mating systems.

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    Martin R Miller

    Full Text Available Although there is growing evidence that males tend to suffer higher levels of parasitism than females, the implications of this for the population dynamics of the host population are not yet understood. Here we build on an established 'two-sex' model and investigate how increased susceptibility to infection in males affects the dynamics, under different mating systems. We investigate the effect of pathogenic disease at different case mortalities, under both monogamous and polygynous mating systems. If the case mortality is low, then male-biased parasitism appears similar to unbiased parasitism in terms of its effect on the population dynamics. At higher case mortalities, we identified significant differences between male-biased and unbiased parasitism. A host population may therefore be differentially affected by male-biased and unbiased parasitism. The dynamical outcome is likely to depend on a complex interaction between the host's mating system and demography, and the parasite virulence.

  17. The effect of mate removal on dawn singing behaviour in male pied bush chats

    Institute of Scientific and Technical Information of China (English)

    Vinaya Kumar SETHI; Dinesh BHATT; Amit KUMAR

    2011-01-01

    To determine the influence of pairing status on dawn singing behaviour in pied bush chats Saxicola caprata, we conducted mate removal experiments across eight territories. The experiment was divided into three stages: pre-removal (pairs were present on theit respective territories), removal (females were experimentally removed), and returned (females were released into the focal pairs' territories). Dawn bout length, song rate, song complexity, percentage performance time, song perch height, and distance of singing location to territory boundary were measured for each male during each experimental stage. We did not find an effect of mate removal on any dawn song characteristics of male pied bush chats suggesting that the presence or absence of a mate does not influence male dawn singing behaviour. Our findings further suggest that males use dawn chorus to mediate social relationships with neighbouring males to proclaim an established territory.

  18. Interdependent effects of male and female body size plasticity on mating behaviour of predatory mites.

    Science.gov (United States)

    Walzer, Andreas; Schausberger, Peter

    2015-02-01

    The adaptive canalization hypothesis predicts that traits with low phenotypic plasticity are more fitness relevant, because they have been canalized via strong past selection, than traits with high phenotypic plasticity. Based on differing male body size plasticities of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity), we accordingly hypothesized that small male body size entails higher costs in female choice and male-male competition in P. persimilis than N. californicus. Males of both species are highly polygynous but females differ in the level of polyandry (low level in P. persimilis; medium level in N. californicus). We videotaped the mating interactions in triplets of either P. persimilis or N. californicus, consisting of a virgin female (small or standard-sized) and a small and a standard-sized male. Mating by both small and standard-sized P. persimilis females was biased towards standard-sized males, resulting from the interplay between female preference for standard-sized males and the inferiority of small males in male-male competition. In contrast, mating by N. californicus females was equally balanced between small and standard-sized males. Small N. californicus males were more aggressive ('Napoleon complex') in male-male competition, reducing the likelihood of encounter between the standard-sized male and the female, and thus counterbalancing female preference for standard-sized males. Our results support the hypothesis that male body size is more important to fitness in the low-level polyandrous P. persimilis than in the medium-level polyandrous N. californicus and provide a key example of the implications of sexually selected body size plasticity on mating behaviour.

  19. Male Age Affects Female Mate Preference, Quantity of Accessory Gland Proteins, and Sperm Traits and Female Fitness in D. melanogaster.

    Science.gov (United States)

    Rezaei, Abolhasan; Krishna, Mysore Siddaiah; Santhosh, Hassan T

    2015-01-01

    For species in which mating is resource-independent and offspring do not receive parental care, theoretical models of age-based female mate preference predict that females should prefer to mate with older males as they have demonstrated ability to survive. Thus, females should obtain a fitness benefit from mating with older males. However, male aging is often associated with reductions in quantity of sperm. The adaptive significance of age-based mate choice is therefore unclear. Various hypotheses have made conflicting predictions concerning this issue, because published studies have not investigated the effect of age on accessory gland proteins and sperm traits. D. melanogaster exhibits resource-independent mating, and offspring do not receive parental care, making this an appropriate model for studying age-based mate choice. In the present study, we found that D. melanogaster females of all ages preferred to mate with the younger of two competing males. Young males performed significantly greater courtship attempts and females showed least rejection for the same than middle-aged and old males. Young males had small accessory glands that contained very few main cells that were larger than average. Nevertheless, compared with middle-aged or old males, the young males transferred greater quantities of accessory gland proteins and sperm to mated females. As a result, females that mated with young male produced more eggs and progeny than those that mated with older males. Furthermore, mating with young male reduced female's lifespan. These studies indicate that quantity of accessory gland proteins and sperm traits decreased with male age and females obtain direct fitness benefit from mating with preferred young males.

  20. Multiple mating and a low incidence of cuckoldry for nest-holding males in the two-spotted goby, Gobiusculus flavescens

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    Forsgren Elisabet

    2009-01-01

    Full Text Available Abstract Background A major question in behavioural ecology concerns the relationship between genetic mating systems and the strength of sexual selection. In this study, we investigated the genetic mating system of the two-spotted goby (Gobiusculus flavescens, a useful fish model for the study of sexual selection whose genetic mating system remains uncharacterized. We developed four polymorphic microsatellite markers and used them to conduct parentage analyses on 21 nests collected during the breeding season to examine the rates of multiple mating by males and to test for evidence of alternative mating strategies. Results Results of this study indicate that male G. flavescens mate with multiple females and enjoy confidence of paternity. We detected only one instance of sneaking, so cuckoldry contributed a very small percentage (~0.1% of the total fertilizations in this population. Nests were nearly full and males that maintain larger nests have higher mating and reproductive success, irrespective of body size. Conclusion Overall, our investigation shows that G. flavescens is similar to other, related gobies in that the nests of care-giving males often contain eggs from multiple females. However, G. flavescens differs from other gobies in displaying an extremely low rate of cuckoldry. The study of ecological factors responsible for this important difference between G. flavescens and related species should be a fertile area for future work.

  1. Plant mating system transitions drive the macroevolution of defense strategies.

    Science.gov (United States)

    Campbell, Stuart A; Kessler, André

    2013-03-05

    Understanding the factors that shape macroevolutionary patterns in functional traits is a central goal of evolutionary biology. Alternative strategies of sexual reproduction (inbreeding vs. outcrossing) have divergent effects on population genetic structure and could thereby broadly influence trait evolution. However, the broader evolutionary consequences of mating system transitions remain poorly understood, with the exception of traits related to reproduction itself (e.g., pollination). Across a phylogeny of 56 wild species of Solanaceae (nightshades), we show here that the repeated, unidirectional transition from ancestral self-incompatibility (obligate outcrossing) to self-compatibility (increased inbreeding) leads to the evolution of an inducible (vs. constitutive) strategy of plant resistance to herbivores. We demonstrate that inducible and constitutive defense strategies represent evolutionary alternatives and that the magnitude of the resulting macroevolutionary tradeoff is dependent on the mating system. Loss of self-incompatibility is also associated with the evolution of increased specificity in induced plant resistance. We conclude that the evolution of sexual reproductive variation may have profound effects on plant-herbivore interactions, suggesting a new hypothesis for the evolution of two primary strategies of plant defense.

  2. Retention of Ejaculate by Drosophila melanogaster Females Requires the Male-Derived Mating Plug Protein PEBme.

    Science.gov (United States)

    Avila, Frank W; Cohen, Allie B; Ameerudeen, Fatima S; Duneau, David; Suresh, Shruthi; Mattei, Alexandra L; Wolfner, Mariana F

    2015-08-01

    Within the mated reproductive tracts of females of many taxa, seminal fluid proteins (SFPs) coagulate into a structure known as the mating plug (MP). MPs have diverse roles, including preventing female remating, altering female receptivity postmating, and being necessary for mated females to successfully store sperm. The Drosophila melanogaster MP, which is maintained in the mated female for several hours postmating, is comprised of a posterior MP (PMP) that forms quickly after mating begins and an anterior MP (AMP) that forms later. The PMP is composed of seminal proteins from the ejaculatory bulb (EB) of the male reproductive tract. To examine the role of the PMP protein PEBme in D. melanogaster reproduction, we identified an EB GAL4 driver and used it to target PEBme for RNA interference (RNAi) knockdown. PEBme knockdown in males compromised PMP coagulation in their mates and resulted in a significant reduction in female fertility, adversely affecting postmating uterine conformation, sperm storage, mating refractoriness, egg laying, and progeny generation. These defects resulted from the inability of females to retain the ejaculate in their reproductive tracts after mating. The uncoagulated MP impaired uncoupling by the knockdown male, and when he ultimately uncoupled, the ejaculate was often pulled out of the female. Thus, PEBme and MP coagulation are required for optimal fertility in D. melanogaster. Given the importance of the PMP for fertility, we identified additional MP proteins by mass spectrometry and found fertility functions for two of them. Our results highlight the importance of the MP and the proteins that comprise it in reproduction and suggest that in Drosophila the PMP is required to retain the ejaculate within the female reproductive tract, ensuring the storage of sperm by mated females. Copyright © 2015 by the Genetics Society of America.

  3. Female-borne cues affecting Psyttalia concolor (Hymenoptera: Braconidae) male behavior during courtship and mating

    Institute of Scientific and Technical Information of China (English)

    Angelo Canale; Giovanni Benelli; Andrea Lucchi

    2013-01-01

    Knowledge of the mechanisms that regulate courtship and mating behavior in Psyttalia concolor (Szépligeti)-a koinobiont endophagous solitary parasitoid of the olive fruit fly,Bactrocera oleae (Rossi),and of other fruit flies-is essential to its mass rearing and management.Augmentative releases ofP.concolor for olive fruit fly control started in the Mediterranean areas in the 1950s and still continue with limited success.We determined the influence of visual and chemical cues on courtship and mating behavior of this braconid and the possible effect of the mating status of males and females in the perception of these cues.Our results suggest that integration of visual and chemical stimuli are fundamental for mate location and courtship.Indeed,the optimal response of the male was achieved when physical and chemical cues were simultaneously presented and vision and olfaction worked synergistically.

  4. The mate choice brain: comparing gene profiles between female choice and male coercive poeciliids.

    Science.gov (United States)

    Lynch, K S; Ramsey, M E; Cummings, M E

    2012-03-01

    Genes that mediate mate preferences potentially play a key role in promoting and maintaining biological diversity. In this study, we compare mate preference behavior in two related poeciliid fishes with contrasting behavioral phenotypes and relate these behavioral differences to gene profiles in the brain. Results reveal that one poeciliid fish, the Northern swordtail, exhibits robust mate preference as compared to the Western mosquitofish, which utilizes a coercive mating system. Female swordtails display no significant difference in association time between male- and female-exposure trials, whereas female mosquitofish spend significantly less time associating with males relative to females. Furthermore, the preference strength for large males is significantly lower in female mosquitofish relative to swordtails. We then examine expression of three candidate genes previously shown to be associated with mate preference behavior in female swordtails and linked to neural plasticity in other vertebrates: neuroserpin (NS), neuroligin-3 (NLG-3) and N-methyl-d-aspartate receptor (NMDA-R). Whole brain gene expression patterns reveal that two genes (NS and NLG-3) are positively associated with mate preference behavior in female swordtails, a pattern opposing that of the mosquitofish. In mosquitofish females, these genes are downregulated when females express biases toward males yet are elevated in association with total motor activity patterns under asocial conditions, suggesting that the presence of males in mosquitofish species may inhibit expression of these genes. Both gene expression and female behavioral responses to males exhibit opposing patterns between these species, suggesting that this genetic pathway may potentially act as a substrate for the evolution of mate preference behavior.

  5. Do males evaluate female age for precopulatory mate guarding in the two-spotted spider mite?

    NARCIS (Netherlands)

    Oku, K.; Saito, Y.

    2014-01-01

    In the two-spotted spider mite Tetranychus urticae (Acari: Tetranychidae), because only the first mating results in fertilisation, adult males guard quiescent deutonymph females, the stage immediately before adult emergence. Previous studies showed that T. urticae males prefer to guard older rather

  6. Exposure to tea tree oil enhances the mating success of male Mediterranean fruit flies (Diptera: Tephritidae)

    Science.gov (United States)

    The aroma of various plant essential oils has been shown to enhance the mating competitiveness of males of the Mediterranean fruit fly (medfly), Ceratitis capitata (Wiedemann). Laboratory observations revealed that male medflies show strong short-range attraction to tea tree oil (TTO hereafter) deri...

  7. Male Enchenopa treehoppers (Hemiptera: Membracidae) vary mate-searching behavior but not signaling behavior in response to spider silk

    Science.gov (United States)

    Fowler-Finn, Kasey D.; Al-Wathiqui, Nooria; Cruz, Daniel; Al-Wathiqui, Mishal; Rodríguez, Rafael L.

    2014-03-01

    Finding and attracting mates can impose costs on males in terms of increased encounters with, and attraction of, predators. To decrease the likelihood of predation, males may modify mate-acquisition efforts in two main ways: they may reduce mate-searching efforts or they may reduce mate-attraction efforts. The specific behavior that males change in the presence of predator cues should depend upon the nature of risk imposed by the type of predator present in the environment. For example, sit-and-wait predators impose greater costs to males moving in search of mates. Here, we test whether cues of the presence of a sit-and-wait predator lead to a reduction in mate-searching but not mate-acquisition behavior. We used a member of the Enchenopa binotata complex of treehoppers—a clade of vibrationally communicating insects in which males fly in search of mates and produce mate-attraction signals when they land on plant stems. We tested for changes in mate-searching and signaling behaviors when silk from a web-building spider was present or absent. We found that males delayed flight when spider silk was present but only if they were actively searching for mates. These results suggest that males have been selected to reduce predation risk by adjusting how they move about their environment according to the cues of sit-and-wait predators.

  8. Large males have a mating advantage in a species of darter with smaller, allopaternal males Etheostoma olmstedi

    Directory of Open Access Journals (Sweden)

    Kelly A. STIVER,Suzanne H. ALONZO

    2010-02-01

    Full Text Available Theory suggests that males that are larger than their competitors may have increased mating success, due to both greater competitive ability and increased attractiveness to females. We examined how male mating success varies with male size in the tessellated darter Etheostoma olmstedi. Previous work has shown that large males tend to move around and breed in vacant breeding sites, and consequently provide less care for their eggs, while smaller individuals can be allopaternal, caring for the eggs of other males as well as for their own. We studied female egg deposition in a natural breeding population using artificial breeding sites and in the laboratory, where female choice of spawning site was restricted to two breeding sites tended by two males of different sizes. In both the field and the laboratory, nests tended by larger males were more likely to receive new eggs. Additionally, the mean size of males associated with a nest was positively correlated with both the maximum coverage of eggs at the nest and the number of times new eggs were deposited. We discuss how the increased mating success of larger males, despite their decreased parental care, may help explain allopaternal care in this species [Current Zoology 56 (1: 1–5 2010].

  9. Male age and female mate choice in a synchronizing katydid.

    Science.gov (United States)

    Hartbauer, M; Siegert, M E; Römer, H

    2015-08-01

    In acoustically communicating species, females often evaluate the frequency content, signal duration and the temporal signal pattern to gain information about the age of the signaller. This is different in the synchronizing bush cricket Mecopoda elongata where females select males on the basis of relative signal timing in duets. In a longitudinal approach, we recorded songs of M. elongata males produced 2 weeks (young male) and 9 weeks (old male) after their ultimate moult. Signal timing of both age categories was studied in acoustic interactions, and female preference was investigated in choice situations. Young male chirps were significantly shorter and contained less energy compared to "old chirps". In mixed-age duets younger males timed their chirps as leader significantly more often. Females preferred the young male chirp when broadcast as leader over the old male chirp, but choice was random when the old male chirp was leader. This choice asymmetry was abolished after reducing the duration of the "old chirp". Results were mirrored in response of a bilateral pair of auditory neurons, where the asymmetry in spike count and first-spike latency correlated with behaviour. We suggest that older males may compensate their disadvantage in a more complex chorus situation.

  10. Working with what you've got: unattractive males show greater mate-guarding effort in a duetting songbird.

    Science.gov (United States)

    Dowling, Jenélle; Webster, Michael S

    2017-01-01

    When mates are limited, individuals should allocate resources to mating tactics that maximize fitness. In species with extra-pair paternity (EPP), males can invest in mate guarding, or, alternatively, in seeking EPP. Males should optimize fitness by adjusting investment according to their attractiveness to females, such that attractive males seek EPP, and unattractive males guard mates. This theory has received little empirical testing, leaving our understanding of the evolution of mating tactics incomplete; it is unclear how a male's relative attractiveness influences his tactics. We conducted observations and experiments on red-backed fairy-wrens (Malurus melanocephalus) to address this question. We found that older, more attractive (red-black) males sought EPP, whereas unattractive (brown) males invested in alternative tactics-physical and acoustic mate guarding. Younger red-black males used intermediate tactics. This suggests that males adopt mating tactics appropriate to their attributes. Males obtained similar reproductive success, suggesting these alternative tactics may maximize each male's paternity gain. Though it is likely that female choice also determines paternity, rather than just male tactics, we establish that the many interconnected components of a male's sexual phenotype influence the evolution of his decision-making rules, deepening our understanding of how mating tactics evolve under sexual selection. © 2017 The Author(s).

  11. Variation in fecal testosterone levels, inter-male aggression, dominance rank and age during mating and post-mating periods in wild adult male ring-tailed lemurs (Lemur catta).

    Science.gov (United States)

    Gould, L; Ziegler, T E

    2007-12-01

    In primate species exhibiting seasonal reproduction, patterns of testosterone excretion in adult males are variable: in some species, peaks correlate with female receptivity periods and heightened male-male aggression over access to estrous females, in others, neither heightened aggression nor marked elevations in testosterone have been noted. In this study, we examined mean fecal testosterone ( f T) levels and intermale aggression in wild adult male ring-tailed lemurs residing in three groups at Beza Mahafaly Reserve, Madagascar. Results obtained from mating and post-mating season 2003 were compared to test Wingfield et al. [1990. Am Nat 136:829-846] "challenge hypothesis", which predicts a strong positive relationship between male testosterone levels and male-male competition for access to receptive females during breeding season. f T levels and rates of intermale aggression were significantly higher during mating season compared to the post-mating period. Mean f T levels and aggression rates were also higher in the first half of the mating season compared with the second half. Number of males in a group affected rates of intermale agonism, but not mean f T levels. The highest-ranking males in two of the groups exhibited higher mean f T levels than did lower-ranking males, and young males exhibited lower f T levels compared to prime-aged and old males. In the post-mating period, mean male f T levels did not differ between groups, nor were there rank or age effects. Thus, although male testosterone levels rose in relation to mating and heightened male-male aggression, f T levels fell to baseline breeding levels shortly after the early mating period, and to baseline non-breeding levels immediately after mating season had ended, offsetting the high cost of maintaining both high testosterone and high levels of male-male aggression in the early breeding period. (c) 2007 Wiley-Liss, Inc.

  12. Behavioural effect of low-dose BPA on male zebrafish: Tuning of male mating competition and female mating preference during courtship process.

    Science.gov (United States)

    Li, Xiang; Guo, Jia-Yu; Li, Xu; Zhou, Hai-Jun; Zhang, Shu-Hui; Liu, Xiao-Dong; Chen, Dong-Yan; Fang, Yong-Chun; Feng, Xi-Zeng

    2017-02-01

    The ubiquity of environmental pollution by endocrine disrupting chemicals (EDCs) such as bisphenol A (BPA) is progressively considered as a major threat to aquatic ecosystems worldwide. Numerous toxicological studies have proved that BPA are hazardous to aquatic environment, along with alterations in the development and physiology of aquatic vertebrates. However, generally, there is a paucity in knowledge of behavioural and physiological effects of BPA with low concentration, for example, 0.22 nM (50 ng/L) and 2.2 nM (500 ng/L). Here we show that treatment of adult male zebrafish (Danio rerio) with 7 weeks low-dose (0.22 nM-2.2 nM) BPA, resulted in alteration in histological structure of testis tissue and abnormality in expression levels of genes involved in testicular steroidogenesis. Furthermore, low-dose BPA treatment decreased the male locomotion during courtship; and was associated with less courtship behaviours to female but more aggressive behaviours to mating competitor. Interestingly, during the courtship test, we observed that female preferred control male to male under low-dose BPA exposure. Subsequently, we found that the ability of female to chose optimal mating male through socially mutual interaction and dynamics of male zebrafish, which was based on visual discrimination. In sum, our results shed light on the potential behavioural and physiological effect of low-dose BPA exposure on courtship behaviours of zebrafish, which could exert profound consequences on natural zebrafish populations.

  13. The male blue crab, Callinectes sapidus, uses both chromatic and achromatic cues during mate choice.

    Science.gov (United States)

    Baldwin, Jamie; Johnsen, Sönke

    2012-04-01

    In the blue crab, Callinectes sapidus, claw color varies by sex, sexual maturity and individual. Males rely in part on color cues to select appropriate mates, and these chromatic cues may be perceived through an opponent interaction between two photoreceptors with maximum wavelength sensitivities at 440 and 508 nm. The range of color discrimination of this dichromatic visual system may be limited, however, and it is unclear whether male blue crabs are capable of discriminating the natural variations in claw color that may be important in mate choice. By testing males' innate color preferences in binary choice tests between photographs of red-clawed females and six variations of orange-clawed females, we examined both the chromatic (opponent interaction) and achromatic (relative luminance) cues used in male mate choice. Males significantly preferred red-clawed females to orange-clawed females, except when the test colors were similar in both opponency and relative luminance. Our results are unusual in that they indicate that male mate choice in the blue crab is not guided solely by achromatic or chromatic mechanisms, suggesting that both color and intensity are used to evaluate female claw color.

  14. Mating competitiveness of Aedes albopictus radio-sterilized males in large enclosures exposed to natural conditions.

    Science.gov (United States)

    Bellini, R; Balestrino, F; Medici, A; Gentile, G; Veronesi, R; Carrieri, M

    2013-01-01

    Mating competitiveness trials have been conducted in large net-screened enclosures (8 by 5 by 2.8 m) built in a natural shaded environment, in the summers of 2006, 2007, 2008, and 2009 in northern Italy. Aedes albopictus (Skuse) males were radio-sterilized by applying gamma radiations at doses in the range 30-60 Gy. Gamma radiation was administered to aged pupae at the rate of 2.3 Gy/min. Reared radiated males (originally collected in Rimini, Forli, Bologna, Matera, Pinerolo) and hybrid radiated males were tested against wild fertile males (originated from eggs collected in Rimini and Cesena) and reared fertile males, in multiple comparisons for mating competitiveness with reared or wild females. The ratio was kept constant at 100-100_100 (fertile males-radiated males_virgin females). Mating competitiveness was estimated through the calculation of the hatching rate of the eggs laid in oviposition traps positioned inside enclosures. No clear effect of the strains tested (reared, wild, or hybrid) was found. Results demonstrated that reducing the radiation dose from 60 to 30 Gy increases males' competitiveness. Laboratory investigations conducted after controversial results in the 2006 preliminary trials, showed that radiation induces precociousness in adult male emergence.

  15. Aedes albopictus (Skuse) males in laboratory and semi-field cages: release ratios and mating competitiveness.

    Science.gov (United States)

    Madakacherry, Odessa; Lees, Rosemary Susan; Gilles, Jeremie Roger Lionel

    2014-04-01

    To control the container-breeding mosquito and major vector of dengue and chikungunya Aedes albopictus, the sterile insect technique (SIT) is proposed as a component of integrated vector management programs in endemic areas. For the technique to be successful, released males, sterilized with 35 Gy of ionizing radiation during the pupal stage, must be able to compete for mating opportunities with wild counterparts and successfully copulate with wild females to induce sterility in the population. Any reduction in competitiveness can be compensated for by increasing the ratio of released sterile to wild males, a ratio which must be optimized for effectiveness and efficiency. Fruit fly SIT programs use field enclosures to test the competitiveness of sterile males to monitor the quality of the colony and adjust release ratios. This is laborious and time consuming, and for mosquito programs it would be advantageous if similarly useful results could be obtained by smaller scale laboratory tests, conducted on a more regular basis. In the present study we compared the competitiveness, as measured by hatching rate of resulting egg batches, of irradiated males measured in small and large laboratory cages and semi-field enclosures in a greenhouse setting, when competing in a 1:1, 3:1, and 5:1 ratio with fertile males. The sterile males were found to be equally competitive when compared to unirradiated counterparts, and a 5:1 ratio was sufficient to reduce, but not eliminate, the fertility of the female populations, irrespective of cage size. Variability in hatch rate in eggs laid by individual females and so-called indeterminate matings, when we could not be certain whether a female had mated a fertile or a sterile male, could be investigated by closer investigation of mating status and the frequency of multiple matings in Ae. albopictus. The laboratory results are encouraging for the effectiveness of the SIT using irradiated males of this species, and we support further

  16. Audience effect alters male mating preferences in zebra finches (Taeniopygia guttata).

    Science.gov (United States)

    Dubois, Frédérique; Belzile, Alexandra

    2012-01-01

    The social environment of animals strongly influences the mating preferences of both the choosing and the observing individuals. Notably, there is recent evidence that polygamous males decrease their selectivity when being observed by competitors in order to direct their rivals' attention away from their true interest and, consequently, reduce sperm competition risk. Yet, other mechanisms, whose importance remains unexplored, could induce similar effects. In monogamous species with mutual choice, particularly, if males adjust their selectivity according to the risk of being rejected by their preferred mate, they should as well become less selective when potential rivals are present. Here, we investigated whether the presence of bystanders modifies male mating preferences when the risk of sperm competition is low, by carrying out mate-choice experiments with male zebra finches (Taeniopygia guttata) whose preferences for two females were measured twice: with and without an audience. We found that the presence of potential rivals had no effect on the males' choosiness. However, with an audience, they spent more time with the female that was considered as the less attractive one in the control condition. These findings support the hypothesis that monogamous males alter their mate choice decisions in the presence of a male audience to reduce the risk of remaining unpaired. Thus, our results indicate that several explanations can account for the changes in male preferences due to the presence of competitors and highlight the importance of assessing the relative role of each mechanism potentially involved, to be able to make conclusions about the effect of an audience on signal evolution.

  17. The mating behaviors of mated male crayfish Procambarus clarkii%婚配后雄性克氏原螯虾的择偶行为

    Institute of Scientific and Technical Information of China (English)

    张丽; 谢春; 唐建清; 黄成

    2014-01-01

    动物在繁殖期间随自身繁殖价值的变化而调整择偶行为,从而导致它们择偶行为的多样性.本文研究具交配经验的雄性克氏原螯虾(Procambarus clarkii )在 Y型水迷宫中对不同婚配状态的潜在配偶的择偶行为.结果表明:雄虾在原配一侧的总访问时间和平均访问时间极显著大于在处女虾一侧(P<0.005);访问原配的次数与处女虾相比没有达到显著水平(双侧检验P=0.086),但倾向性还是偏向原配(单侧检验P=0.043).当原配不在时,雄虾随机选择潜在配偶;面对都具备交配经验的原配和非处女虾,雄虾也随机选择配偶.这说明雄虾一定程度上可以识别潜在配偶的婚配状态,推测雄虾可能通过配偶保卫策略确保父权;但雄虾的忠诚度可能会因原配的存在与否而及时改变.因此,雄虾能根据自身的婚配状态以及获取配偶的成本来调整择偶行为.%During the reproduction period,animals can make adj ustments of selectivity with the changes of their own reproductive values,which will lead to the variation of their mating behaviors.Previous papers have discussed the effects of body size and hierarchical status on mutual mate choice in Procambarus clarkii,while few of them pay attention to mating status as a criterion of sexual selection.Due to the long time retention between mating and ovipo-sition,P.clarkii’s mating status will change accordingly.Based on the knowledge of the unmated males’preferences for virgin females,we conducted an experiment to study the mating behaviors of male P.clarkii with mating experience in a Y maze when confronting potential female mates,which have different mating status.Our study indicates:both the total and mean visiting time that the males spent in their primary partners were significantly longer than the virgin targets(P<0.05);although the visiting frequency of primary partners did not reach the significant level compared with the virgin

  18. Inbreeding depresses sperm competitiveness, but not fertilization or mating success in male Tribolium castaneum

    Science.gov (United States)

    Michalczyk, Łukasz; Martin, Oliver Y.; Millard, Anna L.; Emerson, Brent C.; Gage, Matthew J. G.

    2010-01-01

    As populations decline to levels where reproduction among close genetic relatives becomes more probable, subsequent increases in homozygous recessive deleterious expression and/or loss of heterozygote advantage can lead to inbreeding depression. Here, we measure how inbreeding across replicate lines of the flour beetle Tribolium castaneum impacts on male reproductive fitness in the absence or presence of male–male competition. Effects on male evolution from mating pattern were removed by enforcing monogamous mating throughout. After inbreeding across eight generations, we found that male fertility in the absence of competition was unaffected. However, we found significant inbreeding depression of sperm competitiveness: non-inbred males won 57 per cent of fertilizations in competition, while inbred equivalents only sired 42 per cent. We also found that the P2 ‘offence’ role in sperm competition was significantly more depressed under inbreeding than sperm ‘defence’ (P1). Mating behaviour did not explain these differences, and there was no difference in the viability of offspring sired by inbred or non-inbred males. Sperm length variation was significantly greater in the ejaculates of inbred males. Our results show that male ability to achieve normal fertilization success was not depressed under strong inbreeding, but that inbreeding depression in these traits occurred when conditions of sperm competition were generated. PMID:20554548

  19. Male foraging efficiency, but not male problem-solving performance, influences female mating preferences in zebra finches.

    Science.gov (United States)

    Chantal, Véronique; Gibelli, Julie; Dubois, Frédérique

    2016-01-01

    Experimental evidence suggests that females would prefer males with better cognitive abilities as mates. However, little is known about the traits reflecting enhanced cognitive skills on which females might base their mate-choice decisions. In particular, it has been suggested that male foraging performance could be used as an indicator of cognitive capacity, but convincing evidence for this hypothesis is still lacking. In the present study, we investigated whether female zebra finches (Taeniopygia guttata) modify their mating preferences after having observed the performance of males on a problem-solving task. Specifically, we measured the females' preferences between two males once before and once after an observation period, during which their initially preferred male was incapable of solving the task contrary to their initially less-preferred male. We also conducted a control treatment to test whether the shift in female preferences was attributable to differences between the two stimulus males in their foraging efficiency. Finally, we assessed each bird's performance in a color associative task to check whether females can discriminate among males based on their learning speed. We found that females significantly increased their preference toward the most efficient male in both treatments. Yet, there was no difference between the two treatments and we found no evidence that females assess male cognitive ability indirectly via morphological traits. Thus, our results suggest that females would not use the males' problem-solving performance as an indicator of general cognitive ability to gain indirect fitness benefits (i.e., good genes) but rather to assess their foraging efficiency and gain direct benefits.

  20. Piecing together female extra-pair mate choice: females really do prefer more ornamented males.

    Science.gov (United States)

    Wells, Sarah J; Safran, Rebecca J; Dale, James

    2016-08-01

    Evolutionary biologists have long been fascinated by extravagant male traits that abound across the animal kingdom and yet convey no apparent benefits to survival. From isopods to elephants, from armaments to ornaments, researchers have spent decades studying male-male competition and female mate choice in an effort to understand the significance of these secondary sexual characteristics. Among socially monogamous species, a frequently proposed explanation for the existence of male ornaments is that they are indicators of male genetic quality subject to female extra-pair mate choice. However, despite over two decades of extensive research into extra-pair paternity (EPP), the evidence that females actually choose more ornamented extra-pair sires is surprisingly scant. Consequently, whether EPP and female choice have contributed to the evolution of male ornaments in socially monogamous species, and what fitness benefits (if any) they signal to females, remains unclear. Progress in this field has been hampered by the challenge of dissociating clear female choice for ornamentation from confounding factors. In this issue of Molecular Ecology, Whittingham & Dunn (2016) use an experimental approach in a bird species with very high rates of EPP to tease apart these correlative effects. In doing so, they demonstrate clearly that male ornamentation is subject to female extra-pair mate choice. Their findings further suggest that EPP can be adaptive for females, and represent an important step forward in validating the role of EPP as an evolutionary driver of ornamental elaboration in socially monogamous species.

  1. Cryptic forcible insemination: male snakes exploit female physiology, anatomy, and behavior to obtain coercive matings.

    Science.gov (United States)

    Shine, Richard; Langkilde, Tracy; Mason, Robert T

    2003-11-01

    Whether males can inseminate uncooperative females is a central determinant of mating system evolution that profoundly affects the interpretation of phenomena such as multiple mating by females, mate choice, reproductive seasonality, and courtship tactics. Forcible insemination is usually inferred from direct physical battles between the sexes and has been dismissed on intuitive grounds for many kinds of animals. For example, snakes have elongate flexible bodies (making it difficult for a male to restrain a female physically), males are typically smaller than females, and copulation requires female cloacal gaping to enable intromission. Male garter snakes (Thamnophis sirtalis) do not display any overt aggression during courtship and simply lie over the female and exhibit rhythmic pulsating caudocephalic waves of muscular contraction; previous studies have interpreted this behavior as a mechanism for eliciting female receptivity. In contrast, we show that male garter snakes forcibly inseminate females. They do so by taking advantage of specific features of snake physiology, respiratory anatomy, and antipredator behavior. The snake lung extends along most of the body, with the large posterior section (the saccular lung) lacking any respiratory exchange surface. Rhythmic caudocephalic waves by courting male garter snakes push anoxic air from the saccular lung forward and across the respiratory surfaces such that females cannot obtain oxygen. Their stress response involves cloacal gaping, which functions in other contexts to repel predators by extruding feces and musk but in this situation permits male intromission. Thus, superficially benign courtship behaviors may involve cryptic coercion even in species for which intuition dismisses any possibility of forcible insemination.

  2. Complex mitonuclear interactions and metabolic costs of mating in male seed beetles.

    Science.gov (United States)

    Immonen, E; Rönn, J; Watson, C; Berger, D; Arnqvist, G

    2016-02-01

    The lack of evolutionary response to selection on mitochondrial genes through males predicts the evolution of nuclear genetic influence on male-specific mitochondrial function, for example by gene duplication and evolution of sex-specific expression of paralogs involved in metabolic pathways. Intergenomic epistasis may therefore be a prevalent feature of the genetic architecture of male-specific organismal function. Here, we assess the role of mitonuclear genetic variation for male metabolic phenotypes [metabolic rate and respiratory quotient (RQ)] associated with ejaculate renewal, in the seed beetle Callosobruchus maculatus, by assaying lines with crossed combinations of distinct mitochondrial haplotypes and nuclear lineages. We found a significant increase in metabolic rate following mating relative to virgin males. Moreover, processes associated with ejaculate renewal showed variation in metabolic rate that was affected by mitonuclear interactions. Mitochondrial haplotype influenced mating-related changes in RQ, but this pattern varied over time. Mitonuclear genotype and the energy spent during ejaculate production affected the weight of the ejaculate, but the strength of this effect varied across mitochondrial haplotypes showing that the genetic architecture of male-specific reproductive function is complex. Our findings unveil hitherto underappreciated metabolic costs of mating and ejaculate renewal, and provide the first empirical demonstration of mitonuclear epistasis on male reproductive metabolic processes.

  3. Female mating preferences and male coloration covary with water transparency in a Lake Victoria cichlid fish

    NARCIS (Netherlands)

    Maan, Martine E.; Seehausen, Ole; Van Alphen, Jacques J. M.

    2010-01-01

    Rapid speciation in Lake Victoria cichlid fish of the genus Pundamilia may be facilitated by sexual selection: female mate choice exerts sexual selection on male nuptial coloration within species and maintains reproductive isolation between species. However, declining water transparency coincides wi

  4. Nutritional enrichment increases courtship intensity and improves mating success in male spiders

    DEFF Research Database (Denmark)

    Lomborg, Johannes Peter; Toft, Søren

    2009-01-01

    status (enriched or deficient) and that courtship intensity predicts mating success in males of the same nutritional status. We used wolf spiders, Pardosa prativaga, which have an elaborate display of courtship behaviors, including encircling, palp vibrations, abdomen vibrations, hopping, etc. Viability...

  5. Male foraging efficiency, but not male problem-solving performance, influences female mating preferences in zebra finches

    Directory of Open Access Journals (Sweden)

    Véronique Chantal

    2016-08-01

    Full Text Available Experimental evidence suggests that females would prefer males with better cognitive abilities as mates. However, little is known about the traits reflecting enhanced cognitive skills on which females might base their mate-choice decisions. In particular, it has been suggested that male foraging performance could be used as an indicator of cognitive capacity, but convincing evidence for this hypothesis is still lacking. In the present study, we investigated whether female zebra finches (Taeniopygia guttata modify their mating preferences after having observed the performance of males on a problem-solving task. Specifically, we measured the females’ preferences between two males once before and once after an observation period, during which their initially preferred male was incapable of solving the task contrary to their initially less-preferred male. We also conducted a control treatment to test whether the shift in female preferences was attributable to differences between the two stimulus males in their foraging efficiency. Finally, we assessed each bird’s performance in a color associative task to check whether females can discriminate among males based on their learning speed. We found that females significantly increased their preference toward the most efficient male in both treatments. Yet, there was no difference between the two treatments and we found no evidence that females assess male cognitive ability indirectly via morphological traits. Thus, our results suggest that females would not use the males’ problem-solving performance as an indicator of general cognitive ability to gain indirect fitness benefits (i.e., good genes but rather to assess their foraging efficiency and gain direct benefits.

  6. Paternal inheritance of alternative mating tactics in male Atlantic salmon: Toward an integrated population genomics perspective.

    OpenAIRE

    2014-01-01

    Intraspecific diversity is of paramount importance for species adaptation to global changes. Alternative mating tactics have important ecological and evolutionary implications and are determined by complex interaction between environmental and genetic factors potentially involving phenotypic plasticity. Atlantic salmon is a good example of species showing high life history variability. Here we focused on early male parr maturation, an alternative reproductive tactics allowing male parr to re...

  7. The health of a nation predicts their mate preferences: cross-cultural variation in women's preferences for masculinized male faces

    Science.gov (United States)

    DeBruine, Lisa M.; Jones, Benedict C.; Crawford, John R.; Welling, Lisa L. M.; Little, Anthony C.

    2010-01-01

    Recent formulations of sexual selection theory emphasize how mate choice can be affected by environmental factors, such as predation risk and resource quality. Women vary greatly in the extent to which they prefer male masculinity and this variation is hypothesized to reflect differences in how women resolve the trade-off between the costs (e.g. low investment) and benefits (e.g. healthy offspring) associated with choosing a masculine partner. A strong prediction of this trade-off theory is that women's masculinity preferences will be stronger in cultures where poor health is particularly harmful to survival. We investigated the relationship between women's preferences for male facial masculinity and a health index derived from World Health Organization statistics for mortality rates, life expectancies and the impact of communicable disease. Across 30 countries, masculinity preference increased as health decreased. This relationship was independent of cross-cultural differences in wealth or women's mating strategies. These findings show non-arbitrary cross-cultural differences in facial attractiveness judgements and demonstrate the use of trade-off theory for investigating cross-cultural variation in women's mate preferences. PMID:20236978

  8. Male genital morphology and its influence on female mating preferences and paternity success in guppies.

    Directory of Open Access Journals (Sweden)

    Clelia Gasparini

    Full Text Available In internally fertilizing species male genitalia often show a higher degree of elaboration than required for simply transferring sperm to females. Among the hypotheses proposed to explain such diversity, sexual selection has received the most empirical support, with studies revealing that genital morphology can be targeted by both pre-and postcopulatory sexual selection. Until now, most studies have focused on these two episodes of selection independently. Here, we take an alternative approach by considering both components simultaneously in the livebearing fish, Poecilia reticulata. We allowed females to mate successively (and cooperatively with two males and determined whether male genital length influenced the female's propensity to mate with a male (precopulatory selection, via female choice and whether male genital size and shape predicted the relative paternity share of subsequent broods (postcopulatory selection, via sperm competition/cryptic female choice. We found no evidence that either episode of sexual selection targets male genital size or shape. These findings, in conjunction with our recent work exposing a role of genital morphology in mediating unsolicited (forced matings in guppies, further supports our prior speculation that sexual conflict may be an important broker of genital evolution in this species.

  9. Modelling of Yeast Mating Reveals Robustness Strategies for Cell-Cell Interactions.

    Directory of Open Access Journals (Sweden)

    Weitao Chen

    2016-07-01

    Full Text Available Mating of budding yeast cells is a model system for studying cell-cell interactions. Haploid yeast cells secrete mating pheromones that are sensed by the partner which responds by growing a mating projection toward the source. The two projections meet and fuse to form the diploid. Successful mating relies on precise coordination of dynamic extracellular signals, signaling pathways, and cell shape changes in a noisy background. It remains elusive how cells mate accurately and efficiently in a natural multi-cell environment. Here we present the first stochastic model of multiple mating cells whose morphologies are driven by pheromone gradients and intracellular signals. Our novel computational framework encompassed a moving boundary method for modeling both a-cells and α-cells and their cell shape changes, the extracellular diffusion of mating pheromones dynamically coupled with cell polarization, and both external and internal noise. Quantification of mating efficiency was developed and tested for different model parameters. Computer simulations revealed important robustness strategies for mating in the presence of noise. These strategies included the polarized secretion of pheromone, the presence of the α-factor protease Bar1, and the regulation of sensing sensitivity; all were consistent with data in the literature. In addition, we investigated mating discrimination, the ability of an a-cell to distinguish between α-cells either making or not making α-factor, and mating competition, in which multiple a-cells compete to mate with one α-cell. Our simulations were consistent with previous experimental results. Moreover, we performed a combination of simulations and experiments to estimate the diffusion rate of the pheromone a-factor. In summary, we constructed a framework for simulating yeast mating with multiple cells in a noisy environment, and used this framework to reproduce mating behaviors and to identify strategies for robust cell

  10. Sexual signalling in Propithecus verreauxi: male "chest badge" and female mate choice.

    Science.gov (United States)

    Dall'Olio, Stefania; Norscia, Ivan; Antonacci, Daniela; Palagi, Elisabetta

    2012-01-01

    Communication, an essential prerequisite for sociality, involves the transmission of signals. A signal can be defined as any action or trait produced by one animal, the sender, that produces a change in the behaviour of another animal, the receiver. Secondary sexual signals are often used for mate choice because they may inform on a potential partner's quality. Verreaux's sifaka (Propithecus verreauxi) is characterized by the presence of two different morphs of males (bimorphism), which can show either a stained or clean chest. The chest becomes stained by secretions of the sternal gland during throat marking (rubbing throat and chest on a vertical substrate while smearing the scent deposition). The role of the chest staining in guiding female mate choice was previously hypothesized but never demonstrated probably due to the difficulty of observing sifaka copulations in the wild. Here we report that stained-chested males had a higher throat marking activity than clean-chested males during the mating season, but not during the birth season. We found that females copulated more frequently with stained-chested males than the clean-chested males. Finally, in agreement with the biological market theory, we found that clean-chested males, with a lower scent-releasing potential, offered more grooming to females. This "grooming for sex" tactic was not completely unsuccessful; in fact, half of the clean-chested males copulated with females, even though at low frequency. In conclusion, the chest stain, possibly correlated with different cues targeted by females, could be one of the parameters which help females in selecting mates.

  11. Sexual signalling in Propithecus verreauxi: male "chest badge" and female mate choice.

    Directory of Open Access Journals (Sweden)

    Stefania Dall'Olio

    Full Text Available Communication, an essential prerequisite for sociality, involves the transmission of signals. A signal can be defined as any action or trait produced by one animal, the sender, that produces a change in the behaviour of another animal, the receiver. Secondary sexual signals are often used for mate choice because they may inform on a potential partner's quality. Verreaux's sifaka (Propithecus verreauxi is characterized by the presence of two different morphs of males (bimorphism, which can show either a stained or clean chest. The chest becomes stained by secretions of the sternal gland during throat marking (rubbing throat and chest on a vertical substrate while smearing the scent deposition. The role of the chest staining in guiding female mate choice was previously hypothesized but never demonstrated probably due to the difficulty of observing sifaka copulations in the wild. Here we report that stained-chested males had a higher throat marking activity than clean-chested males during the mating season, but not during the birth season. We found that females copulated more frequently with stained-chested males than the clean-chested males. Finally, in agreement with the biological market theory, we found that clean-chested males, with a lower scent-releasing potential, offered more grooming to females. This "grooming for sex" tactic was not completely unsuccessful; in fact, half of the clean-chested males copulated with females, even though at low frequency. In conclusion, the chest stain, possibly correlated with different cues targeted by females, could be one of the parameters which help females in selecting mates.

  12. Women's Hormonal Status and Mate Value Influence Relationship Satisfaction and Perceived Male Attractiveness

    Directory of Open Access Journals (Sweden)

    Ivana Hromatko

    2006-12-01

    Full Text Available Numerous findings suggest that female preferences for certain features of male faces vary during the menstrual cycle. Similarly, changes during the cycle have also been found in women's commitment to a current relationship. Furthermore, from the perspective of securing benefits from extra-pair affairs, the differences between women with high vs. low mate value could be expected. In this study we have tried to connect these sets of findings: first, we explored differences between partnered and single women in their ratings of male facial attractiveness in different phases of the menstrual cycle; and second, their satisfaction with the current relationship in relation to the cycle phase and selfperceived mate value. Two groups of women (single vs. partnered rated the attractiveness of two sets of male faces (normal vs. symmetrical. Repeated measures ANOVA showed that women in a relationship gave higher ratings of attractiveness for both normal and symmetrical faces in the luteal phase compared to the early follicular phase of a cycle, while single women showed the opposite pattern. Analyses of satisfaction with their current relationship in relation to cycle phase and self-perceived mate value showed that women with higher mate value are generally more satisfied with their current partners, and show smaller differences in satisfaction in various phases of the cycle. The results are interpreted in terms of content-specificity of hormone mediated adaptive design.

  13. Sexual cooperation and conflict in butterflies: a male-transferred anti-aphrodisiac reduces harassment of recently mated females.

    Science.gov (United States)

    Andersson, J; Borg-Karlson, A K; Wiklund, C

    2000-07-07

    Sexual selection theory predicts that the different selection pressures on males and females result in sexual conflict. However, in some instances males and females share a common interest which could lead to sexual cooperation. In the pierid butterfly Pieris napi the male and the recently mated female share a common interest in reducing female harassment by other males soon after mating. Here we show that P. napi males transfer an anti-aphrodisiac to the female at mating, methyl-salicylate (MeS), which is a volatile substance which mated females emit when courted and which makes males quickly abandon them. A 13C-labelling experiment demonstrated that only males synthesize MeS. The effect of this antiaphrodisiac is so strong that most males will refrain from mating with virgin females to whom MeS has been artificially applied. In P. napi, males also transfer nutrients to females at mating. This increases female fecundity and longevity and so females benefit from remating. Hence, sexual cooperation gradually turns to conflict. Future research is required to reveal which sex controls the gradual decrease in the MeS titre which is necessary for allowing mated females to regain attractiveness and remate.

  14. UV-deprived coloration reduces success in mate acquisition in male sand lizards (Lacerta agilis.

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    Mats Olsson

    Full Text Available BACKGROUND: Recent work on animal signals has revealed a wide occurrence of UV signals in tetrapods, in particular birds, but also in lizards (and perhaps other Squamate reptiles. Our previous work on the Swedish sand lizard (Lacerta agilis has verified, both in correlative selection analyses in the wild and with laboratory and field experiments, the importance of the green 'badge' on the body sides of adult males for securing mating opportunities, probably mostly through deterring rival males rather than attracting females. The role of UV in communication has, however, never been examined. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that when measured immediately after spring skin shedding, there is also signaling in the UV. By UV-depriving the signal (reflectance with sun block chemicals fixated with permeable, harmless spray dressing, we show that males in the control group (spray dressing only had significantly higher success in mate acquisition than UV-deprived males. CONCLUSIONS/SIGNIFICANCE: These results suggest that at least two colour traits in sand lizards, badge area and UV, contribute to rival deterrence and/or female choice on UV characters, which elevates success in mate acquisition in UV intact male sand lizards.

  15. Adaptive strategies of overwintering adults: Reproductive diapause and mating behavior in a grasshopper,Stenocatantops splendens (Orthoptera: Catantopidae)

    Institute of Scientific and Technical Information of China (English)

    Dao-Hong Zhu; Shuang-Shuang Cui; Yong-Sheng Fan; Zhiwei Liu

    2013-01-01

    To understand the adaptive strategies of the overwintering adults of Stenocatantops splendens,the mechanism of maintenance and termination of the reproductive diapause,the variation in mortality between overwintering females and males,and the mating strategy of the males were investigated.The results indicated that the adult reproductive diapause in natural conditions was mainly regulated by photoperiod in the fall-long photoperiods promoted reproductive development and short photoperiods maintained reproductive diapause,and the sensitivity of the overwintering adults to photoperiod was over before the end of the winter.When transferred from natural conditions to controlled laboratory conditions on dates from September through February,pre-oviposition became increasingly shorter with increasingly deferred transfer dates regardless of photoperiod conditions.The adults treated with low temperature for 30 days in September through November had significantly shorter pre-oviposition,suggesting that low temperatures in winter had an important role in the termination of reproductive diapause.The female had a significantly lower supercooling point than the male,which was related to their lower mortality after winter.In addition,observations of wild populations of the species indicated that mating behavior prior to winter and the duration of pre-mating period were not affected by photoperiod; mating and sperm transfer were mostly completed by November.Compared with females only mating before winter,females mating in the spring had shorter life span,longer pre-oviposition,lower hatching rate and laid fewer egg pods while showing no significant difference with regard to ovipositional interval,per pod number of eggs and nymph dry weight.

  16. Flexible mating tactics and associated reproductive effort during the rutting season in male reindeer (Rangifer tarandus, L. 1758)

    Institute of Scientific and Technical Information of China (English)

    Eliana PINTUS; Stefania UCCHEDDU; Knut H RED; Javier Prez GONZALZ; Juan CARRANZA; Mauri NIEMINEN; ystein HOLAND

    2015-01-01

    Polygynous males can change their mating tactics across their lifetime, but information is scarce on the flexibility of this trait within a given season and the relative costs and benefits of using different tactics. Here, we monitored individually marked male reindeerRangifer tarandus and classified their mating tactics as harem-defense, sneaking, or mixed. The costs of the male reproductive effort were assessed using both direct (i.e. percentage of body mass lost) and indirect measures (i.e. activity patterns such as feeding, standing, and walking), while mating group size and reproductive success were recorded as mating ef-fort benefits. Our results show that reindeer males may switch between the harem-defense and sneaking tactics throughout the same breeding season, providing further support to the notion that reproductive tactics are flexible in ungulates. The costs and benefits of male mating effort vary according to the mating tactic, reaching the highest values in harem-holders and the lowest values in sneaking males. Moreover, males who switched between the sneaking tactic and the harem-defence tactic tended to achieve higher mating success than males who consistently used the least costly tactic. Indeed, all harem-holders successfully sired offspring, whereas only two out of three mixed-tactic males sired one calf, and sneaking males did not sire any calves. In conclusion, our results show that reindeer males can modulate their mating efforts during the same breeding season by switching between the most costly harem-defense tactic and the least costly sneaking tactic, suggesting individual solutions to the balance between reproductive effort and mating opportunities [Current Zoology 61 (5): 802–810, 2015].

  17. Stay or stray? Evidence for alternative mating strategy phenotypes in both men and women.

    Science.gov (United States)

    Wlodarski, Rafael; Manning, John; Dunbar, R I M

    2015-02-01

    In all comparative analyses, humans always fall on the borderline between obligate monogamy and polygamy. Here, we use behavioural indices (sociosexuality) and anatomical indices (prenatal testosterone exposure indexed by 2D : 4D digit ratio) from three human populations to show that this may be because there are two distinct phenotypes in both sexes. While males are more promiscuous and display higher prenatal testosterone exposure than females overall, our analyses also suggest that the within-sex variation of these variables is best described by two underlying mixture models, suggesting the presence of two phenotypes with a monogamous/promiscuous ratio that slightly favours monogamy in females and promiscuity in males. The presence of two phenotypes implies that mating strategy might be under complex frequency-dependent selection.

  18. Poeciliid male mate preference is influenced by female size but not by fecundity

    Directory of Open Access Journals (Sweden)

    Luis R. Arriaga

    2013-08-01

    Full Text Available While female mate preference is very well studied, male preference has only recently begun to receive significant attention. Its existence is found in numerous taxa, but empirical research has mostly been limited to a descriptive level and does not fully address the factors influencing its evolution. We attempted to address this issue using preference functions by comparing the strength of male preference for females of different sizes in nine populations of four poeciliid species. Due to environmental constraints (water toxicity and surface versus cave habitat, females from these populations vary in the degree to which their size is correlated to their fecundity. Hence, they vary in how their size signals their quality as mates. Since female size is strongly correlated with fecundity in this subfamily, males were sequentially presented with conspecific females of three different size categories and the strength of their preference for each was measured. Males preferred larger females in all populations, as predicted. However, the degree to which males preferred each size category, as measured by association time, was not correlated with its fecundity. In addition, cave males discriminated against smaller females more than surface males. Assuming that male preference is correlated with female fitness, these results suggest that factors other than fecundity have a strong influence on female fitness in these species.

  19. Molecular assessment of mating strategies in a population of Atlantic spotted dolphins.

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    Michelle L Green

    Full Text Available Similar to other small cetacean species, Atlantic spotted dolphins (Stenella frontalis have been the object of concentrated behavioral study. Although mating and courtship behaviors occur often and the social structure of the population is well-studied, the genetic mating system of the species is unknown. To assess the genetic mating system, we genotyped females and their progeny at ten microsatellite loci. Genotype analysis provided estimates of the minimum number of male sires necessary to account for the allelic diversity observed among the progeny. Using the estimates of male sires, we determined whether females mated with the same or different males during independent estrus events. Using Gerud2.0, a minimum of two males was necessary to account for the genetic variation seen among progeny arrays of all tested females. ML-Relate assigned the most likely relationship between offspring pairs; half or full sibling. Relationship analysis supported the conservative male estimates of Gerud2.0 but in some cases, half or full sibling relationships between offspring could not be fully resolved. Integrating the results from Gerud2.0, ML-Relate with previous observational and paternity data, we constructed two-, three-, and four-male pedigree models for each genotyped female. Because increased genetic diversity of offspring may explain multi-male mating, we assessed the internal genetic relatedness of each offspring's genotype to determine whether parent pairs of offspring were closely related. We found varying levels of internal relatedness ranging from unrelated to closely related (range -0.136-0.321. Because there are several hypothesized explanations for multi-male mating, we assessed our data to determine the most plausible explanation for multi-male mating in our study system. Our study indicated females may benefit from mating with multiple males by passing genes for long-term viability to their young.

  20. Protozoan parasite Toxoplasma gondii manipulates mate choice in rats by enhancing attractiveness of males.

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    Shantala Arundathi Hari Dass

    Full Text Available Females in various species typically avoid males infected with parasites, while parasite-free males advertise their status through conspicuous phenotypic traits. This process selects for heritable resistance and reduces direct exposure of the female to parasites. Coevolving parasites are likely to attempt to circumvent this obstacle. In this paper, we demonstrate a case of parasitic manipulation of host mate choice. We report that Toxoplasma gondii, a sexually transmitted infection of brown rats, enhances sexual attractiveness of infected males. Thus under some evolutionary niches, parasites can indeed manipulate host sexual signaling to their own advantage.

  1. Incipient sexual isolation in the nasuta-albomicans complex of Drosophila: mating preference in male-, female– and multiple-choice mating experiments

    Indian Academy of Sciences (India)

    M T Tanuja; N B Ramachandra; H A Ranganath

    2001-09-01

    Interracial divergence is an important facet of speciation. The nasuta-albomicans complex of Drosophila with sixteen morphologically identical, karyotypically different but cross-fertile races is an excellent system to study a few dimensions of raciation. Drosophila nasuta nasuta, Drosophila nasuta albomicans, Cytorace 1, Cytorace 2, Cytorace 3 and Cytorace 4 of this subgroup have been subjected to male-, female- and multiple-choice mating experiments. Out of 8456 crosses conducted, 7185 had successful matings. The overall impression is that mating is far from random amongst these six closely related races of the nasuta-albomicans complex. The males of D. n. albomicans, Cytorace 1 and Cytorace 4 in male-choice, the females of Cytorace 1 and Cytorace 2 in female-choice, and the males and females of D. n. nasuta, D. n. albomicans, Cytorace 1 and Cytorace 4 against the males and females of Cytorace 2 in multiple-choice experiments, had significantly more homogamic matings than expected. Thus in this study of evolutionary experimentation on raciation under laboratory conditions, we have documented the initiation of preference for con-specific matings among closely related and independently evolving members of the nasuta-albomicans complex of Drosophila.

  2. Female brain size affects the assessment of male attractiveness during mate choice

    Science.gov (United States)

    Corral-López, Alberto; Bloch, Natasha I.; Kotrschal, Alexander; van der Bijl, Wouter; Buechel, Severine D.; Mank, Judith E.; Kolm, Niclas

    2017-01-01

    Mate choice decisions are central in sexual selection theory aimed to understand how sexual traits evolve and their role in evolutionary diversification. We test the hypothesis that brain size and cognitive ability are important for accurate assessment of partner quality and that variation in brain size and cognitive ability underlies variation in mate choice. We compared sexual preference in guppy female lines selected for divergence in relative brain size, which we have previously shown to have substantial differences in cognitive ability. In a dichotomous choice test, large-brained and wild-type females showed strong preference for males with color traits that predict attractiveness in this species. In contrast, small-brained females showed no preference for males with these traits. In-depth analysis of optomotor response to color cues and gene expression of key opsins in the eye revealed that the observed differences were not due to differences in visual perception of color, indicating that differences in the ability to process indicators of attractiveness are responsible. We thus provide the first experimental support that individual variation in brain size affects mate choice decisions and conclude that differences in cognitive ability may be an important underlying mechanism behind variation in female mate choice. PMID:28345039

  3. Variability of the Structural Coloration in Two Butterfly Species with Different Prezygotic Mating Strategies

    Science.gov (United States)

    Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

    2016-01-01

    Structural coloration variability was investigated in two Blue butterfly species that are common in Hungary. The males of Polyommatus icarus (Common Blue) and Plebejus argus (Silver-studded Blue) use their blue wing coloration for conspecific recognition. Despite living in the same type of habitat, these two species display differences in prezygotic mating strategy: the males of P. icarus are patrolling, while P. argus males have sedentary behavior. Therefore, the species-specific photonic nanoarchitecture, which is the source of the structural coloration, may have been subjected to different evolutionary effects. Despite the increasing interest in photonic nanoarchitectures of biological origin, there is a lack of studies focused on the biological variability of structural coloration that examine a statistically relevant number of individuals from the same species. To investigate possible structural color variation within the same species in populations separated by large geographical distances, climatic differences, or applied experimental conditions, one has to be able to compare these variations to the normal biological variability within a single population. The structural coloration of the four wings of 25 male individuals (100 samples for each species) was measured and compared using different light-collecting setups: perpendicular and with an integrating sphere. Significant differences were found in the near UV wavelength region that are perceptible by these polyommatine butterflies but are invisible to human observers. The differences are attributed to the differences in the photonic nanoarchitecture in the scales of these butterflies. Differences in the intensity of structural coloration were also observed and were tentatively attributed to the different prezygotic mating strategies of these insects. Despite the optical complexity of the scale covered butterfly wings, for sufficiently large sample batches, the averaged normal incidence measurements and

  4. Variability of the Structural Coloration in Two Butterfly Species with Different Prezygotic Mating Strategies.

    Science.gov (United States)

    Piszter, Gábor; Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

    2016-01-01

    Structural coloration variability was investigated in two Blue butterfly species that are common in Hungary. The males of Polyommatus icarus (Common Blue) and Plebejus argus (Silver-studded Blue) use their blue wing coloration for conspecific recognition. Despite living in the same type of habitat, these two species display differences in prezygotic mating strategy: the males of P. icarus are patrolling, while P. argus males have sedentary behavior. Therefore, the species-specific photonic nanoarchitecture, which is the source of the structural coloration, may have been subjected to different evolutionary effects. Despite the increasing interest in photonic nanoarchitectures of biological origin, there is a lack of studies focused on the biological variability of structural coloration that examine a statistically relevant number of individuals from the same species. To investigate possible structural color variation within the same species in populations separated by large geographical distances, climatic differences, or applied experimental conditions, one has to be able to compare these variations to the normal biological variability within a single population. The structural coloration of the four wings of 25 male individuals (100 samples for each species) was measured and compared using different light-collecting setups: perpendicular and with an integrating sphere. Significant differences were found in the near UV wavelength region that are perceptible by these polyommatine butterflies but are invisible to human observers. The differences are attributed to the differences in the photonic nanoarchitecture in the scales of these butterflies. Differences in the intensity of structural coloration were also observed and were tentatively attributed to the different prezygotic mating strategies of these insects. Despite the optical complexity of the scale covered butterfly wings, for sufficiently large sample batches, the averaged normal incidence measurements and

  5. Post-mating interactions and their effects on fitness of female and male Echinothrips americanus (Thysanoptera: Thripidae, a new insect pest in China.

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Li

    Full Text Available Post-mating, sexual interactions of opposite sexes differ considerably in different organisms. Post-mating interactions such as re-mating behavior and male harassment can affect the fitness of both sexes. Echinothrips americanus is a new insect pest in Mainland China, and little is known about its post-mating interactions. In this study, we observed re-mating frequency and male harassment frequency and their effects on fitness parameters and offspring sex ratios of E. americanus females. Furthermore, we tested the impact of mating and post-mating interactions on fitness parameters of males. Our results revealed that the re-mating frequency in female adults was extremely low during a 30-day period. However, post-mating interactions between females and males, consisting mainly of male harassment and female resistance, did occur and significantly reduced female longevity and fecundity. Interestingly, increased access to males did not affect the ratio of female offspring. For males, mating dramatically reduced their longevity. However, post-mating interactions with females had no effects on the longevity of mated males. These results enrich our basic knowledge about female and male mating and post-mating behaviors in this species and provide important information about factors that may influence population regulation of this important pest species.

  6. Male Megacyllene robiniae (Coleoptera: Cerambycidae) use multiple tactics when aggressively competing for mates.

    Science.gov (United States)

    Ray, Ann M; Ginzel, Matthew D; Hanks, Lawrence M

    2009-04-01

    Adult male Megacyllene robiniae (Förster) (Coleoptera: Cerambycidae) that are paired with a female often are challenged by conspecific males that attempt to displace them. In staged laboratory bouts, challenging males used seven distinct tactics to displace defending males, including wedging their head between the defender and the female (termed wedging), straddling the mated pair and pulling the defender off (prying), pulling it with the mandibles, batting it with the antennae, or pushing, biting, or kicking the defender. Individual challengers attempted as many as six different tactics in a single bout, repeating certain tactics multiple times. They often attempted tactics that were not very effective. For example, prying was one of the most common attempted tactics but was rarely effective. However, few challengers attempted to push defenders off the female, even though that tactic often was effective. Challengers apparently were influenced by context in their choice of particular tactics. For example, males that approached the mated pair from the side were likely to use wedging, whereas those approaching head on were more likely to bat with the antennae. Choice of tactic apparently was not influenced by absolute size of challengers, nor was it strongly influenced by relative size of defenders. However, the effectiveness of tactics varied significantly with relative body size: larger challengers were most successful when prying or pushing, while smaller challengers were most successful when biting and kicking. By using different tactics, relatively small males were as adept as larger males at displacing rivals.

  7. Sexual Reproductive Biology of a Colonial Rotifer Sinantherina socialis (Rotifera: Monogononta): Do mating strategies vary between colonial and solitary rotifer species?

    Science.gov (United States)

    Rico-Martínez, Roberto; Walsh, Elizabeth J.

    2014-01-01

    In many aquatic invertebrates including monogonont rotifers, sex provides genetic variation and dormant stages that allows dispersal in time and space. While the reproductive biology of some solitary monogonont rotifer species is known, little is known concerning mating behaviors in colonial rotifers. Coloniality poses unique challenges to the typical mating behavior of solitary rotifers. For instance, most species engage in circling behavior, where the male swims in close proximity to the female. In colonial forms, access to a particular female may be hindered by nearby colony mates. Here we provide descriptions of (1) male morphology, (2) mating behavior, and (3) types of eggs of the widespread colonial rotifer Sinantherina socialis, and discuss modifications in mating strategies as a consequence of coloniality. Two important differences from mating patterns documented in solitary rotifers were found in S. socialis. First, duration of circling phase of mating is protracted for males encountering small colonies of females as compared to solitary females. Males encountering single females removed from their colonies behave similarly to those of solitary species. Second, duration of copulation in S. socialis is the shortest reported for any rotifer species. Endogamy might occur in this species as sons copulate with their sisters and mothers, at least under laboratory conditions. Examples of behaviour in linked video clips. PMID:24932095

  8. Mating strategies of young women: role of physical attractiveness.

    Science.gov (United States)

    Singh, Devendra

    2004-02-01

    The female physical attractiveness stereotype has been reported to contain both desirable (sociable, poised, interesting) and undesirable (snobbish, likely to request divorce and have extra-marital affairs) personal qualities. To investigate whether such an attractiveness stereotype is cross-cultural, I asked men and women from Azore Island, Guinea-Bissau, Indonesia, and the U.S. to judge the attractiveness of female figures differing in body weight and waist-to-hip ratio (WHR) and to rank these figures according to perceived personal attributes. There was a strong cross-cultural consensus for attractiveness; figures with low WHR were judged to be more attractive than figures with high WHR within each weight category. Participants also judged attractive figures as less faithful than less-attractive figures. To explore the basis of a possible 'darker side ' of the attractiveness stereotype, behavior tactics of young U.S. women were examined. Compared to women with high WHRs, low-WHR women reported engaging in more flirting to make dates jealous, suggesting some truth to the attractiveness stereotype. Taken together, these findings suggest that female attractiveness influences the type of mating strategies employed by women.

  9. A test of genetic association among male nuptial coloration,female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    Institute of Scientific and Technical Information of China (English)

    Inke van der SLUIJS; Peter D.DIJKSTRA; Charlotte M.LINDEYER; Bertanne VISSER; Alan M.SMITH; Ton G.G.GROOTHUIS; Jacques J.M.van ALPHEN

    2013-01-01

    Both inter-and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits.Simultaneous disruptive selection by female mate choice and male-male competition can,in theory,lead to speciation without geographical isolation if both act on the same male trait.Female mate choice can generate discontinuities in gene flow,while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism.Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on.We tested for genetic associations among female mating preference,male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia.We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red).Male offspring of a red sire were significantly redder than males of a blue sire,indicating that intra-population variation in male coloration is heritable.We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests.There was no evidence for associations at the family level between female mating preferences and coloration of sires,but dam identity had a significant effect on female mate preference.Sons of the red sire directed significantly more aggression to red than blue males,whereas sons of the blue sire did not show any bias.There was a positive correlation among individuals between male aggression bias and body coloration,possibly due to pleiotropy or physical linkage,which could facilitate the maintenance of color polymorphism.

  10. A test of genetic association among male nuptial coloration, female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    Directory of Open Access Journals (Sweden)

    Inke van der SLUIJS, Peter D. DIJKSTRA, Charlotte M. LINDEYER et al.

    2013-04-01

    Full Text Available Both inter- and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits. Simultaneous disruptive selection by female mate choice and male-male competition can, in theory, lead to speciation without geographical isolation if both act on the same male trait. Female mate choice can generate discontinuities in gene flow, while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism. Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on. We tested for genetic associations among female mating preference, male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia. We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red. Male offspring of a red sire were significantly redder than males of a blue sire, indicating that intra-population variation in male coloration is heritable. We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests. There was no evidence for associations at the family level between female mating preferences and coloration of sires, but dam identity had a significant effect on female mate preference. Sons of the red sire directed significantly more aggression to red than blue males, whereas sons of the blue sire did not show any bias. There was a positive correlation among individuals between male aggression bias and body coloration, possibly due to pleiotropy or physical linkage, which could facilitate the maintenance of color polymorphism [Current Zoology 59 (2: 221-229, 2013].

  11. Parental care strategies in Eurasian penduline tit are not related to breeding densities and mating opportunities

    NARCIS (Netherlands)

    van Dijk, Rene E.; Brinkhuizen, Dusan M.; Szekely, Tamas; Komdeur, Jan

    2010-01-01

    Population size and density may influence various aspects of breeding systems. For example, the number of potential mates may influence the mating system and parental care strategies. The breeding system of Eurasian penduline fits, Remiz pendulinus, involves sequential polygamy by both sexes and uni

  12. Love is blind: indiscriminate female mating responses to male courtship pheromones in newts (Salamandridae.

    Directory of Open Access Journals (Sweden)

    Dag Treer

    Full Text Available Internal fertilization without copulation or prolonged physical contact is a rare reproductive mode among vertebrates. In many newts (Salamandridae, the male deposits a spermatophore on the substrate in the water, which the female subsequently takes up with her cloaca. Because such an insemination requires intense coordination of both sexes, male newts have evolved a courtship display, essentially consisting of sending pheromones under water by tail-fanning towards their potential partner. Behavioral experiments until now mostly focused on an attractant function, i.e. showing that olfactory cues are able to bring both sexes together. However, since males start their display only after an initial contact phase, courtship pheromones are expected to have an alternative function. Here we developed a series of intraspecific and interspecific two-female experiments with alpine newt (Ichthyosaura alpestris and palmate newt (Lissotriton helveticus females, comparing behavior in male courtship water and control water. We show that male olfactory cues emitted during tail-fanning are pheromones that can induce all typical features of natural female mating behavior. Interestingly, females exposed to male pheromones of their own species show indiscriminate mating responses to conspecific and heterospecific females, indicating that visual cues are subordinate to olfactory cues during courtship.

  13. Individual consistency in exploratory behaviour and mating tactics in male guppies

    Science.gov (United States)

    Kelley, Jennifer L.; Phillips, Samuel C.; Evans, Jonathan P.

    2013-10-01

    While behavioural plasticity is considered an adaptation to fluctuating social and environmental conditions, many animals also display a high level of individual consistency in their behaviour over time or across contexts (generally termed ‘personality’). However, studies of animal personalities that include sexual behaviour, or functionally distinct but correlated traits, are relatively scarce. In this study, we tested for individual behavioural consistency in courtship and exploratory behaviour in male guppies ( Poecilia reticulata) in two light environments (high vs. low light intensity). Based on previous work on guppies, we predicted that males would modify their behaviour from sneak mating tactics to courtship displays under low light conditions, but also that the rank orders of courtship effort would remain unchanged (i.e. highly sexually active individuals would display relatively high levels of courtship under both light regimes). We also tested for correlations between courtship and exploratory behaviour, predicting that males that had high display rates would also be more likely to approach a novel object. Although males showed significant consistency in their exploratory and mating behaviour over time (1 week), we found no evidence that these traits constituted a behavioural syndrome. Furthermore, in contrast to previous work, we found no overall effect of the light environment on any of the behaviours measured, although males responded to the treatment on an individual-level basis, as reflected by a significant individual-by-environment interaction. The future challenge is to investigate how individual consistency across different environmental contexts relates to male reproductive success.

  14. Individual consistency in exploratory behaviour and mating tactics in male guppies.

    Science.gov (United States)

    Kelley, Jennifer L; Phillips, Samuel C; Evans, Jonathan P

    2013-10-01

    While behavioural plasticity is considered an adaptation to fluctuating social and environmental conditions, many animals also display a high level of individual consistency in their behaviour over time or across contexts (generally termed 'personality'). However, studies of animal personalities that include sexual behaviour, or functionally distinct but correlated traits, are relatively scarce. In this study, we tested for individual behavioural consistency in courtship and exploratory behaviour in male guppies (Poecilia reticulata) in two light environments (high vs. low light intensity). Based on previous work on guppies, we predicted that males would modify their behaviour from sneak mating tactics to courtship displays under low light conditions, but also that the rank orders of courtship effort would remain unchanged (i.e. highly sexually active individuals would display relatively high levels of courtship under both light regimes). We also tested for correlations between courtship and exploratory behaviour, predicting that males that had high display rates would also be more likely to approach a novel object. Although males showed significant consistency in their exploratory and mating behaviour over time (1 week), we found no evidence that these traits constituted a behavioural syndrome. Furthermore, in contrast to previous work, we found no overall effect of the light environment on any of the behaviours measured, although males responded to the treatment on an individual-level basis, as reflected by a significant individual-by-environment interaction. The future challenge is to investigate how individual consistency across different environmental contexts relates to male reproductive success.

  15. Variation in mating systems of salamanders: mate guarding or territoriality?

    Science.gov (United States)

    Deitloff, Jennifer; Alcorn, Michael A; Graham, Sean P

    2014-07-01

    Two of the most common mating tactics in vertebrates are mate guarding and territoriality, yet much of the research on these strategies has focused on mating systems in birds, despite novel insights gained from studying less traditional systems. North American stream salamanders that comprise the Eurycea bislineata complex represent an excellent nontraditional system for comparing mating strategies because these species exhibit a continuum of male morphologies, diverse habitat associations, and various potential mating strategies. We studied two species within this complex that exhibit the extremes of this continuum, Eurycea aquatica (robust morph) and Eurycea cirrigera (slender morph). The larger head in males of E. aquatica is due to larger musculature around the jaw and may be associated with aggressive behavior. Therefore, we hypothesized that the robust morphology exhibited by males of E. aquatica provides benefits during either territorial defense or mate defense and that males of E. cirrigera would not exhibit aggression in either scenario. We found that neither species exhibited aggressive behavior to defend a territory. However, in the presence of a female, males of E. aquatica were significantly more aggressive toward intruding males than were males of E. cirrigera. Therefore, mate-guarding behavior occurs in E. aquatica, and the enlarged head of males likely aids in deterring rivals. This is the first demonstration of mate-guarding behavior in a plethodontid, the most speciose family of salamanders.

  16. Optimizing methyl-eugenol aromatherapy to maximize posttreatment effects to enhance mating competitiveness of male Bactrocera carambolae (Diptera: Tephritidae).

    Science.gov (United States)

    Haq, Ihsan ul; Vreysen, Marc J B; Cacéres, Carlos; Shelly, Todd E; Hendrichs, Jorge

    2015-10-01

    Methyl-eugenol (ME) (1,2-dimethoxy-4-(2-propenyl)benzene), a natural phytochemical, did enhance male Bactrocera carambolae Drew & Hancock (Diptera: Tephritidae) mating competitiveness 3 d after ingestion. Enhanced male mating competitiveness can significantly increase the effectiveness of the sterile insect technique (SIT). ME application to mass reared sterile flies by feeding is infeasible. ME application by aromatherapy however, would be a very practical way of ME application in fly emergence and release facilities. This approach was shown to enhance mating competitiveness of B. carambolae 3 d posttreatment (DPT). Despite this added benefit, every additional day of delaying release will reduce sterile fly quality and will add cost to SIT application. The present study was planned to assess the effects of ME-aromatherapy on male B. carambolae mating competitiveness 1DPT and 2DPT. ME aromatherapy 1DPT or 2DPT did enhance mating competitiveness of B. carambolae males whereas ME feeding 1DPT and 2DPT did not. Male mating competitiveness was enhanced by the ME aromatherapy irrespective if they received 1DPT, 2DPT or 3DPT. ME aromatherapy, being a viable approach for its application, did enhance mating competitiveness of male B. carambolae 1 d posttreatment as ME feeding did 3 d after ingestion.

  17. Visual Adaptations for Mate Detection in the Male Carpenter Bee Xylocopa tenuiscapa

    Science.gov (United States)

    Somanathan, Hema; Borges, Renee Maria; Warrant, Eric J.; Kelber, Almut

    2017-01-01

    Sexual dimorphism in eye structure is attributed to sexual selection in animals that employ vision for locating mates. In many male insects, large eyes and eye regions of higher acuity are believed to facilitate the location of females. Here, we compare various features of male and female eyes in three sympatric carpenter bee species, which include two diurnal species (Xylocopa tenuiscapa and X. leucothorax) as well as a nocturnal species (X. tranquebarica). In X. tenuiscapa, males have larger eyes than females, while in the nocturnal X. tranquebarica, males have slightly smaller eyes and in X. leucothorax, the eyes are of similar size in both sexes. X. tenuiscapa males detect females by perching near nest sites (resource defence) or along fly-ways and other open areas with good visibility. Males of the other two species search for females by patrolling. We postulate that the larger eyes of male X. tenuiscapa are beneficial to their mode of mate detection since perching males may benefit from a larger visual area of high resolution detecting moving stimuli across the sky, and which may be germane to the more social and gregarious nesting behaviour of this species, compared to the other solitary bees. We tested the performance of the eyes of male X. tenuiscapa behaviourally and find that a perching male can detect a flying female at a distance of 20 m, which darkens the visual field of a single ommatidium by just 2%. This, together with the bee’s high spatial resolution permits detection of moving stimuli at least as well or even better than achieved by honey bee drones. PMID:28107354

  18. Individual Pheromone Signature in Males: Prerequisite for Pheromone-Mediated Mate Assessment in the Central American Locust, Schistocerca Piceifrons.

    Science.gov (United States)

    Stahr, Christiane; Seidelmann, Karsten

    2016-12-01

    Living in high-density groups of animals has advantages and disadvantages for mating. The advantage of facilitated mate finding is compromised by difficulties in protecting a suitable partner from competitors. Thus, males regularly are faced with increased competition for sperm, and females with harassment by males at high population densities. To cope with these problems, mating tactics and mate choice mechanisms have to be adjusted. An adaptation to gregarious condition observed in locusts includes the use of male-emitted pheromones. Males of the Central American locust, Schistocerca piceifrons, release sex-specific volatiles, which were identified as phenethyl alcohol (synonym: phenyl-ethyl-alcohol, 2-phenyl-1-ethanol, 2-phenylethanol, PEA), (Z)-3-nonen-1-ol (3-Nol), and (Z)-2-octen-1-ol (2-Ool). The emission of the two major compounds, PEA and 3-Nol, was restricted to crowded conditions. Furthermore, the release of both volatiles was coupled to males reaching sexual maturity, indicating a function in reproductive behavior. However, neither the single substances nor their mixtures were attractive or repellent to the locusts. Instead, females prefer the sperm of high pheromone-emitting males to fertilize their ova. In this way, the male-specific volatiles act as mate assessment pheromones utilized in a context of cryptic female choice. This function is well supported by the highly variable but individual-specific emission rates of the three compounds. Schistocerca piceifrons males release a virtually unique personal pheromone signature, a prerequisite for mate assessment pheromones.

  19. Exceptional Use of Sex Pheromones by Parasitoids of the Genus Cotesia: Males Are Strongly Attracted to Virgin Females, but Are No Longer Attracted to or Even Repelled by Mated Females.

    Science.gov (United States)

    Xu, Hao; Veyrat, Nathalie; Degen, Thomas; Turlings, Ted C J

    2014-06-30

    Sex pheromones have rarely been studied in parasitoids, and it remains largely unknown how male and female parasitoids locate each other. We investigated possible attraction (and repellency) between the sexes of two braconid wasps belonging to the same genus, the gregarious parasitoid, Cotesia glomerata (L.), and the solitary parasitoid, Cotesia marginiventris (Cresson). Males of both species were strongly attracted to conspecific virgin females. Interestingly, in C. glomerata, the males were repelled by mated females, as well as by males of their own species. This repellency of mated females was only evident hours after mating, implying a change in pheromone composition. Males of C. marginiventris were also no longer attracted, but not repelled, by mated females. Females of both species showed no attraction to the odors of conspecific individuals, male or female, and C. glomerata females even appeared to be repelled by mated males. Moreover, the pheromones were found to be highly specific, as males were not attracted by females of the other species. Males of Cotesia glomerata even avoided the pheromones of female Cotesia marginiventris, indicating the recognition of non-conspecific pheromones. We discuss these unique responses in the context of optimal mate finding strategies in parasitoids.

  20. Exceptional Use of Sex Pheromones by Parasitoids of the Genus Cotesia: Males Are Strongly Attracted to Virgin Females, but Are No Longer Attracted to or Even Repelled by Mated Females

    Directory of Open Access Journals (Sweden)

    Hao Xu

    2014-06-01

    Full Text Available Sex pheromones have rarely been studied in parasitoids, and it remains largely unknown how male and female parasitoids locate each other. We investigated possible attraction (and repellency between the sexes of two braconid wasps belonging to the same genus, the gregarious parasitoid, Cotesia glomerata (L., and the solitary parasitoid, Cotesia marginiventris (Cresson. Males of both species were strongly attracted to conspecific virgin females. Interestingly, in C. glomerata, the males were repelled by mated females, as well as by males of their own species. This repellency of mated females was only evident hours after mating, implying a change in pheromone composition. Males of C. marginiventris were also no longer attracted, but not repelled, by mated females. Females of both species showed no attraction to the odors of conspecific individuals, male or female, and C. glomerata females even appeared to be repelled by mated males. Moreover, the pheromones were found to be highly specific, as males were not attracted by females of the other species. Males of Cotesia glomerata even avoided the pheromones of female Cotesia marginiventris, indicating the recognition of non-conspecific pheromones. We discuss these unique responses in the context of optimal mate finding strategies in parasitoids.

  1. Is bigger better? Male body size affects wing-borne courtship signals and mating success in the olive fruit fly, Bactrocera oleae (Diptera: Tephritidae).

    Science.gov (United States)

    Benelli, Giovanni; Donati, Elisa; Romano, Donato; Ragni, Giacomo; Bonsignori, Gabriella; Stefanini, Cesare; Canale, Angelo

    2016-12-01

    Variations in male body size are known to affect inter- and intrasexual selection outcomes in a wide range of animals. In mating systems involving sexual signaling before mating, body size often acts as a key factor affecting signal strength and mate choice. We evaluated the effect of male size on courtship displays and mating success of the olive fruit fly, Bactrocera oleae (Diptera: Tephritidae). Wing vibrations performed during successful and unsuccessful courtships by large and small males were recorded by high-speed videos and analyzed through frame-by-frame analysis. Mating success of large and small males was investigated. The effect of male-male competition on mating success was evaluated. Male body size affected both male courtship signals and mating outcomes. Successful males showed wing-borne signals with high frequencies and short interpulse intervals. Wing vibrations displayed by successful large males during copulation attempt had higher frequencies over smaller males and unsuccessful large males. In no-competition conditions, large males achieved higher mating success with respect to smaller ones. Allowing large and small males to compete for a female, large males achieve more mating success over smaller ones. Mate choice by females may be based on selection of the larger males, able to produce high-frequency wing vibrations. Such traits may be indicative of "good genes," which under sexual selection could means good social-interaction genes, or a good competitive manipulator of conspecifics. © 2015 Institute of Zoology, Chinese Academy of Sciences.

  2. Taurine enhances the sexual response and mating ability in aged male rats.

    Science.gov (United States)

    Yang, Jiancheng; Lin, Shumei; Feng, Ying; Wu, Gaofeng; Hu, Jianmin

    2013-01-01

    It has been demonstrated that taurine is abundant in male reproductive organs, and can be biosynthesized by testis, but the taurine concentration will reduce with aging. The levels of serum LH, T, NOS, and NO were found to be obviously increased by taurine supplementation in aged rats in our previous study. In addition, aging will result in a significant decline in sexual response and function, which may be attributed to the androgen deficiency. Furthermore, NO has been proposed as a crucial mediator of penile erection. That makes us hypothesize that there is potential relationship between taurine decline and erection dysfunction in aged males. So the primary aim of the present study was to investigate the effect of taurine on male sexuality in rats. Taurine was offered in water to male aged (20 months old) rats for 110 days. The effects of taurine on the sexual response, mating ability, levels of serum reproductive hormones, and penile NOS and NO levels were investigated. The results showed that taurine can significantly reduce the EL and ML; obviously increase the ERF, MF, IF, and EJF; stimulate the secretion of GnRH, LH, and T; and elevate penis NOS and NO level in aged rats. The results indicated that taurine can enhance the sexual response and mating ability in aged male rats by increasing the level of testosterone and NO, but the exact mechanism of which needs to be further investigated.

  3. Neuropeptides affecting the transfer of juvenile hormones from males to females during mating in Spodoptera frugiperda.

    Science.gov (United States)

    Hassanien, Intisar T E; Grötzner, Manuela; Meyering-Vos, Martina; Hoffmann, Klaus H

    2014-07-01

    In the polyandric moth, Spodopterafrugiperda, juvenile hormone (JH) is transferred from the male accessory reproductive glands (AG) to the female bursa copulatrix (BC) during copulation (see Hassanien et al., 2014). Here we used the RNA interference technique to study the role of allatoregulating neuropeptides in controlling the synthesis and transfer of JH during mating. Knockdown of S. frugiperda allatostatin C (Spofr-AS type C) in freshly emerged males leads to an accumulation of JH in the AG beyond that in the control and mating results in a higher transport of JH I and JH II into the female BC. Knockdown of S. frugiperda allatotropin 2 (Spofr-AT2) significantly reduces the amount of JH in the AG as well as its transfer into the female BC during copulation. Knockdown of S. frugiperda allatostatin A (Spofr-AS type A) and S. frugiperda allatotropin (Spofr-AT; Hassanien et al., 2014) only slightly affects the accumulation of JH in the AG and its transfer from the male to the female. We conclude that Spofr-AS type C and Spofr-AT2 act as true allatostatin and true allatotropin, respectively, on the synthesis of JH I and JH II in the male AG. Moreover, both peptides seem to control the synthesis of JH III in the corpora allata of adult males and its release into the hemolymph.

  4. Male mate choice scales female ornament allometry in a cichlid fish

    Directory of Open Access Journals (Sweden)

    Kullmann Harald

    2010-10-01

    Full Text Available Abstract Background Studies addressing the adaptive significance of female ornamentation have gained ground recently. However, the expression of female ornaments in relation to body size, known as trait allometry, still remains unexplored. Here, we investigated the allometry of a conspicuous female ornament in Pelvicachromis taeniatus, a biparental cichlid that shows mutual mate choice and ornamentation. Females feature an eye-catching pelvic fin greatly differing from that of males. Results We show that allometry of the female pelvic fin is scaled more positively in comparison to other fins. The pelvic fin exhibits isometry, whereas the other fins (except the caudal fin show negative allometry. The size of the pelvic fin might be exaggerated by male choice because males prefer female stimuli that show a larger extension of the trait. Female pelvic fin size is correlated with individual condition, suggesting that males can assess direct and indirect benefits. Conclusions The absence of positive ornament allometry might be a result of sexual selection constricted by natural selection: fins are related to locomotion and thus may be subject to viability selection. Our study provides evidence that male mate choice might scale the expression of a female sexual ornament, and therefore has implications for the understanding of the relationship of female sexual traits with body size in species with conventional sex-roles.

  5. Post-mating shift towards longer-chain cuticular hydrocarbons drastically reduces female attractiveness to males in a digger wasp.

    Science.gov (United States)

    Polidori, Carlo; Giordani, Irene; Wurdack, Mareike; Tormos, José; Asís, Josep D; Schmitt, Thomas

    2017-07-01

    Females of most aculeate Hymenoptera mate only once and males are therefore under a strong competitive pressure which is expected to favour the evolution of rapid detection of virgin females. In several bee species, the cuticular hydrocarbon (CHC) profile exhibited by virgin females elicits male copulation attempts. However, it is still unknown how widespread this type of sexual communication is within Aculeata. Here, we investigated the use of CHCs as mating cues in the digger wasp Stizus continuus, which belongs to the family (Crabronidae) from within bees arose. In field experiments, unmanipulated, recently emerged virgin female dummies promptly elicit male copulation attempts, whereas 1-4days old mated females dummies were still attractive but to a much lesser extent. In contrast, old (10-15days) mated female dummies did not attract males at all. After hexane-washing, attractiveness almost disappeared but could be achieved by adding CHC extracts from virgin females even on hexane-washed old mated females. Thus, the chemical base of recognition of females as appropriate mating partner by males is coded in their CHC profile. Accordingly, differences in CHC profiles can be detected between sexes, with males having larger amounts of alkenes and exclusive long-chain alkanes, and within females specially according to their mating status. Shortly after mating, almost all of the major hydrocarbons found on the cuticle of females undergo significant changes in their abundance, with a clear shift from short-chain to long-chain linear and methyl-branched alkanes. The timely detection of virgin females by males in S. continuus could be advantageous within the narrow period of female emergence, when male-male competition is strongest. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. cdc-25.4, a Caenorhabditis elegans Ortholog of cdc25, Is Required for Male Mating Behavior

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    Sangmi Oh

    2016-12-01

    Full Text Available Cell division cycle 25 (cdc25 is an evolutionarily conserved phosphatase that promotes cell cycle progression. Among the four cdc25 orthologs in Caenorhabditis elegans, we found that cdc-25.4 mutant males failed to produce outcrossed progeny. This was not caused by defects in sperm development, but by defects in male mating behavior. The cdc-25.4 mutant males showed various defects during male mating, including contact response, backing, turning, and vulva location. Aberrant turning behavior was the most prominent defect in the cdc-25.4 mutant males. We also found that cdc-25.4 is expressed in many neuronal cells throughout development. The turning defect in cdc-25.4 mutant males was recovered by cdc-25.4 transgenic expression in neuronal cells, suggesting that cdc-25.4 functions in neurons for male mating. However, the neuronal morphology of cdc-25.4 mutant males appeared to be normal, as examined with several neuronal markers. Also, RNAi depletion of wee-1.3, a C. elegans ortholog of Wee1/Myt1 kinase, failed to suppress the mating defects of cdc-25.4 mutant males. These findings suggest that, for successful male mating, cdc-25.4 does not target cell cycles that are required for neuronal differentiation and development. Rather, cdc-25.4 likely regulates noncanonical substrates in neuronal cells.

  7. An eye for beauty: lateralized visual stimulation of courtship behavior and mate preferences in male zebra finches, Taeniopygia guttata.

    Science.gov (United States)

    Templeton, Jennifer J; McCracken, Brianna G; Sher, Melissa; Mountjoy, D James

    2014-02-01

    Research on intersexual selection focuses on traits that have evolved for attracting mates and the consequences of mate choice. However, little is known about the cognitive and neural mechanisms that allow choosers to discriminate among potential mates and express an attraction to specific traits. Preferential use of the right eye during lateral displays in zebra finches, and lateralized expression of intermediate early genes in the left hemisphere during courtship led us to hypothesize that: (1) visual information from each eye differentially mediates courtship responses to potential mates; and (2) the ability to discriminate among mates and prefer certain mates over others is lateralized in the right eye/left hemisphere system of zebra finch brains. First, we exposed male zebra finches to females when using left, right or both eyes. Males courted more when the right eye was available than when only the left eye was used. Secondly, male preference for females - using beak color to indicate female quality - was tested. Right-eyed and binocular males associated with and courted orange-beaked more than gray-beaked females; whereas left-eyed males showed no preference. Lateral displays and eye use in male zebra finches increase their attractiveness and ability to assess female quality, potentially enhancing reproductive success. This article is part of a Special Issue entitled: CO3 2013.

  8. Costs of mating competition limit male lifetime breeding success in polygynous mammals.

    Science.gov (United States)

    Lukas, Dieter; Clutton-Brock, Tim

    2014-07-01

    Although differences in breeding lifespan are an important source of variation in male fitness, the factors affecting the breeding tenure of males have seldom been explored. Here, we use cross-species comparisons to investigate the correlates of breeding lifespan in male mammals. Our results show that male breeding lifespan depends on the extent of polygyny, which reflects the relative intensity of competition for access to females. Males have relatively short breeding tenure in species where individuals have the potential to monopolize mating with multiple females, and longer ones where individuals defend one female at a time. Male breeding tenure is also shorter in species in which females breed frequently than in those where females breed less frequently, suggesting that the costs of guarding females may contribute to limiting tenure length. As a consequence of these relationships, estimates of skew in male breeding success within seasons overestimate skew calculated across the lifetime and, in several polygynous species, variance in lifetime breeding success is not substantially higher in males than in females.

  9. Regulation of distinct muscle behaviors controls the C. elegans male's copulatory spicules during mating.

    Science.gov (United States)

    Garcia, L R; Mehta, P; Sternberg, P W

    2001-12-14

    We demonstrate through cell ablation, molecular genetic, and pharmacological approaches that during C. elegans male mating behavior, the male inserts his copulatory spicules into the hermaphrodite by regulating periodic and prolonged spicule muscle contractions. Distinct cholinergic neurons use different ACh receptors and calcium channels in the spicule muscles to mediate these contractile behaviors. The PCB and PCC sensory neurons facilitate periodic contraction through muscle-encoded UNC-68 ryanodine receptor calcium channels. The SPC motor neurons trigger prolonged contraction through EGL-19 L-type voltage-gated calcium channels. The male gonad then lengthens the duration of EGL-19-mediated prolonged muscle contraction. This regulation of muscle contraction provides a paradigm to explain how animals initiate, monitor, and maintain a behavioral motor program.

  10. Sugar administration to newly emerged Aedes albopictus males increases their survival probability and mating performance.

    Science.gov (United States)

    Bellini, Romeo; Puggioli, Arianna; Balestrino, Fabrizio; Brunelli, Paolo; Medici, Anna; Urbanelli, Sandra; Carrieri, Marco

    2014-04-01

    capacity of sterile (irradiated with 30 Gy) males to take a sugar meal relative to fertile males was observed in field comparison. A clear effect of temperature and relative humidity (RH) on the rate of sugar positive males was observed, with an increase of temperature and a decrease in RH strongly increasing the % of sugar positive males. In large enclosures we tested the effect of our sugar supplying tool on the mating competitiveness of sterile vs fertile males, which produced an evident favorable effect both on sterile and fertile males. Copyright © 2013 International Atomic Energy Agency 2013. Published by Elsevier B.V. All rights reserved.

  11. Evidence for a receiver bias underlying female preference for a male mating pheromone in sea lamprey

    Science.gov (United States)

    Buchinger, Tyler J.; Wang, Huiyong; Li, Weiming; Johnson, Nicholas S.

    2013-01-01

    Receiver bias models suggest that a male sexual signal became exaggerated to match a pre-existing sensory, perceptual or cognitive disposition of the female. Accordingly, these models predict that females of related taxa possessing the ancestral state of signalling evolved preference for the male trait in a non-sexual context. We postulated that female preference for the male-released bile alcohol mating pheromone, 3 keto petromyzonol sulfate (3kPZS), of the sea lamprey (Petromyzon marinus) evolved as a result of a receiver bias. In particular, we propose that migratory silver lamprey (Ichthyomyzon unicuspis), a basal member of the Petromyzontidae, evolved a preference for 3kPZS released by stream-resident larvae as a means of identifying productive habitat for offspring. Larval silver lamprey released 3kPZS at rates sufficient to be detected by migratory lampreys. Females responded to 3kPZS by exhibiting upstream movement behaviours relevant in a migratory context, but did not exhibit proximate behaviours important to mate search and spawning. Male silver lamprey did not release 3kPZS at rates sufficient to be detected by females in natural high-volume stream environments. We infer that female silver lamprey cue onto 3kPZS excreted by stream-resident larvae as a mechanism to locate habitat conducive to offspring survival and that males do not signal with 3kPZS. We suggest that this female preference for a male signal in a non-sexual context represents a bias leading to the sexual signalling observed in sea lamprey.

  12. Female prairie vole mate-choice is affected by the males' birth litter composition.

    Science.gov (United States)

    Curtis, J Thomas

    2010-08-01

    Experimental testing and retrospective examination of breeding records were used to examine the influence of sex composition and/or size of males' birth litters on female mate-choice. Sexually naïve female prairie voles (Microtus ochrogaster) avoided males derived from all-male litters, but showed no preference for, or aversion to, males from single-male litters or from more typical mixed-sex litters. Examination of the pregnancy status of females after two weeks of pairing with a male allowed us to estimate the probabilites of a pups' intrauterine position relative to siblings for various litter sizes. The typical prairie vole pup derived from a mixed-sex litter comprised of 4.4 pups, and had a 13% chance of being isolated from siblings in utero and a 22% chance of being between siblings in utero. Pups from single-sex litters tended to be larger at weaning than did pups from mixed-sex litters; however, male size did not influence female choice behavior. These results suggest that some aspect of the perinatal experience of prairie vole pups from single sex litters can influence social interactions later in life.

  13. Selection by mating competitiveness improves the performance of Anastrepha ludens males of the genetic sexing strain Tapachula-7.

    Science.gov (United States)

    Quintero-Fong, L; Toledo, J; Ruiz, L; Rendón, P; Orozco-Dávila, D; Cruz, L; Liedo, P

    2016-10-01

    The sexual performance of Anastrepha ludens males of the Tapachula-7 genetic sexing strain, produced via selection based on mating success, was compared with that of males produced without selection in competition with wild males. Mating competition, development time, survival, mass-rearing quality parameters and pheromone production were compared. The results showed that selection based on mating competitiveness significantly improved the sexual performance of offspring. Development time, survival of larvae, pupae and adults, and weights of larvae and pupae increased with each selection cycle. Differences in the relative quantity of the pheromone compounds (Z)-3-nonenol and anastrephin were observed when comparing the parental males with the F4 and wild males. The implications of this colony management method on the sterile insect technique are discussed.

  14. Ontogenetic shifts in male mating preference and morph-specific polyandry in a female colour polymorphic insect

    NARCIS (Netherlands)

    Sanchez-Guillen, Rosa Ana; Hammers, Martijn; Hansson, Bengt; Van Gossum, Hans; Cordero-Rivera, Adolfo; Galicia Mendoza, Dalia Ivette; Wellenreuther, Maren

    2013-01-01

    Background: Sexual conflict over mating rates may favour the origin and maintenance of phenotypes with contrasting reproductive strategies. The damselfly Ischnura elegans is characterised by a female colour polymorphism that consists of one androchrome and two gynochrome female morphs. Previous

  15. Why small males have big sperm: dimorphic squid sperm linked to alternative mating behaviours

    Directory of Open Access Journals (Sweden)

    Shiba Kogiku

    2011-08-01

    Full Text Available Abstract Background Sperm cells are the target of strong sexual selection that may drive changes in sperm structure and function to maximize fertilisation success. Sperm evolution is regarded to be one of the major consequences of sperm competition in polyandrous species, however it can also be driven by adaptation to the environmental conditions at the site of fertilization. Strong stabilizing selection limits intra-specific variation, and therefore polymorphism, among fertile sperm (eusperm. Here we analyzed reproductive morphology differences among males employing characteristic alternative mating behaviours, and so potentially different conditions of sperm competition and fertilization environment, in the squid Loligo bleekeri. Results Large consort males transfer smaller (average total length = 73 μm sperm to a female's internal sperm storage location, inside the oviduct; whereas small sneaker males transfer larger (99 μm sperm to an external location around the seminal receptacle near the mouth. No significant difference in swimming speed was observed between consort and sneaker sperm. Furthermore, sperm precedence in the seminal receptacle was not biased toward longer sperm, suggesting no evidence for large sperm being favoured in competition for space in the sperm storage organ among sneaker males. Conclusions Here we report the first case, in the squid Loligo bleekeri, where distinctly dimorphic eusperm are produced by different sized males that employ alternative mating behaviours. Our results found no evidence that the distinct sperm dimorphism was driven by between- and within-tactic sperm competition. We propose that presence of alternative fertilization environments with distinct characteristics (i.e. internal or external, whether or not in combination with the effects of sperm competition, can drive the disruptive evolution of sperm size.

  16. Mating Strategies and Sexual Functioning in Personality Disorders: A Comprehensive Review of Literature.

    Science.gov (United States)

    Collazzoni, Alberto; Ciocca, Giacomo; Limoncin, Erika; Marucci, Carmela; Mollaioli, Daniele; Di Sante, Stefania; Di Lorenzo, Giorgio; Niolu, Cinzia; Siracusano, Alberto; Maggi, Mario; Castellini, Giovanni; Rossi, Alessandro; Jannini, Emmanuele A

    2017-10-01

    Personality disorders impair several aspects of intrapsychic and interpersonal life. In particular, mating strategies and sexual functioning could manifest in different and/or dysfunctional ways in people with personality disorders. To describe, through a comprehensive review of the literature, the mating strategies and sexual functioning in patients with personality disorders. We listed and discussed the principal studies on the relation between mating strategies and sexual functioning in personality disorders. The search strategy used search terms in PubMed for the main studies published from January 2000 to December 2016. We considered two main sections for our selection according to the aim of the present review: mating and sexuality. Interesting evidence on mating strategies in personality disorders was found. In particular, the major items were found in the dramatic-unpredictable cluster, with borderline personality disorder being the most studied. In contrast, the bizarre-eccentric cluster had fewer items, with the schizoid personality disorder being the least studied. For sexual behavior, borderline personality seems to be the unique disorder sufficiently studied, with evidence of major histories of child sexual abuse, the presence of sexual dysfunctions, and paraphilic interests. A large spectrum of mating strategies characterizes different personality disorders, although an inconsistent knowledge about the relation between sexual function and personality disorders emerged from our analysis of the literature. Hence, we invite clinicians and researchers to integrate psychodiagnostic and sexual assessments in psychiatric disciplines for people with personality disorders. Collazzoni A, Ciocca G, Limoncin E, et al. Mating Strategies and Sexual Functioning in Personality Disorders: A Comprehensive Review of Literature. Sex Med Rev 2017;5:414-428. Copyright © 2017 International Society for Sexual Medicine. All rights reserved.

  17. Female mate choice for multimodal courtship and the importance of the signaling background for selection on male ornamentation

    Institute of Scientific and Technical Information of China (English)

    Jay A.STAFSTROM; Eileen A.HEBETS

    2013-01-01

    Conspicuous visual ornaments are frequently incorporated into complex courtship displays that integrate signal components from multiple sensory modalities.Mature male Schizocosa crassipes (Walckenaer,1837) wolf spiders wave,arch,and tap their ornamented forelegs in a visual courtship display that simultaneously incorporates seismic components.To determine the importance of modality-specific signal components in female mate choice,we used a signal ablation design and compared the mating frequency of female-male pairs across signaling environments with manipulated modality-specific transmission properties.We found that the successful transmission of isolated visual or seismic signaling was sufficient for mating success; neither signaling modality was necessary.Additionally,the environment enabling the successful transmission of composite,multimodal displays yielded the highest mating frequencies.Our results indicate the presence of selection from S.crassipes females for multimodal courtship and suggest that multimodal signaling may facilitate mating across variable signaling environments.We next explored the influence of ornamentation per se on female choice by phenotypically manipulating males into two groups:(i) intact (brushes present) and (ii) shaved (brushes absent).We compared the mating frequencies of intact versus shaved males in the presence versus absence of seismic signaling.Males with brushes intact had higher mating frequencies than shaved males,but only under specific signaling conditions-in the presence of seismic signaling.Female choice for male brushes then appears dependent on the signaling background,making brushes themselves an unlikely target of direct selection.Our results emphasize the complex nature of female choice,highlighting the potential for both trait interactions and environment-dependent selection.

  18. Effects of male fecundity, interindividual distance and anisotropic pollen dispersal on mating success in a Scots pine (Pinus sylvestris) seed orchard.

    Science.gov (United States)

    Torimaru, T; Wennström, U; Lindgren, D; Wang, X-R

    2012-03-01

    Quantifying the effect of pollen dispersal and flowering traits on mating success is essential for understanding evolutionary responses to changing environments and establishing strategies for forest tree breeding. This study examined, quantitatively, the effects of male fecundity, interindividual distance and anisotropic pollen dispersal on the mating success of Scots pine (Pinus sylvestris), utilizing a well-mapped Scots pine seed orchard. Paternity analysis of 1021 seeds sampled from 87 trees representing 28 clones showed that 53% of the seeds had at least one potential pollen parent within the orchard. Pronounced variation in paternal contribution was observed among clones. Variations in pollen production explained up to 78% of the variation in mating success, which was 11.2 times greater for clones producing the largest amount of pollen than for clones producing the least pollen. Mating success also varied with intertree distance and direction, which explained up to 28% of the variance. Fertilization between neighboring trees 2.3 m apart was 2.4 times more frequent than between trees 4.6 m apart, and up to 12.4 times higher for trees downwind of the presumed prevailing wind direction than for upwind trees. The effective number of pollen donors recorded in the seed orchard (12.2) was smaller than the theoretical expectation (19.7). Based on the empirical observations, a mating model that best describes the gene dispersal pattern in clonal seed orchards was constructed.

  19. [Study of male mating behavior in some Drosophila melanogaster strains in experiments with fertilized females].

    Science.gov (United States)

    Subocheva, E A; Romanova, N I; Kim, A I

    2004-07-01

    Male courtship ritual is among the main behavioral characteristics of Drosophila. This is a complex, genetically determined process consisting of four general stages: orientation, vibration, licking, and attempts at copulation (or successful copulation). Several genes are known that control some stages of this behavior. Most of them have pleiotropic effects and are involved in other biological processes. Earlier, we have shown that a mutation in locus flamenco (20A1-3), which controls transposition and infectivity of retrotransposon gypsy (MDG4), is involved in the genetic control of behavior. In strains mutant for this locus, the male mating activity is decreased and the structure of courtship ritual is changed. To understand the mechanisms of these changes, it is important to study all behavioral stages in genetically identical strains. For this purpose, the normal allele of gene flamenco from the X chromosome of the wild-type strain (stock) Canton S was introduced into strain SS carrying flamMS. This offers new opportunities in studying the role of gene flamenco in the control of mating behavior in Drosophila.

  20. Mated Female Mate Choice in Relation to Male Mating Status in Crayfish Procambarus clarkii%已交配雌性克氏原螯虾的择偶行为

    Institute of Scientific and Technical Information of China (English)

    张丽; 乔出; 刘国兴; 黄成

    2014-01-01

    动物在繁殖期间会随自身繁殖状态的变化而调整择偶行为,这会导致它们择偶的多样性.本文研究具交配经验的雌性克氏原螯虾( Procambarus clarkii)在Y型水迷宫中对不同婚配状态的潜在配偶的择偶行为.雌虾对空白与原配、童子、非童子3种信息源虾的访问总时间P值均小于0.05,结果表明雌性克氏原螯虾与原交配雄体有再次交配的显著倾向,对该现象本文从螯虾繁殖成功率方面进行了探讨;面对3种信息源虾的选择差异性的P值均大于0.05,表明雌虾不区分潜在配偶的婚配状态,本文就螯虾的择偶偏好进行了讨论,此外对螯虾定向配种方面的应用进行了初步探讨.本研究以期为克氏原螯虾的繁殖行为学的理论研究及生产实践积累具参考意义的基础数据.%Animals can make adaptive adjustment of selectivity as a function of their own reproductive value which may cause variation in mate choice over the course of reproduction. Here,we examined the mate choice of mated females in the freshwater crayfish Procambarus clarkii. We used a Y-maze,in which mated females made selection between potential mates with different mating status. When faced with primary partners, virgin or unfamiliar mated males and a blank control,females showed significantly preferences for males in terms of the total duration of visits(P0. 05). Females may mate as frequently as possibly out of re-productive success. Besides,we discussed mated female indiscriminating between males’ mating status in terms of their mate preferences. The present study not only provides theoretical basis for reproductive biology and ethology,but it is also of great practical significance to crayfish aquaculture.

  1. Fishery induces sperm depletion and reduction in male reproductive potential for crab species under male-biased harvest strategy.

    Directory of Open Access Journals (Sweden)

    Luis Miguel Pardo

    Full Text Available Sperm depletion in males can occur when polygynous species are intensively exploited under a male-biased management strategy. In fisheries involving crabs species, the effects of this type of management on the reproductive potential is far from being understood. This study tests whether male-biased management of the principal Chilean crab fishery is able to affect the potential capacity of Metacarcinus edwardsii males to transfer sperm to females. Five localities in southern Chile, recording contrasting crab fishery landing, were selected to assess the potential of sperm depletion triggered by fishery. Seasonally, male crabs from each locality were obtained. Dry weight and histological condition of vasa deferentia and the Vaso-Somatic Index (VSI were determined in order to use them as proxies for sperm depletion and male reproductive condition. A manipulative experiment was performed in the laboratory to estimate vasa deferentia weight and VSI from just-mated males in order to obtain a reference point for the potential effects of the fishery on sperm reserves. Sperm storage capacity is significantly affected by fisheries; during the mating season vasa deferentia from localities with low fishery intensity were heavier than those from high intensity fisheries, and these differences were even more evident in large males. Histological section showed that this disparity in vasa deferentia weight was explained principally by differences in the quantity of spermatophores rather than other seminal material. VSI was always higher in males from localities with low fishery intensity. Males from localities with high fishery intensity showed little capacity to recover sperm reserves and the VSI of these males remained below the values of the just-mated males. Detriment in the capacity of males to transfer sperm is the first step to sperm limitation in an exploited population, thus detection of sperm depletion can be an alert to introduce changes in the

  2. Mating choice of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae): influence of male ageing on mating success; Escolha de parceiro para acasalamento em Ceratitis capitata (Wiedemann)(Diptera: Tephritidae): influencia do envelhecimento dos machos no sucesso de copula

    Energy Technology Data Exchange (ETDEWEB)

    Silva Neto, Alberto M. da; Dias, Vanessa S.; Joachim-Bravo, Iara S. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Biologia. Dept. de Biologia Geral], e-mail: bio.alberto@gmail.com, e-mail: vanessasidias@hotmail.com, e-mail: ibravo@ufba.br

    2009-09-15

    The objective of this study was to evaluate the effect of male ageing on male pheromone release and mating success of Ceratitis capitata (Wiedemann). The effects of male ageing on mating were evaluated on fi ve and 21 d-old males by assessing their mating success (males chosen by a female for copulation) and the amount of males releasing the sex pheromone. The mating success was evaluated by using several ratios of young to older males by increasing the number of older males:young males from 1:1 to 5:1. The mating success of the 1:1 ratio was also evaluated in fi eld cages. The evaluation of the mating success (in the 1:1 ratio) showed a clear preference of the females for young males. Sex pheromone emission was much more common on young than older males. Even in cases were older males were more abundant (ratios 2:1 and 3:1), females still chose the young males. However, females could not distinguish young from older males in ratios of 4:1 or 5:1. Our data indicate that the ageing of C. capitata males has a considerable negative effect on their reproductive success, especially if they are found in a proportion any lower than 3:1. (author)

  3. The Drosophila Kctd-family homologue Kctd12-like modulates male aggression and mating behaviour.

    Science.gov (United States)

    Williams, Michael J; Goergen, Philip; Phad, Ganesh; Fredriksson, Robert; Schiöth, Helgi B

    2014-08-01

    In Drosophila, serotonin (5-HT) regulates aggression, mating behaviour and sleep/wake behaviour through different receptors. Currently, how these various receptors are themselves regulated is still not completely understood. The KCTD12-family of proteins, which have been shown to modify G-protein-coupled receptor (GPCR) signalling in mammals, are one possibility of auxiliary proteins modulating 5-HT receptor signalling. The KCTD12-family was found to be remarkably conserved and present in species from C. elegans to humans. The Drosophila KCTD12 homologue Kctd12-like (Ktl) was highly expressed in both the larval and adult CNS. By performing behavioural assays in male Drosophila, we now reveal that Ktl is required for proper male aggression and mating behaviour. Previously, it was shown that Ktl is in a complex with the Drosophila 5-HT receptor 5-HT7, and we observed that both Ktl and the 5-HT1A receptor are required in insulin-producing cells (IPCs) for proper adult male behaviour, as well as for hyperaggressive activity induced by the mammalian 5-HT1A receptor agonist 8-hydroxy-2-dipropylaminotetralin-hydrobromide. Finally, we show that Ktl expression in the IPCs is necessary to regulate locomotion and normal sleep/wake patterns in Drosophila, but not the 5-HT1A receptor. Similar to what was observed with mammalian KCTD12-family members that interact physically with a GPCR receptor to regulate desensitization, in Drosophila Ktl may function in GPCR 5-HT receptor pathways to regulate their signalling, which is required for proper adult male behaviour. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  4. Interspecific aggression, not interspecific mating, drives character displacement in the wing coloration of male rubyspot damselflies (Hetaerina).

    Science.gov (United States)

    Drury, J P; Grether, G F

    2014-12-07

    Traits that mediate intraspecific social interactions may overlap in closely related sympatric species, resulting in costly between-species interactions. Such interactions have principally interested investigators studying the evolution of reproductive isolation via reproductive character displacement (RCD) or reinforcement, yet in addition to reproductive interference, interspecific trait overlap can lead to costly between-species aggression. Previous research on rubyspot damselflies (Hetaerina spp.) demonstrated that sympatric shifts in male wing colour patterns and competitor recognition reduce interspecific aggression, supporting the hypothesis that agonistic character displacement (ACD) drove trait shifts. However, a recent theoretical model shows that RCD overshadows ACD if the same male trait is used for both female mate recognition and male competitor recognition. To determine whether female mate recognition is based on male wing coloration in Hetaerina, we conducted a phenotype manipulation experiment. Compared to control males, male H. americana with wings manipulated to resemble a sympatric congener (H. titia) suffered no reduction in mating success. Thus, female mate recognition is not based on species differences in male wing coloration. Experimental males did, however, experience higher interspecific fighting rates and reduced survival compared to controls. These results greatly strengthen the case for ACD and highlight the mechanistic distinction between ACD and RCD. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  5. Mating order-dependent female mate choice in the polygynandrous common lizard Lacerta vivipara.

    Science.gov (United States)

    Fitze, Patrick S; Cote, Julien; Clobert, Jean

    2010-02-01

    Recent studies indicate that directional female mate choice and order-dependent female mate choice importantly contribute to non-random mating patterns. In species where females prefer larger sized males, disentangling different hypotheses leading to non-random mating patterns is especially difficult, given that male size usually correlates with behaviours that may lead to non-random mating (e.g. size-dependent emergence from hibernation, male fighting ability). Here we investigate female mate choice and order-dependent female mate choice in the polygynandrous common lizard (Lacerta vivipara). By sequentially presenting males in random order to females, we exclude non-random mating patterns potentially arising due to intra-sexual selection (e.g. male-male competition), trait-dependent encounter probabilities, trait-dependent conspicuousness, or trait-dependent emergence from hibernation. To test for order-dependent female mate choice we investigate whether the previous mating history affects female choice. We show that body size and body condition of the male with which a female mated for the first time were bigger and better, respectively, than the average body size and body condition of the rejected males. There was a negative correlation between body sizes of first and second copulating males. This indicates that female mate choice is dependent on the previous mating history and it shows that the female's choice criteria are non-static, i.e. non-directional. Our study therefore suggests that context-dependent female mate choice may not only arise due to genotype-environment interactions, but also due to other female mating strategies, i.e. order-dependent mate choice. Thus context-dependent female mate choice might be more frequent than previously thought.

  6. 11-Ketotestosterone inhibits the alternative mating tactic in sneaker males of the peacock blenny, Salaria pavo.

    Science.gov (United States)

    Oliveira, R F; Carneiro, L A; Gonçalves, D M; Canario, A V; Grober, M S

    2001-01-01

    In the peacock blenny, Salaria pavo, a species with courtship sex-role reversal, smaller, younger males mimic the courtship behavior and the nuptial coloration of females in order to get access to nests during spawning and to parasitize egg fertilization from nest-holder males. Later in their life, sneakers transform both morphologically and behaviorally into nest-holder males. In the present paper we investigate the activational role of 11-ketotestosterone (KT), the most potent androgen in most teleost species, to promote the switch between tactics in sneaker males of S. pavo. Sneakers were implanted either with KT or with control (i.e. castor oil) silastic implants. A week after implantation they were subjected to a set of behavioral tests and morphometric measurements. KT treatment promoted the differentiation of secondary sex characters, such as the anal glands, and inhibited the expression of female courtship behavior. KT-treated sneakers also showed a trend toward less frequent display of female nuptial coloration. There was no effect of KT treatment on the expression of typical nest-holder male behavior. Finally, there was no effect of KT treatment on the number or soma size of arginine vasotocin neurons in the preoptic area, which are often associated with the expression of vertebrate sexual behavior. Thus, KT seems to play a key role in mating tactic switching by inhibiting the expression of female courtship behavior and by promoting the development of male displaying traits (e.g. anal glands). The lack of a KT effect on behavior typical of nest-holding males and vasotocinergic preoptic neurons suggests that a longer time frame or other endocrine/social signals are needed for the initiation of these traits in males that are switching tactics.

  7. Increased pheromone signaling by small male sea lamprey has distinct effects on female mate search and courtship

    Science.gov (United States)

    Buchinger, Tyler J.; Bussy, Ugo; Buchinger, Ethan G.; Fissette, Skye D.; Li, Weiming; Johnson, Nicholas

    2017-01-01

    Male body size affects access to mates in many animals. Attributes of sexual signals often correlate with body size due to physiological constraints on signal production. Larger males generally produce larger signals, but costs of being large or compensation by small males can result in smaller males producing signals of equal or greater magnitude. Female choice following multiple male traits with different relationships to size might further complicate the effect of male body size on access to mates. We report the relationship between male body size and pheromone signaling, and the effects on female mate search and courtship in the sea lamprey (Petromyzon marinus). We predicted that pheromone production in the liver and the liver mass to body mass ratio would remain constant across sizes, resulting in similar mass-adjusted pheromone release rates across sizes but a positive relationship between absolute pheromone release and body mass. Our results confirmed positive relationships between body mass and liver mass, and liver mass and the magnitude of the pheromone signal. Surprisingly, decreasing body mass was correlated with higher pheromone concentrations in the liver, liver mass to body mass ratios, and mass-adjusted pheromone release rates. In a natural stream, females more often entered nests treated with small versus large male odors. However, close-proximity courtship behaviors were similar in nests treated with small or large male odors. We conclude that small males exhibit increased release of the main pheromone component, but female discrimination of male pheromones follows several axes of variation with different relationships to size.

  8. The effect of age on the mating competitiveness of male Glossina fuscipes fuscipes and G. palpalis palpalis

    Directory of Open Access Journals (Sweden)

    P.P. Abila

    2003-05-01

    Full Text Available The effect of age on male Glossina fuscipes fuscipes, Newstead, and Glossina palpalis palpalis, Austin (Diptera: Glossinidae competiveness were investigated with a view to estimate optimal age for sterile male release. Sterile insect technique involves the mass production, sterilization and sequential release of males of the target species to out compete the wild male population. Mating between released sterile males and wild females produce inviable progeny and the population is reduced over several generations to unsustainable levels. It is vital that the released male are of high quality and are sexually competitive. Age is one parameter affecting the sexual competiveness of the male tsetse fly. The optimal release age was estimated by assessing sexual competitiveness of flies of different age categories, 1, 5, 8 and 13-days after adult eclosion. A walk-in field-cage was used in order to approximate as closely as possible the actual field scenario during sterile insect release programes. It was shown that 8 and 13-day old males mated significantly more frequently, i.e. were more competitive, in the presence of equal numbers of 1 and 5-day old males. The age of male tsetse flies significantly affected competitiveness in both species studied. The ability of G. f. fuscipes to inseminate was not age dependent, and insemination occurred in all females that mated regardless of male age. In G. p. palpalis, however, 1-day old males were least able to inseminate. Mating duration was not significantly affected by age in both species. Eight to thirteen day old males of the test species are here recommended as the optimal sterile male release age.

  9. Mate choice for a male carotenoid-based ornament is linked to female dietary carotenoid intake and accumulation

    Directory of Open Access Journals (Sweden)

    Toomey Matthew B

    2012-01-01

    Full Text Available Abstract Background The coevolution of male traits and female mate preferences has led to the elaboration and diversification of sexually selected traits; however the mechanisms that mediate trait-preference coevolution are largely unknown. Carotenoid acquisition and accumulation are key determinants of the expression of male sexually selected carotenoid-based coloration and a primary mechanism maintaining the honest information content of these signals. Carotenoids also influence female health and reproduction in ways that may alter the costs and benefits of mate choice behaviours and thus provide a potential biochemical link between the expression of male traits and female preferences. To test this hypothesis, we manipulated the dietary carotenoid levels of captive female house finches (Carpodacus mexicanus and assessed their mate choice behavior in response to color-manipulated male finches. Results Females preferred to associate with red males, but carotenoid supplementation did not influence the direction or strength of this preference. Females receiving a low-carotenoid diet were less responsive to males in general, and discrimination among the colorful males was positively linked to female plasma carotenoid levels at the beginning of the study when the diet of all birds was carotenoid-limited. Conclusions Although female preference for red males was not influenced by carotenoid intake, changes in mating responsiveness and discrimination linked to female carotenoid status may alter how this preference is translated into choice. The reddest males, with the most carotenoid rich plumage, tend to pair early in the breeding season. If carotenoid-related variations in female choice behaviour shift the timing of pairing, then they have the potential to promote assortative mating by carotenoid status and drive the evolution of carotenoid-based male plumage coloration.

  10. Consideration of Cosmetic Surgery As Part of Women’s Benefit-Provisioning Mate Retention Strategy

    Directory of Open Access Journals (Sweden)

    Mohammad Atari

    2017-08-01

    Full Text Available Individuals perform mate retention behaviors to minimize the risk of partner infidelity and relationship dissolution. The current study investigates whether consideration of cosmetic surgery can be conceptualized as part of a broader strategy of mate retention for women, but not men. We hypothesized that women’s consideration of cosmetic surgery would be positively associated with performance frequencies of Benefit-Provisioning and Cost-Inflicting mate retention behaviors. We recruited 203 individuals (54% women in committed heterosexual relationships from Tehran, Iran. Results indicate a positive association between consideration of cosmetic surgery and Benefit-Provisioning mate retention behaviors for women, but not men. There was no association between consideration of cosmetic surgery and Cost-Inflicting mate retention behaviors. Women therefore may consider cosmetic surgery to improve their physical attractiveness as part of a Benefit-Provisioning strategy to retain a long-term mate. We discuss limitations of the study and highlight future directions for research from an evolutionary perspective.

  11. The Political Divide Over Same-Sex Marriage: Mating Strategies in Conflict?

    Science.gov (United States)

    Pinsof, David; Haselton, Martie

    2016-04-01

    Although support for same-sex marriage has grown dramatically over the past decade, public opinion remains markedly divided. Here, we propose that the political divide over same-sex marriage represents a deeper divide between conflicting mating strategies. Specifically, we propose that opposition to same-sex marriage can be explained in terms of (a) individual differences in short-term mating orientation and (b) mental associations between homosexuality and sexual promiscuity. We created a novel Implicit Association Test to measure mental associations between homosexuality and promiscuity. We found that mental associations between homosexuality and promiscuity, at both the implicit and the explicit levels, interacted with short-term mating orientation to predict opposition to same-sex marriage. Our model accounted for 42.3% of the variation in attitudes toward same-sex marriage, and all predictors remained robust when we controlled for potential confounds. Our results reveal the centrality of mating psychology in attitudes toward same-sex marriage.

  12. When Love Meets Money: Priming the Possession of Money Influences Mating Strategies

    Science.gov (United States)

    Li, Yi Ming; Li, Jian; Chan, Darius K.-S.; Zhang, Bo

    2016-01-01

    Money is an important factor that influences the development of romantic relationships. The current paper examines how the feeling of having relatively more or less money influences human mating strategies in long-term and short-term mating contexts under the framework of evolutionary psychology. We recruited mainland Chinese college students involved in steady, heterosexual romantic relationships to participate in two experiments. In each study, we experimentally triggered participants' feelings of having relatively more or less money and then examined their thoughts and behaviors related to mating. Results of Study 1 showed that men who were primed to feel that they had relatively more money were less satisfied with their partners' physical attractiveness than those primed to feel that they had less money, suggesting that the subjective feeling of having more or less money may affect men's preferences regarding the physical appearance of a mate in a long-term relationship. Interestingly, this difference was not significant for women. Results of Study 2 indicated that both men and women who were primed to feel that they had relatively more money exhibited a greater “behavioral approach tendency” toward an attractive member of the opposite sex than those primed to feel that they had less money. This finding suggests that people who feel they have relatively more money may have more interest in an attractive alternative than those who feel they have relatively less money. The differences in mating strategies between and within the genders brought about by money support the evolutionary hypothesis that individuals adopt conditional mating strategies in response to environmental conditions. Additionally, the results of experimental studies provide evidence for the causal effects of money on mating strategies. These findings have both conceptual and practical implications for the psychology of evolution and romantic relationships. PMID:27047415

  13. When Love Meets Money: Priming the Possession of Money Influences Mating Strategies.

    Science.gov (United States)

    Li, Yi Ming; Li, Jian; Chan, Darius K-S; Zhang, Bo

    2016-01-01

    Money is an important factor that influences the development of romantic relationships. The current paper examines how the feeling of having relatively more or less money influences human mating strategies in long-term and short-term mating contexts under the framework of evolutionary psychology. We recruited mainland Chinese college students involved in steady, heterosexual romantic relationships to participate in two experiments. In each study, we experimentally triggered participants' feelings of having relatively more or less money and then examined their thoughts and behaviors related to mating. Results of Study 1 showed that men who were primed to feel that they had relatively more money were less satisfied with their partners' physical attractiveness than those primed to feel that they had less money, suggesting that the subjective feeling of having more or less money may affect men's preferences regarding the physical appearance of a mate in a long-term relationship. Interestingly, this difference was not significant for women. Results of Study 2 indicated that both men and women who were primed to feel that they had relatively more money exhibited a greater "behavioral approach tendency" toward an attractive member of the opposite sex than those primed to feel that they had less money. This finding suggests that people who feel they have relatively more money may have more interest in an attractive alternative than those who feel they have relatively less money. The differences in mating strategies between and within the genders brought about by money support the evolutionary hypothesis that individuals adopt conditional mating strategies in response to environmental conditions. Additionally, the results of experimental studies provide evidence for the causal effects of money on mating strategies. These findings have both conceptual and practical implications for the psychology of evolution and romantic relationships.

  14. The role of dyadic interactions in the mixed-mating strate-gies of the mangrove rivulus Kryptolebias marmoratus

    Directory of Open Access Journals (Sweden)

    Kelly N. LUKE,David L. BECHLER

    2010-02-01

    Full Text Available The mangrove rivulus Kryptolebias marmoratus a small cyprinodont fish native to tropical and subtropical waters from Florida to Brazil, is one of two known self-fertilizing, hermaphroditic vertebrates of which K. marmoratus displays androdioecy, a complex system of reproduction in which hermaphrodites and males are present. This study describes the behavioral repertoires observed during dyadic interactions in the laboratory. Kryptolebias marmoratus exhibited 23 distinctive acts or behaviors. Acts were divided into four categories: aggressive, submissive, neutral, and reproductive. Leading and following behaviors played important roles in the behavioral repertoires of these fish. In hermaphrodite-male dyads, males exclusively initiated the reproductive process and actively pursued hermaphrodites. When hermaphrodites were paired, there was no evidence that they behaved like other simultaneous hermaphrodites that alternate sexual roles (e.g. serranids. Hermaphrodites were extremely aggressive towards one another, and the aggressor established dominance rapidly. Male-male dyads were divided into two subdivisions based on the presence or absence of the caudal ocellus on one fish. A caudal ocellus on one male appeared to signal the possibility of a potential mating partner to males lacking it. Pairings of males without an ocellus were similar to hermaphrodite-hermaphrodite dyads in that both members of the pair were aggressive towards one another. These observations may be indicative of interactions taking place in natural communities or assemblages of fish in which both males and hermaphrodites occur and provide evidence on the role of dyadic interactions in the mixed-mating strategies [Current Zoology 56 (1: 6–17 2010].

  15. Evidence for mate guarding behavior in the Taylor's checkerspot butterfly

    Science.gov (United States)

    Victoria J. Bennett; Winston P. Smith; Matthew G. Betts

    2011-01-01

    Discerning the intricacies of mating systems in butterflies can be difficult, particularly when multiple mating strategies are employed and are cryptic and not exclusive. We observed the behavior and habitat use of 113 male Taylor's checkerspot butterflies (Euphydryas editha taylori). We confirmed that two distinct mating strategies were...

  16. Comparison of Irradiation and Wolbachia Based Approaches for Sterile-Male Strategies Targeting Aedes albopictus.

    Science.gov (United States)

    Atyame, Célestine M; Labbé, Pierrick; Lebon, Cyrille; Weill, Mylène; Moretti, Riccardo; Marini, Francesca; Gouagna, Louis Clément; Calvitti, Maurizio; Tortosa, Pablo

    2016-01-01

    The global expansion of Aedes albopictus together with the absence of vaccines for most of the arboviruses transmitted by this mosquito has stimulated the development of sterile-male strategies aiming at controlling disease transmission through the suppression of natural vector populations. In this context, two environmentally friendly control strategies, namely the Sterile Insect Technique (SIT) and the Wolbachia-based Incompatible Insect Technique (IIT) are currently being developed in several laboratories worldwide. So far however, there is a lack of comparative assessment of these strategies under the same controlled conditions. Here, we compared the mating capacities, i.e. insemination capacity, sterilization capacity and mating competitiveness of irradiated (35 Gy) and incompatible Ae. albopictus males at different ages and ratios under laboratory controlled conditions. Our data show that there was no significant difference in insemination capacity of irradiated and incompatible males, both male types showing lower capacities than untreated males at 1 day but recovering full capacity within 5 days following emergence. Regarding mating competitiveness trials, a global observed trend is that incompatible males tend to induce a lower hatching rate than irradiated males in cage controlled confrontations. More specifically, incompatible males were found more competitive than irradiated males in 5:1 ratio regardless of age, while irradiated males were only found more competitive than incompatible males in the 1:1 ratio at 10 days old. Overall, under the tested conditions, IIT seemed to be slightly more effective than SIT. However, considering that a single strategy will likely not be adapted to all environments, our data stimulates the need for comparative assessments of distinct strategies in up-scaled conditions in order to identify the most suitable and safe sterilizing technology to be implemented in a specific environmental setting and to identify the

  17. Influence of the male ejaculate on post-mating prezygotic barriers in field crickets.

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    Erica L Larson

    Full Text Available Post-copulatory interactions between males and females involve highly coordinated, complex traits that are often rapidly evolving and divergent between species. Failure to produce and deposit eggs may be a common post-mating prezygotic barrier, yet little is known about what prevents the induction of egg-laying between species. The field crickets, Gryllus firmus and G. pennsylvanicus are isolated by a one-way reproductive incompatibility; G. pennsylvanicus males fail to fertilize G. firmus eggs or to induce normal egg-laying in G. firmus females. We use experimental crosses to elucidate the role of accessory gland-derived vs. testis-derived components of the G. firmus male ejaculate on egg-laying in conspecific and heterospecific crosses. Using surgical castrations to create 'spermless' males that transfer only seminal fluid proteins (SFPs we test whether G. firmus male SFPs can induce egg-laying in conspecific crosses and rescue egg-laying in crosses between G. pennsylvanicus males and G. firmus females. We find G. firmus SFPs induce only a small short-term egg-laying response and that SFPs alone cannot explain the normal induction of egg-laying. Gryllus firmus SFPs also do not rescue the heterospecific cross. Testis-derived components, such as sperm or prostaglandins, most likely stimulate egg-laying or act as transporters for SFPs to targets in the female reproductive tract. These results highlight the utility of experimental approaches for investigating the phenotypes that act as barriers between species and suggest that future work on the molecular basis of the one-way incompatibility between G. firmus and G. pennsylvanicus should focus on divergent testis-derived compounds or proteins in addition to SFPs.

  18. Condition-dependent mate choice: A stochastic dynamic programming approach.

    Science.gov (United States)

    Frame, Alicia M; Mills, Alex F

    2014-09-01

    We study how changing female condition during the mating season and condition-dependent search costs impact female mate choice, and what strategies a female could employ in choosing mates to maximize her own fitness. We address this problem via a stochastic dynamic programming model of mate choice. In the model, a female encounters males sequentially and must choose whether to mate or continue searching. As the female searches, her own condition changes stochastically, and she incurs condition-dependent search costs. The female attempts to maximize the quality of the offspring, which is a function of the female's condition at mating and the quality of the male with whom she mates. The mating strategy that maximizes the female's net expected reward is a quality threshold. We compare the optimal policy with other well-known mate choice strategies, and we use simulations to examine how well the optimal policy fares under imperfect information.

  19. Male Seminal Relaxin Contributes to Induction of the Post-mating Cytokine Response in the Female Mouse Uterus

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    Danielle J. Glynn

    2017-06-01

    Full Text Available The hormone relaxin is important in female reproduction for embryo implantation, cardiovascular function, and during labor and lactation. Relaxin is also synthesized in males by organs of the male tract. We hypothesized that relaxin might be one component of seminal plasma responsible for eliciting the female cytokine response induced in the uterus at mating. When recombinant relaxin was injected into the uterus of wild-type (Rln+/+ mice at estrus, it evoked the production of Cxcl1 mRNA and its secreted protein product CXCL1 in four of eight animals. Mating experiments were then conducted using mice with a null mutation in the relaxin gene (Rln−/− mice. qRT-PCR analysis of mRNA expression in wild-type females showed diminished uterine expression of several cytokine and chemokine genes in the absence of male relaxin. Similar differences were also noted comparing Rln−/− and Rln+/+ females mated to wild-type males. Quantification of uterine luminal fluid cytokine content confirmed that male relaxin provokes the production of CXCL10 and CSF3 in Rln+/+ females. Differences were also seen comparing Rln−/− and Rln+/+ females mated with Rln−/− males for CXCL1, CSF3, and CCL5, implying that endogenous relaxin in females might prime the uterus to respond appropriately to seminal fluid at coitus. Finally, pan-leukocyte CD45 mRNA was increased in wild-type matings compared to other combinations, implying that male and female relaxin may trigger leukocyte expansion in the uterus. We conclude that male and/or female relaxin may be important in activating the uterine cytokine/chemokine network required to initiate maternal immune adaptation to pregnancy.

  20. Sterile medfly males of the tsl Vienna 8 genetic sexing strain display improved mating performance with ginger root oil

    Energy Technology Data Exchange (ETDEWEB)

    Paranhos, Beatriz Jordao; Alves, Renata Morelli, E-mail: bjordao@cpatsa.embrapa.b [EMBRAPA Semi-Arido, Petrolina, PE (Brazil); McInnis, Donald [U.S. Department of Agriculture (USDA/ARS/PBARC), Honolulu, HI (United States). Agricultural Research Service. Pacific Basin Agricultural Research Center; Uramoto, Keiko [Universidade de Sao Paulo (USP), SP (Brazil); Damasceno, Itala; Malavasi, Aldo [Biofabrica Moscamed Brasil, Juazeiro, BA (Brazil); Goncalves, Nilmara [Valexport, Petrolina, PE (Brazil); Costa, Maria de Lourdes; Walder, Julio [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Nascimento, Antonio [EMBRAPA Mandioca e Fruticultura, Cruz das Almas, BA (Brazil)

    2006-07-01

    A key point of the sterile insect technique applied to the medfly, Ceratitis capitata, is that the sterile males produced in the laboratory should have at least a minimal sexual compatibility with wild females. Among several genetic sexing tsl (Temperature Sensitive Lethal) strains of C. capitata mass-reared around the world, the Biofabrica Moscamed Brasil has chosen the most recent mass produced tsl strain, Vienna 8 (V8), which has been evaluated in the San Francisco River Valley, Brazil, since April, 2005. The tests were accomplished in field cages, with different treatments for V8 males, sterile or fertile, exposed to the aroma of ginger root oil (GRO) or not, versus wild males and females. Males of one strain (V8 or wild) were painted white on the thorax the day before the mating tests. All the insects were virgin, and early in the morning (7-8 A.M.) males were released inside the field cages, 10 min. before females. Mating pairs were collected in glass vials, until early afternoon. From this raw data, both the type of male mating and the time in copula were recorded for each pair. Then, the total percentage of mated females, the RSI (Relative Sterility Index), and Fried's competitiveness values (C), were calculated for each field cage. The percentage of females mated was statistically higher to sterile males exposed to GRO than to non exposed to GRO. Time in copula was significantly higher for wild flies than for laboratory flies, except for the case of fertile V8 males exposed to GRO x wild females. The RSI and C values were significantly higher for V8 males (irradiated and fertile) treated with GRO than for V8 males not treated with GRO. The results indicate that there is adequate sexual compatibility between sterile males of the tsl Vienna 8 strain and wild C. capitata females from the San Francisco River Valley, Brazil. Also, the radiation dose of 95 Gy, used to sterilize the males, did not affect their sexual activity. Ginger root oil acted as a

  1. Are larger and/or more symmetrical Drosophila melanogaster (Diptera, Drosophilidae males more successful in matings in nature?

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    Sofija Pavković-Lučić

    Full Text Available Are larger and/or more symmetrical Drosophila melanogaster (Diptera, Drosophilidae males more successful in matings in nature? Sexual selection in Drosophila melanogaster, related to body size and fluctuating asymmetry in wing length and number of sex comb teeth in males, was tested in natural conditions. Males collected in copula were significantly larger than those collected as a single, while no difference in mean number of sex comb teeth between copulating and single males was observed. On the other hand, single males had greater asymmetry both for wing length and number of sex comb teeth than their mating counterparts. It looks like that symmetry of these bilateral traits also may play a role in sexual selection in this dipteran species in nature.

  2. Silencing of the Hsf gene, the transcriptional regulator of A. gambiae male accessory glands, inhibits the formation of the mating plug in mated females and disrupts their monogamous behaviour.

    Science.gov (United States)

    Dottorini, Tania; Persampieri, Tania; Palladino, Pietro; Spaccapelo, Roberta; Crisanti, Andrea

    2012-11-01

    Discovering the molecular factors that shape the mating behaviour and the fertility of the mosquito Anopheles gambiae, the principal vector of human malaria, is regarded as critical to better understand its reproductive success as well as for identifying new leads for malaria control measures. In A. gambiae mating induces complex behavioural and physiological changes in the females, including refractoriness to subsequent mating and induction of egg-laying. In other insects including Drosophila a group of proteins named Accessory gland proteins (Acps), produced by males and transferred with sperm to the female reproductive tract, have been implicated in this post-mating response. Although Acps represent a set of promising candidates for unravelling the mating physiology, their role in inducing behavioural changes in mated A. gambiae females remains largely unknown. In this work, we demonstrate that a down-regulation of a large fraction of Acp genes via silencing of the Acp regulating transcription factor Hsf, abolishes the formation of mating plug in mated females and fails to induce refractoriness of mated female to subsequent inseminations. A significant fraction of females mated to Hsf silenced males (66%) failed to receive the mating plug though seminal fluid had been transferred as documented by the presence of spermatozoa in the female sperm storage organ. Furthermore, nearly all females (95%) mated to HSF-silenced males were re-inseminated when exposed to males carrying EGPF marked sperm. Our findings provide evidence showing that Acp genes regulated by the transcription factor HSF play a key role in the function of the male accessory glands.

  3. The Exploitive Mating Strategy of the Dark Triad Traits: Tests of Rape-Enabling Attitudes.

    Science.gov (United States)

    Jonason, Peter K; Girgis, Mary; Milne-Home, Josephine

    2017-01-24

    The Dark Triad traits have been repeatedly labeled as facilitating an exploitive mating strategy. However, various researchers have repeatedly conflated short-term mating or casual sex with an exploitive mating strategy. In this study using Mechanical Turk participants (N = 252; 142 men, 110 women), we provided a better test of just how sexually exploitive those high on the Dark Triad traits might be by examining how the traits related to rape-enabling attitudes. We examined how each trait may facilitate rape, whether these associations were robust to partialing the variance associated with the Big Five traits and similar in men and women, and showed that one reason why men may be more likely to rape than women is they are characterized by the Dark Triad traits more than women are. In so doing, we test the confluence model of rape that asserts that personality traits similar to the Dark Triad traits act as one pathway to rape.

  4. Courtship raises male fertilization success through post-mating sexual selection in a spider

    OpenAIRE

    Schneider, Jutta M; Lesmono, Kristiani

    2009-01-01

    Courtship is well known for its positive effects on mating success. However, in polyandrous species, sexual selection continues to operate after copulation. Cryptic female choice is expected under unpredictable mating rates in combination with sequential mate encounters. However, there are very few accounts of the effects of courtship on cryptic female choice, and the available evidence is often correlative.

  5. Behaviour of Arctic charr Salvelinus alpinus during an induced mating season in captivity: how male relative size influences male behavioural investment and female preference over time.

    Science.gov (United States)

    Bolgan, M; O'Brien, J; Picciulin, M; Manning, L; Gammell, M

    2017-04-01

    The behaviour of sexually mature Arctic charr Salvelinus alpinus specimens (fifth farm generation) was observed in captivity for four consecutive days. Only agonistic interactions between males of different size were facilitated on the first 2 days, while both agonistic and courtship interactions were possible from the third day up to the end of the experiment. The reliability of behavioural analysis was assessed in order to reduce the possibility of observer errors within the generated datasets. The behavioural investment of big males, small males and females was analysed using general linear models (two-way repeated measures ANOVAs with time and male size as factors). A peak in the agonistic interactions between males occurred during the first day of interactions, where the agonistic investment of big males was significantly higher than that of small males. This resulted in an increased investment in submissive behaviour by the small males, who consistently performed submissive behaviours from the second day of interactions up to the end of the trial. Big males were found to invest significantly more than small males in courtship behaviours for the duration of the trial. Even though females performed inter-sexual behaviours towards both big and small males for the entire observation period, female interaction rate towards big males was higher than towards small males. This study suggests that both male investment in mating behaviour and female preference might be related to male characteristics such as body length and that S. alpinus behavioural patterns and mate choice cues might be strongly context-related and characterized by high levels of behavioural plasticity (i.e. presence-absence of certain behavioural units or potential reversal of a mate choice cue) within the same species. Finally, in light of this, some conservation measures are discussed. In particular, effective management plans should take into account the high level of behavioural plasticity

  6. Practical implementation of optimal management strategies in conservation programmes: a mate selection method

    Directory of Open Access Journals (Sweden)

    Fernández, J.

    2001-12-01

    Full Text Available The maintenance of genetic diversity is, from a genetic point of view, a key objective of conservation programmes. The selection of individuals contributing offspring and the decision of the mating scheme are the steps on which managers can control genetic diversity, specially on ‘ex situ’ programmes. Previous studies have shown that the optimal management strategy is to look for the parents’ contributions that yield minimum group coancestry (overall probability of identity by descent in the population and, then, to arrange mating couples following minimum pairwise coancestry. However, physiological constraints make it necessary to account for mating restrictions when deciding the contributions and, therefore, these should be implemented in a single step along with the mating plan. In the present paper, a single-step method is proposed to optimise the management of a conservation programme when restrictions on the mating scheme exist. The performance of the method is tested by computer simulation. The strategy turns out to be as efficient as the two-step method, regarding both the genetic diversity preserved and the fitness of the population.

  7. When Love Meets Money: Priming the Possession of Money Influences Mating Strategies

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    Yi Ming eLi

    2016-03-01

    Full Text Available Money is an important factor that influences the development of romantic relationships. The current paper examines how the feeling of having relatively more or less money influences human mating strategies in long-term and short-term mating contexts under the framework of evolutionary psychology. We recruited mainland Chinese college students involved in steady, heterosexual romantic relationships to participate in two experiments. In each study, we experimentally triggered participants’ feelings of having relatively more or less money and then examined their thoughts and behaviors related to mating. Results of Study 1 showed that men who were primed to feel that they had relatively more money were less satisfied with their partners’ physical attractiveness than those primed to feel that they had less money, suggesting that the subjective feeling of having more or less money may affect men’s preferences regarding the physical appearance of a mate in a long-term relationship. Interestingly, this difference was not significant for women. Results of Study 2 indicated that both men and women who were primed to feel that they had relatively more money exhibited a greater behavioral approach tendency toward an attractive member of the opposite sex than those primed to feel that they had less money. This finding suggests that people who feel they have relatively more money may have more interest in an attractive alternative than those who feel they have relatively less money. The differences in mating strategies between and within the genders brought about by money support the evolutionary hypothesis that individuals adopt conditional mating strategies in response to environmental conditions. These findings have both conceptual and practical implications for the psychology of evolution and romantic relationships.

  8. Male mate location behaviour and encounter sites in a community of tropical butterflies: taxonomic and site associations and distinctions

    Indian Academy of Sciences (India)

    Ashish D Tiple; Sonali V Padwad; Leonardo Dapporto; Roger L H Dennis

    2010-12-01

    Male mate location behaviour and encounter sites have been studied in 72 butterfly species at Nagpur, India, and related to taxonomy, morphology, habitat and population parameters. Species can be placed in three broad classes of mate location behaviour: invariant patrolling, invariant perching, and perch-patrol, the latter associated with increasing site fidelity, territorial defence and male assemblages. Significant taxonomic differences occur, closely related species tending to share mate location behaviours. Morphological differences are found with heavier and larger butterflies displaying greater site fidelity and territorial defence, and differences occur between individuals of species which both perch and patrol. Invariant patrolling is particularly associated with tracks through vegetation, host plant-track distributions, and high female to male numbers observed on transects; invariant perching is linked more to edge features than patrolling, and to lower population counts on transects. Species which perch-patrol, defend territories and establish male assemblages are associated with more complex vegetation structures, and have encounter sites at vegetation edges, landforms and predictable resource (host plant) concentrations. Attention is drawn to the importance of distinctive mate encounter sites for the conservation of butterfly species’ habitats.

  9. Female fitness optimum at intermediate mating rates under traumatic mating.

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    Rolanda Lange

    Full Text Available Traumatic mating behaviors often bear signatures of sexual conflict and are then typically considered a male strategy to circumvent female choice mechanisms. In an extravagant mating ritual, the hermaphroditic sea slug Siphopteron quadrispinosum pierces the integument of their mating partners with a syringe-like penile stylet that injects prostate fluids. Traumatic injection is followed by the insertion of a spiny penis into the partner's gonopore to transfer sperm. Despite traumatic mating, field mating rates exceed those required for female fertilization insurance, possibly because costs imposed on females are balanced by direct or indirect benefits of multiple sperm receipt. To test this idea, we exposed animals to a relevant range of mating opportunity regimes and assessed the effects on mating behavior and proxies of female fitness. We find penis intromission duration to decrease with mating rates, and a female fecundity maximum at intermediate mating rates. The latter finding indicates that benefits beyond fertilization insurance can make higher mating rates also beneficial from a female perspective in this traumatically mating species.

  10. Male alliance behaviour and mating access varies with habitat in a dolphin social network.

    Science.gov (United States)

    Connor, Richard C; Cioffi, William R; Randić, Srđan; Allen, Simon J; Watson-Capps, Jana; Krützen, Michael

    2017-04-13

    Within-species variation in social structure has attracted interest recently because of the potential to explore phenotypic plasticity and, specifically, how demographic and ecological variation influence social structure. Populations of bottlenose dolphins (Tursiops spp.) vary in male alliance formation, from no alliances to simple pairs to, in Shark Bay, Western Australia, the most complex nested alliances known outside of humans. Examination of ecological contributions to this variation is complicated by differences among populations in other potentially explanatory traits, such as phylogenetic distance, as well as female reproductive schedules, sexual size dimorphism, and body size. Here, we report our discovery of systematic spatial variation in alliance structure, seasonal movements and access to mates within a single continuous social network in the Shark Bay population. Participation in male trios (versus pairs), the sizes of seasonal range shifts and consortship rates all decrease from north to south along the 50 km length of the study area. The southern habitat, characterised by shallow banks and channels, may be marginal relative to the open northern habitat. The discovery of variation in alliance behaviour along a spatial axis within a single population is unprecedented and demonstrates that alliance complexity has an ecological component.

  11. Determinants of natural mating success in the cannibalistic orb-web spider Argiope bruennichi.

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    Stefanie M Zimmer

    Full Text Available Monogynous mating systems (low male mating rates occur in various taxa and have evolved several times independently in spiders. Monogyny is associated with remarkable male mating strategies and predicted to evolve under a male-biased sex ratio. While male reproductive strategies are well documented and male mating rates are easy to quantify, especially in sexually cannibalistic species, female reproductive strategies, the optimal female mating rate, and the factors that affect the evolution of female mating rates are still unclear. In this study, we examined natural female mating rates and tested the assumption of a male-biased sex ratio and female polyandry in a natural population of Argiope bruennichi in which we controlled female mating status prior to observations. We predicted variation in female mating frequencies as a result of spatial and temporal heterogeneity in the distribution of mature females and males. Females had a low average mating rate of 1.3 and the majority copulated only once. Polyandry did not entirely result from a male-biased sex-ratio but closely matched the rate of male bigamy. Male activity and the probability of polyandry correlated with factors affecting pheromone presence such as virgin females' density. We conclude that a strong sex ratio bias and high female mating rates are not necessary components of monogynous mating systems as long as males protect their paternity effectively and certain frequencies of bigyny stabilise the mating system.

  12. Casanovas are liars: behavioral syndromes, sperm competition risk, and the evolution of deceptive male mating behavior in live-bearing fishes [v2; ref status: indexed, http://f1000r.es/1ko

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    David Bierbach

    2013-08-01

    Full Text Available Male reproductive biology can by characterized through competition over mates as well as mate choice. Multiple mating and male mate choice copying, especially in internally fertilizing species, set the stage for increased sperm competition, i.e., sperm of two or more males can compete for fertilization of the female’s ova. In the internally fertilizing fish Poecilia mexicana, males respond to the presence of rivals with reduced expression of mating preferences (audience effect, thereby lowering the risk of by-standing rivals copying their mate choice. Also, males interact initially more with a non-preferred female when observed by a rival, which has been interpreted in previous studies as a strategy to mislead rivals, again reducing sperm competition risk (SCR. Nevertheless, species might differ consistently in their expression of aggressive and reproductive behaviors, possibly due to varying levels of SCR. In the current study, we present a unique data set comprising ten poeciliid species (in two cases including multiple populations and ask whether species can be characterized through consistent differences in the expression of aggression, sexual activity and changes in mate choice under increased SCR. We found consistent species-specific differences in aggressive behavior, sexual activity as well as in the level of misleading behavior, while decreased preference expression under increased SCR was a general feature of all but one species examined. Furthermore, mean sexual activity correlated positively with the occurrence of potentially misleading behavior. An alternative explanation for audience effects would be that males attempt to avoid aggressive encounters, which would predict stronger audience effects in more aggressive species. We demonstrate a positive correlation between mean aggressiveness and sexual activity (suggesting a hormonal link as a mechanistic explanation, but did not detect a correlation between aggressiveness and

  13. Casanovas are liars: behavioral syndromes, sperm competition risk, and the evolution of deceptive male mating behavior in live-bearing fishes [v3; ref status: indexed, http://f1000r.es/1zi

    Directory of Open Access Journals (Sweden)

    David Bierbach

    2013-10-01

    Full Text Available Male reproductive biology can by characterized through competition over mates as well as mate choice. Multiple mating and male mate choice copying, especially in internally fertilizing species, set the stage for increased sperm competition, i.e., sperm of two or more males can compete for fertilization of the female’s ova. In the internally fertilizing fish Poecilia mexicana, males respond to the presence of rivals with reduced expression of mating preferences (audience effect, thereby lowering the risk of by-standing rivals copying their mate choice. Also, males interact initially more with a non-preferred female when observed by a rival, which has been interpreted in previous studies as a strategy to mislead rivals, again reducing sperm competition risk (SCR. Nevertheless, species might differ consistently in their expression of aggressive and reproductive behaviors, possibly due to varying levels of SCR. In the current study, we present a unique data set comprising ten poeciliid species (in two cases including multiple populations and ask whether species can be characterized through consistent differences in the expression of aggression, sexual activity and changes in mate choice under increased SCR. We found consistent species-specific differences in aggressive behavior, sexual activity as well as in the level of misleading behavior, while decreased preference expression under increased SCR was a general feature of all but one species examined. Furthermore, mean sexual activity correlated positively with the occurrence of potentially misleading behavior. An alternative explanation for audience effects would be that males attempt to avoid aggressive encounters, which would predict stronger audience effects in more aggressive species. We demonstrate a positive correlation between mean aggressiveness and sexual activity (suggesting a hormonal link as a mechanistic explanation, but did not detect a correlation between aggressiveness and

  14. Behavioural determinants of gene flow in malaria vector populations: Anopheles gambiae males select large females as mates

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    Yan G

    2002-08-01

    Full Text Available Abstract Background Plasmodium-refractory mosquitoes are being rapidly developed for malaria control but will only succeed if they can successfully compete for mates when released into the wild. Pre-copulatory behavioural traits maintain genetic population structure in wild mosquito populations and mating barriers have foiled previous attempts to control malaria vectors through sterile male release. Methods Varying numbers of virgin male and female Anopheles gambiae Giles, from two strains of different innate sizes, were allowed to mate under standardized conditions in laboratory cages, following which, the insemination status, oviposition success and egg batch size of each female was assessed. The influence of male and female numbers, strain combination and female size were determined using logistic regression, correlation analysis and a simple mechanistic model of male competition for females. Results Male An. gambiae select females on the basis of size because of much greater fecundity among large females. Even under conditions where large numbers of males must compete for a smaller number of females, the largest females are more likely to become inseminated, to successfully oviposit and to produce large egg batches. Conclusions Sexual selection, on the basis of size, could either promote or limit the spread of malaria-refractory genes into wild populations and needs to be considered in the continued development and eventual release of transgenic vectors. Fundamental studies of behavioural ecology in malaria vectors such as An. gambiae can have important implications for malaria control and should be prioritised for more extensive investigation in the future.

  15. Wing Morphometry and Acoustic Signals in Sterile and Wild Males: Implications for Mating Success in Ceratitis capitata.

    Science.gov (United States)

    de Souza, João Maria Gomes Alencar; de Lima-Filho, Paulo Augusto; Molina, Wagner Franco; de Almeida, Lúcia Maria; de Gouveia, Milson Bezerra; de Macêdo, Francisco Pepino; Laumann, Raul Alberto; Paranhos, Beatriz Aguiar Jordão

    2015-01-01

    The sterile insect technique (SIT) is widely utilized in the biological control of fruit flies of the family Tephritidae, particularly against the Mediterranean fruit fly. This study investigated the interaction between mating success and morphometric variation in the wings and the production of acoustic signals among three male groups of Ceratitis capitata (Wiedemann): (1) wild males, (2) irradiated with Co-60 (steriles), and (3) irradiated (steriles) and treated with ginger oil. The canonical variate analysis discriminated two groups (males irradiated and males wild), based on the morphological shape of the wings. Among males that emit buzz signals, wild males obtained copulation more frequently than males in Groups 2 and 3. The individuals of Group 3 achieved more matings than those in Group 2. Wild males displayed lower pulse duration, higher intervals between pulses, and higher dominant frequency. Regarding the reproductive success, the morphological differences in the wings' shape between accepted and nonaccepted males are higher in wild males than in the irradiated ones. The present results can be useful in programs using the sterile insect technique for biological control of C. capitata.

  16. Wing Morphometry and Acoustic Signals in Sterile and Wild Males: Implications for Mating Success in Ceratitis capitata

    Directory of Open Access Journals (Sweden)

    João Maria Gomes Alencar de Souza

    2015-01-01

    Full Text Available The sterile insect technique (SIT is widely utilized in the biological control of fruit flies of the family Tephritidae, particularly against the Mediterranean fruit fly. This study investigated the interaction between mating success and morphometric variation in the wings and the production of acoustic signals among three male groups of Ceratitis capitata (Wiedemann: (1 wild males, (2 irradiated with Co-60 (steriles, and (3 irradiated (steriles and treated with ginger oil. The canonical variate analysis discriminated two groups (males irradiated and males wild, based on the morphological shape of the wings. Among males that emit buzz signals, wild males obtained copulation more frequently than males in Groups 2 and 3. The individuals of Group 3 achieved more matings than those in Group 2. Wild males displayed lower pulse duration, higher intervals between pulses, and higher dominant frequency. Regarding the reproductive success, the morphological differences in the wings’ shape between accepted and nonaccepted males are higher in wild males than in the irradiated ones. The present results can be useful in programs using the sterile insect technique for biological control of C. capitata.

  17. Monogamy versus Consensual Non-Monogamy: Alternative Approaches to Pursuing a Strategically Pluralistic Mating Strategy.

    Science.gov (United States)

    Mogilski, Justin K; Memering, Stacy L; Welling, Lisa L M; Shackelford, Todd K

    2017-02-01

    This study examined the frequency of partner-directed mate retention behaviors and several self- and partner-rated romantic relationship evaluations (i.e., sociosexuality, relationship satisfaction, mate value, and partner ideal measures) within monogamous and consensually non-monogamous (CNM) relationships. Measures were compared (1) between monogamous and CNM participants and (2) between two concurrent partners within each CNM relationship (i.e., primary and secondary partners). We found that individuals in currently monogamous relationships (n = 123) performed more mate retention behaviors compared to those currently in CNM relationships (n = 76). Within CNM relationships, participants reported engaging in more mate retention behaviors with primary partners compared to secondary partners. Likewise, CNM participants reported talking about their extra-dyadic sexual experiences and downplaying these sexual experiences more often with their primary partner compared to their secondary partner. There were no significant differences between ratings of monogamous and primary partners in participants' overall relationship satisfaction. However, monogamous participants reported less satisfaction with the amount of communication and openness they had with their partner compared to CNM participants' reports of their primary partner, but not secondary partner. By comparison, CNM participants reported higher overall relationship satisfaction with primary compared to secondary partners and considered their primary partner to be more desirable as a long-term mate than their secondary partner. We interpret these results within the context of previous research on monogamous and CNM relationships and hypothesize that these relationship configurations are alternative strategies for pursuing a strategically pluralistic mating strategy.

  18. Heaven it's my wife! Male canaries conceal extra-pair courtships but increase aggressions when their mate watches.

    Directory of Open Access Journals (Sweden)

    Davy Ung

    Full Text Available Many animals live in a communication network, an environment where individuals can obtain information about competitors or potential mates by observing interactions between conspecifics. In such an environment, interactants might benefit by changing their signalling behaviour in the presence of an audience. This audience effect seems widespread among species, has been observed during various types of interaction (e.g. intra-sexual vs. inter-sexual interaction and varies according to the social context (e.g. gender, hierarchical or mating status of the audience. However, the way individuals might adapt their signalling behaviour to a combination of these factors remains poorly understood. To address this question, we studied how the presence of an audience affects the behaviour of male domestic canaries Serinus canaria during two types of interactions: (i an extra-pair interaction and (ii a male-male competition for food. Males were observed under three conditions: (a in the absence of audience, (b in the presence of their mate or (c of a familiar female. Our results show that male domestic canaries minutely adapt their courting and agonistic behaviours to a combination of: (i the type of interaction (extra-pair interaction/male-male competition, (ii the social context (mate, familiar female or nobody in audience and (iii the behaviours of both the audience and the interactant. These results highlight the ability of animals to subtly adapt their behaviour to the social environment. This also raises questions about the cognitive foundations and evolution of these processes especially considering that canaries are known neither for having high cognitive abilities nor for being a typical example for the social intelligence hypothesis.

  19. A combined approach to heat stress effect on male fertility in Nasonia vitripennis: from the physiological consequences on spermatogenesis to the reproductive adjustment of females mated with stressed males.

    Directory of Open Access Journals (Sweden)

    Marlène Chirault

    Full Text Available In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological control agents, such as parasitic wasps used to control crop pests. Here Nasonia vitripennis, a parasitic wasp of various fly species, was studied to test the effects of 24h-heat stress applied during the first pupal stage on male fertility. Results showed that only primary spermatocytes were present at the first pupal stage in all cysts of the testes. Heat stress caused a delay in spermatogenesis during development and a significant decrease in sperm stock at emergence. Females mated with these heat-stressed males showed a reduce sperm count stored in their spermatheca. Females did not appear to distinguish heat-stressed from control males and did not remate more frequently to compensate for the lack of sperm transferred. As a result, females mated with heat-stressed males produced a suboptimal lifetime offspring sex ratio compared to those mated with control males. This could further impact the population dynamics of this species. N. vitripennis appears to be an interesting biological model to study the mechanisms of subfertility and its consequence on female reproductive strategies and provides new research perspectives in both invertebrates and vertebrates.

  20. A combined approach to heat stress effect on male fertility in Nasonia vitripennis: from the physiological consequences on spermatogenesis to the reproductive adjustment of females mated with stressed males.

    Science.gov (United States)

    Chirault, Marlène; Lucas, Christophe; Goubault, Marlène; Chevrier, Claude; Bressac, Christophe; Lécureuil, Charlotte

    2015-01-01

    In recent years, several studies have shown a decline in reproductive success in males in both humans and wildlife. Research on male fertility has largely focused on vertebrates, although invertebrates constitute the vast majority of terrestrial biodiversity. The reduction of their reproductive capacities due to environmental stresses can have strong negative ecological impacts, and also dramatic consequences on world food production if it affects the reproductive success of biological control agents, such as parasitic wasps used to control crop pests. Here Nasonia vitripennis, a parasitic wasp of various fly species, was studied to test the effects of 24h-heat stress applied during the first pupal stage on male fertility. Results showed that only primary spermatocytes were present at the first pupal stage in all cysts of the testes. Heat stress caused a delay in spermatogenesis during development and a significant decrease in sperm stock at emergence. Females mated with these heat-stressed males showed a reduce sperm count stored in their spermatheca. Females did not appear to distinguish heat-stressed from control males and did not remate more frequently to compensate for the lack of sperm transferred. As a result, females mated with heat-stressed males produced a suboptimal lifetime offspring sex ratio compared to those mated with control males. This could further impact the population dynamics of this species. N. vitripennis appears to be an interesting biological model to study the mechanisms of subfertility and its consequence on female reproductive strategies and provides new research perspectives in both invertebrates and vertebrates.

  1. Attraction and consumption of methyl eugenol by male Bactrocera umbrosa Fabricius (Diptera: Tephritidae) promotes conspecific sexual communication and mating performance.

    Science.gov (United States)

    Wee, S L; Abdul Munir, M Z; Hee, A K W

    2017-06-19

    The Artocarpus fruit fly, Bactrocera umbrosa (Fabricius) (Diptera: Tephritidae), is an oligophagous fruit pest infesting Moraceae fruits, including jackfruit (Artocarpus heterophyllus Lamarck), a fruit commodity of high value in Malaysia. The scarcity of fundamental biological, physiological and ecological information on this pest, particularly in relation to behavioural response to phytochemical lures, which are instrumental to the success of many area-wide fruit fly control and management programmes, underpins the need for studies on this much-underrated pest. The positive response of B. umbrosa males to methyl eugenol (ME), a highly potent phytochemical lure, which attracts mainly males of many Bactrocera species, was shown to increase with increasing age. As early as 7 days after emergence (DAE), ca. 22% of males had responded to ME and over 50% by 10 DAE, despite no occurrence of matings (i.e. the males were still sexually immature). Male attraction to ME peaked from 10 to 27 DAE, which corresponded with the flies' attainment of sexual maturity. In wind-tunnel assays during the dusk courtship period, ME-fed males exhibited earlier calling activity and attracted a significantly higher percentage of virgin females compared with ME-deprived males. ME-fed males enjoyed a higher mating success than ME-deprived males at 1-day post ME feeding in semi-field assays. ME consumption also promotes aggregation behaviour in B. umbrosa males, as demonstrated in wind-tunnel and semi-field assays. We suggest that ME plays a prominent role in promoting sexual communication and enhancing mating performance of the Artocarpus fruit fly, a finding that is congruent with previous reports on the consequences of ME acquisition by other economically important Bactrocera species.

  2. No evidence for heritability of male mating latency or copulation duration across social environments in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Michelle L Taylor

    Full Text Available A key assumption underpinning major models of sexual selection is the expectation that male sexual attractiveness is heritable. Surprisingly, however, empirical tests of this assumption are relatively scarce. Here we use a paternal full-sib/half-sib breeding design to examine genetic and environmental variation in male mating latency (a proxy for sexual attractiveness and copulation duration in a natural population of Drosophila melanogaster. As our experimental design also involved the manipulation of the social environment within each full-sibling family, we were able to further test for the presence of genotype-by-environment interactions (GEIs in these traits, which have the potential to compromise mate choice for genetic benefits. Our experimental manipulation of the social environment revealed plastic expression of both traits; males exposed to a rival male during the sensitive period of adult sexual maturation exhibited shorter mating latencies and longer copulation durations than those who matured in isolation. However, we found no evidence for GEIs, and no significant additive genetic variation underlying these traits in either environment. These results undermine the notion that the evolution of female choice rests on covariance between female preference and male displays, an expectation that underpins indirect benefit models such as the good genes and sexy sons hypotheses. However, our results may also indicate depletion of genetic variance in these traits in the natural population studied, thus supporting the expectation that traits closely aligned with reproductive fitness can exhibit low levels of additive genetic variance.

  3. A PDF/NPF neuropeptide signaling circuitry of male Drosophila melanogaster controls rival-induced prolonged mating.

    Science.gov (United States)

    Kim, Woo Jae; Jan, Lily Yeh; Jan, Yuh Nung

    2013-12-04

    A primary function of males for many species involves mating with females for reproduction. Drosophila melanogaster males respond to the presence of other males by prolonging mating duration to increase the chance of passing on their genes. To understand the basis of such complex behaviors, we examine the genetic network and neural circuits that regulate rival-induced Longer-Mating-Duration (LMD). Here, we identify a small subset of clock neurons in the male brain that regulate LMD via neuropeptide signaling. LMD requires the function of pigment-dispersing factor (PDF) in four s-LNv neurons and its receptor PDFR in two LNd neurons per hemisphere, as well as the function of neuropeptide F (NPF) in two neurons within the sexually dimorphic LNd region and its receptor NPFR1 in four s-LNv neurons per hemisphere. Moreover, rival exposure modifies the neuronal activities of a subset of clock neurons involved in neuropeptide signaling for LMD. Copyright © 2013 Elsevier Inc. All rights reserved.

  4. Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements.

    Science.gov (United States)

    Liendo, M C; Devescovi, F; Bachmann, G E; Utgés, M E; Abraham, S; Vera, M T; Lanzavecchia, S B; Bouvet, J P; Gómez-Cendra, P; Hendrichs, J; Teal, P E A; Cladera, J L; Segura, D F

    2013-02-01

    Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competitiveness of sterile laboratory males and females that were treated with methoprene (either the pupal or adult stage) and were kept under different regimes of adult food, which varied in the protein source and the sugar:protein ratio. Experiments were carried out under semi-natural conditions, where laboratory flies competed over copulations with sexually mature wild flies. Sterile, methoprene-treated males that reached sexual maturity earlier (six days old), displayed the same lekking behaviour, attractiveness to females and mating competitiveness as mature wild males. This effect depended on protein intake. Diets containing sugar and hydrolyzed yeast allowed sterile males to compete with wild males (even at a low concentration of protein), while brewer´s yeast failed to do so even at a higher concentration. Sugar only fed males were unable to achieve significant numbers of copulations. Methoprene did not increase the readiness to mate of six-day-old sterile females. Long pre-copulatory periods create an additional cost to the management of fruit fly pests through the sterile insect technique (SIT). Our findings suggest that methoprene treatment will increase SIT effectiveness against A. fraterculus when coupled with a diet fortified with protein. Additionally, methoprene acts as a physiological sexing method, allowing the release of mature males and immature females and hence increasing SIT efficiency.

  5. Natural variation in the strength and direction of male mating preferences for female pheromones in Drosophila melanogaster.

    Science.gov (United States)

    Pischedda, Alison; Shahandeh, Michael P; Cochrane, Wesley G; Cochrane, Veronica A; Turner, Thomas L

    2014-01-01

    Many animal species communicate using chemical signals. In Drosophila, cuticular hydrocarbons (CHCs) are involved in species and sexual identification, and have long been thought to act as stimulatory pheromones as well. However, a previous study reported that D. melanogaster males were more attracted to females that were lacking CHCs. This surprising result is consistent with several evolutionary hypotheses but is at odds with other work demonstrating that female CHCs are attractive to males. Here, we investigated natural variation in male preferences for female pheromones using transgenic flies that cannot produce CHCs. By perfuming females with CHCs and performing mate choice tests, we found that some male genotypes prefer females with pheromones, some have no apparent preference, and at least one male genotype prefers females without pheromones. This variation provides an excellent opportunity to further investigate the mechanistic causes and evolutionary implications of divergent pheromone preferences in D. melanogaster males.

  6. The study and analysis of the mating behavior and sound production of male cicada Psalmocharias alhageos (Kol.) (Homoptera:Cicadidae) to make disruption in mating.

    Science.gov (United States)

    Zamanian, H; Mehdipour, M; Ghaemi, N

    2008-09-01

    Psalmocharias alhageos is an important pest of vine in most parts of Iran, Afghanistan, Pakistan, southern areas of Russia, Turkey and Iraq. This cicada is spread in most provinces in Iran such as Esfahan, Hamedan, Qazvin, Markazi, Lorestan, Qom, Kerman, Tehran and Kordestan. In addition to vine, this insect damages some other fruit trees, such as apple, sour cherry, quince, peach, pomegranate and pear trees and some non-fruit trees, namely white poplar, ash, elm, eglantine, silk and black poplar trees. The nymphs of cicada damage the trees by feeding on root, adult insects on young bud and by oviposition under branch barks. Nourishing root by nymph leads to the weakness of the tree and hinder its growth. The high density oviposition of adult insects inside young barks causes withering of branches. The resulted damage on vine products is 40% which is one of the most important factors in product reduction in vineyard. This research was conducted in Takestan in Qazvin. It was conducted for the first time to study the behaviors of the mates of this vine cicada in order to manage it. Two systems were used to record the sound of male cicada called analog voice-recorder and digital voice recorder. To analyze the recorded sound of the male cicada we used of spectrum analyzer, digital storage oscilloscope and protens 7 computer softwares. We could call the attention of natural enemies an disturb the male insect's attracting sound by producing natural and artificial sound in the range of 1-6 kHz in two different ripeness status of the fruits and could prevent mating and oviposition of female cicadas.

  7. Don't get the blues: conspicuous nuptial colouration of male moor frogs (Rana arvalis) supports visual mate recognition during scramble competition in large breeding aggregations.

    Science.gov (United States)

    Sztatecsny, Marc; Preininger, Doris; Freudmann, Anita; Loretto, Matthias-Claudio; Maier, Franziska; Hödl, Walter

    2012-12-01

    Conspicuous male colouration is expected to have evolved primarily through selection by female choice. In what way conspicuous colours could be advantageous to males scrambling for mates remains largely unknown. The moor frog (Rana arvalis) belongs to the so-called explosive breeders in which spawning period is short; intrasexual competition is strong, and males actively search and scramble for females. During breeding, male body colouration changes from a dull brown (similar to females) to a conspicuous blue, and we wanted to test if male blueness influences mating success or facilitates male mate recognition. To do so, we first measured the colour of mated and non-mated males using a spectrophotometer. In an experiment, we then analysed interactions of actual male moor frogs in natural spawning aggregations with a brown (resembling a female or a non-breeding male) and a blue model frog. Mated and non-mated males did not differ in colouration, suggesting that female choice based on colour traits was unlikely. In our behavioural experiment, male moor frogs spent significantly more time in contact and in amplexus with the brown model than with the blue model. Our results suggest that the nuptial colouration in moor frogs can act as a new type of visual signal in anurans evolved to promote instantaneous mate recognition allowing males to quickly move between rivals while scrambling for females. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00265-012-1412-6) contains supplementary material, which is available to authorized users.

  8. Evidence for small scale variation in the vertebrate brain: mating strategy and sex affect brain size and structure in wild brown trout (Salmo trutta).

    Science.gov (United States)

    Kolm, N; Gonzalez-Voyer, A; Brelin, D; Winberg, S

    2009-12-01

    The basis for our knowledge of brain evolution in vertebrates rests heavily on empirical evidence from comparative studies at the species level. However, little is still known about the natural levels of variation and the evolutionary causes of differences in brain size and brain structure within-species, even though selection at this level is an important initial generator of macroevolutionary patterns across species. Here, we examine how early life-history decisions and sex are related to brain size and brain structure in wild populations using the existing natural variation in mating strategies among wild brown trout (Salmo trutta). By comparing the brains of precocious fish that remain in the river and sexually mature at a small size with those of migratory fish that migrate to the sea and sexually mature at a much larger size, we show, for the first time in any vertebrate, strong differences in relative brain size and brain structure across mating strategies. Precocious fish have larger brain size (when controlling for body size) but migratory fish have a larger cerebellum, the structure in charge of motor coordination. Moreover, we demonstrate sex-specific differences in brain structure as female precocious fish have a larger brain than male precocious fish while males of both strategies have a larger telencephalon, the cognitive control centre, than females. The differences in brain size and structure across mating strategies and sexes thus suggest the possibility for fine scale adaptive evolution of the vertebrate brain in relation to different life histories.

  9. Impact of salivary gland hypertrophy virus infection on the mating success of male Glossina pallidipes: consequences for the sterile insect technique.

    Directory of Open Access Journals (Sweden)

    Gratian N Mutika

    Full Text Available Many species of tsetse flies are infected by a virus (GpSGHV that causes salivary gland hypertrophy (SGH. Female Glossina pallidipes (Austen with SGH symptoms (SGH+ have reduced fecundity and SGH+ male G. pallidipes are unable to inseminate female flies. Consequently, G. pallidipes laboratory colonies with a high prevalence of SGH have been difficult to maintain and have collapsed on several occasions. To assess the potential impact of the release of SGH+ sterile male G. pallidipes on the efficacy of an integrated control programme with a sterile insect technique (SIT component, we examined the mating efficiency and behaviour of male G. pallidipes in field cages in relation to SGH prevalence. The results showed in a field cage setting a significantly reduced mating frequency of 19% for a male G. pallidipes population with a high prevalence of SGH (83% compared to 38% for a male population with a low prevalence of SGH (7%. Premating period and mating duration did not vary significantly with SGH status. A high percentage (>80% of females that had mated with SGH+ males had empty spermathecae. The remating frequency of female G. pallidipes was very low irrespective of the SGH status of the males in the first mating. These results indicate that a high prevalence of SGH+ in G. pallidipes not only affects colony stability and performance but, in view of their reduced mating propensity and competitiveness, releasing SGH+ sterile male G. pallidipes will reduce the efficiency of a sterile male release programme.

  10. Transcriptional profiles of mating-responsive genes from testes and male accessory glands of the Mediterranean fruit fly, Ceratitis capitata.

    Directory of Open Access Journals (Sweden)

    Francesca Scolari

    Full Text Available BACKGROUND: Insect seminal fluid is a complex mixture of proteins, carbohydrates and lipids, produced in the male reproductive tract. This seminal fluid is transferred together with the spermatozoa during mating and induces post-mating changes in the female. Molecular characterization of seminal fluid proteins in the Mediterranean fruit fly, Ceratitis capitata, is limited, although studies suggest that some of these proteins are biologically active. METHODOLOGY/PRINCIPAL FINDINGS: We report on the functional annotation of 5914 high quality expressed sequence tags (ESTs from the testes and male accessory glands, to identify transcripts encoding putative secreted peptides that might elicit post-mating responses in females. The ESTs were assembled into 3344 contigs, of which over 33% produced no hits against the nr database, and thus may represent novel or rapidly evolving sequences. Extraction of the coding sequences resulted in a total of 3371 putative peptides. The annotated dataset is available as a hyperlinked spreadsheet. Four hundred peptides were identified with putative secretory activity, including odorant binding proteins, protease inhibitor domain-containing peptides, antigen 5 proteins, mucins, and immunity-related sequences. Quantitative RT-PCR-based analyses of a subset of putative secretory protein-encoding transcripts from accessory glands indicated changes in their abundance after one or more copulations when compared to virgin males of the same age. These changes in abundance, particularly evident after the third mating, may be related to the requirement to replenish proteins to be transferred to the female. CONCLUSIONS/SIGNIFICANCE: We have developed the first large-scale dataset for novel studies on functions and processes associated with the reproductive biology of Ceratitis capitata. The identified genes may help study genome evolution, in light of the high adaptive potential of the medfly. In addition, studies of male

  11. Transcriptional profiles of mating-responsive genes from testes and male accessory glands of the Mediterranean fruit fly, Ceratitis capitata.

    Science.gov (United States)

    Scolari, Francesca; Gomulski, Ludvik M; Ribeiro, José M C; Siciliano, Paolo; Meraldi, Alice; Falchetto, Marco; Bonomi, Angelica; Manni, Mosè; Gabrieli, Paolo; Malovini, Alberto; Bellazzi, Riccardo; Aksoy, Serap; Gasperi, Giuliano; Malacrida, Anna R

    2012-01-01

    Insect seminal fluid is a complex mixture of proteins, carbohydrates and lipids, produced in the male reproductive tract. This seminal fluid is transferred together with the spermatozoa during mating and induces post-mating changes in the female. Molecular characterization of seminal fluid proteins in the Mediterranean fruit fly, Ceratitis capitata, is limited, although studies suggest that some of these proteins are biologically active. We report on the functional annotation of 5914 high quality expressed sequence tags (ESTs) from the testes and male accessory glands, to identify transcripts encoding putative secreted peptides that might elicit post-mating responses in females. The ESTs were assembled into 3344 contigs, of which over 33% produced no hits against the nr database, and thus may represent novel or rapidly evolving sequences. Extraction of the coding sequences resulted in a total of 3371 putative peptides. The annotated dataset is available as a hyperlinked spreadsheet. Four hundred peptides were identified with putative secretory activity, including odorant binding proteins, protease inhibitor domain-containing peptides, antigen 5 proteins, mucins, and immunity-related sequences. Quantitative RT-PCR-based analyses of a subset of putative secretory protein-encoding transcripts from accessory glands indicated changes in their abundance after one or more copulations when compared to virgin males of the same age. These changes in abundance, particularly evident after the third mating, may be related to the requirement to replenish proteins to be transferred to the female. We have developed the first large-scale dataset for novel studies on functions and processes associated with the reproductive biology of Ceratitis capitata. The identified genes may help study genome evolution, in light of the high adaptive potential of the medfly. In addition, studies of male recovery dynamics in terms of accessory gland gene expression profiles and correlated remating

  12. Reproductive effort of both male and female bar-throated Apalis apalis thoracica is predicted by ornamentation of self and mate

    NARCIS (Netherlands)

    van Dijk, Rene E.; Robles, Raquel; Groothuis, Ton G. G.; de Vries, Bonnie; Eising, Corine M.

    2015-01-01

    Melanin-based plumage ornaments have been shown to play an important role in male-male competition, but also influence inter-sexual communication. Consequently, ornaments may be associated with reproductive effort of both males and females. Females mated to males with larger melanin ornaments may ac

  13. Relative importance of the area and intensity of the orange spots of male guppies Poecilia reticulata as mating traits preferred by females.

    Science.gov (United States)

    Karino, K; Shimada, Y; Kudo, H; Sato, A

    2010-07-01

    Digitally modified videos of male guppies Poecilia reticulata were used to examine the relative importance of the area and intensity of the orange spots as mating traits preferred by females. The females prioritized the area of the orange spots over intensity for their mate preference.

  14. It takes two to tango: reproductive skew and social correlates of male mating success in a lek-breeding bird.

    Science.gov (United States)

    Ryder, Thomas B; Parker, Patricia G; Blake, John G; Loiselle, Bette A

    2009-07-01

    Variance in reproductive success among individuals is a defining characteristic of many social vertebrates. Yet, our understanding of which male attributes contribute to reproductive success is still fragmentary in most cases. Male-male reproductive coalitions, where males jointly display to attract females, are of particular interest to evolutionary biologists because one male appears to forego reproduction to assist the social partner. By examining the relationship between social behaviour and reproductive success, we can elucidate the proximate function of coalitions in the context of mate choice. Here, we use data from a 4-year study of wire-tailed manakins (Pipra filicauda) to provide molecular estimates of reproductive skew and to test the hypothesis that male-male social interactions, in the context of coordinated displays, positively influence a male's reproductive success. More specifically, we quantify male-male social interactions using network metrics and predict that greater connectivity will result in higher relative reproductive success. Our data show that four out of six leks studied had significant reproductive skew, with success apportioned to very few individuals in each lek. Metrics of male social affiliations derived from our network analysis, especially male connectivity, measured as the number of males with whom the focal male has extended interactions, were strong predictors of the number of offspring sired. Thus, network connectivity is associated with male fitness in wire-tailed manakins. This pattern may be the result of shared cues used by both sexes to assess male quality, or the result of strict female choice for coordinated display behaviour.

  15. Female preference for multi-modal courtship: multiple signals are important for male mating success in peacock spiders.

    Science.gov (United States)

    Girard, Madeline B; Elias, Damian O; Kasumovic, Michael M

    2015-12-07

    A long-standing goal for biologists has been to understand how female preferences operate in systems where males have evolved numerous sexually selected traits. Jumping spiders of the Maratus genus are exceptionally sexually dimorphic in appearance and signalling behaviour. Presumably, strong sexual selection by females has played an important role in the evolution of complex signals displayed by males of this group; however, this has not yet been demonstrated. In fact, despite apparent widespread examples of sexual selection in nature, empirical evidence is relatively sparse, especially for species employing multiple modalities for intersexual communication. In order to elucidate whether female preference can explain the evolution of multi-modal signalling traits, we ran a series of mating trials using Maratus volans. We used video recordings and laser vibrometry to characterize, quantify and examine which male courtship traits predict various metrics of mating success. We found evidence for strong sexual selection on males in this system, with success contingent upon a combination of visual and vibratory displays. Additionally, independently produced, yet correlated suites of multi-modal male signals are linked to other aspects of female peacock spider behaviour. Lastly, our data provide some support for both the redundant signal and multiple messages hypotheses for the evolution of multi-modal signalling. © 2015 The Author(s).

  16. Coevolutionary Feedbacks between Female Mating Interval and Male Allocation to Competing Sperm Traits Can Drive Evolution of Costly Polyandry.

    Science.gov (United States)

    Bocedi, Greta; Reid, Jane M

    2016-03-01

    Complex coevolutionary feedbacks between female mating interval and male sperm traits have been hypothesized to explain the evolution and persistence of costly polyandry. Such feedbacks could potentially arise because polyandry creates sperm competition and consequent selection on male allocation to sperm traits, while the emerging sperm traits could create female sperm limitation and, hence, impose selection for increased polyandry. However, the hypothesis that costly polyandry could coevolve with male sperm dynamics has not been tested. We built a genetically explicit individual-based model to simulate simultaneous evolution of female mating interval and male allocation to sperm number versus longevity, where these two sperm traits trade off. We show that evolution of competing sperm traits under polyandry can indeed cause female sperm limitation and, hence, promote further evolution and persistence of costly polyandry, particularly when sperm are costly relative to the degree of female sperm limitation. These feedbacks were stronger, and greater polyandry evolved, when postcopulatory competition for paternity followed a loaded rather than fair raffle and when sperm traits had realistically low heritability. We therefore demonstrate that the evolution of allocation to sperm traits driven by sperm competition can prevent males from overcoming female sperm limitation, thereby driving ongoing evolution of costly polyandry.

  17. The effect of aqueous extract of gross and commercial yerba mate (Ilex paraguariensis) on intra-abdominal and epididymal fat and glucose levels in male Wistar rats.

    Science.gov (United States)

    Silva, Raquel D'Agostini; Bueno, Audrin Loss Scopel; Gallon, Carin Weirich; Gomes, Luana Ferreira; Kaiser, Samuel; Pavei, Cabral; Ortega, George González; Kucharski, Luiz Carlos; Jahn, Matheus Parmegiani

    2011-09-01

    This study analyzed the plasma lipid profile, glucose levels and fat deposits in male rats treated with aqueous extract of gross yerba mate, commercial yerba mate or water. Yerba mate treatment did not change body weight gain and lipid profile. The consumption of gross yerba mate significantly increased blood glucose (6.6 mmol/L) as compared to the water (4.8 mmol/L) and commercial group (5.2 mmol/L) and decreased epididymal and intra-abdominal deposits (10.1mg/g and 23.7 mg/g of weight) as compared to the water (15.4 mg/g and 36.9 mg/g of weight) and commercial group (12.5mg/g and 28 mg/g of weight). The results suggest that gross yerba mate reduces fat more efficiently but produces a greater increase in blood glucose when compared to commercial yerba mate and water groups.

  18. Males and Females Contribute Unequally to Offspring Genetic Diversity in the Polygynandrous Mating System of Wild Boar

    Science.gov (United States)

    Pérez-González, Javier; Costa, Vânia; Santos, Pedro; Slate, Jon; Carranza, Juan; Fernández-Llario, Pedro; Zsolnai, Attila; Monteiro, Nuno M.; Anton, István; Buzgó, József; Varga, Gyula; Beja-Pereira, Albano

    2014-01-01

    The maintenance of genetic diversity across generations depends on both the number of reproducing males and females. Variance in reproductive success, multiple paternity and litter size can all affect the relative contributions of male and female parents to genetic variation of progeny. The mating system of the wild boar (Sus scrofa) has been described as polygynous, although evidence of multiple paternity in litters has been found. Using 14 microsatellite markers, we evaluated the contribution of males and females to genetic variation in the next generation in independent wild boar populations from the Iberian Peninsula and Hungary. Genetic contributions of males and females were obtained by distinguishing the paternal and maternal genetic component inherited by the progeny. We found that the paternally inherited genetic component of progeny was more diverse than the maternally inherited component. Simulations showed that this finding might be due to a sampling bias. However, after controlling for the bias by fitting both the genetic diversity in the adult population and the number of reproductive individuals in the models, paternally inherited genotypes remained more diverse than those inherited maternally. Our results suggest new insights into how promiscuous mating systems can help maintain genetic variation. PMID:25541986

  19. Males and females contribute unequally to offspring genetic diversity in the polygynandrous mating system of wild boar.

    Directory of Open Access Journals (Sweden)

    Javier Pérez-González

    Full Text Available The maintenance of genetic diversity across generations depends on both the number of reproducing males and females. Variance in reproductive success, multiple paternity and litter size can all affect the relative contributions of male and female parents to genetic variation of progeny. The mating system of the wild boar (Sus scrofa has been described as polygynous, although evidence of multiple paternity in litters has been found. Using 14 microsatellite markers, we evaluated the contribution of males and females to genetic variation in the next generation in independent wild boar populations from the Iberian Peninsula and Hungary. Genetic contributions of males and females were obtained by distinguishing the paternal and maternal genetic component inherited by the progeny. We found that the paternally inherited genetic component of progeny was more diverse than the maternally inherited component. Simulations showed that this finding might be due to a sampling bias. However, after controlling for the bias by fitting both the genetic diversity in the adult population and the number of reproductive individuals in the models, paternally inherited genotypes remained more diverse than those inherited maternally. Our results suggest new insights into how promiscuous mating systems can help maintain genetic variation.

  20. Mate choice on leks.

    Science.gov (United States)

    Balmford, A

    1991-03-01

    In lek-breeding animals, males defend tiny territories clustered into arenas, where females come to mate. Typically, most lek males secure relatively few copulations while a small number are highly successful. Recent studies suggest that the skewed distribution of matings seen at leks may be the result of females using a variety of criteria to select particular mating partners. Nevertheless, the possible benefits to females of mate choice at leks, where males offer neither resources nor paternal care, remain obscure.

  1. Copulation is reactivated by bromocriptine in male rats after reaching sexual satiety with a same sexual mate.

    Science.gov (United States)

    Rojas-Hernández, Jorge; Juárez, Jorge

    2015-11-01

    Male sexual satiety has been associated with a decrease in dopamine levels. Spontaneous recovery of copulatory behavior begins at least 72 h after sexual satiety is reached or in the condition in which a sexually-satiated male is exposed to a new receptive female distinct from the one with which sexual satiety was reached. The aim of the present study was to explore whether dopaminergic activation by bromocriptine (BrCr) can reactivate copulatory behavior with the same sexual mate immediately after sexual satiety is reached. Male rats were divided into three groups exposed to one of the following three conditions: 1) administration of 2 mg/kgs.c. of BrCr and exposure to the same female with whom sexual satiety was previously reached; 2) administration of 0.3 mLs.c. of the vehicle solution with exposure to the same female with whom sexual satiety was reached; and, 3) exposure to a new receptive female after sexual satiety was reached. Results showed that BrCr significantly reactivated copulatory capability in sexually-satiated males with the same receptive female. In contrast, no males in the vehicle group ejaculated with the same female after reaching sexual exhaustion. Copulation was reactivated by BrCr in a way similar to that observed in untreated males exposed to a new receptive female (i.e., the Coolidge effect). The reversal of sexual satiety in the males treated with BrCr could be explained by its action on D2 family receptors, which promotes a reactivation of sexual motivation at a level sufficient to allow renewed copulation with the same female mate.

  2. Ciliates learn to diagnose and correct classical error syndromes in mating strategies

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    Kevin Bradley Clark

    2013-08-01

    Full Text Available Preconjugal ciliates learn classical repetition error-correction codes to safeguard mating messages and replies from corruption by rivals and local ambient noise. Because individual cells behave as memory channels with Szilárd engine attributes, these coding schemes also might be used to limit, diagnose, and correct mating-signal errors due to noisy intracellular information processing. The present study, therefore, assessed whether heterotrich ciliates effect fault-tolerant signal planning and execution by modifying engine performance, and consequently entropy content of codes, during mock cell-cell communication. Socially meaningful serial vibrations emitted from an ambiguous artificial source initiated ciliate behavioral signaling performances known to advertise mating fitness with varying courtship strategies. Microbes, employing calcium-dependent Hebbian-like decision making, learned to diagnose then correct error syndromes by recursively matching Boltzmann entropies between signal planning and execution stages via power or refrigeration cycles. All eight serial contraction and reversal strategies incurred errors in entropy magnitude by the execution stage of processing. Absolute errors, however, subtended expected threshold values for single bit-flip errors in three-bit replies, indicating coding schemes protected information content throughout signal production. Ciliate preparedness for vibrations selectively and significantly affected the magnitude and valence of Szilárd engine performance during modal and nonmodal strategy corrective cycles. But entropy fidelity for all replies mainly improved across learning trials as refinements in engine efficiency. Fidelity neared maximum levels for only modal signals coded in resilient three-bit repetition error-correction sequences. Together, these findings demonstrate microbes can elevate survival/reproductive success by learning to implement classical fault-tolerant information processing in

  3. Humor Ability Reveals Intelligence, Predicts Mating Success, and Is Higher in Males

    Science.gov (United States)

    Greengross, Gil; Miller, Geoffrey

    2011-01-01

    A good sense of humor is sexually attractive, perhaps because it reveals intelligence, creativity, and other "good genes" or "good parent" traits. If so, intelligence should predict humor production ability, which in turn should predict mating success. In this study, 400 university students (200 men and 200 women) completed…

  4. Humor Ability Reveals Intelligence, Predicts Mating Success, and Is Higher in Males

    Science.gov (United States)

    Greengross, Gil; Miller, Geoffrey

    2011-01-01

    A good sense of humor is sexually attractive, perhaps because it reveals intelligence, creativity, and other "good genes" or "good parent" traits. If so, intelligence should predict humor production ability, which in turn should predict mating success. In this study, 400 university students (200 men and 200 women) completed…

  5. Proper and dark heroes as DADS and CADS : Alternative mating strategies in British Romantic literature.

    Science.gov (United States)

    Kruger, Daniel J; Fisher, Maryanne; Jobling, Ian

    2003-09-01

    Empirical tests described in this article support hypotheses derived from evolutionary theory on the perceptions of literary characters. The proper and dark heroes in British Romantic literature of the late eighteenth and early nineteenth centuries respectively represent long-term and short-term mating strategies. Recent studies indicate that for long-term relationships, women seek partners with the ability and willingness to sustain paternal investment in extended relationships. For short-term relationships, women choose partners whose features indicate high genetic quality. In hypothetical scenarios, females preferred proper heroes for long-term relationships. The shorter the relationship under consideration, the more likely women were to choose dark heroes as partners.

  6. Infanticide as sexual conflict: coevolution of male strategies and female counterstrategies.

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    Palombit, Ryne A

    2015-05-18

    One of the earliest recognized forms of sexual conflict was infanticide by males, which imposes serious costs on female reproductive success. Here I review two bodies of evidence addressing coevolved strategies of males and females. The original sexual selection hypothesis arguing that infanticide improves male mating success by accelerating the return of females to fertilizable condition has been generally supported in some taxa--notably, some primates, carnivores, rodents, and cetaceans--but not in other taxa. One result of recent research has been to implicate other selective benefits of infanticide by males in various taxa from insects to birds to mammals, such as acquisition of breeding status or improvement of the female breeding condition. In some cases, however, the adaptive significance of male infanticide remains obscure. The second body of data I review is arguably the most important result of recent research: clarifying the possible female counterstrategies to infanticide. These potential counterstrategies span diverse biological systems, ranging from sexual behavior (e.g., polyandrous mating), to physiology (e.g., the Bruce effect), to individual behavior (e.g., maternal aggression), to social strategies (e.g., association with coalitionary defenders of either sex). Although much remains to be studied, these current data provide compelling evidence of sexually antagonistic coevolution surrounding the phenomenon of infanticide.

  7. Social and hormonal mechanisms underlying male reproductive strategies in black howler monkeys (Alouatta pigra).

    Science.gov (United States)

    Van Belle, S; Estrada, A; Ziegler, T E; Strier, K B

    2009-10-01

    We investigated the social and hormonal mechanisms underlying male reproductive strategies in two multimale-multifemale groups of black howler monkeys (Alouatta pigra) during a 14-month study in Palenque National Park, Mexico. Fecal glucocorticoid (fGC) and androgen (fA) levels were analyzed for 343 fecal samples collected from 14 males during their presence in the study groups. Neither immigrating males nor resident males that remained in the group had elevated fGC and fA levels during 11 observed male migration events, suggesting that competition over group membership was not associated with variation in the fecal hormonal levels of males. Instead, fGC and fA levels were significantly higher in males who maintained a central position in the group and had almost exclusive access to fertile females than in other resident males. These "central" males were responsible for maintaining close spatial associations and cultivating strong affiliative relationships with cycling, sexually active females but not with noncycling, sexually inactive females. "Noncentral" males did not form strong social relationships with either cycling or noncycling females and had no or very few mating opportunities. Our findings suggest that male black howler monkeys compete nonaggressively by fostering relationships with cycling females and that the elevated fGC levels of central males may be indicative of the social challenges involved in their indirect competition.

  8. Caenorhabditis elegans UNC-103 ERG-like potassium channel regulates contractile behaviors of sex muscles in males before and during mating.

    Science.gov (United States)

    Garcia, L Rene; Sternberg, Paul W

    2003-04-01

    During mating behavior the Caenorhabditis elegans male must regulate periodic and prolonged protractor muscle contractions to insert his copulatory spicules into his mate. The protractors undergo periodic contractions to allow the spicules to reattempt insertion if a previous thrust failed to breach the vulva. When the spicule tips penetrate the vulva, the protractors undergo prolonged contraction to keep the spicules inside the hermaphrodite until sperm transfer is complete. To understand how these contractions are regulated, we isolated EMS-induced mutations that cause males to execute prolonged contraction inappropriately. Loss-of-function mutations in the unc-103 ERG-like K(+) channel gene cause the protractor muscles to contract in the absence of mating stimulation. unc-103-induced spicule protraction can be suppressed by killing the SPC motor neurons and the anal depressor muscle: cells that directly contact the protractors. Also, reduction in acetylcholine suppresses unc-103-induced protraction, suggesting that UNC-103 keeps cholinergic neurons from stimulating the protractors before mating behavior. UNC-103 also regulates the timing of spicule protraction during mating behavior. unc-103 males that do not display mating-independent spicule protraction show abnormal spicule insertion behavior during sex. In contrast to wild-type males, unc-103 mutants execute prolonged contractions spontaneously within sequences of periodic protractor contractions. The premature prolonged contractions cause the spicules to extend from the male tail before the spicule tips penetrate the vulva. These observations demonstrate that unc-103 controls various aspects of spicule function.

  9. The evolution of multiple mating: Costs and benefits of polyandry to females and of polygyny to males.

    Science.gov (United States)

    Gowaty, Patricia Adair

    2012-01-01

    Polyandry is a paradox: why do females mate multiple times when a single ejaculate often provides enough sperm for lifetime egg production? Gowaty et al. addressed explanations for polyandry in Drosophila pseudoobscura from the perspective of hypotheses based on sex differences in costs of reproduction (CoR). Contrary to CoR, Gowaty et al. showed that (1) a single ejaculate was inadequate for lifetime egg production; (2) polyandry provided fitness benefits to females beyond provision of adequate sperm and (3) fitness benefits of polyandry were not offset by costs. Here, I discuss predictions of the ad hoc hypotheses of CoR and three alternative hypotheses to CoR to facilitate a discussion and further development of a strong inference approach to experiments on the adaptive significance of polyandry for females. Each of the hypotheses makes testable predictions; simultaneous tests of the predictions will provide a strong inference approach to understanding the adaptive significance of multiple mating. I describe a sex-symmetric experiment meant to evaluate variation in fitness among lifelong virgins (V); monogamous females and males with one copulation (MOC); monogamous females and males with multiple copulations (MMC); PAND, polyandrous females; and PGYN, polygynous males. Last, I recommend the study of many different species, while taking care in choice of study species and attention to the assumptions of specific hypotheses. I particularly urge the study of many more Drosophila species both in laboratory and the wild to understand the "nature of flies in nature," where opportunities and constraints mold evolutionary responses.

  10. Microsatellite analysis of maternity and the mating system in the Gulf pipefish Syngnathus scovelli, a species with male pregnancy and sex-role reversal.

    Science.gov (United States)

    Jones, A G; Avise, J C

    1997-03-01

    Highly variable microsatellite loci were employed to study the mating system of the sexually dimorphic Gulf pipefish Syngnathus scovelli. In this species, like others in the family Syngnathidae, 'pregnant' males provide all parental care. Gulf pipefish were collected from one locale in the northern Gulf of Mexico, and internally carried broods of 40 pregnant males were analysed genetically. By comparing multilocus microsatellite fingerprints for the inferred mothers against expected genotypic distributions from the population sample, it was determined that: (i) only one male had received eggs from more than a single female; and (ii) on two separate occasions, two different males had received eggs from the same female. Given the high power to detect multiple matings by males, the first finding indicates that only rarely are individual males impregnated by multiple females during the course of a pregnancy. Conversely, given the lower power to detect multiple matings by females due to sampling constraints, the second finding suggests a high frequency of multiple successful matings by females. Thus, this population of Gulf pipefish displays a polyandrous genetic mating system. The relevance of these genetic findings is discussed with regard to the evolution of secondary sex traits in this species, and in other syngnathids.

  11. Structure of social networks in a passerine bird: consequences for sexual selection and the evolution of mating strategies.

    Science.gov (United States)

    Oh, Kevin P; Badyaev, Alexander V

    2010-09-01

    The social environment is a critical determinant of fitness and, in many taxa, is shaped by an individual's behavioral discrimination among social contexts, suggesting that animals can actively influence the selection they experience. In competition to attract females, males may modify sexual selection by choosing social environments in which they are more attractive relative to rivals. Across the population, such behaviors should influence sexual selection patterns by altering the relationship between male mating success and sexual ornament elaboration. Here we use network analysis to examine patterns of male social behavior in relation to plumage ornamentation and mating success in a free-living population of house finches. During the nonbreeding season, less elaborate males changed associations with distinct social groups more frequently, compared to more elaborate males that showed greater fidelity to a single social group. By the onset of pair formation, socially labile males effectively increased their attractiveness relative to other males in the same flocks. Consequently, males that frequently moved between social groups had greater pairing success than less social individuals with equivalent sexual ornamentation. We discuss these results in relation to conditional mating tactics and the role of social behavior in evolutionary change by sexual selection.

  12. 圈养猞猁多雄交配雄性的成功繁殖%Eurasian lynx male reproductive success with multi-male mating in captivity

    Institute of Scientific and Technical Information of China (English)

    Sergey NAIDENKO; Mariya EROFEEVA; Frank GOERITZ; Katrin NEUBAUER; Joerns FICKEL; Katarina JEWGENOW

    2007-01-01

    The consequences of multi-male mating and male reproductive success in Eurasian lynx Lynx lynx in captivity were investigated. Males were paired at random with females in estrus. Their reproductive success (numbers of kittens sired) did not depend on mating order, number and duration of copulations, genetic relatedness to the females or the behavioral traits of males, but seemed to depend on sperm quality, particularly the percentage of morphologically normal spermatozoa. The reproductively more successful male had a higher percentage of morphologically normal sperm than its competitors and appeared to be more successful in stimulating the ovulation of its female partner. Dual paternities were proved in 20% of all litters. In all these cases the two competing males mated with the female within a 24 hour interval[Acta Zoologica Sinica 53(3):408-416,2007].%研究了笼养猞猁多雄交配的结果以及雄性的成功繁殖. 雄兽与发情雌兽随机配对,其繁殖成功(所产生的后代数量)不取决于与雌兽的交配顺序、交配次数与持续时间、遗传关系或雄兽的行为特征,但似乎取决于精子质量,特别是取决于形态正常精子的百分率. 繁殖成功的雄兽比其竞争对手具有更多的形态正常的精子,似乎更能成功地诱发交配雌兽的排卵.证实了4窝(占总窝数的20%)幼兽的双重父亲身份.在所有情形下,2雄1雌的交配间隔为24 h[动物学报 53(3):408-416,2007].

  13. Alternative Mating Tactics in Male Chameleons (Chamaeleo chamaeleon Are Evident in Both Long-Term Body Color and Short-Term Courtship Pattern.

    Directory of Open Access Journals (Sweden)

    Tammy Keren-Rotem

    Full Text Available Alternative mating tactics in males of various taxa are associated with body color, body size, and social status. Chameleons are known for their ability to change body color following immediate environmental or social stimuli. In this study, we examined whether the differential appearance of male common chameleon during the breeding season is indeed an expression of alternative mating tactics. We documented body color of males and used computer vision techniques to classify images of individuals into discrete color patterns associated with seasons, individual characteristics, and social contexts. Our findings revealed no differences in body color and color patterns among males during the non-breeding season. However, during the breeding season males appeared in several color displays, which reflected body size, social status, and behavioral patterns. Furthermore, smaller and younger males resembled the appearance of small females. Consequently, we suggest that long-term color change in males during the breeding season reflects male alternative mating tactics. Upon encounter with a receptive female, males rapidly alter their appearance to that of a specific brief courtship display, which reflects their social status. The females, however, copulated indiscriminately in respect to male color patterns. Thus, we suggest that the differential color patterns displayed by males during the breeding season are largely aimed at inter-male signaling.

  14. Reproductive Ecology of Male and Female Strobili and Mating System in Two Different Populations of Pinus roxburghii

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    Chandra Mohan Sharma

    2012-01-01

    Full Text Available We studied several flowering traits, namely, male-female cone phenology, male-female cone production per tree, mating system, sex ratio, air-borne pollen grains and pollen migration, over four successive years in two different natural populations of P. roxburghii from Garhwal Himalaya, India. Assessment of each trait mentioned except pollen dispersion was done by selecting five representative trees randomly in each population. The pollen migration was studied on naturally isolated source trees. The pollen trapping was done in all directions up to 2.5 km. The average reproductive period in P. roxburghii was 36 days with 3–5 days protandry. There were significant year and population effects for male and female cone output and pollen grains production per tree. In mass production year (1999, an average production of pollen cone per tree was estimated as 42.44±8.32×103 at lower altitude and 28.1±0.89×103 at higher altitude. The controlled pollination results in high level of outcrossing with 90% seed setting. We conclude that the high male-female ratio and tremendous pollen production capacity in P. roxburghii indicate high male competition among trees within populations. The isolation strip of 600 m is considered minimal for the management of seed orchard.

  15. Status and mating success amongst visual artists.

    Science.gov (United States)

    Clegg, Helen; Nettle, Daniel; Miell, Dorothy

    2011-01-01

    Geoffrey Miller has hypothesized that producing artwork functions as a mating display. Here we investigate the relationship between mating success and artistic success in a sample of 236 visual artists. Initially, we derived a measure of artistic success that covered a broad range of artistic behaviors and beliefs. As predicted by Miller's evolutionary theory, more successful male artists had more sexual partners than less successful artists but this did not hold for female artists. Also, male artists with greater artistic success had a mating strategy based on longer term relationships. Overall the results provide partial support for the sexual selection hypothesis for the function of visual art.

  16. Variation in the strength of male mate choice allows long-term coexistence of sperm-dependent asexuals and their sexual hosts.

    Science.gov (United States)

    Mee, Jonathan A; Otto, Sarah P

    2010-10-01

    In several asexual taxa, reproduction requires mating with related sexual species to stimulate egg development, even though genetic material is not incorporated from the sexuals (gynogenesis). In cases in which gynogens do not invest in male function, they can potentially have a twofold competitive advantage over sexuals because the asexuals avoid the cost of producing males. If unmitigated, however, the competitive success of the asexuals would ultimately lead to their own demise, following the extinction of the sexual species that stimulate egg development. We have studied a model of mate choice among sexual individuals and asexual gynogens, where males of the sexual species preferentially mate with sexual females over gynogenetic females, to determine if such mating preferences can stably maintain both gynogenetic and sexual individuals within a community. Our model shows that stable coexistence of gynogens and their sexual hosts can occur when there is variation among males in the degree of preference for mating with sexual females and when pickier males pay a higher cost of preference.

  17. Somatic development and embryo yield in crossbred F1 mice generated by different mating strategies

    Directory of Open Access Journals (Sweden)

    RITP. Batista

    Full Text Available The aim of this study was to evaluate different mating strategies among endogamic strains to create F1 populations of mice, minimising the effect of inbreeding depression on somatic development and embryo yield. Females from the strains Swiss, CBA and C57Bl/6 were divided in nine experimental mate arrangements. The total numbers of pups born alive per dam and somatic development, estimated by weighing and measuring the crown-rump length, were recorded. Superovulation response was evaluated in outbreed females. Litter size differed among endogamic dams, irrespective of the sire. Somatic development results suggest heterosis and imprinting phenomena, once a differential parental effect was demonstrated. There was no difference in corpora lutea, ova or embryos recovered (P > 0.05, but recovery and viability rates differ among F1 groups (P < 0.05. The association of dam prolificity with somatic development and superovulation response of the pups should be considered for experimental F1 populations establishment. The use of outbreed animals, however, did not reduce response variability to hormone treatment.

  18. Colour Cues That Are Not Directly Attached to the Body of Males Do Not Influence the Mate Choice of Zebra Finches.

    Science.gov (United States)

    Krause, E Tobias

    2016-01-01

    Mate choice decisions of female zebra finches are generally thought to rely on the assessment of male quality, which includes the specific ornamentation of males. A commonly used paradigm to experimentally manipulate a male's attractiveness is to add a coloured leg ring to the bird. Some studies have shown that female zebra finches prefer or alter their investment in males that have an additional red leg ring compared with males with green leg rings. Whether the coloured artificial ornaments need to be attached to the male's body or whether environmental colouration could have a similar effect on male attractiveness remains unclear. Here, I investigated this novel context to determine whether female choice between males is affected by environmental colour cues that are not directly attached to the male's body in four experiments involving 220 zebra finches (Taeniopygia guttata). A first experiment revealed that females chose males with red colour cues in the environmental background over males with green cues in the background. Based on this finding, I conducted follow-up experiments to obtain a deeper understanding of how environmental colour cues affect mate choice. Therefore, I examined whether female choice behaviour or male behaviour was altered in two additional experiments. Both experiments failed to show any effects of environmental colour cues on female choice or on male behaviour. Therefore, I replicated the initial experiment in a fourth experiment. Again replication failed; thus, the initial results indicating that environmental colouration affects mate choice behaviour of female zebra finches were not supported by the three subsequent experiments; thus, the outcome of the first experiment seems to be a false positive. Taking my results together, I found no robust support for the idea that environmental colour cues that are not directly attached to the body of male zebra finches affect female mate choice decisions.

  19. The Mating Game: A Classroom Activity for Undergraduates that Explores the Evolutionary Basis of Sex Roles

    Science.gov (United States)

    Moore, Dani; Holbrook, C. Tate; Meadows, Melissa G.; Taylor, Lisa A.

    2012-01-01

    In species that reproduce sexually, an individual's fitness depends on its ability to secure a mate (or mates). Although both males and females are selected to maximize their reproductive output, the mating strategies of the two sexes can differ dramatically. We present a classroom simulation that allows undergraduates to actively experience how…

  20. Male Drosophila melanogaster learn to prefer an arbitrary trait associated with female mating status

    DEFF Research Database (Denmark)

    Verzijden, Machteld Nicolette; Abbott, Jessica K.; Philipsborn, Anne von

    2015-01-01

    for female eye color (red versus brown), 2) if males could learn to associate an eye color cue with female receptivity, and 3) whether this association disappeared when the males were unable to use this visual cue in the dark. We found that naïve males had no baseline preference for females of either eye...... color, but that males which were trained with sexually receptive females of a given eye color showed a preference for that color during a standard binary choice experiment. The learned cue was indeed likely to be truly visual, since the preference disappeared when the binary choice phase...

  1. Mate Choice and Copulation Frequency in the Burying Beetle Nicrophorus quadripunctatus (Coleoptera: Silphidae: Effect of Male Body Size and Presence of a Rival

    Directory of Open Access Journals (Sweden)

    Seizi Suzuki

    2009-01-01

    Full Text Available It is widely assumed that there exists a competition between males for mating and that females prefer males with elaborate male traits. Further, such traits are considered to be synonymous with high quality in terms of benefits to females. The number and duration of copulations and the frequency of mate refusal between large and small Nicrophorus quadripunctatus males were examined both for single males and for two males competing. The number of copulations was not affected by the size of the male or by the presence of a rival, but there was a significant interaction such that large males increased their number of copulations when a small rival was present. Copulation duration was not affected by male size but was shortened by a rival male. Females rejected copulation attempts of small males more often than of large males, whether the males were alone or paired with a rival. These results suggest that large males have two advantages: they win contests between males and are preferred by females.

  2. The smell of virgins: mating status of females affects male swimming behaviour in Oithona davisae

    DEFF Research Database (Denmark)

    Heuschele, Jan; Kiørboe, Thomas

    2012-01-01

    Many copepod species rely on pheromone cues to find partners. Some parasitic and benthic copepod males are able to distinguish between females of different reproductive states. Here, we demonstrate that the swimming activity and velocity of males of a pelagic copepod, Oithona davisae, increases...

  3. The influence of late-stage pupal irradiation and increased irradiated: un-irradiated male ratio on mating competitiveness of the malaria mosquito Anopheles arabiensis Patton.

    Science.gov (United States)

    Helinski, M E H; Knols, B G J

    2009-06-01

    Competitiveness of released males in genetic control programmes is of critical importance. In this paper, we explored two scenarios to compensate for the loss of mating competitiveness after pupal stage irradiation in males of the malaria mosquito Anopheles arabiensis. First, competition experiments with a higher ratio of irradiated versus un-irradiated males were performed. Second, pupae were irradiated just prior to emergence and male mating competitiveness was determined. Males were irradiated in the pupal stage with a partially or fully-sterilizing dose of 70 or 120 Gy, respectively. Pupae were irradiated aged 20-26 h (young) as routinely performed, or the pupal stage was artificially prolonged by cooling and pupae were irradiated aged 42-48 h (old). Irradiated males competed at a ratio of 3:1:1 to un-irradiated males for mates in a large cage design. At the 3:1 ratio, the number of females inseminated by males irradiated with 70 Gy as young pupae was similar to the number inseminated by un-irradiated males for the majority of the replicates. At 120 Gy, significantly fewer females were inseminated by irradiated than by un-irradiated males. The irradiation of older pupae did not result in a significantly improved male mating competitiveness compared to the irradiation of young pupae. Our findings indicate that the loss of competitiveness after pupal stage irradiation can be compensated for by a threefold increase of irradiated males, but only for the partially-sterilizing dose. In addition, cooling might be a useful tool to facilitate handling processes of large numbers of mosquitoes in genetic control programmes.

  4. Mating strategies and pollen limitation in a globally threatened perennial Polemonium vanbruntiae

    Science.gov (United States)

    Hill, Laura M.; Brody, Alison K.; Tedesco, Connie L.

    2008-05-01

    Knowledge of the factors that limit reproduction is critical to an understanding of plant ecology, and is particularly important for predicting population viability for threatened species. Here, we investigated the pollination biology of a globally threatened plant, Polemonium vanbruntiae, using hand-pollination experiments in four natural populations to determine the degree of pollen limitation. In addition, we investigated the mating system and extent to which plants can self-fertilize by comparing geitonogamously and autonomously self-fertilized plants with purely outcrossed and open-pollinated plants. In contrast to several of the more common species of Polemonium, we found no pollen limitation in any of the four populations of P. vanbruntiae over two years. The lack of pollen limitation was best explained by the capacity for P. vanbruntiae to both geitonogamously and autonomously self-fertilize, unlike some of its more common congeners. Geitonogamously selfed flowers set equivalent numbers of seeds when compared to purely outcrossed and open-pollinated flowers. However, autonomously selfed flowers produced significantly fewer seeds, demonstrating that pollinators play an important role as inter- and intra-plant pollen vectors in this system. Our results support the reproductive assurance hypothesis, whereby the ability to self assures fertilization for plants in small populations. Self-compatibility in Polemonium vanbruntiae may decrease extinction risk of isolated populations experiencing a stochastic pollinator pool within a restricted geographic range. In addition, a mixed-mating strategy, including the ability for clonal reproduction, may explain the ability for this rare species to persist in small, fragmented populations.

  5. Reproduction in free-ranging male Propithecus verreauxi: the hormonal correlates of mating and aggression.

    Science.gov (United States)

    Brockman, D K; Whitten, P L; Richard, A F; Schneider, A

    1998-02-01

    Endocrine studies of captive strepsirrhine primates suggest that physical environment and social factors mediate inter-individual variations in testicular function and serum testosterone (sT) in males. While these studies have made major contributions to our understanding of the individual proximate mechanisms influencing androgen activity in male strepsirrhines, none have investigated how these mechanisms work coincidentally in free-ranging populations. In this study we used fecal steroid analysis to examine androgen-behavior interactions associated with reproduction in free-ranging male Propithecus verreauxi. Behavioral and hormone data were collected from two social groups during the 1990-91 and 1991-92 breeding seasons at Beza Mahafaly, Madagascar. Solid phase and radioimmunoassay techniques were used to quantify testosterone (T) in 105 desiccated fecal samples collected weekly from seven males. Results suggest that 1) solid phase extraction and radioimmunoassay techniques were reliable and accurate methods for quantifying T in sifaka feces; 2) fecal T (fT) elevations spanned a minimum of 4 months, peak levels occurring 1 month prior to the January onset of the breeding season; 3) fecal T concentrations were influenced by developmental factors and, among mature males, social factors associated with rank, intergroup aggression, and group instability.

  6. Telipogon peruvianus (Orchidaceae) Flowers Elicit Pre-Mating Behaviour in Eudejeania (Tachinidae) Males for Pollination

    Science.gov (United States)

    Cairampoma, Lianka; Stauffer, Fred W.; Ayasse, Manfred

    2016-01-01

    Several neotropical orchid genera have been proposed as being sexually deceptive; however, this has been carefully tested in only a few cases. The genus Telipogon has long been assumed to be pollinated by male tachinid flies during pseudocopulatory events but no detailed confirmatory reports are available. Here, we have used an array of methods to elucidate the pollination mechanism in Telipogon peruvianus. The species presents flowers that have a mean floral longevity of 33 days and that are self-compatible, although spontaneous self-pollination does not occur. The flowers attract males of four tachinid species but only the males of an undescribed Eudejeania (Eudejeania aff. browni; Tachinidae) species are specific pollinators. Males visit the flowers during the first few hours of the day and the pollination success is very high (42% in one patch) compared with other sexually deceptive species. Female-seeking males are attracted to the flowers but do not attempt copulation with the flowers, as is usually described in sexually deceptive species. Nevertheless, morphological analysis and behavioural tests have shown an imperfect mimicry between flowers and females suggesting that the attractant stimulus is not based only on visual cues, as long thought. Challenging previous conclusions, our chemical analysis has confirmed that flowers of Telipogon release volatile compounds; however, the role of these volatiles in pollinator behaviour remains to be established. Pollinator behaviour and histological analyses indicate that Telipogon flowers possess scent-producing structures throughout the corolla. Our study provides the first confirmed case of (i) a sexually deceptive species in the Onciidinae, (ii) pollination by pre-copulatory behaviour and (iii) pollination by sexual deception involving tachinid flies. PMID:27812201

  7. Telipogon peruvianus (Orchidaceae) Flowers Elicit Pre-Mating Behaviour in Eudejeania (Tachinidae) Males for Pollination.

    Science.gov (United States)

    Martel, Carlos; Cairampoma, Lianka; Stauffer, Fred W; Ayasse, Manfred

    2016-01-01

    Several neotropical orchid genera have been proposed as being sexually deceptive; however, this has been carefully tested in only a few cases. The genus Telipogon has long been assumed to be pollinated by male tachinid flies during pseudocopulatory events but no detailed confirmatory reports are available. Here, we have used an array of methods to elucidate the pollination mechanism in Telipogon peruvianus. The species presents flowers that have a mean floral longevity of 33 days and that are self-compatible, although spontaneous self-pollination does not occur. The flowers attract males of four tachinid species but only the males of an undescribed Eudejeania (Eudejeania aff. browni; Tachinidae) species are specific pollinators. Males visit the flowers during the first few hours of the day and the pollination success is very high (42% in one patch) compared with other sexually deceptive species. Female-seeking males are attracted to the flowers but do not attempt copulation with the flowers, as is usually described in sexually deceptive species. Nevertheless, morphological analysis and behavioural tests have shown an imperfect mimicry between flowers and females suggesting that the attractant stimulus is not based only on visual cues, as long thought. Challenging previous conclusions, our chemical analysis has confirmed that flowers of Telipogon release volatile compounds; however, the role of these volatiles in pollinator behaviour remains to be established. Pollinator behaviour and histological analyses indicate that Telipogon flowers possess scent-producing structures throughout the corolla. Our study provides the first confirmed case of (i) a sexually deceptive species in the Onciidinae, (ii) pollination by pre-copulatory behaviour and (iii) pollination by sexual deception involving tachinid flies.

  8. Experimental evidence for chemical mate guarding in a moth

    Science.gov (United States)

    Hosseini, Seyed Ali; van Wijk, Michiel; Ke, Gao; Goldansaz, Seyed Hossein; Schal, Coby; Groot, Astrid T.

    2016-01-01

    In polyandrous species, males seek to maximize their reproductive output by monopolizing their mate. Often the male transfers substances to the female that suppress her sexual receptivity or antagonize the behavior of competing males; both are usually transferred in seminal fluids and represent forms of chemical mate guarding. In moths, more long-range female sex pheromones have been identified than in any other animal group, and males often display with close-range sex pheromones, yet odor-based post-copulatory mate guarding has not been described in moths so far. We tested the hypothesis that the male sex pheromone in the noctuid moth Heliothis virescens perfumes the female and functions as an anti-aphrodisiac. Indeed, virgin females perfumed with male pheromone extract, or with its main component, mated significantly less than control virgin females, and this effect persisted for two successive nights. This chemical mate guarding strategy was disadvantageous for H. virescens females, because the reproductive output of twice-mated females was significantly higher than that of once-mated females. Since the female and male sex pheromones are biosynthetically related in this and other moth species, chemical mate guarding may also impose selection pressure on the long-range female sex pheromone channel and consequently affect the evolution of sexual communication. PMID:27934963

  9. Telipogon peruvianus (Orchidaceae) Flowers Elicit Pre-Mating Behaviour in Eudejeania (Tachinidae) Males for Pollination

    OpenAIRE

    2016-01-01

    Several neotropical orchid genera have been proposed as being sexually deceptive; however, this has been carefully tested in only a few cases. The genus Telipogon has long been assumed to be pollinated by male tachinid flies during pseudocopulatory events but no detailed confirmatory reports are available. Here, we have used an array of methods to elucidate the pollination mechanism in Telipogon peruvianus. The species presents flowers that have a mean floral longevity of 33 days and that are...

  10. Fos expression at the cerebellum following non-contact arousal and mating behavior in male rats

    Science.gov (United States)

    Manzo, Jorge; Miquel, Marta; Toledo, Rebeca; Mayor-Mar, Justo Abraham; Garcia, Luis I.; Aranda-Abreu, Gonzalo E.; Caba, Mario; Hernandez, Maria Elena

    2010-01-01

    The cerebellum is considered a center underlying fine movements, cognition, memory and sexual responses. The latter feature led us to correlate sexual arousal and copulation in male rats with neural activity at the cerebellar cortex. Two behavioral paradigms were used in this investigation: the stimulation of males by distant receptive females (non-contact sexual stimulation), and the execution of up to three consecutive ejaculations. The vermis area of the cerebellum was removed following behavioral experiments, cut into sagittal sections, and analyzed with Fos immunohistochemistry to determine neuronal activation. At the mid-vermis region (sections from the midline to 0.1 mm laterally), non-contact stimulation significantly increased the activity of granule neurons. The number of activated cells increased in every lobule, but lobules 1 and 6 to 9 showed the greatest increment. In sexual behavior tests, males reaching one ejaculation had a high number of activated neurons similar to those counted after non-contact stimulation. However, two or three consecutive ejaculations showed a smaller number of Fos-ir cells. In contrast to the mid-vermis region, sections farthest from the midline (0.1 to 0.9 mm laterally) revealed that only lobule 7 expressed activated neurons. These data suggest that a well-delineated group of granule neurons have a sexual biphasic response at the cerebellar vermis, and that Fos in them is under an active degradation mechanism. Thus, they participate as a neural substrate for male rat sexual responses with an activation-deactivation process corresponding with the sensory stimulation and motor performance occurring during copulation. PMID:17936859

  11. The role of sexual selection and conflict in mediating among-population variation in mating strategies and sexually dimorphic traits in Sepsis punctum.

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    Caitlin Dmitriew

    Full Text Available The black scavenger fly Sepsis punctum exhibits striking among-population variation in the direction and magnitude of sexual size dimorphism, modification to the male forelimb and pre-copulatory behaviour. In some populations, male-biased sexual size dimorphism is observed; in other, less dimorphic, populations males court prior to mating. Such variation in reproductive traits is of interest to evolutionary biologists because it has the potential to limit gene flow among populations, contributing to speciation. Here, we investigate whether large male body size and modified forefemur are associated with higher male mating success within populations, whether these traits are associated with higher mating success among populations, and if these traits carry viability costs that could constrain their response to sexual selection. Flies from five distinct populations were reared at high or low food, generating high and low quality males. The expression of body size, forelimb morphology and courtship rate were each greater at high food, but high food males experienced higher mating success or reduced latency to first copulation in only one of the populations. Among populations, overall mating success increased with the degree of male-bias in overall body size and forelimb modification, suggesting that these traits have evolved as a means of increasing male mating rate. The increased mating success observed in large-male populations raises the question of why variation in magnitude of dimorphism persists among populations. One reason may be that costs of producing a large size constrain the evolution of ever-larger males. We found no evidence that juvenile mortality under food stress was greater for large-male populations, but development time was considerably longer and may represent an important constraint in an ephemeral and competitive growth environment.

  12. Male emergence schedule and dispersal behaviour are modified by mate availability in heterogeneous landscapes: evidence from the orange-tip butterfly

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    W James Davies

    2015-01-01

    Full Text Available Protandry (prior emergence of males in insect populations is usually considered to be the result of natural selection acting directly on eclosion timing. When females are monandrous (mate once, males in high density populations benefit from early emergence in the intense scramble competition for mates. In low density populations, however, scramble competition is reduced or absent, and theoretical models predict that protandry will be less favoured. This raises the question of how males behave in heterogeneous landscapes characterized by high density core populations in a low density continuum. We hypothesized that disadvantaged late emerging males in a core population would disperse to the continuum to find mates. We tested this idea using the protandrous, monandrous, pierid butterfly Anthocharis cardamines (the orange-tip in a core population in Cheshire, northwest England. Over a six-year period, predicted male fitness (the number of matings a male can expect during his residence time, determined by the daily ratio of virgin females to competing males consistently declined to <1 in late season. This decline affected a large proportion (∼44% of males in the population and was strongly associated with decreased male recapture-rates, which we attribute to dispersal to the surrounding continuum. In contrast, reanalysis of mark-release-recapture data from an isolated population in Durham, northeast England, showed that in the absence of a continuum very few males (∼3% emerged when fitness declined to <1 in late season. Hence the existence of a low density continuum may lead to the evolution of plastic dispersal behaviour in high density core populations, maintaining late emerging males which would otherwise be eliminated by selection. This has important theoretical consequences, since a truncated male emergence curve is a key prediction in game theoretic models of emergence timing which has so far received limited support. Our results have

  13. Mate choice in adult female Bengalese finches: females express consistent preferences for individual males and prefer female-directed song performances.

    Science.gov (United States)

    Dunning, Jeffery L; Pant, Santosh; Bass, Aaron; Coburn, Zachary; Prather, Jonathan F

    2014-01-01

    In the process of mate selection by female songbirds, male suitors advertise their quality through reproductive displays in which song plays an important role. Females evaluate the quality of each signal and the associated male, and the results of that evaluation guide expression of selective courtship displays. Some studies reveal broad agreement among females in their preferences for specific signal characteristics, indicating that those features are especially salient in female mate choice. Other studies reveal that females differ in their preference for specific characteristics, indicating that in those cases female evaluation of signal quality is influenced by factors other than simply the physical properties of the signal. Thus, both the physical properties of male signals and specific traits of female signal evaluation can impact female mate choice. Here, we characterized the mate preferences of female Bengalese finches. We found that calls and copulation solicitation displays are equally reliable indicators of female preference. In response to songs from an array of males, each female expressed an individual-specific song preference, and those preferences were consistent across tests spanning many months. Across a population of females, songs of some males were more commonly preferred than others, and females preferred female-directed songs more than undirected songs, suggesting that some song features are broadly attractive. Preferences were indistinguishable for females that did or did not have social experience with the singers, indicating that female preference is strongly directed by song features rather than experiences associated with the singer. Analysis of song properties revealed several candidate parameters that may influence female evaluation. In an initial investigation of those parameters, females could be very selective for one song feature yet not selective for another. Therefore, multiple song parameters are evaluated independently

  14. Different Reproductive Strategies in Males and Females.

    Science.gov (United States)

    Maccoby, Eleanor E.

    1991-01-01

    Comments on Belsky, Steinberg, and Draper's article in this issue. Discusses the claim for a connection of stressful childhood environments and early pubertal maturation. Argues that early puberty need not imply a shift from a "quality" toward a "quantity" reproductive strategy and that nonevolutionary factors can account for…

  15. Mating behaviour in laevicaudatan clam shrimp (Crustacea, Branchiopoda and functional morphology of male claspers in a phylogenetic context: a video-based analysis.

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    Zandra M S Sigvardt

    Full Text Available Clam shrimps are freshwater branchiopod crustaceans which often present complicated breeding systems including asexual reproduction (parthenogenesis and mixed mating systems (in androdioecious species both selfing and outcrossing occurs due to the co-presence of hermaphrodites and males. Reproductive patterns of Spinicaudata, which contains most clam shrimp species, have received much attention. Another group of clam shrimps, Laevicaudata, which holds a key position in branchiopod phylogeny, has practically not been studied. As a part of the mating process, males clasp to the carapace margin of the females with a pair (or two pairs of anterior trunk limbs modified as claspers. Previous studies have shown that clasper morphology is important in a phylogenetic context, and that some parts of the claspers in Spinicaudata and Laevicaudata may have undergone a remarkable parallel evolution. Here we have used video microscopy to study aspects of the mating behaviour, egg extrusion, and fertilization in Lynceus brachyurus (Laevicaudata. It is shown that fertilization is likely to be external and that the peculiar tri-lobed lateral lamellae of female's hind body assist in guiding the egg mass to the exopodal egg carriers where they are collected by their distal setation. The functional morphology of the male claspers was studied in detail by close-up video recordings. The movable "finger" of the clasper bends around the female's carapace edge and serves to hold the female during mating. The larger palp grasps around the female carapace margin in a way very similar to the movable "finger", possibly indirectly providing sensory input on the "finger" position. A brief comparative study of the claspers of a spinicaudatan clam shrimp showed both similarities and differences to the laevicaudatan claspers. The presence of two pairs of claspers in Spinicaudata seems to give males a better hold of the female which may play a role during extended mate guarding.

  16. Androgen receptors and estrogen receptors are colocalized in male rat hypothalamic and limbic neurons that express Fos immunoreactivity induced by mating.

    Science.gov (United States)

    Gréco, B; Edwards, D A; Michael, R P; Clancy, A N

    1998-01-01

    Conversion of testosterone into estradiol is important for male rat sexual behavior, and both steroids probably contribute to mating. The distributions of neurons containing androgen receptors (AR) and estrogen receptors (ER) overlap, and many AR-immunoreactive (AR-ir) neurons express Fos immunoreactivity (Fos-ir) induced by mating. Because mating-induced Fos-ir in the male rat occurs mainly in AR-ir neurons, and because both steroids are important for mating, we hypothesized that (i) AR-ir and ER-ir are colocalized and that (ii) some of these neurons are activated during mating. We examined, in adjacent sections from the medial preoptic area (MPN) through the central tegmental field (CTF), the expression of ER-ir in: (i) AR-ir-containing neurons, and (ii) Fos-ir-expressive neurons. PG21 anti-AR, OA-11-824 anti-c-fos, H222 or 1D5 anti-ER primary antibodies were visualized, respectively, with cyanine-conjugated, fluorescein- or cyanine-conjugated, and fluorescein-conjugated secondary antibodies in male rats which were killed 1 h after ejaculating with a receptive female. In MPN, bed nucleus of the stria terminalis (BNST), and medial amygdala (MEA), 80-90% of ER-ir labeling occurred in AR-ir-positive neurons but only about 30% of AR-ir neurons were ER-ir-positive. No ER-ir was found in the CTF. This suggests the presence of three types of brain neurons sensitive to gonadal steroid hormones: neurons sensitive to androgens only, neurons sensitive to both androgens and estrogens, and neurons sensitive to estrogens only. About 50% of ER-ir labeling occurred in cells expressing mating-induced Fos-ir but only about 30% of Fos-ir neurons were ER-ir-positive. These findings suggest that, in the MPN, at least two different neuronal populations are activated during mating: the first contains AR-ir only and the second contains AR-ir and ER-ir. In the BNST and MEA, at least three hormonally sensitive populations are activated during mating: the two described above plus a third

  17. Mating behavior induces changes of expression of Fos protein, plasma testosterone and androgen receptors in the accessory olfactory bulb (AOB of the male mandarin vole Microtus mandarinus

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    Fengqin HE, Fadao TAI

    2009-08-01

    Full Text Available In order to investigate the neuroendocrine mechanism of the mating behavior in the adult male mandarin voles Microtus mandarinus, the radioimmunoassay (RIA and immunohistochemistry methods were used to investigate the differences in plasma testosterone (T concentrations and distribution of T immunoreactive neurons (T-IRs, androgen receptor immunoreactive neurons (AR-IRs and Fos protein immunoreactive neurons (Fos-IRs in the accessory olfactory bulb (AOB and the main olfactory bulb (MOB following exposure to clean hard-wood shavings (control group, soiled bedding (exposure group or contact with an estrous female (mating group. Results showed that plasma T concentration was significantly higher in the mating group than that in the exposure group, and both the mating group and the exposure group displayed significantly higher plasma T concentration than the control group. T-IRs, AR-IRs and Fos-IRs were investigated with the immunohistochemistry method in granule cell (GC and mitral cell (MC of the MOB and the AOB in the three groups. There were significantly more T-IRs, AR-IRs and Fos-IRs in MC and GC of the AOB in the mating group than that in the exposure group or the control group. T-IRs, AR-IRs and Fos-IRs did not show significant differences between the exposure group and the control group. Furthermore, obvious differences in MC and GC of the MOB were not found among the three groups. The results confirm that both changes of T and AR in the AOB might be underlying mating behavior in the adult male mandarin voles [Current Zoology 55 (4: 288–295, 2009].

  18. Colony size, but not density, affects survival and mating success of alternative male reproductive tactics in a polyphenic mite, Rhizoglyphus echinopus.

    Science.gov (United States)

    Radwan, Jacek; Lukasiewicz, Aleksandra; Twardawa, Mateusz

    2014-01-01

    Among acarid mites, a number of species are characterised by the presence of discontinuous morphologies (armed heteromorphs vs. unarmed homeomorphs) associated with alternative mating tactics (fighting vs. scramble competition). In Rhizoglyphus echinopus, expression of the fighter morph is suppressed, via pheromones, in large, dense colonies. If this mechanism is adaptive, fighters should have relatively lower fitness in large and/or dense colonies, due to costs incurred from fighting, which is often fatal. In order to test these predictions, we quantified the survival and mating success of fighters and scramblers in colonies of equal sex and morph ratios; these colonies either differed in size (4, 8, or 32 individuals) but not density or differed in density but not size (all consisted of 8 individuals). We found that the relative survival and mating success of fighters was inversely related to colony size, but we did not find a significant effect of colony density. The higher mating success of fighters in small colonies was due to the fact that, after killing rival males, these fighters were able to monopolise females. This situation was not found in larger colonies, in which there was a larger number of competitors and fighters suffered relatively higher mortality. These results indicate that morph determination, guided by social cues, allows for the adaptive adjustment of mating tactics to existing demographic conditions.

  19. Infanticide as a male reproductive strategy has a nutritive risk effect in brown bears.

    Science.gov (United States)

    Steyaert, S M J G; Reusch, C; Brunberg, S; Swenson, J E; Hackländer, K; Zedrosser, A

    2013-10-23

    Behavioural strategies to reduce predation risk can incur costs, which are often referred to as risk effects. A common strategy to avoid predation is spatio-temporal avoidance of predators, in which prey typically trade optimal resources for safety. Analogous with predator-prey theory, risk effects should also arise in species with sexually selected infanticide (SSI), in which females with dependent offspring avoid infanticidal males. SSI can be common in brown bear (Ursus arctos) populations and explains spatio-temporal segregation among reproductive classes. Here, we show that in a population with SSI, females with cubs-of-the-year had lower quality diets than conspecifics during the SSI high-risk period, the mating season. After the mating season, their diets were of similar quality to diets of their conspecifics. Our results suggest a nutritive risk effect of SSI, in which females with cubs-of-the-year alter their resource selection and trade optimal resources for offspring safety. Such risk effects can add to female costs of reproduction and may be widespread among species with SSI.

  20. Mating behavior of Daphnia: impacts of predation risk, food quantity, and reproductive phase of females.

    Directory of Open Access Journals (Sweden)

    Geung-Hwan La

    Full Text Available High predation risk and food depletion lead to sexual reproduction in cyclically parthenogenetic Daphnia. Mating, the core of sexual reproduction, also occurs under these conditions. Assessment of the environmental conditions and alteration of mating efforts may aid in determining the success of sexual reproduction. Here, we evaluated the impacts of predation risk, food quantity, and reproductive phase of females on the mating behavior of Daphnia obtusa males including contact frequency and duration using video analysis. Mating-related behavior involved male-female contact (mating as well as male-male contact (fighting. Mating frequency increased while unnecessary fighting decreased in the presence of predation risk. In addition, low food concentration reduced fighting between males. Males attempted to attach to sexual females more than asexual females, and fighting occurred more frequently in the presence of sexual females. Duration of mating was relatively long; however, males separated shortly after contact in terms of fighting behavior. Thus, assessment of environmental factors and primary sexing of mates were performed before actual contact, possibly mechanically, and precise sex discrimination was conducted after contact. These results suggest that mating in Daphnia is not a random process but rather a balance between predation risk and energetic cost that results in changes in mating and fighting strategies.

  1. Post-mating clutch piracy in an amphibian.

    Science.gov (United States)

    Vieites, David R; Nieto-Román, Sandra; Barluenga, Marta; Palanca, Antonio; Vences, Miguel; Meyer, Axel

    2004-09-16

    Female multiple mating and alternative mating systems can decrease the opportunity for sexual selection. Sperm competition is often the outcome of females mating with multiple males and has been observed in many animals, and alternative reproductive systems are widespread among species with external fertilization and parental care. Multiple paternity without associated complex behaviour related to mating or parental care is also seen in simultaneously spawning amphibians and fishes that release gametes into water. Here we report 'clutch piracy' in a montane population of the common frog Rana temporaria, a reproductive behaviour previously unknown in vertebrates with external fertilization. Males of this species clasp the females and the pair deposits one spherical clutch of eggs. No parental care is provided. 'Pirate' males search for freshly laid clutches, clasp them as they would do a female and fertilize the eggs that were left unfertilized by the 'parental' male. This behaviour does not seem to be size-dependent, and some males mate with a female and perform clutch piracy in the same season. Piracy affected 84% of the clutches and in some cases increased the proportion of eggs fertilized, providing direct fitness benefits both for the pirate males and the females. Sexual selection--probably caused by a strong male-biased sex ratio--occurs in this population, as indicated by size-assortative mating; however, clutch piracy may reduce its impact. This provides a good model to explore how alternative mating strategies can affect the intensity of sexual selection.

  2. Mate choice decisions by searchers

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    Daniel D. WIEGMANN, Lisa M. ANGELONI, Steven M. SEUBERT, J. Gordon WADE

    2013-04-01

    Full Text Available For more than two decades rudimentary versions of the fixed sample and sequential search strategies have provided the primary theoretical foundation for the study of mate choice decisions by searchers. The theory that surrounds these models has expanded markedly over this time period. In this paper, we review and extend results derived from these models, with a focus on the empirical analysis of searcher behavior. The basic models are impractical for empirical purposes because they rely on the assumption that searchers—and, for applied purposes, researchers—assess prospective mates based on their quality, the fitness consequences of mate choice decisions. Here we expound versions of the models that are more empirically useful, reformulated to reflect decisions based on male phenotypic characters. For some organisms, it may be possible to use preference functions to derive predictions from the reformulated models and thereby avoid difficulties associated with the measurement of male quality per se. But predictions derived from the two models are difficult to differentiate empirically, regardless of how the models are formulated. Here we develop ideas that illustrate how this goal might be accomplished. In addition, we clarify how the variability of male quality should be evaluated and we extend what is known about how this variability influences searcher behavior under each model. More general difficulties associated with the empirical study of mate choice decisions by searchers are also discussed [Current Zoology 59 (2: 184–199, 2013].

  3. Mate choice decisions by searchers

    Institute of Scientific and Technical Information of China (English)

    Daniel D.WIEGMANN; Lisa M.ANGELONI; Steven M.SEUBERT; J.Gordon WADE

    2013-01-01

    For more than two decades rudimentary versions of thefixed sample and sequential search strategies have provided the primary theoretical foundation for the study of mate choice decisions by searchers.The theory that surrounds these models has expanded markedly over this time period.In this paper,we review and extend results derived from these models,with a focus on the empirical analysis of searcher behavior.The basic models are impractical for empirical purposes because they rely on the assumption that searchers-and,for applied purposes,researchers-assess prospective mates based on their quality,the fitness consequences of mate choice decisions.Here we expound versions of the models that are more empirically useful,reformulated to reflect decisions based on male phenotypic characters.For some organisms,it may be possible to use preference functions to derive predictions from the reformulated models and thereby avoid difficulties associated with the measurement of male quality per se.But predictions derived from the two models are difficult to differentiate empirically,regardless of how the models are formulated.Here we develop ideas that illustrate how this goal might be accomplished.In addition,we clarify how the variability of male quality should be evaluated and we extend what is known about how this variability influences searcher behavior under each model.More general difficulties associated with the empirical study of mate choice decisions by searchers are also discussed.

  4. Mating competitiveness of male Anopheles arabiensis mosquitoes irradiated with a partially or fully sterilizing dose in small and large laboratory cages.

    Science.gov (United States)

    Helinski, M E H; Knols, B G J

    2008-07-01

    Male mating competitiveness is a crucial parameter in many genetic control programs including the sterile insect technique (SIT). We evaluated competitiveness of male Anopheles arabiensis Patton as a function of three experimental variables: (1) small or large cages for mating, (2) the effects of either a partially sterilizing (70 Gy) or fully sterilizing (120 Gy) dose, and (3) pupal or adult irradiation. Irradiated males competed for females with an equal number of unirradiated males. Competitiveness was determined by measuring hatch rates of individually laid egg batches. In small cages, pupal irradiation with the high dose resulted in the lowest competitiveness, whereas adult irradiation with the low dose gave the highest, with the latter males being equal in competitiveness to unirradiated males. In the large cage, reduced competitiveness of males irradiated in the pupal stage was more pronounced compared with the small cage; the males irradiated as adults at both doses performed similarly to unirradiated males. Unexpectedly, males irradiated with the high dose performed better in a large cage than in a small one. A high proportion of intermediate hatch rates was observed for eggs collected in the large cage experiments with males irradiated at the pupal stage. It is concluded that irradiation of adult An. arabiensis with the partially sterilizing dose results in the highest competitiveness for both cage designs. Cage size affected competitiveness for some treatments; therefore, competitiveness determined in laboratory experiments must be confirmed by releases into simulated field conditions. The protocols described are readily transferable to evaluate male competitiveness for other genetic control techniques.

  5. Mate choice and uncertainty in the decision process.

    Science.gov (United States)

    Wiegmann, Daniel D; Angeloni, Lisa M

    2007-12-21

    The behavior of females in search of a mate determines the likelihood that a high quality male is encountered in the search process and alternative search strategies provide different fitness returns to searchers. Models of search behavior are typically formulated on an assumption that the quality of prospective mates is revealed to searchers without error, either directly or by inspection of a perfectly informative phenotypic character. But recent theoretical developments suggest that the relative performance of a search strategy may be sensitive to any uncertainty associated with the to-be-realized fitness benefit of mate choice decisions. Indeed, uncertainty in the decision process is inevitable whenever unobserved male attributes influence the fitness of searchers. In this paper, we derive solutions to the sequential search strategy and the fixed sample search strategy for the general situation in which observed and unobserved male attributes affect the fitness consequences of female mate choice decisions and we determine how the magnitude of various parameters that are influential in the standard models alter these more general solutions. The distribution of unobserved attributes amongst prospective mates determines the uncertainty of mate choice decisions-the reliability of an observed male character as a predictor of male quality-and the realized functional relationship between an observed male character and the fitness return to searchers. The uncertainty of mate choice decisions induced by unobserved male attributes has no influence on the generalized model solutions. Thus, the results of earlier studies of these search models that rely on the use of a perfectly informative male character apply even if an observed male trait does not reveal the quality of prospective mates with certainty. But the solutions are sensitive to any changes of the distribution of unobserved male attributes that alter the realized functional relationship between an observed

  6. A novel function for the Hox gene Abd-B in the male accessory gland regulates the long-term female post-mating response in Drosophila.

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    Dragan Gligorov

    2013-03-01

    Full Text Available In insects, products of the male reproductive tract are essential for initiating and maintaining the female post-mating response (PMR. The PMR includes changes in egg laying, receptivity to courting males, and sperm storage. In Drosophila, previous studies have determined that the main cells of the male accessory gland produce some of the products required for these processes. However, nothing was known about the contribution of the gland's other secretory cell type, the secondary cells. In the course of investigating the late functions of the homeotic gene, Abdominal-B (Abd-B, we discovered that Abd-B is specifically expressed in the secondary cells of the Drosophila male accessory gland. Using an Abd-B BAC reporter coupled with a collection of genetic deletions, we discovered an enhancer from the iab-6 regulatory domain that is responsible for Abd-B expression in these cells and that apparently works independently from the segmentally regulated chromatin domains of the bithorax complex. Removal of this enhancer results in visible morphological defects in the secondary cells. We determined that mates of iab-6 mutant males show defects in long-term egg laying and suppression of receptivity, and that products of the secondary cells are influential during sperm competition. Many of these phenotypes seem to be caused by a defect in the storage and gradual release of sex peptide in female mates of iab-6 mutant males. We also found that Abd-B expression in the secondary cells contributes to glycosylation of at least three accessory gland proteins: ovulin (Acp26Aa, CG1656, and CG1652. Our results demonstrate that long-term post-mating changes observed in mated females are not solely induced by main cell secretions, as previously believed, but that secondary cells also play an important role in male fertility by extending the female PMR. Overall, these discoveries provide new insights into how these two cell types cooperate to produce and maintain a

  7. Sex roles and mutual mate choice matter during mate sampling.

    Science.gov (United States)

    Myhre, Lise Cats; de Jong, Karen; Forsgren, Elisabet; Amundsen, Trond

    2012-06-01

    The roles of females and males in mating competition and mate choice have lately proven more variable, between and within species, than previously thought. In nature, mating competition occurs during mate search and is expected to be regulated by the numbers of potential mates and same-sex competitors. Here, we present the first study to test how a temporal change in sex roles affects mating competition and mate choice during mate sampling. Our model system (the marine fish Gobiusculus flavescens) is uniquely suitable because of its change in sex roles, from conventional to reversed, over the breeding season. As predicted from sex role theory, courtship was typically initiated by males and terminated by females early in the breeding season. The opposite pattern was observed late in the season, at which time several females often simultaneously courted the same male. Mate-searching females visited more males early than late in the breeding season. Our study shows that mutual mate choice and mating competition can have profound effects on female and male behavior. Future work needs to consider the dynamic nature of mating competition and mate choice if we aim to fully understand sexual selection in the wild.

  8. Mating behavior induces changes of expression of Fos protein, plasma testosterone and androgen receptors in the accessory olfactory bulb (AOB) of the male mandarin vole Microtus mandarinus

    OpenAIRE

    Fengqin HE, Fadao TAI

    2009-01-01

    In order to investigate the neuroendocrine mechanism of the mating behavior in the adult male mandarin voles Microtus mandarinus, the radioimmunoassay (RIA) and immunohistochemistry methods were used to investigate the differences in plasma testosterone (T) concentrations and distribution of T immunoreactive neurons (T-IRs), androgen receptor immunoreactive neurons (AR-IRs) and Fos protein immunoreactive neurons (Fos-IRs) in the accessory olfactory bulb (AOB) and the main olfactory bulb (MOB)...

  9. Importance of adult protein ingestion on the mating success of Ceratitis capitata Wiedemann males (Diptera: Tephritidae); Importancia da ingestao de proteina na fase adulta para o sucesso de acasalamento dos machos de Ceratitis capitata Wiedemann (Diptera: Tephritidae)

    Energy Technology Data Exchange (ETDEWEB)

    Silva Neto, Alberto M. da; Dias, Vanessa S.; Joachim-Bravo, Iara S., E-mail: bio.alberto@gmail.co, E-mail: vanessasidias@hotmail.co, E-mail: ibravo@ufba.b [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Biologia. Dept. de Biologia Geral

    2010-04-15

    The importance of the protein ingestion during the adult stage on the mating success of males of Ceratitis capitata Wiedemann was evaluated in experiments of laboratory and fi eld cage. In laboratory, the effects of protein ingestion during the fi rst four or 12 days of the male adult life was assessed by the following parameters: mating success (capacity of being chosen by the female) and the number of males that give out pheromonal signals. Some experiments of mating success had been carried through with males in different ratios. In these tests, the number of males which had ingested protein (an unique male) was remained constant and the number of males fed without protein was gradually increased from 1:1 to 1:5. In the fi eld cages, the mating success experiments were done using a 1:1 ratio. The results showed that the protein ingestion in the fi rst four days of life did not influence any of the analyzed parameters. When the period of ingestion of protein was extended to 12 days, protein-fed males fed produced more pheromonal signals and had a higher mating success when at a 1:1 ratio in laboratory and fi eld cage assays. In laboratory, females randomly chose males in any other tested ratio (1:2, 1:3, 1:4 and 1:5), indicating that the female may lose the perception to identify the male who ingested protein in the fi rst 12 days. (author)

  10. Social exclusion and female mating behavior: rejected women show strategic enhancement of short-term mating interest.

    Science.gov (United States)

    Sacco, Donald F; Young, Steven G; Brown, Christina M; Bernstein, Michael J; Hugenberg, Kurt

    2012-08-22

    Because cost asymmetries in sexual reproduction have historically enabled women to exchange sexual access for other resources, including social resources, we tested the possibility that social exclusion would lead women to display an elevated preference for short-term mating strategies in the service of reaffiliation. In Study 1, women were given false feedback to manipulate social inclusion or exclusion prior to indicating their endorsement of short and long-term mating behaviors. Socially excluded women indicated greater interest in short-term mating and reduced interest in long-term mating. In Study 2, women wrote about a social inclusion, social exclusion, or control experience and then indicated their preference for different male body types. Women in the social exclusion condition preferred more muscular male partners--a pattern of preference typical of short-term mating--than women in the other conditions. Collectively, these results are consistent with a social exchange theory of women's sexual behavior following social exclusion.

  11. Optogenetic Activation of Accessory Olfactory Bulb Input to the Forebrain Differentially Modulates Investigation of Opposite versus Same-Sex Urinary Chemosignals and Stimulates Mating in Male Mice

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    McCarthy, Elizabeth A.; Korzan, Wayne J.; Doctor, Danielle; Han, Xue; Baum, Michael J.

    2017-01-01

    Abstract Surgical or genetic disruption of vomeronasal organ (VNO)-accessory olfactory bulb (AOB) function previously eliminated the ability of male mice to processes pheromones that elicit territorial behavior and aggression. By contrast, neither disruption significantly affected mating behaviors, although VNO lesions reduced males’ investigation of nonvolatile female pheromones. We explored the contribution of VNO-AOB pheromonal processing to male courtship using optogenetic activation of AOB projections to the forebrain. Protocadherin-Cre male transgenic mice received bilateral AOB infections with channelrhodopsin2 (ChR2) viral vectors, and an optical fiber was implanted above the AOB. In olfactory choice tests, males preferred estrous female urine (EFU) over water; however, this preference was eliminated when diluted (5%) EFU was substituted for 100% EFU. Optogenetic AOB activation concurrent with nasal contact significantly augmented males’ investigation compared to 5% EFU alone. Conversely, concurrent optogenetic AOB activation significantly reduced males’ nasal investigation of diluted urine from gonadally intact males (5% IMU) compared to 5% IMU alone. These divergent effects of AOB optogenetic activation were lost when males were prevented from making direct nasal contact. Optogenetic AOB stimulation also failed to augment males’ nasal investigation of deionized water or of food odors. Finally, during mating tests, optogenetic AOB stimulation delivered for 30 s when the male was in physical contact with an estrous female significantly facilitated the occurrence of penile intromission. Our results suggest that VNO-AOB signaling differentially modifies males’ motivation to seek out female vs male urinary pheromones while augmenting males’ sexual arousal leading to intromission and improved reproductive performance. PMID:28374006

  12. Probable neuro sexual mode of action of Casimiroa edulis seed extract versus [correction of verses] sildenafil citrate (Viagra(tm)) on mating behavior in normal male rats.

    Science.gov (United States)

    Ali, Syed Tabrez; Rakkah, Nabeeh I

    2008-01-01

    The present study deals with the aphrodisiac actions of the aqueous extract of the seeds of the hypotensive plant Casimiroa edulis on the sexual behavior of normal male rats. In this investigation 30 healthy male Wister strain white albino rats showing the brisk sexual activity age 15 weeks, weighing 400-450 grams were included. Female rats were artificially brought into estrous by hormonal treatment. Receptivity was checked by exposing them to the male rats and the most receptive females were selected for the stud The mating responses including Mounting Frequency (MF), Intromission Frequency (IF), Mounting Latency (ML), Intromission Latency (IL), Ejaculatory Latency in first and second series (EL1 and EL2) and Post Ejaculatory Interval (PEI) were recorded after treating the animals with 250 mg/kg casimiroa edulis extract (test reference) and 5 mg/kg sildenafil citrate (standard reference) respectively orally per day for 7 days. Both the groups exhibited a significant increase in Mounting Frequency, Intromission Frequency, and first and second ejaculatory latencies, where as Mounting and Intromission latencies and the Post Ejaculatory Interval showed a significant reduction than the controls. Although a similar pattern of mating behavior was observed among the test and the standard groups, however in all the cases as expected, sildenafil produced greater activity than the casimiroa edulis extract. These results suggest the possibility of a similar mode of action of casimiroa edulis and sildenafil citrate on mating behavior in these animals. Our work reported in this research thus provide preliminary evidence that the aqueous seed extract of casimiroa edulis possesses alphrodisiac activity and may be used as an alternative drug therapy to restore sexual functions probably via a neurogenic mode of action.

  13. In three brain regions central to maternal behaviour, neither male nor female Phodopus dwarf hamsters show changes in oestrogen receptor alpha distribution with mating or parenthood.

    Science.gov (United States)

    Timonin, M E; Cushing, B S; Wynne-Edwards, K E

    2008-12-01

    Oestrogen receptor (ER)alpha immunoreactivity in three brain regions relevant to maternal behaviour (medial preoptic area, bed nucleus of the stria terminalis and medial amygdala) was measured in two species of dwarf hamster that both mate during a postpartum oestrous but differ in expression of paternal behaviour. Male and female Phodopus campbelli and Phodopus sungorus were sampled as sexually naive adults, following mating to satiety, and as new parents. In all brain regions, females expressed higher levels of ER alpha than males. Species did not have an effect on ER alpha distribution except in the medial amygdala, where P. sungorus females had higher expression levels than all other groups. Behavioural status was not associated with altered ER alpha expression. These results were not expected for females and suggest that a primary activational role for oestrogen, acting through ER alpha in these regions, does not generalize to maternal behaviour in Phodopus. In males, these results are consistent with previous manipulations of the ER alpha ligand, oestrogen, and suggest that paternal behaviour in P. campbelli is likely to be regulated by developmental effects of oestrogen on the brain during early life (similar to Microtus ochrogaster), rather than through activation by oestrogen at the time of fatherhood (similar to Peromyscus californicus).

  14. Pre-Release Consumption of Methyl Eugenol Increases the Mating Competitiveness of Sterile Males of the Oriental Fruit Fly, Bactrocera dorsalis, in Large Field Enclosures

    Science.gov (United States)

    Shelly, Todd E.; Edu, James; McInnis, Donald

    2010-01-01

    The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1–4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost

  15. Using video playback to study the effect of an audience on male mating behavior in the Sailfin molly (Poecilia latipinna).

    Science.gov (United States)

    Makowicz, A M; Plath, M; Schlupp, I

    2010-09-01

    Sexual conflict in poeciliid fishes is well-documented, particularly male sexual harassment and its effects on females. For instance, male attempts to force copulations influence female feeding, energy allocation, and preference for shoaling partners. However, there has been little research conducted to determine how the social environment shapes the occurrence and intensity of sexual harassment. In this study we ask whether an audience male influences the sexual behaviors of a focal male, the correlated feeding time reduction of female Poecilia latipinna, and if the size of the audience male (larger or smaller than the focal male) influences these behaviors. We presented a video of a male, either smaller or larger than the focal male, or an empty tank (control) to a female interacting with a male or female partner and measured feeding times and sexual behaviors. We found that male sexual behaviors increased in the presence of an audience male, especially if the audience male was larger than the focal male. Females fed more in the presence of a partner female than in the presence of a male, which was independent of the audience (i.e., video treatment). Focal female aggression towards the partner female increased with the size of the audience male. The present study shows that an audience male has multiple interacting influences on both male and female behavior.

  16. Mating Behavior of Daphnia: Impacts of Predation Risk, Food Quantity, and Reproductive Phase of Females

    Science.gov (United States)

    La, Geung-Hwan; Choi, Jong-Yun; Chang, Kwang-Hyeon; Jang, Min-Ho; Joo, Gea-Jae; Kim, Hyun-Woo

    2014-01-01

    High predation risk and food depletion lead to sexual reproduction in cyclically parthenogenetic Daphnia. Mating, the core of sexual reproduction, also occurs under these conditions. Assessment of the environmental conditions and alteration of mating efforts may aid in determining the success of sexual reproduction. Here, we evaluated the impacts of predation risk, food quantity, and reproductive phase of females on the mating behavior of Daphnia obtusa males including contact frequency and duration using video analysis. Mating–related behavior involved male–female contact (mating) as well as male–male contact (fighting). Mating frequency increased while unnecessary fighting decreased in the presence of predation risk. In addition, low food concentration reduced fighting between males. Males attempted to attach to sexual females more than asexual females, and fighting occurred more frequently in the presence of sexual females. Duration of mating was relatively long; however, males separated shortly after contact in terms of fighting behavior. Thus, assessment of environmental factors and primary sexing of mates were performed before actual contact, possibly mechanically, and precise sex discrimination was conducted after contact. These results suggest that mating in Daphnia is not a random process but rather a balance between predation risk and energetic cost that results in changes in mating and fighting strategies. PMID:25111600

  17. Resistance evolution to Bt crops: predispersal mating of European corn borers.

    Directory of Open Access Journals (Sweden)

    Ambroise Dalecky

    2006-06-01

    Full Text Available Over the past decade, the high-dose refuge (HDR strategy, aimed at delaying the evolution of pest resistance to Bacillus thuringiensis (Bt toxins produced by transgenic crops, became mandatory in the United States and is being discussed for Europe. However, precopulatory dispersal and the mating rate between resident and immigrant individuals, two features influencing the efficiency of this strategy, have seldom been quantified in pests targeted by these toxins. We combined mark-recapture and biogeochemical marking over three breeding seasons to quantify these features directly in natural populations of Ostrinia nubilalis, a major lepidopteran corn pest. At the local scale, resident females mated regardless of males having dispersed beforehand or not, as assumed in the HDR strategy. Accordingly, 0-67% of resident females mating before dispersal did so with resident males, this percentage depending on the local proportion of resident males (0% to 67.2%. However, resident males rarely mated with immigrant females (which mostly arrived mated, the fraction of females mating before dispersal was variable and sometimes substantial (4.8% to 56.8%, and there was no evidence for male premating dispersal being higher. Hence, O. nubilalis probably mates at a more restricted spatial scale than previously assumed, a feature that may decrease the efficiency of the HDR strategy under certain circumstances, depending for example on crop rotation practices.

  18. Fighting for a harem of queens: physiology of reproduction in Cardiocondyla male ants.

    Science.gov (United States)

    Heinze, J; Hölldobler, B

    1993-09-15

    Several species of the ant genus Cardiocondyla produce dimorphic males, which exhibit sharply different mating strategies. Winged males typically disperse to mate outside the nest, whereas wingless, ergatoid males stay in the nest and aggressively employ their mandibles against competing ergatoid males to monopolize the virgin queens eclosing in the nest. Such aggressive mating strategy would only be adaptive if the males had unlimited sperm supply. Histological studies showed that, contrary to the rule in the Hymenoptera order, the ergatoid Cardiocondyla males are indeed able to produce sperm during their entire adult life. Winged males, on the other hand, have only a limited sperm supply since spermatogenesis ceases in the late pupal stage.

  19. Diclofenac can exhibit estrogenic modes of action in male Xenopus laevis, and affects the hypothalamus-pituitary-gonad axis and mating vocalizations.

    Science.gov (United States)

    Efosa, Norah Johanna; Kleiner, Wibke; Kloas, Werner; Hoffmann, Frauke

    2017-04-01

    Diclofenac (DCF) is a non-steroidal analgesic and antiphlogistic. Due to its tremendous use, DCF can be found in the environment, especially in sewage, but also surface waters, ground and drinking water. Previous studies indicated that DCF can modulate the reproductive physiology of fish by altering the expression of important key enzymes of the hypothalamus-pituitary-gonad-axis (HPG-axis) and might act as an estrogenic endocrine disrupting chemical (EDC). Other studies, however, demonstrated that DCF does not exhibit any estrogenicity. Thus, in the present study we investigated whether an exposure to DCF can affect reproductive behavior and physiology of adult male X. laevis by analyzing DCF effects on the mate calling behavior of the frogs and on gene expression patterns of key biomarkers of the HPG-axis. In addition, plasma sex steroid levels were determined to gain detailed insights into the mechanisms of DCF action. We could demonstrate that DCF can act as EDC by exhibiting slight estrogenic modes of action. In addition, pharmacological impacts on gonadal steroidogenesis could be revealed leading to imbalances in sex steroid levels and ratios. DCF furthermore altered the calling behavior of exposed males, potentially reducing the mating and reproductive success of the frogs, possibly leading to severe population effects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Size-assortative mating and sexual size dimorphism are predictable from simple mechanics of mate-grasping behavior

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    Jablonski Piotr G

    2010-11-01

    Full Text Available Abstract Background A major challenge in evolutionary biology is to understand the typically complex interactions between diverse counter-balancing factors of Darwinian selection for size assortative mating and sexual size dimorphism. It appears that rarely a simple mechanism could provide a major explanation of these phenomena. Mechanics of behaviors can predict animal morphology, such like adaptations to locomotion in animals from various of taxa, but its potential to predict size-assortative mating and its evolutionary consequences has been less explored. Mate-grasping by males, using specialized adaptive morphologies of their forelegs, midlegs or even antennae wrapped around female body at specific locations, is a general mating strategy of many animals, but the contribution of the mechanics of this wide-spread behavior to the evolution of mating behavior and sexual size dimorphism has been largely ignored. Results Here, we explore the consequences of a simple, and previously ignored, fact that in a grasping posture the position of the male's grasping appendages relative to the female's body is often a function of body size difference between the sexes. Using an approach taken from robot mechanics we model coercive grasping of females by water strider Gerris gracilicornis males during mating initiation struggles. We determine that the male optimal size (relative to the female size, which gives the males the highest grasping force, properly predicts the experimentally measured highest mating success. Through field sampling and simulation modeling of a natural population we determine that the simple mechanical model, which ignores most of the other hypothetical counter-balancing selection pressures on body size, is sufficient to account for size-assortative mating pattern as well as species-specific sexual dimorphism in body size of G. gracilicornis. Conclusion The results indicate how a simple and previously overlooked physical mechanism

  1. Weighing costs and benefits of mating in bushcrickets (Insecta: Orthoptera: Tettigoniidae, with an emphasis on nuptial gifts, protandry and mate density

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    Lehmann Gerlind U C

    2012-08-01

    Full Text Available Abstract Sexual selection is a major force driving evolution and is intertwined with ecological factors. Differential allocation of limited resources has a central role in the cost of reproduction. In this paper, I review the costs and benefits of mating in tettigoniids, focussing on nuptial gifts, their trade-off with male calling songs, protandry and how mate density influences mate choice. Tettigoniids have been widely used as model systems for studies of mating costs and benefits; they can provide useful general insights. The production and exchange of large nuptial gifts by males for mating is an important reproductive strategy in tettigoniids. As predicted by sexual selection theory spermatophylax size is condition dependent and is constrained by the need to invest in calling to attract mates also. Under some circumstances, females benefit directly from the nuptial gifts by an increase in reproductive output. However, compounds in the nuptial gift can also benefit the male by prolonging the period before the female remates. There is also a trade-off between adult male maturation and mating success. Where males mature before females (protandry the level of protandry varies in the direction predicted by sperm competition theory; namely, early male maturation is correlated with a high level of first inseminations being reproductively successful. Lastly, mate density in bushcrickets is an important environmental factor influencing the behavioural decisions of individuals. Where mates are abundant, individuals are more choosey of mates; when they are scarce, individuals are less choosey. This review reinforces the view that tettigoniids provide excellent models to test and understand the economics of matings in both sexes.

  2. 男性择偶策略改变的前提:自感配偶价值提高%Enhancement of Self-perceived Mate Value Precedes a Shift in Men's Preferred Mating Strategy

    Institute of Scientific and Technical Information of China (English)

    Michele. K. Surbey; Gavin. R. Brice

    2007-01-01

    研究分为问卷调查与实验研究两部分.首先,40名女性和33名男性完成有关自感配偶价值评价(SPMV)和择偶偏爱策略的问卷调查,问卷调查结果是实验研究中数据分析的基线.其次,第二部分实验开始后,被试会得到实验者编造的他人潜在择偶对象的积极正面评价,其目的在于提高被试的SPMV.可以假设,男性的SPMV与随意性行为的认同或追求有正相关,男性SPMV的提高将会更加偏爱短期的性策略;女性SPMV与随意性行为不存在相关,女性SPMV的提高不会改变女性的性策略.研究结果显示,SPMV高基线水平的男性更加认可随意性行为,男性SPMV的提高与短期策略选择的增加有关.另外,SPMV提高,而不是一般自尊的提高,与择偶策略的改变具有相关.本研究结果没有证实,与长期稳定的性关系相比,SPMV的基线水平或是提高与女性对随意性行为的认同或追求之间存在相关.%Seventy-three participants (40 women, 33 men) completed questionnaires conceming their self-perceived mate value (SPMV) and preferred mating strategy in two separate sessions, with baseline measures collected during the first stage. At the commencement of the second testing session, participants were provided with a fictitious positive assessment of their worth as a mate in an attempt to manipulate their SPMV upward. It was hypothesized that higher SPMV and the endorsement or pursuit of casual sexual activity would be positively related in men and that raising men's SPMV would increase the bias toward this mating strategy. A strong relationship between SPMV and mating strategy was not expected in women, nor was increasing SPMV expected to alter women's mating strategy. As predicted, high baseline levels of SPMV were positively related with the endorsement of casual sexual activity in men, and an elevation in men's SPMV following the manipulation was associated with the increased choice of this mating strategy

  3. Direct and indirect mate choice on leks.

    Science.gov (United States)

    Saether, Stein Are; Baglo, Ragnhild; Fiske, Peder; Ekblom, Robert; Höglund, Jacob; Kålås, John Atle

    2005-08-01

    Indirect mate choice is any behavior that restricts the individual's set of potential mates without discrimination of mate attributes directly, for example, by having preferences about where to mate. We analyzed a 14-year data set from great snipe (Gallinago media) leks for evidence of indirect mate choice based on relative and absolute position of lek territories. We found little or no effect of the centrality of territories on mating and no between-year consistency in the spatial distribution of matings within leks. Instead, the probability of matings occurring at a particular site increased if the current territory owner had mated the previous year. Furthermore, individual females returned in later seasons to mate with the same male as previously rather than at the same site. Previous work found that male interactions and dominance do not control matings and that females are very choosy about which territory they mate in. Here we show that this is because of the male occupying the territory rather than its position. We therefore conclude that direct female mate choice is the main behavioral process affecting variation in mating success among great snipe males, unlike in some lekking mammals where male competition and/or indirect mate choice appears more important.

  4. The role of protein in the sexual behaviour of males of Ceratitis capitata (Diptera: Tephritidae: mating success, copula duration and number of copulations

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    Iara Sordi Joachim-Bravo

    2009-09-01

    Full Text Available In this paper, we investigated the influence of protein ingestion during the early adult phase on the sexual behavior of males of Ceratitis capitata (Wiedemann, 1824. The following parameters were evaluated: mating success (ability to be chosen by females, number of copulations, and copula duration. Experiments were carried out using a fifteen-year old laboratory lineage with the occasional introduction of wild flies. Two groups of adult males fed a high-protein diet during their larval phase were given either a high-protein diet (based on Brewer's yeast, concentration = 6.5 g/100 ml or a no-protein diet. Both groups of males were exposed to females fed either a high-protein diet or a no-protein diet and were subsequently evaluated for the parameters listed above. All experiments were conducted at 25ºC, 70% R.H. and with a photoperiod of L12:D12. The number of copulations was the only parameter affected by adult diet. Males fed a high-protein diet and exposed to females fed a no-protein diet had a greater number of copulations compared with males fed a no-protein diet.

  5. Annual cycle of plasma testosterone in male copperheads, Agkistrodon contortrix (Serpentes, Viperidae): relationship to timing of spermatogenesis, mating, and agonistic behavior.

    Science.gov (United States)

    Schuett, G W; Harlow, H J; Rose, J D; Van Kirk, E A; Murdoch, W J

    1997-03-01

    Reproductive cycles of the majority of squamate reptiles remain undescribed. Few studies are available on seasonal patterns of circulating steroid hormones in snakes. The goal of this study was to document the annual cycle of plasma testosterone (T) in male copperheads Agkistrodon contortrix, a North American pitviper (Serpentes, Viperidae). Two experimental conditions were used in this laboratory study. One condition (repeat-test group) consisted of 10 adult males that were sampled once each month for 11 months. The other condition (single-test groups) consisted of 10 groups each with 5 males (N = 50), and each male was tested a single time. The single-test condition was used to evaluate whether or not repeated handling and sampling affected T levels. The study was conducted from February-December, 1992. A well-defined seasonal pattern of plasma T levels was detected; patterns were similar under both experimental conditions with the exception that the repeat-test group had slightly lower levels. Levels of T were lowest (baseline) in April-May, increased in early summer (June), and were highest in late summer (August). Thereafter, T levels declined up to the time of hibernation (early November) and changed little during hibernation (November-January). Upon emergence from hibernation in late winter (February), T levels increased sharply from February to March and then decreased from March to April. The results are discussed in the context of timing of spermatogenesis, mating, and male agonistic behavior.

  6. Pollen Performance in Clarkia Taxa with Contrasting Mating Systems: Implications for Male Gametophytic Evolution in Selfers and Outcrossers

    Directory of Open Access Journals (Sweden)

    Alisa A. Hove

    2013-04-01

    Full Text Available We tested three predictions regarding the joint evolution of pollen performance and mating system. First, due to the potential for intense intrasexual competition in outcrossing populations, we predicted that outcrossers would produce faster-growing pollen than their selfing relatives. Second, if elevated competition promotes stronger selection on traits that improve pollen performance, then, among-plant variation in pollen performance would be lower in outcrossers than in selfers. Third, given successive generations of adaptation to the same maternal genotype in selfers, we predicted that, in selfing populations (but not in outcrossing ones, pollen would perform better following self- than cross-pollinations. We tested these predictions in field populations of two pairs of Clarkia (Onagraceae sister taxa. Consistent with our predictions, one outcrosser (C. unguiculata exhibited faster pollen germination and less variation in pollen tube growth rate (PTGR among pollen donors than its selfing sister species, C. exilis. Contrary to our predictions, the selfing C. xantiana ssp. parviflora exhibited faster PTGR than the outcrossing ssp. xantiana, and these taxa showed similar levels of variation in this trait. Pollen performance following self- vs. cross-pollinations did not differ within either selfing or outcrossing taxa. While these findings suggest that mating system and pollen performance may jointly evolve in Clarkia, other factors clearly contribute to pollen performance in natural populations.

  7. The effects of genetic manipulation, dieldrin treatment and irradiation on the mating competitiveness of male Anopheles arabiensis in field cages.

    Science.gov (United States)

    Yamada, Hanano; Vreysen, Marc J B; Gilles, Jeremie R L; Munhenga, Givemore; Damiens, David D

    2014-08-13

    To enable the release of only sterile male Anopheles arabiensis mosquitoes for the sterile insect technique, the genetic background of a wild-type strain was modified to create a genetic sexing strain ANO IPCL1 that was based on a dieldrin resistance mutation. Secondly, the eggs of ANO IPCL1 require treatment with dieldrin to allow complete elimination of female L1 larvae from the production line. Finally, male mosquito pupae need to be treated with an irradiation dose of 75 Gy for sterilization. The effects of these treatments on the competitiveness of male An. arabiensis were studied. The competitiveness of ANO IPCL1 males that were treated either with irradiation or both dieldrin and irradiation, was compared with that of the wild-type strain (An. arabiensis Dongola) at a 1:1 ratio in 5.36 m3 semi-field cages located in a climate-controlled greenhouse. In addition, three irradiated: untreated male ratios were tested in semi-field cages (1:1, 5:1 and 10:1) and their competition for virgin wild-type females was assessed. The ANO IPCL1 males were equally competitive as the wild-type males in this semi-field setting. The ANO IPCL1 males irradiated at 75 Gy were approximately half as competitive as the unirradiated wild-type males. ANO IPCL1 males that had been treated with dieldrin as eggs, and irradiated with 75 Gy as pupae were slightly more competitive than males that were only irradiated. Ratios of 1:1, 5:1 and 10:1 irradiated ANO IPCL1 males: untreated wild-type males resulted in 31, 66 and 81% induced sterility in the female cage population, respectively. An irradiation dose of 75 Gy reduced the competitiveness of male ANO IPCL1 significantly and will need to be compensated by releasing higher numbers of sterile males in the field. However, the dieldrin treatment used to eliminate females appears to have an unexpected radioprotectant effect, however the mechanism is not understood. A sterile to wild-type ratio of 10:1 effectively reduced the population

  8. Worthless and Nutritive Nuptial Gifts: Mating Duration, Sperm Stored and Potential Female Decisions in Spiders

    Science.gov (United States)

    Albo, Maria J.; Peretti, Alfredo V.

    2015-01-01

    In nuptial gift-giving species females sometimes select their potential mates based on the presence and size of the gift. But in some species, such as the Neotropical polyandrous spider Paratrechalea ornate male gifts vary in quality, from nutritive to worthless, and this male strategy can be in conflict with female nutritional benefits. In this species, males without gifts experience a reduction in mating success and duration, while males that offer worthless or genuine nutritive gifts mate with similar frequencies and durations. The female apparently controls the duration of copulation. Thus, there is scope for females to favour males offering gifts and further if these are nutritious, via post-copulatory processes. We first tested whether females differentially store sperm from males that offer the highest nutritional benefits by experimentally presenting females with males that offer either nutritive or worthless gifts (uninterrupted matings). Second, we carried out another set of experiments to examine whether females can select sperm based only on gift presence. This time we interrupted matings after the first pedipalp insertion, thus matching number of insertions and mating duration for males that: offered and did not offer gift. Our results showed that the amount of sperm stored is positive related to mating duration in all groups, except in matings with worthless gifts. Gift presence itself did not affect the sperm stored by females, while they store similar number of sperm in matings with males offering either nutritive or worthless gifts. We discuss whether females prefer males with gifts regardless, if content, because it represents an attractive and/or reliable signal. Or alternatively, they prefer nutritive nuptial gifts, as they are an important source of food supply and/or signal of male donor ability. PMID:26107397

  9. Worthless and Nutritive Nuptial Gifts: Mating Duration, Sperm Stored and Potential Female Decisions in Spiders.

    Directory of Open Access Journals (Sweden)

    Maria J Albo

    Full Text Available In nuptial gift-giving species females sometimes select their potential mates based on the presence and size of the gift. But in some species, such as the Neotropical polyandrous spider Paratrechalea ornate male gifts vary in quality, from nutritive to worthless, and this male strategy can be in conflict with female nutritional benefits. In this species, males without gifts experience a reduction in mating success and duration, while males that offer worthless or genuine nutritive gifts mate with similar frequencies and durations. The female apparently controls the duration of copulation. Thus, there is scope for females to favour males offering gifts and further if these are nutritious, via post-copulatory processes. We first tested whether females differentially store sperm from males that offer the highest nutritional benefits by experimentally presenting females with males that offer either nutritive or worthless gifts (uninterrupted matings. Second, we carried out another set of experiments to examine whether females can select sperm based only on gift presence. This time we interrupted matings after the first pedipalp insertion, thus matching number of insertions and mating duration for males that: offered and did not offer gift. Our results showed that the amount of sperm stored is positive related to mating duration in all groups, except in matings with worthless gifts. Gift presence itself did not affect the sperm stored by females, while they store similar number of sperm in matings with males offering either nutritive or worthless gifts. We discuss whether females prefer males with gifts regardless, if content, because it represents an attractive and/or reliable signal. Or alternatively, they prefer nutritive nuptial gifts, as they are an important source of food supply and/or signal of male donor ability.

  10. The Size Advantage Model of Sex Allocation in the Protandrous Sex-Changer Crepidula fornicata: Role of the Mating System, Sperm Storage, and Male Mobility.

    Science.gov (United States)

    Broquet, Thomas; Barranger, Audrey; Billard, Emmanuelle; Bestin, Anastasia; Berger, Rémy; Honnaert, Gaelle; Viard, Frédérique

    2015-09-01

    Sequential hermaphroditism is adaptive when the reproductive value of an individual varies with size or age, and this relationship differs between males and females. In this case, theory shows that the lifetime reproductive output of an individual is increased by changing sex (a hypothesis referred to as the size-advantage model). Sex-linked differences in size-fitness curves can stem from differential costs of reproduction, the mating system, and differences in growth and mortality between sexes. Detailed empirical data is required to disentangle the relative roles of each of these factors within the theory. Quantitative data are also needed to explore the role of sperm storage, which has not yet been considered with sequential hermaphrodites. Using experimental rearing and paternity assignment, we report relationships between size and reproductive success of Crepidula fornicata, a protandrous (male-first) gastropod. Male reproductive success increased with size due to the polygamous system and stacking behavior of the species, but females nonetheless had greater reproductive success than males of the same size, in agreement with the size-advantage theory. Sperm storage appeared to be a critical determinant of success for both sexes, and modeling the effect of sperm storage showed that it could potentially accelerate sex change in protandrous species.

  11. One-shot genitalia are not an evolutionary dead end - Regained male polygamy in a sperm limited spider species

    Directory of Open Access Journals (Sweden)

    Michalik Peter

    2011-07-01

    Full Text Available Abstract Background Monogynous mating systems with extremely low male mating rates have several independent evolutionary origins and are associated with drastic adaptations involving self-sacrifice, one-shot genitalia, genital damage, and termination of spermatogenesis immediately after maturation. The combination of such extreme traits likely restricts evolutionary potential perhaps up to the point of making low male mating rates irreversible and hence may constitute an evolutionary dead end. Here, we explore the case of a reversion to multiple mating from monogynous ancestry in golden orb-web spiders, Nephila senegalensis. Results Male multiple mating is regained by the loss of genital damage and sexual cannibalism but spermatogenesis is terminated with maturation, restricting males to a single loading of their secondary mating organs and a fixed supply of sperm. However, males re-use their mating organs and by experimentally mating males to many females, we show that the sperm supply is divided between copulations without reloading the pedipalps. Conclusion By portioning their precious sperm supply, males achieve an average mating rate of four females which effectively doubles the maximal mating rate of their ancestors. A heritage of one-shot genitalia does not completely restrict the potential to increase mating rates in Nephila although an upper limit is defined by the available sperm load. Future studies should now investigate how males use this potential in the field and identify selection pressures responsible for a reversal from monogynous to polygynous mating strategies.

  12. Mating competitiveness of sterile genetic sexing strain males (GAMA) under laboratory and semi-field conditions: Steps towards the use of the Sterile Insect Technique to control the major malaria vector Anopheles arabiensis in South Africa.

    Science.gov (United States)

    Munhenga, Givemore; Brooke, Basil D; Gilles, Jeremie R L; Slabbert, Kobus; Kemp, Alan; Dandalo, Leonard C; Wood, Oliver R; Lobb, Leanne N; Govender, Danny; Renke, Marius; Koekemoer, Lizette L

    2016-03-02

    Anopheles arabiensis Patton is primarily responsible for malaria transmission in South Africa after successful suppression of other major vector species using indoor spraying of residual insecticides. Control of An. arabiensis using current insecticide based approaches is proving difficult owing to the development of insecticide resistance, and variable feeding and resting behaviours. The use of the sterile insect technique as an area-wide integrated pest management system to supplement the control of An. arabiensis was proposed for South Africa and is currently under investigation. The success of this technique is dependent on the ability of laboratory-reared sterile males to compete with wild males for mates. As part of the research and development of the SIT technique for use against An. arabiensis in South Africa, radio-sensitivity and mating competitiveness of a local An. arabiensis sexing strain were assessed. The optimal irradiation dose inducing male sterility without compromising mating vigour was tested using Cobalt 60 irradiation doses ranging from 70-100 Gy. Relative mating competitiveness of sterile laboratory-reared males (GAMA strain) compared to fertile wild-type males (AMAL strain) for virgin wild-type females (AMAL) was investigated under laboratory and semi-field conditions using large outdoor cages. Three different sterile male to fertile male to wild-type female ratios were evaluated [1:1:1, 5:1:1 and 10:1:1 (sterile males: fertile, wild-type males: fertile, wild-type females)]. Irradiation at the doses tested did not affect adult emergence but had a moderate effect on adult survivorship and mating vigour. A dose of 75 Gy was selected for the competitiveness assays. Mating competitiveness experiments showed that irradiated GAMA male mosquitoes are a third as competitive as their fertile AMAL counterparts under semi-field conditions. However, they were not as competitive under laboratory conditions. An inundative ratio of 10:1 induced the

  13. Old female reed buntings (Emberiza schoeniclus) increase extra-pair paternity in their broods when mated to young males

    NARCIS (Netherlands)

    Bouwman, KM; Komdeur, J

    2005-01-01

    In birds, females are generally assumed to determine whether extra-pair copulations occur, and thus most studies on extra-pair paternity (EPP) have focussed on female preference for male traits, whereas female traits have been largely neglected. However, the occurrence of EPP is likely to be a resul

  14. Mate Choice Copying in Humans.

    Science.gov (United States)

    Waynforth, D

    2007-09-01

    There is substantial evidence that in human mate choice, females directly select males based on male display of both physical and behavioral traits. In non-humans, there is additionally a growing literature on indirect mate choice, such as choice through observing and subsequently copying the mating preferences of conspecifics (mate choice copying). Given that humans are a social species with a high degree of sharing information, long-term pair bonds, and high parental care, it is likely that human females could avoid substantial costs associated with directly searching for information about potential males by mate choice copying. The present study was a test of whether women perceived men to be more attractive when men were presented with a female date or consort than when they were presented alone, and whether the physical attractiveness of the female consort affected women's copying decisions. The results suggested that women's mate choice decision rule is to copy only if a man's female consort is physically attractive. Further analyses implied that copying may be a conditional female mating tactic aimed at solving the problem of informational constraints on assessing male suitability for long-term sexual relationships, and that lack of mate choice experience, measured as reported lifetime number of sex partners, is also an important determinant of copying.

  15. Transcriptome profiling of sexual maturation and mating in the Mediterranean fruit fly, Ceratitis capitata.

    Directory of Open Access Journals (Sweden)

    Ludvik M Gomulski

    Full Text Available Sexual maturation and mating in insects are generally accompanied by major physiological and behavioural changes. Many of these changes are related to the need to locate a mate and subsequently, in the case of females, to switch from mate searching to oviposition behaviour. The prodigious reproductive capacity of the Mediterranean fruit fly, Ceratitis capitata, is one of the factors that has led to its success as an invasive pest species. To identify the molecular changes related to maturation and mating status in male and female medfly, a microarray-based gene expression approach was used to compare the head transcriptomes of sexually immature, mature virgin, and mated individuals. Attention was focused on the changes in abundance of transcripts related to reproduction, behaviour, sensory perception of chemical stimulus, and immune system processes. Broad transcriptional changes were recorded during female maturation, while post-mating transcriptional changes in females were, by contrast, modest. In male medfly, transcriptional changes were consistent both during maturation and as a consequence of mating. Of particular note was the lack of the mating-induced immune responses that have been recorded for Drosophila melanogaster, that may be due to the different reproductive strategies of these species. This study, in addition to increasing our understanding of the molecular machinery behind maturation and mating in the medfly, has identified important gene targets that might be useful in the future management of this pest.

  16. Transcriptome profiling of sexual maturation and mating in the Mediterranean fruit fly, Ceratitis capitata.

    Science.gov (United States)

    Gomulski, Ludvik M; Dimopoulos, George; Xi, Zhiyong; Scolari, Francesca; Gabrieli, Paolo; Siciliano, Paolo; Clarke, Anthony R; Malacrida, Anna R; Gasperi, Giuliano

    2012-01-01

    Sexual maturation and mating in insects are generally accompanied by major physiological and behavioural changes. Many of these changes are related to the need to locate a mate and subsequently, in the case of females, to switch from mate searching to oviposition behaviour. The prodigious reproductive capacity of the Mediterranean fruit fly, Ceratitis capitata, is one of the factors that has led to its success as an invasive pest species. To identify the molecular changes related to maturation and mating status in male and female medfly, a microarray-based gene expression approach was used to compare the head transcriptomes of sexually immature, mature virgin, and mated individuals. Attention was focused on the changes in abundance of transcripts related to reproduction, behaviour, sensory perception of chemical stimulus, and immune system processes. Broad transcriptional changes were recorded during female maturation, while post-mating transcriptional changes in females were, by contrast, modest. In male medfly, transcriptional changes were consistent both during maturation and as a consequence of mating. Of particular note was the lack of the mating-induced immune responses that have been recorded for Drosophila melanogaster, that may be due to the different reproductive strategies of these species. This study, in addition to increasing our understanding of the molecular machinery behind maturation and mating in the medfly, has identified important gene targets that might be useful in the future management of this pest.

  17. Female mate fidelity in a Lek mating system and its implications for the evolution of cooperative lekking behavior.

    Science.gov (United States)

    DuVal, E H

    2013-02-01

    The extent and importance of female mate fidelity in polygynous mating systems are poorly known. Fidelity may contribute to high variance in male reproductive success when it favors attractive mates or may stabilize social interactions if females are faithful to mating sites rather than males. Using 12 years of data on genetic mate choice in the cooperatively lekking lance-tailed manakin (Chiroxiphia lanceolata), I investigated the frequency of fidelity within and between years, whether females were faithful to individual males or to mating sites across years, and whether fidelity favored attractive males. Mate fidelity occurred in 41.7% of 120 between-year comparisons and was observed for 41.1% of 73 individual females that had the opportunity to mate faithfully. Females were not more likely to mate at prior mating sites when previous mates were replaced. Faithful females mated with the same male in up to four consecutive years but were not disproportionately faithful to attractive partners. Mating history influences current mate choice, and fidelity in this lekking system apparently represents active mate choice by females but little is not cited in the text. Please provide a citation or mark this reference for deletion.consensus in mate choices among faithful females. This study underscores the prevalence of mate fidelity in polygynous mating systems and emphasizes the need to consider the larger context of lifetime reproductive behavior when interpreting patterns of female choice.

  18. Combining the Sterile Insect Technique with the Incompatible Insect Technique: III-Robust Mating Competitiveness of Irradiated Triple Wolbachia-Infected Aedes albopictus Males under Semi-Field Conditions

    Science.gov (United States)

    Zhang, Dongjing; Lees, Rosemary Susan; Xi, Zhiyong; Bourtzis, Kostas; Gilles, Jeremie R. L.

    2016-01-01

    Combination of the sterile insect technique with the incompatible insect technique is considered to be a safe approach to control Aedes albopictus populations in the absence of an accurate and scalable sex separation system or genetic sexing strain. Our previous study has shown that the triple Wolbachia-infected Ae. albopictus strain (wAlbA, wAlbB and wPip) was suitable for mass rearing and females could be completely sterilized as pupae with a radiation dose of at least 28 Gy. However, whether this radiation dose can influence the mating competitiveness of the triple infected males was still unknown. In this study we aimed to evaluate the effects of irradiation on the male mating competitiveness of the triple infected strain under laboratory and semi-field conditions. The results herein indicate that irradiation with a lower, female-sterilizing dose has no negative impact on the longevity of triple infected males while a reduced lifespan was observed in the wild type males (wAlbA and wAlbB) irradiated with a higher male-sterilizing dose, in small cages. At different sterile: fertile release ratios in small cages, triple-infected males induced 39.8, 81.6 and 87.8% sterility in a wild type female population at 1:1, 5:1 and 10:1 release ratios, respectively, relative to a fertile control population. Similarly, irradiated triple infected males induced 31.3, 70.5 and 89.3% sterility at 1:1, 5:1 and 10:1 release ratios, respectively, again relative to the fertile control. Under semi-field conditions at a 5:1 release ratio, relative to wild type males, the mean male mating competitiveness index of 28 Gy irradiated triple-infected males was significantly higher than 35 Gy irradiated wild type males, while triple infected males showed no difference in mean mating competitiveness to either irradiated triple-infected or irradiated wild type males. An unexpected difference was also observed in the relative male mating competitiveness of the triple infected strain after

  19. Banded mongooses avoid inbreeding when mating with members of the same natal group.

    Science.gov (United States)

    Sanderson, Jennifer L; Wang, Jinliang; Vitikainen, Emma I K; Cant, Michael A; Nichols, Hazel J

    2015-07-01

    Inbreeding and inbreeding avoidance are key factors in the evolution of animal societies, influencing dispersal and reproductive strategies which can affect relatedness structure and helping behaviours. In cooperative breeding systems, individuals typically avoid inbreeding through reproductive restraint and/or dispersing to breed outside their natal group. However, where groups contain multiple potential mates of varying relatedness, strategies of kin recognition and mate choice may be favoured. Here, we investigate male mate choice and female control of paternity in the banded mongoose (Mungos mungo), a cooperatively breeding mammal where both sexes are often philopatric and mating between relatives is known to occur. We find evidence suggestive of inbreeding depression in banded mongooses, indicating a benefit to avoiding breeding with relatives. Successfully breeding pairs were less related than expected under random mating, which appeared to be driven by both male choice and female control of paternity. Male banded mongooses actively guard females to gain access to mating opportunities, and this guarding behaviour is preferentially directed towards less closely related females. Guard-female relatedness did not affect the guard's probability of gaining reproductive success. However, where mate-guards are unsuccessful, they lose paternity to males that are less related to the females than themselves. Together, our results suggest that both sexes of banded mongoose use kin discrimination to avoid inbreeding. Although this strategy appears to be rare among cooperative breeders, it may be more prominent in species where relatedness to potential mates is variable, and/or where opportunities for dispersal and mating outside of the group are limited. © 2015 John Wiley & Sons Ltd.

  20. Development of the main olfactory system and main olfactory epithelium-dependent male mating behavior are altered in Go-deficient mice

    Science.gov (United States)

    Choi, Jung-Mi; Kim, Sung-Soo; Choi, Chan-Il; Cha, Hye Lim; Oh, Huy-Hyen; Ghil, Sungho; Lee, Young-Don; Birnbaumer, Lutz; Suh-Kim, Haeyoung

    2016-01-01

    In mammals, initial detection of olfactory stimuli is mediated by sensory neurons in the main olfactory epithelium (MOE) and the vomeronasal organ (VNO). The heterotrimeric GTP-binding protein Go is widely expressed in the MOE and VNO of mice. Early studies indicated that Go expression in VNO sensory neurons is critical for directing social and sexual behaviors in female mice [Oboti L, et al. (2014) BMC Biol 12:31]. However, the physiological functions of Go in the MOE have remained poorly defined. Here, we examined the role of Go in the MOE using mice lacking the α subunit of Go. Development of the olfactory bulb (OB) was perturbed in mutant mice as a result of reduced neurogenesis and increased cell death. The balance between cell types of OB interneurons was altered in mutant mice, with an increase in the number of tyrosine hydroxylase-positive interneurons at the expense of calbindin-positive interneurons. Sexual behavior toward female mice and preference for female urine odors by olfactory sensory neurons in the MOE were abolished in mutant male mice. Our data suggest that Go signaling is essential for the structural and functional integrity of the MOE and for specification of OB interneurons, which in turn are required for the transmission of pheromone signals and the initiation of mating behavior with the opposite sex. PMID:27625425

  1. Male and female condition influence mating performance and sexual receptivity in two tropical fruit flies (Diptera: Tephritidae) with contrasting life histories

    Science.gov (United States)

    Recent recognition of widespread polyandry in insects has generated considerable interest in understanding why females mate multiply and at identifying factors that affect mating rate and inhibit female remating. However, little attention has been paid to understanding the question from both a fema...

  2. Switching attraction to inhibition: mating-induced reversed role of sex pheromone in an insect.

    Science.gov (United States)

    Barrozo, Romina B; Gadenne, Christophe; Anton, Sylvia

    2010-09-01

    In the moth, Agrotis ipsilon, newly mated males cease to be attracted to the female-produced sex pheromone, preventing them from re-mating until the next night, by which time they would have refilled their reproductive glands for a potential new ejaculate. The behavioural plasticity is accompanied by a decrease in neuron sensitivity within the primary olfactory centre, the antennal lobe (AL). However, it was not clear whether the lack of the sexually guided behaviour results from the absence of sex pheromone detection in the ALs, or if they ignore it in spite of detection, or if the sex pheromone itself inhibits attraction behaviour after mating. To test these hypotheses, we performed behavioural tests and intracellular recordings of AL neurons to non-pheromonal odours (flower volatiles), different doses of sex pheromone and their mixtures in virgin and newly mated males. Our results show that, although the behavioural and AL neuron responses to flower volatiles alone were similar between virgin and mated males, the behavioural response of mated males to flower odours was inhibited by adding pheromone doses above the detection threshold of central neurons. Moreover, we show that the sex pheromone becomes inhibitory by differential central processing: below a specific threshold, it is not detected within the AL; above this threshold, it becomes inhibitory, preventing newly mated males from responding even to plant odours. Mated male moths have thus evolved a strategy based on transient odour-selective central processing, which allows them to avoid the risk-taking, energy-consuming search for females and delay re-mating until the next night for a potential new ejaculate.

  3. Open-nucleus breeding strategies compared with population-wide positive assortative mating: I. Equal distribution of testing efforts.

    Science.gov (United States)

    Lstibůrek, M; Mullin, T J; Lindgren, D; Rosvall, O

    2004-10-01

    Positive assortative mating (PAM) can enhance the additive genetic variance in a breeding population(BP). This increases the potential for gains in the production population (PP, selected subset of the BP) for recurrent selection programs in forest trees. The assortment of mates can be either: (1) by individual tree rank across the whole BP (PAM), or (2) trees of similar rank can be merged into larger hierarchical groups and then mated randomly within group ("open"-nucleus breeding,NB). The objective of this study was to compare PAM and NB in quantitative terms. The NB simulation model assumed two tiers (nucleus, main) with unrestricted migration between the tiers. Clonal tests were used to predict breeding values and test resources per mate were kept constant for all mates. Both gain and diversity were combined into a single selection criterion, "group-merit selection." Alternatives were compared over five breeding cycles by considering genetic gain and diversity in a selected PP established in a seed orchard. The assortment of mates in both alternatives enhanced additive variance and increased the additive effect in the BP, leading to additional gain in the PP. Gains generated under PAM always exceeded gains under NB. Thus, the main message from this study is that PAM in both the short- and long-term results in more gain at any target level of diversity in the PP (the breeder's target) than is achieved by the NB alternative. The optimum size of the nucleus varies with the desired level of seed orchard diversity. At lower target diversity, smaller nucleus sizes are favorable, while larger sizes result in more gain when seed orchard diversity is considered more important.

  4. Do female Siamese fighting fish copy the mate choice of others?

    DEFF Research Database (Denmark)

    Durey, Maëlle; Dabelsteen, Torben; Matessi, Giuliano

    mollies and guppies. Female Siamese fighting fish (Betta splendens) have been reported to eavesdrop and exploit social information in aggressive interactions and may therefore also use information contained in other’s mate choice. In this experiment, we aimed at establishing if female fighting fish copy...... the mate choice of others. We examined if the initial choice of a female between two males can be changed by observing another female with the previously rejected male. The two males and the model female(s) were exposed in different settings to the female subject to test the relative effects of mere...... association and active courtship behaviour. We also recorded and analyzed the effects of male body size, colour and behaviour on the subjects’ responses. Our experiments provide a detailed analysis of the interplay of male properties and female independent and dependent mate choice strategies....

  5. Friendship as a Relationship Infiltration Tactic during Human Mate Poaching

    Directory of Open Access Journals (Sweden)

    Justin K. Mogilski

    2013-10-01

    Full Text Available Previous research has characterized human mate poaching as a prevalent alternative mating strategy that entails risks and costs typically not present during general romantic courtship and attraction. This study is the first to experimentally investigate friendship between a poacher and his/her target as a risk mitigation tactic. Participants (N = 382 read a vignette that differed by whether the poacher was male/female and whether the poacher and poached were friends/acquaintances. Participants assessed the likelihood of the poacher being successful and incurring costs. They also rated the poacher and poached on several personality and mate characteristics. Results revealed that friendship increased the perceived likelihood of success of a mate poaching attempt and decreased the perceived likelihood of several risks typically associated with mate poaching. However, friend-poachers were rated less favorably than acquaintance-poachers across measures of warmth, nurturance, and friendliness. These findings are interpreted using an evolutionary perspective. This study complements and builds upon previous findings and is the first experimental investigation of tactics poachers may use to mitigate risks inherent in mate poaching.

  6. Yerba Mate

    Science.gov (United States)

    ... with this combination.Talk with your health provider.Birth control pills (Contraceptive drugs)The body breaks down the caffeine in yerba mate to get rid of it. Birth control pills can decrease how quickly the body breaks down ...

  7. Mating scars reveal mate size in immature female blue shark Prionace glauca.

    Science.gov (United States)

    Calich, H J; Campana, S E

    2015-06-01

    The objective of this study was to determine the size and maturity status of the male blue sharks Prionace glauca attempting to mate with small, immature females in the north-west Atlantic Ocean. The relationship between male curved fork length (LFC ) and jaw gape was used in conjunction with the diameter of the mating scar to estimate the LFC and infer the maturity status of the male shark that produced the mating scar. The results indicate that mature males with a mean ± s.d. LFC of 218 cm ± 23 cm were attempting to mate with sexually immature females. © 2015 The Fisheries Society of the British Isles.

  8. 猫蚤的交配习性及雄蚤对雌蚤提取物的反应%MATING BEHAVIOR OF THE CAT FLEA, CTENOCEPHALIDES FELIS BOUCHE ( SIPHONAPTERA: PULICIDAE) AND MALE RESPONSE TO FEMALE EXTRACT ON AN ARTIFICIAL FEEDING SYSTEM

    Institute of Scientific and Technical Information of China (English)

    岳碧松; 邹方东; 孙奇志; 李静

    2002-01-01

    The mating behavior of cat flea, Ctenocephalidesfelis (Bouche) was studied on an artificial feeding de-.vice. Male and female can mate repeatedly with same partner or different ones. In the situation of male: female ratio of1: 5, each mating lasted an average of 6.6 min, with a mean interval between matings at 2.5 min., compared to 11.1 min and 12.1 min respectively in a cell with 5 males and 1 female. As many as 48 mating events were observed forone male during.an 8 h period. One female mated 27 times in 7 h with 5 males in the same cell. Newly emerged malesand females can not mate before blood meal and about 24 h blood feeding is required for successful mating. Newlyemerged males can not mate with fed females (fed for 48 h), but fed males can mate with newly emerged females whoare feeding the blood. Significantly more male contacts and male-male mating attempts were observed after the papertreated with female extract was introduced into the cell. The paper contacts and mating attempts were 16.75 - 32.25times and 15.75 -31.38 times, respectively, on average during a period of 20 min when different doses (FE) of ex-tract were provided.%在人工饲喂系统上研究了猫蚤的交配习性及雄蚤对雌蚤化学提取物的发应.结果表明,当5雌1雄在饲养盒内时,该雄虫可与其他雌虫进行多次交配,连续8小时内交配达48次,交配时间平均持续6.6分钟,两次交配的间隔时间平均为2.5分钟.当1雌5雄时,交配时间平均持续11.1分钟,交配间隔时间为12.1分钟,连续7小时内,该雌虫与雄虫交配27次.新羽化的雌雄虫吸血前不能交配.当把用雌虫提取物处理过的黑色滤纸片放进只有雄虫的饲养盒时,雄虫接触纸片的次数及雄-雄交配企图明显增加.

  9. Chinese undergraduates' preferences for altruistic traits in mate selection and personal advertisement: Evidence from Q-sort technique.

    Science.gov (United States)

    Guo, Qingke; Feng, Linlin; Wang, Mingming

    2017-04-01

    Human's preferences for altruistic mates have been confirmed by many researchers. Under the deep influence of Confucianism that authorised more parental control over offspring's mate selection, Chinese people's mating strategies and mate preferences may be different from what the evolutionary psychologists have suggested. This study used the Q-sort technique to assess the roles of altruistic traits in mate selection and personal advertisement. A total of 200 university students participated in the Q-sort procedures and were asked to sort 50 traits (among which altruistic traits were mixed) according to their importance when choosing (or advertising to) a long-term (LT) or a short-term (ST) mate. Our findings were quite different from prior studies. When Chinese participants chose a mate or advertised themselves to a potential mate, kin altruism was considered to be the most important trait; altruistic traits were more preferred by males than by females and females tended to advertise themselves as more altruistic; preferences for altruistic traits showed no difference between LT and ST mate selections (or between personal advertisement to a LT and a ST mate).

  10. Mate choice on fallow deer leks.

    Science.gov (United States)

    Clutton-Brock, T H; Hiraiwa-Hasegawa, M; Robertson, A

    1989-08-10

    Leks, on which males defend small clustered mating territories, may have evolved because of the unusual opportunities they provide for female choice of mating partners, and several studies of lek-breeding animals have demonstrated correlations between the mating success of males and their phenotype or behaviour. However, these could arise because (1) females select mates on the basis of male phenotypic traits; (2) males interfere with each other's mating attempts; or (3) females show preferences for particular mating territories, and larger or stronger males are more likely to win access to these territories. Here we report that when fallow bucks on a traditional lek were experimentally induced to change their territories, differences in the mating success of bucks persisted, whereas differences in the position of their territories relative to the centre of the lek did not. The observation that bucks rarely interfered with their neighbours' harems and females moved freely between bucks suggests that females choose their mates on the basis of male phenotype rather than territory type or location. In this population, the immediate factor affecting the movements of females between males was the size of a buck's harem.

  11. Leaf gas exchange differences between males and females of yerba-mate Condutância estomática, fotossíntese, luz, temperatura, transpiração

    Directory of Open Access Journals (Sweden)

    Miroslava Rakocevic

    2010-06-01

    Full Text Available A preliminary study was developed on leaf gas exchange properties of males and females in yerbamate (Ilex paraguariensis St. Hil., planted in open growth conditions. The photosynthesic photon flux density (PPFD on leaf level, stomatal conductance (gs, net photosynthesis (A, transpiration (E, and leaf temperature (Tl was measured during the biennial production period: in the summer during the fruit ripening when there is a pause in its growth (January, February, spring  sprouting (November and autumn sprouting (March, Jun. The measurements have been taken in different tree crown positions (inside, exterior and tips. First indications of sex physiological  dimorphism in yerba-mate have been shown.  Conductance was superior on female plants, with exception on tips, whereas the A and E were superior on females, on the exterior of the third medium of the tree crown. Positive correlations among gas exchange properties and PPFD were established. The seasonality in gas exchange was observed. The maximum gas exchange values were registered in active sprouting whereas the minimum values were registered during fruit ripening, in full summer. A and E were positively correlated with gs for both males and females. The functional strategy of females, aiming to finish the reproductive process, is to proportionate the relative increase of A and E on self-shaded leaves, through the superior gs compared to males.
    Neste estudo preliminar foram determinadas as propriedades ecofisiológicas de plantas femininas e masculinas da erva-mate (Ilex paraguariensis St.Hil.  cultivadas no campo. Fluxo de fótons ativo na  fotossíntese (PPFD, condutância estomática (gs, fotossíntese liquida (A, transpiração (E e temperatura foliar (Tl foram avaliados em um ciclo bienal de  produção: no verão (janeiro e fevereiro durante o  período de maturação dos frutos quando ocorre pausa no crescimento; na primavera (novembro e no outono (março a junho durante

  12. Subsocial Cockroaches Nauphoeta cinerea Mate Indiscriminately with Kin Despite High Costs of Inbreeding

    Science.gov (United States)

    Bouchebti, Sofia; Durier, Virginie; Pasquaretta, Cristian; Rivault, Colette; Lihoreau, Mathieu

    2016-01-01

    Many animals have evolved strategies to reduce risks of inbreeding and its deleterious effects on the progeny. In social arthropods, such as the eusocial ants and bees, inbreeding avoidance is typically achieved by the dispersal of breeders from their native colony. However studies in presocial insects suggest that kin discrimination during mate choice may be a more common mechanism in socially simpler species with no reproductive division of labour. Here we examined this possibility in the subsocial cockroach Nauphoeta cinerea, a model species for research in sexual selection, where males establish dominance hierarchies to access females and control breeding territories. When given a binary choice between a sibling male and a non-sibling male that had the opportunity to establish a hierarchy prior to the tests, females mated preferentially with the dominant male, irrespective of kinship or body size. Despite the lack of kin discrimination during mate choice, inbred-mated females incurred significant fitness costs, producing 20% less offspring than outbred-mated females. We discuss how the social mating system of this territorial cockroach may naturally limit the probability of siblings to encounter and reproduce, without the need for evolving active inbreeding avoidance mechanisms, such as kin recognition. PMID:27655156

  13. Male sexual strategies modify ratings of female models with specific waist-to-hip ratios.

    Science.gov (United States)

    Brase, Gary L; Walker, Gary

    2004-06-01

    Female waist-to-hip ratio (WHR) has generally been an important general predictor of ratings of physical attractiveness and related characteristics. Individual differences in ratings do exist, however, and may be related to differences in the reproductive tactics of the male raters such as pursuit of short-term or long-term relationships and adjustments based on perceptions of one's own quality as a mate. Forty males, categorized according to sociosexual orientation and physical qualities (WHR, Body Mass Index, and self-rated desirability), rated female models on both attractiveness and likelihood they would approach them. Sociosexually restricted males were less likely to approach females rated as most attractive (with 0.68-0.72 WHR), as compared with unrestricted males. Males with lower scores in terms of physical qualities gave ratings indicating more favorable evaluations of female models with lower WHR. The results indicate that attractiveness and willingness to approach are overlapping but distinguishable constructs, both of which are influenced by variations in characteristics of the raters.

  14. A time-sequence functional analysis of mating behaviour and genital coupling in Drosophila: role of cryptic female choice and male sex-drive in the evolution of male genitalia.

    Science.gov (United States)

    Jagadeeshan, S; Singh, R S

    2006-07-01

    Male genitalia in Drosophila exemplify strikingly rapid and divergent evolution, whereas female genitalia are relatively invariable. Whereas precopulatory and post-copulatory sexual selection has been invoked to explain this trend, the functional significance of genital structures during copulation remains obscure. We used time-sequence analysis to study the functional significance of external genitalic structures during the course of copulation, between D. melanogaster and D. simulans. This functional analysis has provided new information that reveals the importance of male-driven copulatory mechanics and strategies in the rapid diversification of genitalia. The posterior process, which is a recently evolved sexual character and present only in males of the melanogaster clade, plays a crucial role in mounting as well as in genital coupling. Whereas there is ample evidence for precopulatory and/or post-copulatory female choice, we show here that during copulation there is little or no physical female choice, consequently, males determine copulation duration. We also found subtle differences in copulatory mechanics between very closely related species. We propose that variation in male usage of novel genitalic structures and shifts in copulatory behaviour have played an important role in the diversification of genitalia in species of the Drosophila subgroup.

  15. The energetic cost of mating in a promiscuous cephalopod.

    Science.gov (United States)

    Franklin, Amanda Michelle; Squires, Zoe Elizabeth; Stuart-Fox, Devi

    2012-10-23

    Costs that individuals incur through mating can play an important role in understanding the evolution of life histories and senescence, particularly in promiscuous species. Copulation costs, ranging from energy expenditure to reduced longevity, are widely studied in insects but have received substantially less attention in other taxa. One cost of mating, the energetic cost, is poorly studied across all taxa despite its potential importance for the many species where copulation is physically demanding and/or frequent. Here, we investigated the energetic cost of mating in both male and female dumpling squid (Euprymna tasmanica). In this species, copulation can last up to 3 h and requires that the male physically restrains the female. We report that the act of copulation halves the swimming endurance of both sexes, and that they take up to 30 min to recover. Such a reduction in post-copulatory performance may have important implications for predator avoidance, foraging ability and energy allocation. Therefore, quantifying this cost is essential to understand the evolution of reproductive strategies and behaviours such as female receptivity and male and female mating frequency.

  16. Genetic and environmental factors associated with laboratory rearing affect survival and assortative mating but not overall mating success in Anopheles gambiae sensu stricto.

    Science.gov (United States)

    Paton, Doug; Touré, Mahamoudou; Sacko, Adama; Coulibaly, Mamadou B; Traoré, Sékou F; Tripet, Frédéric

    2013-01-01

    Anopheles gambiae sensu stricto, the main vector of malaria in Africa, is characterized by its vast geographical range and complex population structure. Assortative mating amongst the reproductively isolated cryptic forms that co-occur in many areas poses unique challenges for programs aiming to decrease malaria incidence via the release of sterile or genetically-modified mosquitoes. Importantly, whether laboratory-rearing affects the ability of An. gambiae individuals of a given cryptic taxa to successfully mate with individuals of their own form in field conditions is still unknown and yet crucial for mosquito-releases. Here, the independent effects of genetic and environmental factors associated with laboratory rearing on male and female survival, mating success and assortative mating were evaluated in the Mopti form of An. gambiae over 2010 and 2011. In semi-field enclosures experiments and despite strong variation between years, the overall survival and mating success of male and female progeny from a laboratory strain was not found to be significantly lower than those of the progeny of field females from the same population. Adult progeny from field-caught females reared at the larval stage in the laboratory and from laboratory females reared outdoors exhibited a significant decrease in survival but not in mating success. Importantly, laboratory individuals reared as larvae indoors were unable to mate assortatively as adults, whilst field progeny reared either outdoors or in the laboratory, as well as laboratory progeny reared outdoors all mated significantly assortatively. These results highlight the importance of genetic and environment interactions for the development of An. gambiae's full mating behavioral repertoire and the challenges this creates for mosquito rearing and release-based control strategies.

  17. Impact of Managerial Power on Persuasive Strategy Selection by Female and Male Managers.

    Science.gov (United States)

    Hirokawa, Randy Y.; And Others

    1990-01-01

    Investigates the persuasive communication of male and female middle managers, focusing on the mediating influence of a manager's power on his or her selection of anticipated compliance-gaining message strategies. Finds no marked differences between the genders in the types of strategies and tactics used to influence subordinates. (KEH)

  18. Fertility assurance through extrapair fertilization, and male parental effort.

    Science.gov (United States)

    Fishman, Michael A; Stone, Lewi

    2002-07-01

    Extrapair paternity (EPP) has been observed in many formally monogamous species. Male pursuit of extrapair fertilizations (EPF) is explained by the advantages of having offspring that receive essential paternal care from other males. Because females are capable of exercising a degree of control over the post-copulatory sperm competition, EPP's persistence indicates that females benefit from EPF. Thus, EPP involves cooperation between mated females and extrapair males. On the other hand, mated males exhibit a spectrum of anti-cuckolding strategies. Hence, extrapair attributes of diverse species and populations reported in the literature are particular solutions of evolutionary games involving gender-specific cuckolding/anti-cuckolding strategies. Here we use game theoretical methods to study the effect of male paternal effort conserving strategies in situations where females seek EPF for reasons of genetic compatibility and/or in pursuit of genetic diversity for their offspring. Our results indicate that in these circumstances pursuit of EPF is the only evolutionary stable female strategy. Males, on the other hand, have two, mutually exclusive, evolutionary stable strategies: males that restrict parental care regardless of their mate's fidelity, and males that never restrict parental care. That is, when females seek EPF for reasons of fertility assurance and/or genetic diversity, the conditional male strategy--therein the male's parental efforts are based on his certainty of paternity--loses in competition with the unconditional strategies.

  19. Male reproductive system and spermatophores production and storage in Histioteuthis bonnellii (Cephalopoda: Histioteuthidae): A look into deep-sea squids' reproductive strategy

    Science.gov (United States)

    Cuccu, Danila; Mereu, Marco; Agus, Blondine; Cau, Angelo; Culurgioni, Jacopo; Sabatini, Andrea; Jereb, Patrizia

    2014-09-01

    Coleoid cephalopods go through a single breeding period in their life cycle, i.e., they are semelparous, although a great flexibility has been observed in their reproductive strategies, which range from simultaneous terminal spawning over a short period at the end of the animal's life to continuous spawning over a long period of the animal's life. So far, the information available on deep-sea species reproductive strategies is still poor and most of our knowledge about squid reproduction relates to females. In particular, not much is known on what strategy male squids have evolved to store sperm into spermatophores and adapt to semelparity. In this study an investigation of male reproductive strategy of the deep-sea umbrella squid Histioteuthis bonnellii (Férussac, 1835) is presented. The reproductive system was examined in 119 males caught in the Sardinian waters (Central Western Mediterranean) and is described for the first time. Results indicate that this species produces and stores spermatophores over a considerable period of time. The total number of spermatophores found in the reproductive system ranged between 12 and 3097 and the size of spermatophores stored by a single individual varied greatly, up to over 300%. Spermatophore length (SpL) gradually decreased towards the distal end of the reproductive system, so that spermatophores found in the proximal part of Needham's Sac were larger than those found in the terminal organ. Body size and SpL of spermatophores from the proximal part of Needham's Sac were positively correlated. Both indices of the sperm mass and of the ejaculatory apparatus decreased with the increase of SpL, while the cement body index increased, indicating that larger spermatophores contain less sperm and are equipped with larger cement bodies. Up to 64 spermatangia were found, exclusively in the terminal organ. The large size range of mature males (ML: 60.0-198.0 mm; TW: 113.50-2409.00 g) and the variation in spermatophore number and

  20. Direct costs and benefits of multiple mating: Are high female mating rates due to ejaculate replenishment?

    Science.gov (United States)

    Worthington, Amy M; Kelly, Clint D

    2016-03-01

    Females often mate more than is necessary to ensure reproductive success even when they incur significant costs from doing so. Direct benefits are hypothesized to be the driving force of high female mating rates, yet species in which females only receive an ejaculate from their mate still realize increased fitness from multiple mating. Using the Texas field cricket, Gryllus texensis, we experimentally test the hypothesis that multiple mating via monandry or polyandry increases female fitness by replenishing ejaculates, thereby allowing females to produce more offspring for a longer period of time. We found that higher rates of female mating significantly increased lifetime fecundity and oviposition independent of whether females mated with one or two males. Further, although interactions with males significantly increased rates of injury or death, females that replenished ejaculates experienced an increased rate and duration of oviposition, demonstrating that the immediate benefits of multiple mating may greatly outweigh the long-term costs that mating poses to female condition and survival. We suggest that ejaculate replenishment is a driving factor of high mating rates in females that do not receive external direct benefits from mating and that a comparative study across taxa will provide additional insight into the role that ejaculate size plays in the evolution of female mating rates.

  1. Formant tuning strategies in professional male opera singers.

    Science.gov (United States)

    Sundberg, Johan; Lã, Filipa M B; Gill, Brian P

    2013-05-01

    The term "formant tuning" is generally used for the case that one of the lowest formant frequencies coincides with the frequency of a source spectrum partial. Some authors claim that such coincidence is favorable and belongs to the goals of classical opera voice training, whereas other authors have found evidence for advising against it. This investigation analyzes the relationships between formant frequencies and partials in professional singers, who sang scales on the vowels /a/, /u/, /i/, and /ae/ in a pitch range including the passaggio, that is, the fundamental frequency range of approximately 300-400Hz, applying either of the two singing strategies that are typically used (1) in classical and (2) in nonclassical singing, respectively. Formant frequencies of each note in the scales were measured by inverse-filtering the acoustic signal. In the classical style, the first formant tended to be lower than in the nonclassical style. Neither the first nor the second formant tended to change systematically between scale tones, such that on some scale tones either or both formants was just below, just above, or right on a spectrum partial. In many cases, singers produced similar spectrum characteristics of the top tones of the scales with different first and second formant frequencies. Regardless of whether the first formant was slightly lower, slightly higher, or right on a partial, the properties of the voice source did not seem to be affected.

  2. A novel mating approach for genetic algorithms.

    Science.gov (United States)

    Galán, Severino F; Mengshoel, Ole J; Pinter, Rafael

    2013-01-01

    Genetic algorithms typically use crossover, which relies on mating a set of selected parents. As part of crossover, random mating is often carried out. A novel approach to parent mating is presented in this work. Our novel approach can be applied in combination with a traditional similarity-based criterion to measure distance between individuals or with a fitness-based criterion. We introduce a parameter called the mating index that allows different mating strategies to be developed within a uniform framework: an exploitative strategy called best-first, an explorative strategy called best-last, and an adaptive strategy called self-adaptive. Self-adaptive mating is defined in the context of the novel algorithm, and aims to achieve a balance between exploitation and exploration in a domain-independent manner. The present work formally defines the novel mating approach, analyzes its behavior, and conducts an extensive experimental study to quantitatively determine its benefits. In the domain of real function optimization, the experiments show that, as the degree of multimodality of the function at hand grows, increasing the mating index improves performance. In the case of the self-adaptive mating strategy, the experiments give strong results for several case studies.

  3. Mutual mate choice in a female-dominant and sexually monomorphic primate.

    Science.gov (United States)

    Gomez, Doris; Huchard, Elise; Henry, Pierre-Yves; Perret, Martine

    2012-03-01

    Sexual dimorphism is common in polygynous species, where intrasexual competition is often thought to drive the evolution of large male body size, and in turn, male behavioral dominance over females. In Madagascar, the entire lemur radiation, which embraces diverse mating systems, lacks sexual dimorphism and exhibits frequent female dominance over males. The evolution of such morphological and behavioral peculiarities, often referred to as "the lemur syndrome," has proven difficult to understand. Among other hypotheses, a potential role of intersexual selection has been repeatedly proposed but hardly ever tested. Here, we investigate whether female choice favors small and compliant males, and whether male choice favors large females in captive gray mouse lemurs (Microcebus murinus). Detailed analysis of a combination of behavioral observations and hormonal data available for both sexes shows that (1) females accept more matings from males with higher fighting abilities, (2) males adjust their investment in intrasexual competition to female fertility, and (3) both male and female strategies are weakly influenced by the body mass of potential partners, in directions contradicting our predictions. These results do not suggest a prominent role of intersexual selection in the evolution and maintenance of the lemur syndrome but rather point to alternative mechanisms relating to male-male competition, specifically highlighting an absence of relationship between male body mass and fighting ability. Finally, our findings add to the growing body of evidence suggesting flexible sex roles, by showing the expression of mutual mate choice in a female-dominant, sexually monomorphic and promiscuous primate.

  4. Female mate choice across mating stages and between sequential mates in flour beetles.

    Science.gov (United States)

    Fedina, T Y; Lewis, S M

    2007-11-01

    Few studies have examined how female premating choice correlates with the outcome of copulatory and post-copulatory processes. It has been shown that polyandrous Tribolium castaneum females discriminate among males before mating based on olfactory cues, and also exert cryptic choice during mating through several mechanisms. This study tested whether a male's relative attractiveness predicted his insemination success during copulation. Bioassays with male olfactory cues were used to rank two males as more and less attractive to females; each female was then mated to either her more attractive male followed by less attractive male, or vice versa. Dissections immediately after second copulations revealed a significantly higher percent of successful inseminations for females that remated with more attractive males compared with those that remated with less attractive males. These results indicate that cryptic female choice during copulation reinforces precopulatory female choice in T. castaneum, and suggest that females could use cryptic choice to trade up to more attractive males, possibly gaining better phenotypic or genetic quality of sires.

  5. Sneaker Males Affect Fighter Male Body Size and Sexual Size Dimorphism in Salmon.

    Science.gov (United States)

    Weir, Laura K; Kindsvater, Holly K; Young, Kyle A; Reynolds, John D

    2016-08-01

    Large male body size is typically favored by directional sexual selection through competition for mates. However, alternative male life-history phenotypes, such as "sneakers," should decrease the strength of sexual selection acting on body size of large "fighter" males. We tested this prediction with salmon species; in southern populations, where sneakers are common, fighter males should be smaller than in northern populations, where sneakers are rare, leading to geographical clines in sexual size dimorphism (SSD). Consistent with our prediction, fighter male body size and SSD (fighter male∶female size) increase with latitude in species with sneaker males (Atlantic salmon Salmo salar and masu salmon Oncorhynchus masou) but not in species without sneakers (chum salmon Oncorhynchus keta and pink salmon Oncorhynchus gorbuscha). This is the first evidence that sneaker males affect SSD across populations and species, and it suggests that alternative male mating strategies may shape the evolution of body size.

  6. Indirect mate choice, direct mate choice and species recognition in a bower-building cichlid fish lek.

    Science.gov (United States)

    Genner, M J; Young, K A; Haesler, M P; Joyce, D A

    2008-09-01

    Sexual selection arising through female mate choice typically favours males with larger, brighter and louder signals. A critical challenge in sexual selection research is to determine the degree to which this pattern results from direct mate choice, where females select individual males based on variation in signalling traits, or indirect mate choice, where male competition governs access to reproductively active females. We investigated female mate choice in a lekking Lake Malawi cichlid fish, Hemitilapia oxyrhynchus, in which males build and aggressively defend sand 'bowers'. Similar to previous studies, we found that male reproductive success was positively associated with bower height and centrality on the lek. However, this pattern resulted from males holding these territories encountering more females, and thus their greater success was due to indirect mate choice. Following initial male courtship, an increase in the relative mating success of some males was observed, but this relative increase was unrelated to bower size or position. Crucially, experimentally manipulating bowers to resemble those of a co-occurring species had no appreciable effect on direct choice by females or male spawning success. Together, these results suggest indirect mate choice is the dominant force determining male-mating success in this species, and that bowers are not signals used in direct mate choice by females. We propose that, in this species, bowers have a primary function in intraspecific male competition, with the most competitive males maintaining larger and more central bowers that are favoured by sexual selection due to higher female encounter rates.

  7. Choosy but not chaste: multiple mating in human females.

    Science.gov (United States)

    Scelza, Brooke A

    2013-01-01

    When Charles Darwin set out to relate his theory of evolution by natural selection to humans he discovered that a complementary explanation was needed to properly understand the great variation seen in human behavior. The resulting work, The Descent of Man and Selection in Relation to Sex, laid out the defining principles and evidence of sexual selection. In brief, this work is best known for illuminating the typically male strategy of intrasexual competition and the typically female response of intersexual choice. While these sexual stereotypes were first laid out by Darwin, they grew in importance when, years later, A. J. Bateman, in a careful study of Drosophila mating strategies, noted that multiple mating appeared to provide great benefit to male reproductive success, but to have no such effect on females. As a result, female choice soon became synonymous with being coy, and only males were thought to gain from promiscuous behavior. However, the last thirty years of research have served to question much of the traditional wisdom about sex differences proposed by Darwin and Bateman, illuminating the many ways that women (and females more generally) can and do engage in multiple mating.

  8. Influence of Microsporidium on Female Silkworm Moth after Mating of the Female and Male Silkworm Moth%家蚕微孢子虫感染雄蛾交配对雌蛾的影响

    Institute of Scientific and Technical Information of China (English)

    陈世良; 高建华; 杨荣贵; 高翔; 张金祥; 朱峰

    2015-01-01

    微孢子虫是母蛾检疫的唯一对象,为探明家蚕微孢子虫感染雄蛾交配对雌蛾的影响,了解其对蚕种生产的危害性,用患微粒子病的家蚕雄蛾与未患病雌蛾(各50只)进行交配试验,并统计分析交配后的感染率。结果表明:患有家蚕微孢子虫的雄蛾,能通过雌雄蛾交配把微孢子虫传给雌蛾,雌蛾微孢子虫检出率为66%,其交配传染率达78.57%,增加了各级蚕种因母蛾检测有微孢子虫而淘汰的风险系数。因此,蚕种生产过程中防微病工作很重要,必须贯彻预防为主、综合防治的方针,切断幼虫期食下感染的途径,减少因雄蛾感病通过交配而传给雌蛾的概率,减少蚕种损失。%Micropsoridia is the only target on the quarantine of female silkworm moth.In order to clarify the influence of microsporidium on the female silkworm moth after mating of the female and male silkworm,and understand the harmfulness of silkworm egg production.The authors conducted mating test of infected male silkworm moth and uninfected female silkworm moth.And the infection rate was analyzed after mating.The result indicated that the microsporidian spores,N .bombycis,can be transmitted from infected male silkworm moth to uninfected female silkworm moth by mating.The detection rate and mating infection rate reached 66% and 78.57% respectively,and increased the elimination rate of silkworm eggs because of the Pebrine mother moth.So,the work of prevention to pebrine is very important in the process of the silkworm eggs production.The principle of prevention first,comprehensive control must be executed.In order to cut off the way of food transmission of infection,reduce the infective probability of female silkworm moth which was infected by mating with the infected male silkworm moth,and reduce the loss of silkworm eggs.

  9. Mating behavior and sexual selection in a polygamous beetle

    Directory of Open Access Journals (Sweden)

    Wen LU, Qiao WANG, Mingyi TIAN, Jin XU, Jian LV, Aizhi QIN

    2013-04-01

    Full Text Available Mating behavior and sexual selection in relation to morphometric traits in a polygamous beetle, Glenea cantor (F. (Coleoptera: Cerambycidae, were investigated. Upon encounter, a male approached a female, mounted her, grasped her terminal abdomen with his hind tarsi, and attempted to mate. Successful mating lasted about 3.5 h. Although all traits measured in females and half of traits in males were significantly correlated with mating success, the primary selection on virgin females was the genital trait, the bursa copulatrix length, and that on males was the body length and hind tarsal length. Longer bursa copulatrix accommodated a larger ejaculate, suggesting that this female trait benefits the male that first mates with the female in terms of increasing ejaculate size to beat subsequent males in sperm competition. Under a female-biased sex ratio, more than 20% of matings failed within 20s after the male genitalia had been inserted into hers, suggesting that males assess genital features of the female before insemination and undertake cryptic male mate choice. Larger males were more capable of grasping females and achieving mating. During the premating struggle the male almost always used his hind tarsi to lift the female terminal abdomen to the position for his genitalia to insert, and as a result, males with longer hind tarsi achieved higher mating success [Current Zoology 59 (2 : 257-264, 2013]. 

  10. Mating behavior and sexual selection in a polygamous beetle

    Institute of Scientific and Technical Information of China (English)

    Wen LU; Qiao WANG; Mingyi TIAN; Jin XU; Jian LV; Aizhi QIN

    2013-01-01

    Mating behavior and sexual selection in relation to morphometric traits in a polygamous beetle,Glenea cantor (F.)(Coleoptera:Cerambycidae),were investigated.Upon encounter,a male approached a female,mounted her,grasped her terminal abdomen with his hind tarsi,and attempted to mate.Successful mating lasted about 3.5 h.Although all traits measured in females and half of traits in males were significantly correlated with mating success,the primary selection on virgin females was the genital trait,the bursa copulatrix length,and that on males was the body length and hind tarsal length.Longer bursa copulatrix accommodated a larger ejaculate,suggesting that this female trait benefits the male that first mates with the female in terms of increasing ejaculate size to beat subsequent males in sperm competition.Under a female-biased sex ratio,more than 20% of matings failed within 20s after the male genitalia had been inserted into hers,suggesting that males assess genital features of the female before insemination and undertake cryptic male mate choice.Larger males were more capable of grasping females and achieving mating.During the premating struggle the male almost always used his hind tarsi to lift the female terminal abdomen to the position for his genitalia to insert,and as a result,males with longer hind tarsi achieved higher mating success.

  11. Grooming reciprocity in male Tibetan macaques.

    Science.gov (United States)

    Xia, Dong-Po; Li, Jin-Hua; Garber, Paul A; Matheson, Megan D; Sun, Bing-Hua; Zhu, Yong

    2013-10-01

    In several primate species, adult males are reported to compete for access to reproductive partners as well as forming affiliative and cohesive social bonds based on the exchange of goods or services. We hypothesized that among a broad set of fitness-maximizing strategies, grooming can be used by individual adult males to enhance social relationships through reciprocity and/or through the interchange of grooming for a different but equivalent good or service. We used focal animal sampling and continuously recorded dyadic grooming and agonistic interactions to test a series of predictions regarding male social interactions in a free-ranging group of Tibetan macaques (Macaca thibetana) at Huangshan, China. During the non-mating season or between males of similar rank throughout the year, grooming effort given was matched by grooming effort received. However, lower ranking males groomed higher ranking males at a greater rate and/or for a longer duration during both the mating and non-mating periods. We found that higher ranking males directed less aggression towards males with whom they formed a frequent grooming partnership, indicating that grooming received was interchanged for increased social tolerance. These data suggest that individual male Tibetan macaques employ alternative social strategies associated with grooming reciprocity or interchange depending on dominance rank and rates of aggression, and highlight the importance of both biological markets and grooming reciprocity as behavioral mechanisms used by resident adult males to form and maintain affiliative social bonds.

  12. Male sexual behavior and pheromone emission is enhanced by exposure to guava fruit volatiles in Anastrepha fraterculus

    Science.gov (United States)

    Host plant chemicals can influence sex pheromone communication of tephritid fruit flies, and affect strategies optimizing mating and reproduction. Previous studies suggest that females of the South American fruit fly, Anastrepha fraterculus, prefer to mate with laboratory males previously exposed to...

  13. Interacciones macho-hembra del pulpo rojo patagónico Enteroctopus megalocyathus (Cephalopoda: Octopodidae durante el comportamiento de apareamiento Male-female interactions of Patagonian red octopus Enteroctopus megalocyathus (Cephalopoda: Octopodidae during mating behavior

    Directory of Open Access Journals (Sweden)

    Ranferi Gutiérrez

    2012-09-01

    Full Text Available Se evalúa, en condiciones de laboratorio, el comportamiento de apareamiento de ocho parejas de Enteroctopus megalocyathus mediante videograbaciones durante 24 h. El comportamiento precopulatorio (CP se caracterizó por presentar tres eventos (natación, exhibición y contacto y el comportamiento copulatorio (CC se caracterizó por mostrar un solo evento (cópula. Del tiempo total de interacción de las parejas, el 34,4% correspondió al CP y el 65,6% correspondió al CC. Entre los tiempos de machos y hembras no hubo diferencias significativas por evento. Al compararse todos los eventos entre sí en relación al tiempo de duración, se presentó el siguiente orden: cópula > contacto > exhibición > natación. Se observó una tendencia a periodos de apareamiento más largos donde el peso de la hembra fue superior al macho, sugiriendo que el peso de la hembra es un factor determinante en la duración de los encuentros de apareamiento.The mating behavior of eight couples of Enteroctopus megalocyathus was evaluated under laboratory conditions by videotaping for 24 h. The precopulatory behavior (CP was characterized by three patterns (swimming, exhibition and contact and copulatory behavior (CC was characterized by display of a single pattern (copulation. Of the total interaction time between octopuses, 34.4% corresponds to CP and 65.6% corresponds to CC. Between times of males and females were not significantly different by pattern. In all events, compared to each other for the duration, presented the following order: copulation > contact > exhibition > swimming. There was a trend towards longer periods of mating where the female weight was higher than the male, suggesting that female weight is a determining factor in the duration of mating encounters.

  14. Urban women's negotiation strategies for safer sex with their male partners.

    Science.gov (United States)

    Williams, S P; Gardos, P S; Ortiz-Torres, B; Tross, S; Ehrhardt, A A

    2001-01-01

    Heterosexual transmission of HIV is growing at an increasing rate. One primary prevention strategy is to consistently use condoms. With the exception of female condoms, women do not "wear" condoms and therefore must negotiate condom use with their male partners. This present study examines the strategies women believe they would use in a safer sex negotiation with a male partner including (1) initiating negotiations, (2) resolving conflict, and (3) maintaining the intention to practice safer sex. The findings highlight the importance of understanding women's patterns of negotiation as well as their repertoire of negotiation skills prior to their exposure to behavioral interventions and prevention programs.

  15. The dilemma of female mate selection in the brown bear, a species with sexually selected infanticide.

    Science.gov (United States)

    Bellemain, Eva; Zedrosser, Andreas; Manel, Stéphanie; Waits, Lisette P; Taberlet, Pierre; Swenson, Jon E

    2006-02-07

    Because of differential investment in gametes between sexes, females tend to be the more selective sex. Based on this concept, we investigate mate selection in a large carnivore: the brown bear (Ursus arctos). We hypothesize that, in this species with sexually selected infanticide (SSI), females may be faced with a dilemma: either select a high-quality partner based on phenotypic criteria, as suggested by theories of mate choice, or rather mate with future potentially infanticidal males as a counter-strategy to SSI. We evaluated which male characteristics were important in paternity assignment. Among males available in the vicinity of the females, the largest, most heterozygous and less inbred and also the geographically closest males were more often the fathers of the female's next litter. We suggest that female brown bears may select the closest males as a counter-strategy to infanticide and exercise a post-copulatory cryptic choice, based on physical attributes, such as a large body size, reflecting male genetic quality. However, male-male competition either in the form of fighting before copulation or during the post-copulatory phase, in the form of sperm competition, cannot entirely be ruled out.

  16. Flexible mate choice when mates are rare and time is short.

    Science.gov (United States)

    Tinghitella, Robin M; Weigel, Emily G; Head, Megan; Boughman, Janette W

    2013-09-01

    Female mate choice is much more dynamic than we once thought. Mating decisions depend on both intrinsic and extrinsic factors, and these two may interact with one another. In this study, we investigate how responses to the social mating environment (extrinsic) change as individuals age (intrinsic). We first conducted a field survey to examine the extent of natural variation in mate availability in a population of threespine sticklebacks. We then manipulated the sex ratio in the laboratory to determine the impact of variation in mate availability on sexual signaling, competition, and mating decisions that are made throughout life. Field surveys revealed within season heterogeneity in mate availability across breeding sites, providing evidence for the variation necessary for the evolution of plastic preferences. In our laboratory study, males from both female-biased and male-biased treatments invested most in sexual signaling late in life, although they competed most early in life. Females became more responsive to courtship over time, and those experiencing female-biased, but not male-biased sex ratios, relaxed their mating decisions late in life. Our results suggest that social experience and age interact to affect sexual signaling and female mating decisions. Flexible behavior could mediate the potentially negative effects of environmental change on population viability, allowing reproductive success even when preferred mates are rare.

  17. Mating first, mating more: biological market fluctuation in a wild prosimian.

    Directory of Open Access Journals (Sweden)

    Ivan Norscia

    Full Text Available In biology, economics, and politics, distributive power is the key for understanding asymmetrical relationships and it can be obtained by force (dominance or trading (leverage. Whenever males cannot use force, they largely depend on females for breeding opportunities and the balance of power tilts in favour of females. Thus, males are expected not only to compete within their sex-class but also to exchange services with the opposite sex. Does this mating market, described for humans and apes, apply also to prosimians, the most ancestral primate group? To answer the question, we studied a scent-oriented and gregarious lemur, Propithecus verreauxi (sifaka, showing female dominance, promiscuous mating, and seasonal breeding. We collected 57 copulations involving 8 males and 4 females in the wild (Berenty Reserve, South Madagascar, and data (all occurrences on grooming, aggressions, and marking behaviour. We performed the analyses via exact Spearman and matrix correlations. Male mating priority rank correlated with the frequency of male countermarking over female scents but not with the proportion of fights won by males over females. Thus, males competed in an olfactory tournament more than in an arena of aggressive encounters. The copulation frequency correlated neither with the proportion of fights won by males nor with the frequency of male countermarking on female scents. Male-to-female grooming correlated with female-to-male grooming only during premating. Instead, in the mating period male-to-female grooming correlated with the copulation frequency. In short, the biological market underwent seasonal fluctuations, since males bargained grooming for sex in the mating days and grooming for itself in the premating period. Top scent-releasers gained mating priority (they mated first and top groomers ensured a higher number of renewed copulations (they mated more. In conclusion, males maximize their reproduction probability by adopting a double

  18. Mating first, mating more: biological market fluctuation in a wild prosimian.

    Science.gov (United States)

    Norscia, Ivan; Antonacci, Daniela; Palagi, Elisabetta

    2009-01-01

    In biology, economics, and politics, distributive power is the key for understanding asymmetrical relationships and it can be obtained by force (dominance) or trading (leverage). Whenever males cannot use force, they largely depend on females for breeding opportunities and the balance of power tilts in favour of females. Thus, males are expected not only to compete within their sex-class but also to exchange services with the opposite sex. Does this mating market, described for humans and apes, apply also to prosimians, the most ancestral primate group? To answer the question, we studied a scent-oriented and gregarious lemur, Propithecus verreauxi (sifaka), showing female dominance, promiscuous mating, and seasonal breeding. We collected 57 copulations involving 8 males and 4 females in the wild (Berenty Reserve, South Madagascar), and data (all occurrences) on grooming, aggressions, and marking behaviour. We performed the analyses via exact Spearman and matrix correlations. Male mating priority rank correlated with the frequency of male countermarking over female scents but not with the proportion of fights won by males over females. Thus, males competed in an olfactory tournament more than in an arena of aggressive encounters. The copulation frequency correlated neither with the proportion of fights won by males nor with the frequency of male countermarking on female scents. Male-to-female grooming correlated with female-to-male grooming only during premating. Instead, in the mating period male-to-female grooming correlated with the copulation frequency. In short, the biological market underwent seasonal fluctuations, since males bargained grooming for sex in the mating days and grooming for itself in the premating period. Top scent-releasers gained mating priority (they mated first) and top groomers ensured a higher number of renewed copulations (they mated more). In conclusion, males maximize their reproduction probability by adopting a double tactic and by

  19. Variation in human mate choice: simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating.

    Science.gov (United States)

    Zietsch, Brendan P; Verweij, Karin J H; Heath, Andrew C; Martin, Nicholas G

    2011-05-01

    Human mate choice is central to individuals' lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we looked at a large community-based sample of twins and their partners and parents ([Formula: see text] individuals) to test for genetic and family environmental influences on mate choice, while controlling for and not controlling for the effects of assortative mating. Key traits were analyzed, including height, body mass index, age, education, income, personality, social attitudes, and religiosity. This revealed near-zero genetic influences on male and female mate choice over all traits and no significant genetic influences on mate choice for any specific trait. A significant family environmental influence was found for the age and income of females' mate choices, possibly reflecting parental influence over mating decisions. We also tested for evidence of sexual imprinting, where individuals acquire mate-choice criteria during development by using their opposite-sex parent as the template of a desirable mate; there was no such effect for any trait. The main discernible pattern of mate choice was assortative mating; we found that partner similarity was due to initial choice rather than convergence and also at least in part to phenotypic matching.

  20. Does predation risk affect mating behavior? An experimental test in dumpling squid (Euprymna tasmanica.

    Directory of Open Access Journals (Sweden)

    Amanda M Franklin

    Full Text Available INTRODUCTION: One of the most important trade-offs for many animals is that between survival and reproduction. This is particularly apparent when mating increases the risk of predation, either by increasing conspicuousness, reducing mobility or inhibiting an individual's ability to detect predators. Individuals may mitigate the risk of predation by altering their reproductive behavior (e.g. increasing anti-predator responses to reduce conspicuousness. The degree to which individuals modulate their reproductive behavior in relation to predation risk is difficult to predict because both the optimal investment in current and future reproduction (due to life-history strategies and level of predation risk may differ between the sexes and among species. Here, we investigate the effect of increased predation risk on the reproductive behavior of dumpling squid (Euprymna tasmanica. RESULTS: Females, but not males, showed a substantial increase in the number of inks (an anti-predator behavior before mating commenced in the presence of a predator (sand flathead Platycephalus bassensis. However, predation risk did not affect copulation duration, the likelihood of mating, female anti-predator behavior during or after mating or male anti-predator behavior at any time. CONCLUSIONS: Inking is a common anti-predator defense in cephalopods, thought to act like a smokescreen, decoy or distraction. Female dumpling squid are probably using this form of defense in response to the increase in predation risk prior to mating. Conversely, males were undeterred by the increase in predation risk. A lack of change in these variables may occur if the benefit of completing mating outweighs the risk of predation. Prioritizing current reproduction, even under predation risk, can occur when the chance of future reproduction is low, there is substantial energetic investment into mating, or the potential fitness payoffs of mating are high.

  1. Forced monogamy in a multiply mating species does not impede colonisation success.

    Science.gov (United States)

    Deacon, Amy E; Barbosa, Miguel; Magurran, Anne E

    2014-06-12

    The guppy (Poecilia reticulata) is a successful invasive species. It is also a species that mates multiply; previous studies have demonstrated that this strategy carries fitness benefits. Guppies are routinely introduced to tanks and troughs in regions outside their native range for mosquito-control purposes, and often spread beyond these initial confines into natural water bodies with negative ecological consequences. Here, using a mesocosm set up that resembles the containers into which single guppies are typically introduced for mosquito control, we ask whether singly-mated females are at a disadvantage, relative to multiply-mated females, when it comes to founding a population. Treatments were monitored for one year. A key finding was that mating history did not predict establishment success, which was 88% in both treatments. Furthermore, analysis of behavioural traits revealed that the descendants of singly-mated females retained antipredator behaviours, and that adult males showed no decrease in courtship vigour. Also, we detected no differences in behavioural variability between treatments. These results suggest that even when denied the option of multiple mating, singly-mated female guppies can produce viable populations, at least at the founder stage. This may prove to be a critical advantage in typical introduction scenarios where few individuals are released into enclosed water bodies before finding their way into natural ecosystems.

  2. Attraction of spathius agrili yang (Hymenoptera: eulophidae) to male-produced "aggregation-sex pheromone:" differences between the sexes and mating status

    Science.gov (United States)

    Male and female Spathius agrili Yang were tested for attraction to the synthetic male pheromone. Lures consisting of a 3-component pheromone blend were placed in the center of a white filter paper target used to activate upwind flight in the wind tunnel. When virgin males and females were tested for...

  3. Mate choice turns cognitive.

    Science.gov (United States)

    Miller, G F; Todd, P M

    1998-05-01

    Evolutionary psychology has revolutionized research on human mate choice and sexual attraction in recent years, combining a rigorous Darwinian framework based on sexual selection theory with a loosely cognitivist orientation to task analysis and mechanism modelling. This hard Darwinian, soft computational approach has been most successful at revealing the adaptive logic behind physical beauty, demonstrating that many sexual cues computed from face and body shape are not arbitrary, but function as reliable indicators of phenotypic and genetic quality. The same approach could be extended from physical to psychological cues if evolutionary psychology built stronger ties with personality psychology, psychometrics and behavioral genetics. A major challenge for mate choice research is to develop more explicit computational models at three levels, specifying: (1) the perceptual adaptations that register sexual cues given sensory input, (2) the judgment adaptations that integrate multiple cues into assessments of overall attractiveness, and (3) the search strategies that people follow in trying to form mutually attracted pairs. We describe both recent efforts and possible extensions in these directions. The resulting confluence between evolutionary principles, cognitive models and game-theoretic insights can put mate choice research at the vanguard of an emerging `evolutionary cognitive science' more concerned with domain-specific mental adaptations than with domain-general intelligence.

  4. Mate sampling and choosiness in the sand goby.

    Science.gov (United States)

    Lindström, Kai; Lehtonen, Topi K

    2013-08-22

    To date, mate choice studies have mostly focused on establishing which mates are chosen or how the choices are performed. Here, we combined these two approaches by empirically testing how latency to mate is affected by various search costs, variation in mate quality and female quality in the sand goby (Pomatoschistus minutus). Our results show that females adjust their mating behaviour according to the costs and benefits of the choice situation. Specifically, they mated sooner when access to males was delayed and when the presence of other females presented a mate sampling cost. We also found a positive link between size variation among potential mating partners and spawning delay in some (but not all) experimental conditions. By contrast, we did not find the number of available males or the females' own body size ('quality') to affect mating latency. Finally, female mating behaviour varied significantly between years. These findings are notable for demonstrating that (i) mate sampling time is particularly sensitive to costs and, to a lesser degree, to variation among mate candidates, (ii) females' mating behaviour is sensitive to qualitative rather than to quantitative variation in their environment, and (iii) a snapshot view may describe mate sampling behaviour unreliably.

  5. Sperm competition, alternative mating tactics and context-dependent fertilization success in the burying beetle, Nicrophorus vespilloides.

    Science.gov (United States)

    House, Clarissa M; Hunt, John; Moore, Allen J

    2007-05-22

    Fertilization success in sperm competition is often determined by laboratory estimates of the proportion of offspring sired by the first (P1) or second (P2) male that mates. However, inferences from such data about how sexual selection acts on male traits in nature may be misleading if fertilization success depends on the biological context in which it is measured. We used the sterile male technique to examine the paternity of the same male in two mating contexts in the burying beetle, Nicrophorus vespilloides, a species where males have alternative mating strategies based on the presence or absence of resources. We found no congruence in the paternity achieved by a given male when mating under different social conditions. P2 estimates were extremely variable under both conditions. Body size was unrelated to success in sperm competition away from a carcass but, most probably through pre-copulatory male-male competition, influenced fertilization success on a carcass. The contribution of sperm competition is therefore dependent on the conditions under which it is measured. We discuss our findings in relation to sperm competition theory and highlight the need to consider biological context in order to link copulation and fertilization success for competing males.

  6. Infanticide by male house sparrows: gaining time or manipulating females?

    Science.gov (United States)

    Veiga, José P

    2003-08-07

    The killing of genetically unrelated young by males has been viewed as a strategy that forces victimized females to advance the onset of their next fertile period, thus infanticidal males gain a time advantage that may be crucial to maximize reproductive success. Among females that may raise several broods in a year, a failure occurring relatively earlier in the time-course of the previous breeding attempt may result in an increased investment in the next breeding attempt. This female strategy may be exploited by males in their own interest, and may strongly select for male infanticidal behaviour. I demonstrate that, in the house sparrow, females mated with infanticidal males re-laid earlier, initiated more breeding attempts and fledged more offspring than females mated with non-infanticidal males. These results suggest that both the time saving and the manipulation of female investment are independent mechanisms conferring advantages that may have selected for male infanticide in the studied population.

  7. First report of satellite males during breeding in Leptodactylus latrans (Amphibia, Anura

    Directory of Open Access Journals (Sweden)

    Gabriel Laufer

    2014-05-01

    Full Text Available The occurrence of satellite males is a common behaviour across anuran taxa. Satellite males take peripheral positions to calling males and adopt tactics in an attempt to intercept females that are attracted to calling males to increase their own mating success. Satellite males could have an inexpensive form of mate-locating, avoiding predators, and saving energy. Furthermore, this strategy could play an important role in the genetic structure of populations. The genus Leptodactylus consists of approximately 70 described species that are widely distributed in South America. The literature on the biology of this genus is extensive; however, we found only two reports on the existence of multi-male mating behavior in the genus (L. chaquensis and L. podicipinus. Herein, we report intrasexual competition in the form of satellite behavior in Leptodactylus latrans, where multiple satellite males were observed in close vicinity to a calling male.

  8. A molecular genetic examination of the mating system of pumpkinseed sunfish reveals high pay-offs for specialized sneakers.

    Science.gov (United States)

    Rios-Cardenas, Oscar; Webster, Michael S

    2008-05-01

    Intrasexual variation in reproductive behaviour and morphology are common in nature. Often, such variation appears to result from conditional strategies in which some individuals (e.g. younger males or those in poor condition) adopt a low pay-off phenotype as a 'best of a bad job'. Alternatively, reproductive polymorphisms can be maintained by balancing selection, with male phenotypes having equal fitnesses at equilibrium, but examples from nature are rare. Many species of sunfish (genus Lepomis) are thought to have alternative male reproductive behaviours, but most empirical work has focused on the bluegill sunfish and the mating systems of other sunfish remain poorly understood. We studied a population of pumpkinseed sunfish (Lepomis gibbosus) in upstate New York. Field observations confirm the existence of two male reproductive strategies: 'parentals' were relatively old and large males that maintained nests, and 'sneakers' were relatively young and small males that fertilize eggs by darting into nests of parentals during spawning. The sneaker and parental male strategies appear to be distinct life-history trajectories. Sneaker males represented 39% of the males observed spawning, and sneakers intruded on 43% of all mating attempts. Microsatellite analyses revealed that sneaker males fertilized an average of 15% of the eggs within a nest. This level of paternity by sneaker males appears to be higher than seen in most other fishes, and preliminary analyses suggest that the two male reproductive strategies are maintained as a balanced polymorphism.

  9. Ant parasite queens revert to mating singly

    DEFF Research Database (Denmark)

    Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe

    2004-01-01

    A parasitic ant has abandoned the multiple mating habit of the queens of its related host. Multiple mating (polyandry) is widespread among animal groups, particularly insects 1 . But the factors that maintain it and underlie its evolution are hard to verify because benefits and costs are not easily...... quantified and they tend to be similar in related species. Here we compare the mating strategies of the leaf-cutting ant Acromyrmex echinatior and its recently derived social parasite Acromyrmex insinuator, which is also its closest relative 2 (see Fig. 1 ). We find that although the host queens mate with up...

  10. Blackmailing: the keystone in the human mating system

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    Watve Milind G

    2011-11-01

    Full Text Available Abstract Background The human mating system is characterized by bi-parental care and faithful monogamy is highly valued in most cultures. Marriage has evolved as a social institution and punishment for extra pair mating (EPM or adultery is common. However, similar to other species with bi-parental care, both males and females frequently indulge in EPM in secrecy since it confers certain gender specific genetic benefits. Stability of faithful monogamy is therefore a conundrum. We model human mating system using game theory framework to study the effects of factors that can stabilize or destabilize faithful committed monogamy. Results Although mate guarding can partly protect the genetic interests, we show that it does not ensure monogamy. Social policing enabled by gossiping is another line of defense against adultery unique to humans. However, social policing has a small but positive cost to an individual and therefore is prone to free riding. We suggest that since exposure of adultery can invite severe punishment, the policing individuals can blackmail opportunistically whenever the circumstances permit. If the maximum probabilistic benefit of blackmailing is greater than the cost of policing, policing becomes a non-altruistic act and stabilizes in the society. We show that this dynamics leads to the coexistence of different strategies in oscillations, with obligate monogamy maintained at a high level. Deletion of blackmailing benefit from the model leads to the complete disappearance of obligate monogamy. Conclusions Obligate monogamy can be maintained in the population in spite of the advantages of EPM. Blackmailing, which makes policing a non-altruistic act, is crucial for the maintenance of faithful monogamy. Although biparental care, EPM, mate guarding and punishment are shared by many species, gossiping and blackmailing make the human mating system unique.

  11. Interspecific Cross-Mating Between Aedes aegypti and Aedes albopictus Laboratory Strains: Implication of Population Density on Mating Behaviors.

    Science.gov (United States)

    Marcela, P; Hassan, A Abu; Hamdan, A; Dieng, H; Kumara, T K

    2015-12-01

    Mating behavior between Aedes aegypti and Ae. albopictus, established colony strains were examined under laboratory conditions (30-cm(3) screened cages) for 5 consecutive days. The effect of selected male densities (30, 20, 10) and female density (20) on the number of swarming, mating pairs, eggs produced, and inseminated females were evaluated. Male densities significantly increased swarming behavior, mating pairs, and egg production of heterospecific females, but female insemination was reduced. Aedes aegypti males mate more readily with heterospecific females than do Ae. albopictus males. The current study suggests that Ae. aegypti males were not species-specific in mating, and if released into the field as practiced in genetically modified mosquito techniques, they may mate with both Ae. aegypti and Ae. albopictus females, hence reducing populations of both species by producing infertile eggs.

  12. Lifetime number of mates interacts with female age to determine reproductive success in female guppies.

    Directory of Open Access Journals (Sweden)

    Jonathan P Evans

    Full Text Available In many species, mating with multiple males confers benefits to females, but these benefits may be offset by the direct and indirect costs associated with elevated mating frequency. Although mating frequency (number of mating events is often positively associated with the degree of multiple mating (actual number of males mated, most studies have experimentally separated these effects when exploring their implications for female fitness. In this paper I describe an alternative approach using the guppy Poecilia reticulata, a livebearing freshwater fish in which females benefit directly and indirectly from mating with multiple males via consensual matings but incur direct and indirect costs of mating as a consequence of male sexual harassment. In the present study, females were experimentally assigned different numbers of mates throughout their lives in order to explore how elevated mating frequency and multiple mating combine to influence lifetime reproductive success (LRS and survival (i.e. direct components of female fitness. Under this mating design, survival and LRS were not significantly affected by mating treatment, but there was a significant interaction between brood size and reproductive cycle (a correlate of female age because females assigned to the high mating treatment produced significantly fewer offspring later in life compared to their low-mating counterparts. This negative effect of mating treatment later in life may be important in these relatively long-lived fishes, and this effect may be further exacerbated by the known cross-generational fitness costs of sexual harassment in guppies.

  13. Height, Relationship Satisfaction, Jealousy, and Mate Retention

    Directory of Open Access Journals (Sweden)

    Gayle Brewer

    2009-07-01

    Full Text Available Male height is associated with high mate value. In particular, tall men are perceived as more attractive, dominant and of a higher status than shorter rivals, resulting in a greater lifetime reproductive success. Female infidelity and relationship dissolution may therefore present a greater risk to short men. It was predicted that tall men would report greater relationship satisfaction and lower jealousy and mate retention behavior than short men. Ninety eight heterosexual men in a current romantic relationship completed a questionnaire. Both linear and quadratic relationships were found between male height and relationship satisfaction, cognitive and behavioral jealousy. Tall men reported greater relationship satisfaction and lower levels of cognitive or behavioral jealousy than short men. In addition, linear and quadratic relationships were found between male height and a number of mate retention behaviors. Tall and short men engaged in different mate retention behaviors. These findings are consistent with previous research conducted in this area detailing the greater attractiveness of tall men.

  14. Female Mate Choice

    Directory of Open Access Journals (Sweden)

    Melanie Li-Wen Long

    2015-07-01

    Full Text Available Information about prospective mates is typically acquired in a sequential and cumulative fashion. The aim of this study was to examine whether a reject-the-worst strategy is more efficient than an accept-the-best strategy for women in response to serial information and to identify the point at which a woman will terminate her assessment of a prospective mate’s attributes. A pilot survey was conducted to determine the chronological order in which attribute information typically becomes available during the early stages of a relationship. Using this order of presentation, attributes were presented to participants one at a time. After participants specified their minimum acceptable percentile level for each attribute, they were given numerical feedback about the extent to which the prospect exceeded or failed to meet their standard. Participants were randomly assigned to either the accept-the-best condition (accept a date or request more information or the reject-the-worst condition (reject a date or request more information. Participants in the reject-the-worst condition requested more trait information before making a decision than those in the accept-the-best condition. This suggests that the costs of a false-negative error exceed those of a false-positive error and that in actively accepting a mate, women satisfice rather than optimize.

  15. 小麦杂交组合选配策略探讨%Discussion on Strategies for Wheat Cross Combination and Assortative Mating

    Institute of Scientific and Technical Information of China (English)

    刘兆晔; 孙妮娜; 巴信斌; 李林志; 辛庆国; 于经川

    2015-01-01

    对小麦杂交组合选配策略进行了探讨。认为:小麦杂交双亲均应具有较高的产量水平和较好的适应性,主要优点多且能互补;双亲要有一定程度的性状差异和中等大小的遗传距离;双亲在一般配合力高的基础上,特殊配合力要大;要重视具有亲缘或地理近缘关系双亲的利用。%The strategies of wheat cross combination and assortative mating were discussed in this paper. The points were that the parents of wheat cross combination should both have higher yield and better adaptabil-ity,and the major advantages should be more and complementary;the parents should have character differ-ences in some degree and medium sized genetic distance;specific combining ability should be big on the basis of higher general combining ability;more attention should be paid to the utilization of parents with genetic re-lationship or geographical relationship.

  16. Heterozygosity-based assortative mating in blue tits (Cyanistes caeruleus): implications for the evolution of mate choice

    Science.gov (United States)

    García-Navas, Vicente; Ortego, Joaquín; Sanz, Juan José

    2009-01-01

    The general hypothesis of mate choice based on non-additive genetic traits suggests that individuals would gain important benefits by choosing genetically dissimilar mates (compatible mate hypothesis) and/or more heterozygous mates (heterozygous mate hypothesis). In this study, we test these hypotheses in a socially monogamous bird, the blue tit (Cyanistes caeruleus). We found no evidence for a relatedness-based mating pattern, but heterozygosity was positively correlated between social mates, suggesting that blue tits may base their mating preferences on partner's heterozygosity. We found evidence that the observed heterozygosity-based assortative mating could be maintained by both direct and indirect benefits. Heterozygosity reflected individual quality in both sexes: egg production and quality increased with female heterozygosity while more heterozygous males showed higher feeding rates during the brood-rearing period. Further, estimated offspring heterozygosity correlated with both paternal and maternal heterozygosity, suggesting that mating with heterozygous individuals can increase offspring genetic quality. Finally, plumage crown coloration was associated with male heterozygosity, and this could explain unanimous mate preferences for highly heterozygous and more ornamented individuals. Overall, this study suggests that non-additive genetic traits may play an important role in the evolution of mating preferences and offers empirical support to the resolution of the lek paradox from the perspective of the heterozygous mate hypothesis. PMID:19474042

  17. Evaluation of mating behaviour and mating compatibility methods for the Old World screwworm fly, Chrysomya bezziana.

    Directory of Open Access Journals (Sweden)

    April H. Wardhana

    2013-12-01

    Full Text Available The effectiveness of the Sterile Insect Technique program (SIT to eradicate pest insects relies on the success of mating competitiveness between irradiated male flies and wild type males for the wild type females. It has been successfully applied for the New World screwworm fly (NWSF, Cochliomyia hominivorax but remains unproven for the Old World screwworm fly (OWSF, Chrysomya bezziana. The aim of the study was to develop methods for investigating mating behaviour and mating compatibility of C. bezziana under laboratory conditions. Two methods were used for studying mating: individual mating (method 1 and group mating (method 2. The flies used in this study were 5-7 days old. Twenty four hours after emergence, adult flies were sexed and placed into different cages until studied. The female : male ratio in the group mating was 1 : 5 and the males were marked by painting a dot on the thorax using different oil colours. Observation of mating behaviour was investigated every 30 minutes through 10-20 replications for all methods depending on the availability of flies. Data were analysed using ANOVA and the Student’s t-test, with significance demonstrated at the 95% confidence level. The results demonstrated that the frequency of contacts between males and females at different ages was a significantly different (p 0.05 and method 2 (p > 0.05. Copulation was only initiated following longer periods of contact, mainly in the range of 270-449 seconds. The highest frequency of copulation occurred between 7-8 days, but the duration of mating was similar between 5-8 days old. The study demonstrated that the methods developed were suitable for a mating compatibility study of C. bezziana.

  18. Attraction of Drosophila melanogaster males to food-related and fly odours.

    Science.gov (United States)

    Lebreton, Sébastien; Becher, Paul G; Hansson, Bill S; Witzgall, Peter

    2012-01-01

    The fruit fly Drosophila melanogaster has become a model for olfaction and odour-mediated behaviour. In the wild, Drosophila flies aggregate on decaying fruit where they mate and oviposit and a strategy to find mates would be to locate fruit which has already been colonized by other flies. We therefore developed a bioassay to investigate attraction of males to food and fly odours. We showed that upwind flights are initiated by food odours. At shorter distances, males are attracted by volatiles produced by conspecifics. However, only odours produced by copulating flies attract males. This suggests either a synergistic effect of both male and female odours or changes in pheromone release during mating, that indicate the presence of sexually receptive females. Our findings demonstrate the essential role of food odours and pheromones for mate location in D. melanogaster. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Why do female Callosobruchus maculatus kick their mates?

    Directory of Open Access Journals (Sweden)

    Emile van Lieshout

    Full Text Available Sexual conflict is now recognised as an important driver of sexual trait evolution. However, due to their variable outcomes and effects on other fitness components, the detection of sexual conflicts on individual traits can be complicated. This difficulty is exemplified in the beetle Callosobruchus maculatus, where longer matings increase the size of nutritious ejaculates but simultaneously reduce female future receptivity. While previous studies show that females gain direct benefits from extended mating duration, females show conspicuous copulatory kicking behaviour, apparently to dislodge mating males prematurely. We explore the potential for sexual conflict by comparing several fitness components and remating propensity in pairs of full sibling females where each female mated with a male from an unrelated pair of full sibling males. For one female, matings were terminated at the onset of kicking, whereas the other's matings remained uninterrupted. While fecundity (number of eggs was similar between treatments, uninterrupted matings enhanced adult offspring numbers and fractionally also longevity. However, females whose matings were interrupted at the onset of kicking exhibited an increased propensity to remate. Since polyandry can benefit female fitness in this species, we argue that kicking, rather than being maladaptive, may indicate that females prefer remating over increased ejaculate size. It may thus be difficult to assess the presence of sexual conflict over contested traits such as mating duration when females face a trade off between direct benefits gained from one mating and indirect benefits from additional matings.

  20. Mating duration and sperm precedence in the spider Linyphia triangularis

    DEFF Research Database (Denmark)

    Weldingh, Ditte L.; Toft, Søren; Larsen, Ole Næsbye

    2011-01-01

    , especially the males, are able to influence the outcome of mating for their own benefit. We studied the linyphiid spider Linyphia triangularis in which mating follows a strict sequence during which the male inducts two droplets of sperm and transfers them to the female. We performed sperm competition...

  1. ATTRACTION OF MALE SUMMERFORM PEAR PSYLLA TO VOLATILES FROM FEMALE PSYLLA: EFFECTS OF FEMALE AGE, MATING STATUS, AND PRESENCE OF HOST PLANT

    Science.gov (United States)

    Pear psylla, Cacopsylla pyricola (Förster) (Hemiptera: Psyllidae), is a pest of pears throughout North America and western Europe. Previous studies in our laboratory showed that males of the overwintering form (winterform morphotype) were attracted to volatiles from pear shoots infested with post-d...

  2. Inbreeding avoidance drives consistent variation of fine-scale genetic structure caused by dispersal in the seasonal mating system of Brandt's voles.

    Directory of Open Access Journals (Sweden)

    Xiao Hui Liu

    Full Text Available Inbreeding depression is a major evolutionary and ecological force influencing population dynamics and the evolution of inbreeding-avoidance traits such as mating systems and dispersal. Mating systems and dispersal are fundamental determinants of population genetic structure. Resolving the relationships among genetic structure, seasonal breeding-related mating systems and dispersal will facilitate our understanding of the evolution of inbreeding avoidance. The goals of this study were as follows: (i to determine whether females actively avoided mating with relatives in a group-living rodent species, Brandt's voles (Lasiopodomys brandtii, by combined analysis of their mating system, dispersal and genetic structure; and (ii to analyze the relationships among the variation in fine-genetic structure, inbreeding avoidance, season-dependent mating strategies and individual dispersal. Using both individual- and population-level analyses, we found that the majority of Brandt's vole groups consisted of close relatives. However, both group-specific FISs, an inbreeding coefficient that expresses the expected percentage rate of homozygosity arising from a given breeding system, and relatedness of mates showed no sign of inbreeding. Using group pedigrees and paternity analysis, we show that the mating system of Brandt's voles consists of a type of polygyny for males and extra-group polyandry for females, which may decrease inbreeding by increasing the frequency of mating among distantly-related individuals. The consistent variation in within-group relatedness, among-group relatedness and fine-scale genetic structures was mostly due to dispersal, which primarily occurred during the breeding season. Biologically relevant variation in the fine-scale genetic structure suggests that dispersal during the mating season may be a strategy to avoid inbreeding and drive the polygynous and extra-group polyandrous mating system of this species.

  3. Mate value asymmetry and relationship satisfaction in female opinion.

    Science.gov (United States)

    Nowak, Natalia; Danel, Dariusz

    2014-01-01

    A considerable amount of studies highlight positive assortative mating in terms of various aspects of mate value. However, there is a lack of studies that directly show how both partners' mate value and mate value differences are related to the satisfaction in heterosexual relationship. In the present study, the authors focused on women and analyzed how their mate value self-assessment and perception of their partners' mate value are related to female relationship satisfaction. The authors also classified them under 3 categories of couples defined by partners' mate value discrepancy, that is, in which a woman has higher, lower, and equal mate value than does her male partner. Women's relationship satisfaction was positively related to the perception of their partners' mate value but negatively correlated to their mate value self-assessment. Moreover, relationship satisfaction was the lowest in the category where woman has higher self-assessed mate value. The level of women's relationship satisfaction did not differ in 2 other categories of relationships. Our results suggest that women's perception of mate value and mate value asymmetry may significantly affect women's satisfaction from their relationships. The authors provide several possible, evolutionary-based explanatory mechanisms.

  4. Burnout and Coping Strategies in Male Staff from National Police in Valparaíso Chile

    Directory of Open Access Journals (Sweden)

    Daniel Briones Mella

    2013-09-01

    Full Text Available Background: This cross-sectional study aimed to examine the relationship between several dimensions of the burnout syndrome with certain stress-coping strategies, seniority level and marital status in male staff from National Police in Vaparaíso, Chile.Methods: The sample collected in 2010 was composed of 338 male officers coming from various special units of a National Police in Valparaíso. Burnout and Coping Strategies were assessed and classified according Maslach Burnout Inventory (MBI and COPE Inventory, respectively. Data was analyzed using Pearson product-moment correlation, t-test for independent measures and Multiple Linear Regression to generate a predictive model.Results: The prevalence of the burnout syndrome disaggregated by grouping criteria, the dimensions concentrated in middle levels for emotional exhaustion with a 52.1%, a 51.8% for depersonalization and finally, personal achievement with a 48.8%. Only 28% of participants showed more exacerbated dimensions of the burnout syndrome. There was a weak and direct yet statistically significant relationship between personal achievement and active coping. Mental disconnection had a weak direct relationship between both coping strategies and emotional exhaustion also existed. Certain correlations between burnout dimensions and coping strategies focused on emotion as predictor variables over the criterion variable corresponding to emotional exhaustion were mental disconnection in first place, secondly, focusing on emotions, and emotional social support.Conclusions: Burnout dimensions scored medium values ​​focusing mainly on emotional exhaustion and reduced personal accomplishment. Coping strategies are used in parallel and in general are not mutually exclusive. Finally, there were not any relationship between variables seniority level and marital status.

  5. He votes or she votes? Female and male discursive strategies in Twitter political hashtags.

    Directory of Open Access Journals (Sweden)

    Evandro Cunha

    Full Text Available In this paper, we conduct a study about differences between female and male discursive strategies when posting in the microblogging service Twitter, with a particular focus on the hashtag designation process during political debate. The fact that men and women use language in distinct ways, reverberating practices linked to their expected roles in the social groups, is a linguistic phenomenon known to happen in several cultures and that can now be studied on the Web and on online social networks in a large scale enabled by computing power. Here, for instance, after analyzing tweets with political content posted during Brazilian presidential campaign,we found out that male Twitter users, when expressing their attitude toward a given candidate, are more prone to use imperative verbal forms in hashtags, while female users tend to employ declarative forms. This difference can be interpreted as a sign of distinct approaches in relation to other network members: for example, if political hashtags are seen as strategies of persuasion in Twitter, imperative tags could be understood as more overt ways of persuading and declarative tags as more indirect ones. Our findings help to understand human gendered behavior in social networks and contribute to research on the new fields of computer-enabled Internet linguistics and social computing, besides being useful for several computational tasks such as developing tag recommendation systems based on users' collective preferences and tailoring targeted advertising strategies, among others.

  6. Mating systems, reproductive success, and sexual selection in secretive species: a case study of the western diamond-backed rattlesnake, Crotalus atrox.

    Science.gov (United States)

    Clark, Rulon W; Schuett, Gordon W; Repp, Roger A; Amarello, Melissa; Smith, Charles F; Herrmann, Hans-Werner

    2014-01-01

    Long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. Such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. Even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. Here, we used molecular genetic techniques in a 10-year radio-telemetric investigation of the western diamond-backed rattlesnake (Crotalus atrox) for an analysis of its mating system and to measure sexual selection. Specifically, we used microsatellite markers to genotype 299 individuals, including neonates from litters of focal females to ascertain parentage using full-pedigree likelihood methods. We detected high levels of multiple paternity within litters, yet found little concordance between paternity and observations of courtship and mating behavior. Larger males did not father significantly more offspring, but we found evidence for size-specific male-mating strategies, with larger males guarding females for longer periods in the mating seasons. Moreover, the spatial proximity of males to mothers was significantly associated with reproductive success. Overall, our field observations alone would have been insufficient to quantitatively measure the mating system of this population of C. atrox, and we thus urge more widespread adoption of molecular tools by field researchers studying the mating systems and sexual selection of snakes and other secretive taxa.

  7. Mating Systems, Reproductive Success, and Sexual Selection in Secretive Species: A Case Study of the Western Diamond-Backed Rattlesnake, Crotalus atrox

    Science.gov (United States)

    Clark, Rulon W.; Schuett, Gordon W.; Repp, Roger A.; Amarello, Melissa; Smith, Charles F.; Herrmann, Hans-Werner

    2014-01-01

    Long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. Such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. Even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. Here, we used molecular genetic techniques in a 10-year radio-telemetric investigation of the western diamond-backed rattlesnake (Crotalus atrox) for an analysis of its mating system and to measure sexual selection. Specifically, we used microsatellite markers to genotype 299 individuals, including neonates from litters of focal females to ascertain parentage using full-pedigree likelihood methods. We detected high levels of multiple paternity within litters, yet found little concordance between paternity and observations of courtship and mating behavior. Larger males did not father significantly more offspring, but we found evidence for size-specific male-mating strategies, with larger males guarding females for longer periods in the mating seasons. Moreover, the spatial proximity of males to mothers was significantly associated with reproductive success. Overall, our field observations alone would have been insufficient to quantitatively measure the mating system of this population of C. atrox, and we thus urge more widespread adoption of molecular tools by field researchers studying the mating systems and sexual selection of snakes and other secretive taxa. PMID:24598810

  8. Mating systems, reproductive success, and sexual selection in secretive species: a case study of the western diamond-backed rattlesnake, Crotalus atrox.

    Directory of Open Access Journals (Sweden)

    Rulon W Clark

    Full Text Available Long-term studies of individual animals in nature contribute disproportionately to our understanding of the principles of ecology and evolution. Such field studies can benefit greatly from integrating the methods of molecular genetics with traditional approaches. Even though molecular genetic tools are particularly valuable for species that are difficult to observe directly, they have not been widely adopted. Here, we used molecular genetic techniques in a 10-year radio-telemetric investigation of the western diamond-backed rattlesnake (Crotalus atrox for an analysis of its mating system and to measure sexual selection. Specifically, we used microsatellite markers to genotype 299 individuals, including neonates from litters of focal females to ascertain parentage using full-pedigree likelihood methods. We detected high levels of multiple paternity within litters, yet found little concordance between paternity and observations of courtship and mating behavior. Larger males did not father significantly more offspring, but we found evidence for size-specific male-mating strategies, with larger males guarding females for longer periods in the mating seasons. Moreover, the spatial proximity of males to mothers was significantly associated with reproductive success. Overall, our field observations alone would have been insufficient to quantitatively measure the mating system of this population of C. atrox, and we thus urge more widespread adoption of molecular tools by field researchers studying the mating systems and sexual selection of snakes and other secretive taxa.

  9. Familiarity adds to attractiveness in matters of siskin mate choice.

    Science.gov (United States)

    Senar, J C; Mateos-Gonzalez, F; Uribe, F; Arroyo, L

    2013-12-22

    There is currently considerable controversy in evolutionary ecology revolving around whether social familiarity brings attraction when a female chooses a mate. The topic of familiarity is significant because by avoiding or preferring familiar individuals as mates, the potential for local adaptation may be reduced or favoured. The topic becomes even more interesting if we simultaneously analyse preferences for familiarity and sexual ornaments, because when familiarity influences female mating preferences, this could very significantly affect the strength of sexual selection on male ornamentation. Here, we have used mate-choice experiments in siskins Carduelis spinus to analyse how familiarity and patterns of ornamentation (i.e. the size of wing patches) interact to influence mating success. Our results show that females clearly prefer familiar individuals when choosing between familiar and unfamiliar males with similar-sized wing patches. Furthermore, when females were given the choice between a highly ornamented unfamiliar male and a less ornamented familiar male, half of the females still preferred the socially familiar birds as mates. Our finding suggests that male familiarity may be as important as sexual ornaments in affecting female behaviour in mate choice. Given that the potential for local adaptation may be favoured by preferring familiar individuals as mates, social familiarity as a mate-choice criterion may become a potential area of fruitful research on sympatric speciation processes.

  10. Reduced mate availability leads to evolution of self-fertilization and purging of inbreeding depression in a hermaphrodite.

    Science.gov (United States)

    Noël, Elsa; Chemtob, Yohann; Janicke, Tim; Sarda, Violette; Pélissié, Benjamin; Jarne, Philippe; David, Patrice

    2016-03-01

    Basic models of mating-system evolution predict that hermaphroditic organisms should mostly either cross-fertilize, or self-fertilize, due to self-reinforcing coevolution of inbreeding depression and outcrossing rates. However transitions between mating systems occur. A plausible scenario for such transitions assumes that a decrease in pollinator or mate availability temporarily constrains outcrossing populations to self-fertilize as a reproductive assurance strategy. This should trigger a purge of inbreeding depression, which in turn encourages individuals to self-fertilize more often and finally to reduce male allocation. We tested the predictions of this scenario using the freshwater snail Physa acuta, a self-compatible hermaphrodite that preferentially outcrosses and exhibits high inbreeding depression in natural populations. From an outbred population, we built two types of experimental evolution lines, controls (outcrossing every generation) and constrained lines (in which mates were often unavailable, forcing individuals to self-fertilize). After ca. 20 generations, individuals from constrained lines initiated self-fertilization earlier in life and had purged most of their inbreeding depression compared to controls. However, their male allocation remained unchanged. Our study suggests that the mating system can rapidly evolve as a response to reduced mating opportunities, supporting the reproductive assurance scenario of transitions from outcrossing to selfing.

  11. Heterosis Increases Fertility, Fecundity, and Survival of Laboratory-Produced F1 Hybrid Males of the Malaria Mosquito Anopheles coluzzii

    Science.gov (United States)

    Ekechukwu, Nkiru E.; Baeshen, Rowida; Traorè, Sékou F.; Coulibaly, Mamadou; Diabate, Abdoulaye; Catteruccia, Flaminia; Tripet, Frédéric

    2015-01-01

    The success of vector control strategies aiming to decrease disease transmission via the release of sterile or genetically-modified male mosquitoes critically depends on mating between laboratory-reared males and wild females. Unfortunately, mosquito colonization, laboratory rearing, and genetic manipulations can all negatively affect male competitiveness. Heterosis is commonly used to produce domestic animals with enhanced vigor and homogenous genetic background and could therefore potentially improve the mating performance of mass-reared male mosquitoes. Here, we produced enhanced hybrid males of the malaria mosquito Anopheles coluzzii by crossing two strains colonized >35 and 8 years ago. We compared the amount of sperm and mating plug proteins they transferred to females, as well as their insemination rate, reproductive success and longevity under various experimental conditions. Across experiments, widespread adaptations to laboratory mating were detected in the older strain. In large-group mating experiments, no overall hybrid advantage in insemination rates and the amount of sperm and accessory gland proteins transferred to females was detected. Despite higher sperm activity, hybrid males did not appear more fecund. However, individual-male mating and laboratory-swarm experiments revealed that hybrid males, while inseminating fewer females than older inbred males, were significantly more fertile, producing larger mating plugs and drastically increasing female fecundity. Heterotic males also showed increased longevity. These results validate the use of heterosis for creating hybrid males with improved fitness from long-established inbred laboratory strains. Therefore, this simple approach could facilitate disease control strategies based on male mosquito releases with important ultimate benefits to human health. PMID:26497140

  12. Negative-assortative mating for color in wolves.

    Science.gov (United States)

    Hedrick, Philip W; Smith, Douglas W; Stahler, Daniel R

    2016-04-01

    There is strong negative-assortative mating for gray and black pelage color in the iconic wolves in Yellowstone National Park. This is the first documented case of significant negative-assortative mating in mammals and one of only a very few cases in vertebrates. Of 261 matings documented from 1995 to 2015, 63.6% were between gray and black wolves and the correlation between mates for color was -0.266. There was a similar excess of matings of both gray males × black females and black males × gray females. Using the observed frequency of negative-assortative mating in a model with both random and negative-assortative mating, the estimated proportion of negative-assortative mating was 0.430. The estimated frequency of black wolves in the population from 1996 to 2014 was 0.452 and these frequencies appear stable over this 19-year period. Using the estimated level of negative-assortative mating, the predicted equilibrium frequency of the dominant allele was 0.278, very close to the mean value of 0.253 observed. In addition, the patterns of genotype frequencies, that is, the observed proportion of black homozygotes and the observed excess of black heterozygotes, are consistent with negative-assortative mating. Importantly these results demonstrate that negative-assortative mating could be entirely responsible for the maintenance of this well-known color polymorphism. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  13. Polyandry and alternative mating tactics.

    Science.gov (United States)

    Neff, Bryan D; Svensson, Erik I

    2013-03-05

    Many species in the animal kingdom are characterized by alternative mating tactics (AMTs) within a sex. In males, such tactics include mate guarding versus sneaking behaviours, or territorial versus female mimicry. Although AMTs can occur in either sex, they have been most commonly described in males. This sex bias may, in part, reflect the increased opportunity for sexual selection that typically exists in males, which can result in a higher probability that AMTs evolve in that sex. Consequently, females and polyandry can play a pivotal role in governing the reproductive success associated with male AMTs and in the evolutionary dynamics of the tactics. In this review, we discuss polyandry and the evolution of AMTs. First, we define AMTs and review game theoretical and quantitative genetic approaches used to model their evolution. Second, we review several examples of AMTs, highlighting the roles that genes and environment play in phenotype expression and development of the tactics, as well as empirical approaches to differentiating among the mechanisms. Third, ecological and genetic constraints to the evolution of AMTs are discussed. Fourth, we speculate on why female AMTs are less reported on in the literature than male tactics. Fifth, we examine the effects of AMTs on breeding outcomes and female fitness, and as a source, and possibly also a consequence, of sexual conflict. We conclude by suggesting a new model for the evolution of AMTs that incorporates both environmental and genetic effects, and discuss some future avenues of research.

  14. The Young Male Cigarette and Alcohol Syndrome

    Directory of Open Access Journals (Sweden)

    Eveline Vincke

    2016-02-01

    Full Text Available Despite the many health risks of tobacco and alcohol use, high levels of smoking and drinking are being persisted. Moreover, young men engage more in these behaviors as compared to women. As male physical risk-taking behavior gains attractiveness in short-term mating contexts and given that smoking and drinking have considerable physical costs, this study explores the possibility that tobacco and alcohol use is part of a male short-term mating strategy. By means of a between-subjects experiment (N = 239, women’s perceptions of young male smoking and drinking were investigated. The experiment showed that women perceive men who smoke and drink as being more short-term oriented in their sexuality than nonusers. Moreover, both tobacco and (especially alcohol use brought some attractiveness benefits in short-term mating contexts. A follow-up study (N = 171 confirmed that men’s behavior corresponds with women’s perceptions. Overall, these findings show that cigarette and alcohol use can operate as a short-term mating strategy.

  15. The Sexual Behaviour of Chagas' Disease Vectors: Chemical Signals Mediating Communication between Male and Female Triatomine Bugs

    Directory of Open Access Journals (Sweden)

    Gabriel Manrique

    2012-01-01

    Full Text Available Chemical communication mechanisms that mediate sexual behaviour in triatomine bugs are reviewed with regard to source, identity, and function of sex pheromones. Males attempt to copulate but may be rejected, depending on female age and nutritional status. Triatomine males locate partners through sex pheromones emitted by the metasternal glands (MGs of females. These activate males, inducing them to leave their refuges and initiate flight. Wandering males display anemotactic orientation modulated by chemical signals emitted from female MGs. Analyses of the MG secretions of several species resulted in the identification of numerous ketones, acetals, and alcohols. Occlusion experiments showed that Brindley’s gland products were not required for mating. Metasternal gland volatiles are emitted by virgin male and female bugs, with detection over females occurring more consistently, especially during the early scotophase, suggesting female calling behaviour. Mating triatomine females have been reported to attract males that tend to copulate successively with them. Mating males prolong mating and postcopulatory mate guarding in the presence of other males. This is indicative of a polyandrous mating system in several triatomine species. Its potential advantages remain unknown, and comparative studies are required to increase our understanding of triatomine reproductive strategies.

  16. Negotiating Dominant Masculinity Ideology: Strategies Used by Gay, Bisexual and Questioning Male Adolescents

    Science.gov (United States)

    Wilson, Bianca D. M.; Harper, Gary W.; Hidalgo, Marco A.; Jamil, Omar B.; Torres, Rodrigo Sebastián; Fernandez, M. Isabel

    2010-01-01

    In the context of a U.S. dominant masculinity ideology, which devalues men who are not heterosexually identified, many gay, bisexual and questioning (GBQ) adolescent males must develop their own affirming and health-promoting sense of masculinity. In order to promote the well-being of GBQ young men, exploration of their reactions and responses to dominant images of masculinity is needed. We qualitatively analyzed interviews with 39 GBQ African American, Latino, and European American male adolescents (15–23 years old). Participants reported a range of responses to traditional masculinity ideologies, most of which centered on balancing presentations of masculine and feminine characteristics. Negotiation strategies served a variety of functions, including avoiding anti-gay violence, living up to expected images of masculinity, and creating unique images of personhood free of gender role expectations. These data suggest a complex picture of GBQ male adolescents’ management of masculinity expectations and serve as a basis for culturally and developmentally specific HIV prevention programs. PMID:20082238

  17. Negotiating dominant masculinity ideology: strategies used by gay, bisexual and questioning male adolescents.

    Science.gov (United States)

    Wilson, Bianca D M; Harper, Gary W; Hidalgo, Marco A; Jamil, Omar B; Torres, Rodrigo Sebastián; Fernandez, M Isabel

    2010-03-01

    In the context of a U.S. dominant masculinity ideology, which devalues men who are not heterosexually identified, many gay, bisexual and questioning (GBQ) adolescent males must develop their own affirming and health-promoting sense of masculinity. In order to promote the well-being of GBQ young men, exploration of their reactions and responses to dominant images of masculinity is needed. We qualitatively analyzed interviews with 39 GBQ African American, Latino, and European American male adolescents (15-23 years old). Participants reported a range of responses to traditional masculinity ideologies, most of which centered on balancing presentations of masculine and feminine characteristics. Negotiation strategies served a variety of functions, including avoiding anti-gay violence, living up to expected images of masculinity, and creating unique images of personhood free of gender role expectations. These data suggest a complex picture of GBQ male adolescents' management of masculinity expectations and serve as a basis for culturally and developmentally specific HIV prevention programs.

  18. Mechanism of Sterility and Breeding Strategies for Photoperiod/Thermo- Sensitive Genic Male Sterile Rice

    Institute of Scientific and Technical Information of China (English)

    CHEN Li-yun; XIAO Ying-hui; LEI Dong-yang

    2010-01-01

    To understand the male sterility mechanism of photoperiod/thermo-sensitive genic male sterile [P(T)GMS] lines in rice, the research progress on genetics of photoperiod and/or temperature sensitive genic male sterility in rice was reviewed. A new idea was proposed to explain the sterility mechanism of P(T)GMS rice. The fertility transition from sterile to fertile is the result of cooperative regulation of major-effect sterile genes with photoperiod and/or temperature sensitive genes, but not the so-called pgms gene in P(T)GMS rice. The minor-effect genes, which exhibit accumulative effect on sterility, are the important factors for the critical temperature of sterility transition. The more minor-effect genes the sterile line holds, the lower the critical temperature of sterility transition is. The critical temperature of sterility transition will be invariable if all the minor-effect genes are homozygous. The strategies for breeding P(T)GMS rice were also proposed. The selective indices of critical photoperiod and temperature for sterility transition should be set according to varietal type and ecological region. Imposing selection pressure is a key technology for breeding P(T)GMS rice with lower critical temperature for sterility, and improving the comprehensive performance of the whole traits and combining ability is vital for breeding P(T)GMS rice lines.

  19. Mating behavior of an aphidophagous ladybird beetle,Propylea dissecta (Mulsant)

    Institute of Scientific and Technical Information of China (English)

    OMKAR; AHMADPERVEZ

    2005-01-01

    The mating behavior of Propylea dissecta (Mulsant) was investigated in detail.Protandry was evident, as males mature earlier than females. Predicted age of sexual maturation of male and female ladybirds was 7.12 and 9.33 days, respectively. Males performed courtship in six steps, viz. approach, watch, examine, embrace, mount and attempt. Embrace is possibly an appeasement act, while examine serves to recognize mate.Chemical signals initiate male attraction toward females. Visual and tactile cues appear to secondarily help in mate recognition. Mating lasted longest (275.40 ± 12.23 min) when it occurred between unmated individuals. It was much shorter (176.60 ± 5.60 min) when prior mated individuals copulated. There was a significant decrease in mating durations when adults were subjected to five successive matings. Fecundity and percent egg viability increased significantly with increase in the number of matings.

  20. Variation in the Mating Systems of Wrasses (Labridae at a Spawning Aggregation Site on Guam, Mariana Islands

    Directory of Open Access Journals (Sweden)

    Terry J. Donaldson

    2015-11-01

    Full Text Available The wrasses (family Labridae exhibit a diverse number of mating strategies and behaviors. This diversity is expressed not only interspecifically but also intraspecifically. At Guam, Mariana Islands, over twenty species of wrasses spawn on a small, shallow coral reef known as Finger Reef that projects outward from the main reef into Apra Harbor. Preliminary observations indicated that the mating system utilized by some wrasses varied within species. To examine why this occurs, I utilized direct visual observations supplemented by underwater video and photography. I recorded the identity of the species courting, the number of individuals participating, the distribution of male mating territories, courtship and spawning behaviors, and courtship success. Field work utilized snorkeling for several hours a day variously within the lunar month during 2013-2015. I found that courtship and spawning occurs either in temporary resident spawning aggregations or within a protogynous haremic mating system. Within spawning aggregations, mating systems include a lek-like system with paired spawning, and group or promiscuous spawning. Haremic species followed the traditional single male-multiple female model. Both group-spawning and haremic species, however, also spawned in simple male-female pairs. Sneaking or streaking behavior during pelagic spawning events were observed in all mating systems. The results of these observations found that lek-like behavior and group spawning were dependent upon higher densities of males and females at the site. At lower densities, however, some species reverted to simple paired spawning while others used a haremic system rather than a lek-like system. This suggests that some species of wrasses practice a mixed strategy that is dependent upon fish density during the courtship period.