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Sample records for individual male mating

  1. Personality differentially affects individual mate choice decisions in female and male Western mosquitofish (Gambusia affinis).

    Science.gov (United States)

    Chen, Bo-Jian; Liu, Kai; Zhou, Lin-Jun; Gomes-Silva, Guilherme; Sommer-Trembo, Carolin; Plath, Martin

    2018-01-01

    Consistent individual differences in behavioral tendencies (animal personality) can affect individual mate choice decisions. We asked whether personality traits affect male and female mate choice decisions similarly and whether potential personality effects are consistent across different mate choice situations. Using western mosquitofish (Gambusia affinis) as our study organism, we characterized focal individuals (males and females) twice for boldness, activity, and sociability/shoaling and found high and significant behavioral repeatability. Additionally, each focal individual was tested in two different dichotomous mate choice tests in which it could choose between computer-animated stimulus fish of the opposite sex that differed in body size and activity levels, respectively. Personality had different effects on female and male mate choice: females that were larger than average showed stronger preferences for large-bodied males with increasing levels of boldness/activity (i.e., towards more proactive personality types). Males that were larger than average and had higher shoaling tendencies showed stronger preferences for actively swimming females. Size-dependent effects of personality on the strength of preferences for distinct phenotypes of potential mating partners may reflect effects of age/experience (especially in females) and social dominance (especially in males). Previous studies found evidence for assortative mate choice based on personality types or hypothesized the existence of behavioral syndromes of individuals' choosiness across mate choice criteria, possibly including other personality traits. Our present study exemplifies that far more complex patterns of personality-dependent mate choice can emerge in natural systems.

  2. Male mating biology

    NARCIS (Netherlands)

    Howell, Paul I.; Knols, Bart G. J.

    2009-01-01

    Before sterile mass-reared mosquitoes are released in an attempt to control local populations, many facets of male mating biology need to be elucidated. Large knowledge gaps exist in how both sexes meet in space and time, the correlation of male size and mating success and in which arenas matings

  3. 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.

  4. Age-dependent male mating investment in Drosophila pseudoobscura.

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    Sumit Dhole

    Full Text Available Male mating investment can strongly influence fitness gained from a mating. Yet, male mating investment often changes with age. Life history theory predicts that mating investment should increase with age, and males should become less discriminatory about their mate as they age. Understanding age-dependent changes in male behavior and their effects on fitness is important for understanding how selection acts in age-structured populations. Although the independent effects of male or female age have been studied in many species, how these interact to influence male mating investment and fitness is less well understood. We mated Drosophila pseudoobscura males of five different age classes (4-, 8-, 11-, 15-, 19-day old to either young (4-day or old (11-day females, and measured copulation duration and early post-mating fecundity. Along with their independent effects, we found a strong interaction between the effects of male and female ages on male mating investment and fitness from individual matings. Male mating investment increased with male age, but this increase was more prominent in matings with young females. Male D. pseudoobscura made smaller investments when mating with old females. The level of such discrimination based on female age, however, also changed with male age. Intermediate aged males were most discriminatory, while the youngest and the oldest males did not discriminate between females of different ages. We also found that larger male mating investments resulted in higher fitness payoffs. Our results show that male and female ages interact to form a complex pattern of age-specific male mating investment and fitness.

  5. Sexual Experience Enhances Drosophila melanogaster Male Mating Behavior and Success

    Science.gov (United States)

    Saleem, Sehresh; Ruggles, Patrick H.; Abbott, Wiley K.; Carney, Ginger E.

    2014-01-01

    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. PMID:24805129

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

    Directory of Open Access Journals (Sweden)

    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.

  7. The evolution of postpairing male mate choice.

    Science.gov (United States)

    Lyu, Nan; Servedio, Maria R; Lloyd, Huw; Sun, Yue-Hua

    2017-06-01

    An increasing number of empirical studies in animals have demonstrated male mate choice. However, little is known about the evolution of postpairing male choice, specifically which occurs by differential allocation of male parental care in response to female signals. We use a population genetic model to examine whether such postpairing male mate choice can evolve when males face a trade-off between parental care and extra-pair copulations (EPCs). Specifically, we assume that males allocate more effort to providing parental care when mated to preferred (signaling) females, but they are then unable to allocate additional effort to seek EPCs. We find that both male preference and female signaling can evolve in this situation, under certain conditions. First, this evolution requires a relatively large difference in parental investment between males mated to preferred versus nonpreferred females. Second, whether male choice and female signaling alleles become fixed in a population versus cycle in their frequencies depends on the additional fecundity benefits from EPCs that are gained by choosy males. Third, less costly female signals enable both signaling and choice alleles to evolve under more relaxed conditions. Our results also provide a new insight into the evolution of sexual conflict over parental care. © 2017 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

  8. Male mate choice and female response in relation to mating status and time since mating

    OpenAIRE

    Douglass H. Morse

    2010-01-01

    Models of sperm allocation predict that male mating behavior will vary with a female's reproductive condition and with information about her present and likely future status available to a male. Tests across a wide taxonomic range have shown that males allocate more sperm to previously mated females than to virgins but that in a minority of instances this allocation pattern is reversed. To investigate the basis for this discrepancy I ran sequential pairings of the crab spider Misumena vatia (...

  9. Alternative phenotypes of male mating behaviour in the two-spotted spider mite

    NARCIS (Netherlands)

    Sato, Y.; Sabelis, M.W.; Egas, M.; Faraji, F.

    2013-01-01

    Severe intraspecific competition for mates selects for aggressive individuals but may also lead to the evolution of alternative phenotypes that do not act aggressively, yet manage to acquire matings. The two-spotted spider mite, Tetranychus urticae, shows male mate-guarding behaviour and male-male

  10. 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.

  11. Stress responsiveness predicts individual variation in mate selectivity.

    Science.gov (United States)

    Vitousek, Maren N; Romero, L Michael

    2013-06-15

    Steroid hormones, including glucocorticoids, mediate a variety of behavioral and physiological processes. Circulating hormone concentrations vary substantially within populations, and although hormone titers predict reproductive success in several species, little is known about how individual variation in circulating hormone concentrations is linked with most reproductive behaviors in free-living organisms. Mate choice is an important and often costly component of reproduction that also varies substantially within populations. We examined whether energetically costly mate selection behavior in female Galápagos marine iguanas (Amblyrhynchus cristatus) was associated with individual variation in the concentrations of hormones previously shown to differ between reproductive and non-reproductive females during the breeding season (corticosterone and testosterone). Stress-induced corticosterone levels - which are suppressed in female marine iguanas during reproduction - were individually repeatable throughout the seven-week breeding period. Mate selectivity was strongly predicted by individual variation in stress-induced corticosterone: reproductive females that secreted less corticosterone in response to a standardized stressor assessed more displaying males. Neither baseline corticosterone nor testosterone predicted variation in mate selectivity. Scaled body mass was not significantly associated with mate selectivity, but females that began the breeding period in lower body condition showed a trend towards being less selective about potential mates. These results provide the first evidence that individual variation in the corticosterone stress response is associated with how selective females are in their choice of a mate, an important contributor to fitness in many species. Future research is needed to determine the functional basis of this association, and whether transient acute increases in circulating corticosterone directly mediate mate choice behaviors

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

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    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

  13. Mating choice of Ceratitis capitata (Wiedemann) (Diptera: Tephritidae): influence of male ageing on mating success

    International Nuclear Information System (INIS)

    Silva Neto, Alberto M. da; Dias, Vanessa S.; Joachim-Bravo, Iara S.

    2009-01-01

    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)

  14. 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.

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

    Science.gov (United States)

    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.

  16. Last mated male sperm precedence in doubly mated females is not ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 92; Issue 2. Last mated male sperm precedence in doubly mated females is not ubiquitous: evidence from sperm competition in laboratory populations of Drosophila nasuta nasuta and Drosophila nasuta albomicans. B. Shruthi S. R. Ramesh. Research Note Volume 92 Issue 2 ...

  17. Male choice of mates and mating resources in the rose bitterling (Rhodeus ocellatus)

    Czech Academy of Sciences Publication Activity Database

    Casalini, M.; Reichard, Martin; Phillips, A.; Smith, Carl

    2013-01-01

    Roč. 24, č. 5 (2013), s. 1199-1204 ISSN 1045-2249 R&D Projects: GA ČR GA206/09/1163 Institutional support: RVO:68081766 Keywords : body size * fecundity * male mate choice * mating system * oviposition * sperm competition * territoriality Subject RIV: EG - Zoology Impact factor: 3.157, year: 2013

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

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    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.

  19. Alternative phenotypes of male mating behaviour in the two-spotted spider mite.

    Science.gov (United States)

    Sato, Yukie; Sabelis, Maurice W; Egas, Martijn; Faraji, Farid

    2013-09-01

    Severe intraspecific competition for mates selects for aggressive individuals but may also lead to the evolution of alternative phenotypes that do not act aggressively, yet manage to acquire matings. The two-spotted spider mite, Tetranychus urticae, shows male mate-guarding behaviour and male-male combat for available females. This may provide opportunity for weaker males to avoid fighting by adopting alternative mating behaviour such as sneaker or satellite tactics as observed in other animals. We investigated male precopulatory behaviour in the two-spotted spider mite by means of video-techniques and found three types of male mating behaviour: territorial, sneaker and opportunistic. Territorial and sneaker males associate with female teleiochrysales and spend much time guarding them. Territorial males are easily disturbed by rival males and engage themselves in fights with them. However, sneaker males are not at all disturbed by rival males, never engage in fights and, strikingly, never face attack by territorial males. Opportunistic males wander around in search of females that are in the teleiochrysalis stage but very close to or at emergence. To quickly classify any given mate-guarding male as territorial or sneaker we developed a method based on the instantaneous response of males to disturbance by a live male mounted on top of a brush. We tested this method against the response of the same males to natural disturbance by two or three other males. Because this method proved to be successful, we used it to collect territorial and sneaker males, and subjected them to morphological analysis to assess whether the various behavioural phenotypes are associated with different morphological characters. However, we found no statistical differences between territorial and sneaker males, concerning the length of the first legs, the stylets, the pedipalps or the body.

  20. Male aggression and mating opportunity in a poeciliid fish ...

    African Journals Online (AJOL)

    Male aggression and mating opportunity in a poeciliid fish. ... the strength of which can be assessed using repeatability of aggressive behaviour. ... A surprising finding highlighted by this study was the contradictory results for consistency in ...

  1. Mating with large males decreases the immune defence of females ...

    Indian Academy of Sciences (India)

    1Indian Institute of Science Education and Research, BCVK Campus, ... observed results are very likely due to qualitative/quantitative differences in the .... Materials and methods .... that mated with the three types of males within each block.

  2. Individual differences in valuing mates' physical attractiveness.

    Science.gov (United States)

    Mathes, Eugene W; Bielser, Abby; Cassell, Ticcarra; Summers, Sarah; Witowski, Aggie

    2006-10-01

    To investigate correlates of valuing physical attractiveness in a mate, it was hypothesized that valuing physical attractiveness in a mate would correlate with sex and valuing promiscuous sex, status, personal physical attractiveness, beauty, and order. Men and women college students completed measures of the extent to which they valued physical attractiveness in a mate and other variables. Valuing physical attractiveness in a mate was correlated with sex (men valued physical attractiveness in a mate more than did women) and valuing promiscuous sex and status, and, for women, valuing personal physical attractiveness. The results were explained in terms of evolutionary theory.

  3. Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus.

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    Daniel Shane Wright

    Full Text Available Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks.

  4. Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus).

    Science.gov (United States)

    Wright, Daniel Shane; Pierotti, Michele E R; Rundle, Howard D; McKinnon, Jeffrey S

    2015-01-01

    Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks.

  5. 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.

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

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    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].

  7. Coloured leg bands affect male mate-guarding behaviour in the bluethroat

    Science.gov (United States)

    Johnsen; Lifjeld; Rohde

    1997-07-01

    Artificial traits such as coloured leg bands may affect an individual's mating success, as shown for some birds. One explanation is that colour-matching with a sexual ornament affects the individual's sexual attractiveness. This study reports a colour-band experiment with free-living bluethroats, Luscinia s. svecicaa species where males have a distinct blue and chestnut throat and upper breast. There was no apparent difference in pairing success between males with ornament-matching colour bands (blue and orange) and males with non-ornamental colour bands. However, males with ornamental bands guarded their mates less intensely and spent more time singing, performing song flights and intruding into neighbours' territories than males with non-ornamental bands. We conclude that colour bands affect the trade-off between mate guarding and advertisement behaviour in a way that is consistent with the hypothesis that bands with ornamental colours improve a male's attractiveness. The results are in concordance with a previous study of the same population, showing that males with experimentally reduced attractiveness guarded their mates more closely and advertised less for additional mates, than non-manipulated males.

  8. Last mated male sperm precedence in doubly mated females is not ...

    Indian Academy of Sciences (India)

    DST Unit on Evolution and Genetics, Department of Studies in Zoology, University of Mysore, Manasagangotri,. Mysore 570 006, India .... using SPSS software (ver. 16.0). Results ... Proportions of first male and second male progeny of doubly mated female and the results of paired-sample t-test carried out independently for ...

  9. Male but not female olfaction is crucial for intermolt mating in European lobsters (Homarus gammarus L.).

    Science.gov (United States)

    Skog, Malin

    2009-02-01

    Chemical signals are common in most crustacean social interactions and are often perceived via chemosensory (olfactory) organs on the first antenna. Intermolt courtship behaviors and mating were investigated in size-matched pairs of intermolt European lobsters (Homarus gammarus) where the olfactory receptors of either the male or the female were lesioned with distilled water (olfactory ablation) or seawater (control). Matings or advanced male courtship behaviors (mounting and turning) were common in seawater controls and olfactory-ablated females. In contrast, when male olfaction was ablated with distilled water, there was not a single mating, and the only male courtship behaviors seen were a few very brief and unsuccessful mounting attempts. Individual females mated up to 5 times with different males, showing that previously inseminated females were still attractive to males. Thus, male but not female olfaction is crucial for intermolt mating in H. gammarus, indicating the presence of a female sex pheromone during the entire female molt cycle, not only at the time of molting. Female sex discrimination may be based on other cues from the male in combination with typical male behaviors.

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

    Science.gov (United States)

    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.

  11. 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

  12. 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...

  13. 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

    Males and females often experience different optima in mating rate, which may cause evolution of female resistance to matings and male counter adaptations to increase mating rate. Males of the spider Pisaura mirabilis display a spectacular mating behavior involving a nuptial gift and thanatosis...

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

    Directory of Open Access Journals (Sweden)

    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.

  15. 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

  16. Gender insensitivity and male bias in local advertising | Mate ...

    African Journals Online (AJOL)

    Gender insensitivity and male bias in local advertising. Rekopantswe Mate. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/safere.v3i1.23952 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

  17. Multiple matings among glossina and the sterile male technique

    International Nuclear Information System (INIS)

    Pinhao, R.C.

    1980-01-01

    The fact that multiple matings are a common phenomenon among glossina turns the sterile male technique into a competition not between adult insects but between two types of sperm, and the proportion of females inseminated with the one or the other is given by the binomial (p+q)sup(n), where p is the percentage of normal males, q the percentage of sterile males and n the average number of matings per female. However, multiple matings cannot damage the effectiveness of the technique unless two conditions are present either separately or simultaneously: precocious death of the spermatozoa and reduced inseminating potential among the sterile males. Study of the factors which can alter the inseminating potential is thus important for those who wish to use the sterile male technique. These factors are of three kinds: factors connected with quality, with quantity and with availability. The first are associated with the nature and intensity of the alterations brought about in the spermatozoa by the sterilizing agent, the second with possible variations in the amount of sperm reaching the spermotheca, the third with the behaviour of the sterile males in the nature - that is, the question whether sterilization has a favourable or unfavourable influence on their chances of mating with wild females. The author describes his observations of the quantity of sperm produced by Glossina morsitans submorsitans males from the colony reared at the Institute for Tropical Hygiene and Medicine in Lisbon, compares them with the observations of other authors and discusses their practical significance. Specific research is suggested. Advantages from assessing the behaviour of colonies not by female productivity but by male inseminating potential, and appropriate laboratory techniques

  18. 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].

  19. 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

    in the presence of virgin when compared with mated females and that the cue is waterborne. The ability to distinguish between virgin and mated females may reduce male mortality during mate search and the cost related to mating behaviour (precopula) in both sexes. We estimate that at realistic population densities...... the ability of males to distinguish between virgin and mated females saves them several hours per day of dangerous and energetically expensive fast female tracking...

  20. Postnatal nutrition influences male attractiveness and promotes plasticity in male mating preferences

    Science.gov (United States)

    Noguera, José C.; Metcalfe, Neil B.; Monaghan, Pat

    2017-12-01

    Poor early-life nutrition could reduce adult reproductive success by negatively affecting traits linked to sexual attractiveness such as song complexity. If so, this might favor strategic mate choice, allowing males with less complex songs to tailor their mating tactics to maximize the reproductive benefits. However, this possibility has been ignored in theoretical and empirical studies. By manipulating the micronutrient content of the diet (e.g., low or high) during the postnatal period of male zebra finches, we show for the first time (1) that males reared on a poor (low) micronutrient diet had less complex songs as adults; (2) that these males, in contrast to the high micronutrient diet group, were more selective in their mating strategies, discriminating against those females most likely to reduce their clutch size when paired with males having less complex songs; and (3) that by following different mating strategies, males reared on the contrasting diets obtained similar reproductive benefits. These results suggest that early-life dietary conditions can induce multiple and long-lasting effects on male and female reproductive traits. Moreover, the results seem to reflect a previously unreported case of adaptive plasticity in mate choice in response to a nutritionally mediated reduction in sexual attractiveness.

  1. Postnatal nutrition influences male attractiveness and promotes plasticity in male mating preferences

    OpenAIRE

    Noguera, José C; Metcalfe, Neil B.; Monaghan, Pat

    2017-01-01

    Poor early-life nutrition could reduce adult reproductive success by negatively affecting traits linked to sexual attractiveness such as song complexity. If so, this might favor strategic mate choice, allowing males with less complex songs to tailor their mating tactics to maximize the reproductive benefits. However, this possibility has been ignored in theoretical and empirical studies. By manipulating the micronutrient content of the diet (e.g., low or high) during the postnatal period of m...

  2. 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].

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

    Institute of Scientific and Technical Information of China (English)

    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].

  4. Effects of mating status on copulation investment by male bushcricket Gampsocleis gratiosa (Tettigoniidae, Orthoptera)

    Institute of Scientific and Technical Information of China (English)

    GAO; Yong

    2006-01-01

    Male's copulation investment, including spermatophore and sperm investment were very high in the Chinese bushcricket Gampsocleis gratiosa. The effects of mating status of both males and females on male's copulation investment were examined in this study. The fresh weight of spermatophylax increased positively with the weight of males' body. This indicated that the nutritional investment during copulation depended on male's quality. Spermatophore investment showed insignificant differences in every copulation protocols. This finding supported the paternal investment hypothesis, that is, males contributed to their offspring with little attention to their partners. Sperm releasing per ejaculation varied significantly among the trials. Males decreased 54.19% sperm in second mating than in its first mating, demonsrated that males regarded the first mating highly, and were more prudent in subsequent mating. These males' strategies may contribute to the viability of the offspring.

  5. Mating with an allopatric male triggers immune response and decreases longevity of ant queens.

    Science.gov (United States)

    Schrempf, A; von Wyschetzki, K; Klein, A; Schrader, L; Oettler, J; Heinze, J

    2015-07-01

    In species with lifelong pair bonding, the reproductive interests of the mating partners are aligned, and males and females are expected to jointly maximize their reproductive success. Mating increases both longevity and fecundity of female reproductives (queens) of the ant Cardiocondyla obscurior, indicating a tight co-evolution of mating partners. Here, we show that mating with a male from their own population increases lifespan and reproductive success of queens more than mating with a male from a different population, with whom they could not co-evolve. A comparison of transcriptomes revealed an increased expression of genes involved in immunity processes in queens, which mated with males from a different population. Increased immune response might be proximately associated with decreased lifespan. Our study suggests a synergistic co-evolution between the sexes and sheds light on the proximate mechanisms underlying the decreased fitness of allopatrically mated queens. © 2015 John Wiley & Sons Ltd.

  6. 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

    2017-03-01

    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.

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

    Science.gov (United States)

    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.

  8. 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.

  9. 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.

  10. 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

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

    Directory of Open Access Journals (Sweden)

    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].

  12. Roles of Female and Male Genotype in Post-Mating Responses in Drosophila melanogaster.

    Science.gov (United States)

    Delbare, Sofie Y N; Chow, Clement Y; Wolfner, Mariana F; Clark, Andrew G

    2017-10-30

    Mating induces a multitude of changes in female behavior, physiology, and gene expression. Interactions between female and male genotype lead to variation in post-mating phenotypes and reproductive success. So far, few female molecules responsible for these interactions have been identified. Here, we used Drosophila melanogaster from 5 geographically dispersed populations to investigate such female × male genotypic interactions at the female transcriptomic and phenotypic levels. Females from each line were singly-mated to males from the same 5 lines, for a total of 25 combinations. Reproductive output and refractoriness to re-mating were assayed in females from the 25 mating combinations. Female × male genotypic interactions resulted in significant differences in these post-mating phenotypes. To assess whether female × male genotypic interactions affect the female post-mating transcriptome, next-generation RNA sequencing was performed on virgin and mated females at 5 to 6 h post-mating. Seventy-seven genes showed strong variation in mating-induced expression changes in a female × male genotype-dependent manner. These genes were enriched for immune response and odorant-binding functions, and for expression exclusively in the head. Strikingly, variation in post-mating transcript levels of a gene encoding a spermathecal endopeptidase was correlated with short-term egg production. The transcriptional variation found in specific functional classes of genes might be a read-out of female × male compatibility at a molecular level. Understanding the roles these genes play in the female post-mating response will be crucial to better understand the evolution of post-mating responses and related conflicts between the sexes. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  13. Genetic dissimilarity between mates, but not male heterozygosity, influences divorce in schistosomes.

    Directory of Open Access Journals (Sweden)

    Sophie Beltran

    Full Text Available BACKGROUND: Correlational studies strongly suggest that both genetic similarity and heterozygosity can influence female mate choice. However, the influence of each variable has usually been tested independently, although similarity and heterozygosity might be correlated. We experimentally determined the relative influence of genetic similarity and heterozygosity in divorce and re-mating in the monogamous endoparasite Schistosoma mansoni. METHODOLOGY/PRINCIPAL FINDINGS: We performed sequential infections of vertebrate hosts with controlled larval populations of parasites, where sex and individual genetic diversity and similarity were predetermined before infection. Divorce rate increased significantly when females were given the opportunity to increase genetic dissimilarity through re-mating with a new partner, independently of the intensity of male-male competition. We found however no evidence for females attempting to maximize the level of heterozygosity of their reproductive partner through divorce. CONCLUSIONS/SIGNIFICANCE: Female preference for genetically dissimilar males should result in more heterozygous offspring. Because genetic heterozygosity might partly determine the ability of parasites to counter host resistance, adaptive divorce could be an important factor in the evolutionary arms race between schistosomes and their hosts.

  14. 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.

  15. Male resource defense mating system in primates? An experimental test in wild capuchin monkeys.

    Directory of Open Access Journals (Sweden)

    Barbara Tiddi

    Full Text Available Ecological models of mating systems provide a theoretical framework to predict the effect of the defendability of both breeding resources and mating partners on mating patterns. In resource-based mating systems, male control over breeding resources is tightly linked to female mating preference. To date, few field studies have experimentally investigated the relationship between male resource control and female mating preference in mammals due to difficulties in manipulating ecological factors (e.g., food contestability. We tested the within-group male resource defense hypothesis experimentally in a wild population of black capuchin monkeys (Sapajus nigritus in Iguazú National Park, Argentina. Sapajus spp. represent an ideal study model as, in contrast to most primates, they have been previously argued to be characterized by female mate choice and a resource-based mating system in which within-group resource monopolization by high-ranking males drives female mating preference for those males. Here, we examined whether females (N = 12 showed a weaker preference for alpha males during mating seasons in which food distribution was experimentally manipulated to be less defendable relative to those in which it was highly defendable. Results did not support the within-group male resource defense hypothesis, as female sexual preferences for alpha males did not vary based on food defendability. We discuss possible reasons for our results, including the possibility of other direct and indirect benefits females receive in exercising mate choice, the potential lack of tolerance over food directed towards females by alpha males, and phylogenetic constraints.

  16. Rapid diversification of male genitalia and mating strategies in Ohomopterus ground beetles.

    Science.gov (United States)

    Takami, Y; Sota, T

    2007-07-01

    We analysed evolutionary diversification and covariation in male genitalia and four mating traits related to sexual selection, i.e. testis size, spermatophore size, copulation duration and post-copulatory guarding duration, in Ohomopterus ground beetles using phylogenetically independent contrasts. Male genital size and mating duration have evolved more rapidly than body size and the other traits studied. Male genital size was negatively correlated with copulation duration, suggesting that elongated male genitalia may enable decreased time investment in a single copulation because it is more effective at facilitating spermatophore deposition. Male genital size was positively correlated with spermatophore size, suggesting coevolution between offensive and defensive male mating tactics because the elongated male genitalia may be advantageous in displacement of rivals' plug-like spermatophores, and decreased mating duration may intensify sperm competition. Thus, the remarkable diversity of male genitalia in Ohomopterus may have been facilitated by the interplay between inter- and intrasexual selection processes.

  17. Mating success of males with and without wing patch in Drosophila biarmipes.

    Science.gov (United States)

    Hegde, S N; Chethan, B K; Krishna, M S

    2005-10-01

    Some males of D. biarmipes--synonym of D. rajasekari and D. raychaudhuri have a black patch on the wing. The patch extends from the apical margin of wing to the third longitudinal vein. Field and laboratory studies have been carried out in D. biarmipes to study role of male's wing patch in mating success. The field study shows that nature favors D. biarmipes males with patch. Although males without patch mated, males with patch have higher mating success suggesting the role of wing patch during courtship. Further, among mating males, males with patch had longer wings than males without patch. During courtship, males with patch oriented and mated faster; performed courtship acts such as tapping, scissoring, vibration, licking and twist dance more times than males without patch in both competitive and non-competitive situations. The results indicate that there is a casual relationship between the presence of wing patch, mating speed and success. Also there is a correlation between presence of wing patch, size of the flies and mating success.

  18. 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.

  19. Cue lure and the mating behavior of male melon flies (Diptera: Tephritidae)

    International Nuclear Information System (INIS)

    Shelly, T.E.; Villalobos, E.M.

    1995-01-01

    Laboratory tests were conducted to assess the effect of the parapheromone cue lure on the mating behavior of male Bactrocera cucurbitae (Coquillett). Exposure to cue lure resulted in a short-term mating advantage. For wild flies, treated males that fed on cue lure on the day of testing, or 1 day prior to testing, mated more frequently than control males that had no prior exposure to cue lure. However, control and treated males had similar mating success in tests performed 3 or 7 days after the treated males were exposed to the lure. Exposure to cue lure also increased the mating success of mass-reared, irradiated males relative to unexposed wild males, though this advantage was evident for only 1 day following exposure. Cue lure appeared to enhance mating performance by increasing male wing-fanning activity but not the attractiveness of the signal per se. A field study revealed that irradiated males exposed to cue lure 1 week prior to release were less likely to be captured (in Steiner traps baited with cue lure and naled) than unexposed males. These findings suggest that exposure of sterile males to cue lure might improve the effectiveness of sterile insect release as well as enable simultaneous control programs of sterile insect release and male annihilation

  20. Azadirachtin impact on mate choice, female sexual receptivity and male activity in Drosophila melanogaster (Diptera: Drosophilidae).

    Science.gov (United States)

    Aribi, N; Oulhaci, M C; Kilani-Morakchi, S; Sandoz, J C; Kaiser, L; Denis, B; Joly, D

    2017-11-01

    Azadirachtin, a neem compound (Azadirachta indica) with medical and anti-insect properties, is one the most successful botanical pesticides in agricultural use. However, its controversial impact on non-targeted species and its mechanism of action need to be clarified. In addition, Azadirachtin impact on pre- and post-mating traits remains largely undocumented. The current study examined the effects of Azadirachtin on Drosophila melanogaster as a non-target and model species. Azadirachtin was applied topically at its LD 50 (0.63μg) on the day of adult emergence and its effect was evaluated on several traits of reproductive behavior: mate choice, male activity, female sexual receptivity, sperm storage and female sterility. In choice and no choice conditions, only male treatment reduced mating probability. Female treatment impaired mating probability only when males had the choice. Males' mating ability may have been impaired by an effect of the treatment on their mobility. Such an effect was observed in the actimeter, which revealed that treated males were less active than untreated ones, and this effect persisted over 8days. Azadirachtin treatment had, however, no effect on the nycthemeral rhythm of those males. Even when mating occurred, Azadirachtin treatment impaired post-mating responses especially when females or both sexes were treated: remating probability increases and female fertility (presence of larvae) decreases. No impairment was observed on the efficiency of mating, evaluated by the presence of sperm in the spermatheca or the ventral receptacle. Male treatment only had no significant effect on these post-mating responses. These findings provide clear evidence that Azadirachtin alters the reproductive behavior of both sexes in D. melanogaster via mating and post-mating processes. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Alternative male mating behaviour in the two-spotted spider mite: dependence on age and density

    NARCIS (Netherlands)

    Sato, Y.; Sabelis, M.W.; Egas, M.

    2014-01-01

    Highlights • We investigated alternative male mating behaviour in the two-spotted spider mite. • We found no differences between genetic lines of fighting and sneaking behaviour. • The proportion of sneaker males changed with male density and with male age. • In competition with old males, young

  2. 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.

  3. 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.

  4. Strong reproductive skew among males in the multiply mated swordtail Xiphophorus multilineatus (Teleostei).

    Science.gov (United States)

    Luo, J; Sanetra, M; Schartl, M; Meyer, A

    2005-01-01

    Male swordtails in the genus Xiphophorus display a conspicuous ventral elongation of the caudal fin, the sword, which arose through sexual selection due to female preference. Females mate regularly and are able to store sperm for at least 6 months. If multiple mating is frequent, this would raise the intriguing question about the role of female choice and male-male competition in shaping the mating system of these fishes. Size-dependent alternate mating strategies occur in Xiphophorus; one such strategy is courtship with a sigmoid display by large dominant males, while the other is gonopodial thrusting, in which small subordinate males sneak copulations. Using microsatellite markers, we observed a frequency of multiple paternity in wild-caught Xiphophorus multilineatus in 28% of families analyzed, but the actual frequency of multiple mating suggested by the correction factor PrDM was 33%. The number of fathers contributing genetically to the brood ranged from one to three. Compared to other species in the family Poeciliidae, both frequency and degree of multiple paternity were low. Paternity was found to be highly skewed, with one male on average contributing more than 70% to the offspring. Hence in this Xiphophorus mating system, typically one male dominates and sneaker males do not appear to be particularly effective. Postcopulatory mechanisms, however, such as sperm competition, are also indicated by our data, using sex-linked phenotypes among the offspring.

  5. Morphology and ornamentation in male frigatebirds: variation with age-class and mating status

    DEFF Research Database (Denmark)

    Madsen, Vinni; Dabelsteen, Torben; Osorio, Daniel

    2007-01-01

    of white in the plumage identifies three age classes of nonjuvenile male. Here we investigate how morphological and secondary sexual traits correlate with age class and mating status. Even though several age class-related differences in morphology and visual appearance can be identified, the only features...... with age class, reflecting an increase in gular pouch size. This implies that females prefer older or possibly more experienced or viable males. Drumming cadence speed and stability might reflect male stamina. Apart from the acoustic differences with mating status, there is a nonsignificant tendency...... for back-feather iridescence to be of shorter reflectance wavelength spectra in mated than in unmated males, which, when combined with acoustic variables, improves prediction of age class and mating status....

  6. Gay male attraction toward muscular men: does mating context matter?

    Science.gov (United States)

    Varangis, Eleanna; Lanzieri, Nicholas; Hildebrandt, Tom; Feldman, Matthew

    2012-03-01

    The purpose of this study was to examine gay men's perceived attractiveness of male figures based on short-term and long-term partner contexts. A sample of 190 gay adult men rated the attractiveness of line-drawings depicting male figures varying systematically in muscularity and body fat percentage in both short-term and long-term dating contexts. Mixed effects modeling was used to estimate the effects of figure (muscularity and body fat), dating context (short-term vs. long-term), and individual rater characteristics on attractiveness ratings. Results indicated that figure muscularity and body-fat had significant non-linear (i.e., quadratic) relationships with attractiveness ratings, and short-term dating context was associated with more discriminating ratings of attractiveness. Interactions between individual characteristics and figure characteristics indicated that the more available the individual and lower body fat, the more discriminating they were in ratings of attractiveness. The implications for future investigations considering both object and observer characteristics of attractiveness preferences are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. The complex interplay between macronutrient intake, cuticular hydrocarbon expression and mating success in male decorated crickets.

    Science.gov (United States)

    Rapkin, J; Jensen, K; House, C M; Sakaluk, S K; Sakaluk, J K; Hunt, J

    2017-04-01

    The condition dependence of male sexual traits plays a central role in sexual selection theory. Relatively little, however, is known about the condition dependence of chemical signals used in mate choice and their subsequent effects on male mating success. Furthermore, few studies have isolated the specific nutrients responsible for condition-dependent variation in male sexual traits. Here, we used nutritional geometry to determine the effect of protein (P) and carbohydrate (C) intake on male cuticular hydrocarbon (CHC) expression and mating success in male decorated crickets (Gryllodes sigillatus). We show that both traits are maximized at a moderate-to-high intake of nutrients in a P:C ratio of 1 : 1.5. We also show that female precopulatory mate choice exerts a complex pattern of linear and quadratic sexual selection on this condition-dependent variation in male CHC expression. Structural equation modelling revealed that although the effect of nutrient intake on mating success is mediated through condition-dependent CHC expression, it is not exclusively so, suggesting that other traits must also play an important role. Collectively, our results suggest that the complex interplay between nutrient intake, CHC expression and mating success plays an important role in the operation of sexual selection in G. sigillatus. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

  8. Age-dependent male mating tactics in a spider mite — A life-history perspective

    NARCIS (Netherlands)

    Sato, Y.; Rühr, P.T.; Schmitz, H.; Egas, M.; Blanke, A.

    2016-01-01

    Males often fight with rival males for access to females. However, some males display nonfighting tactics such as sneaking, satellite behavior, or female mimicking. When these mating tactics comprise a conditional strategy, they are often thought to be explained by resource holding potential (RHP),

  9. Variability of female responses to conspecific vs. heterospecific male mating calls in polygynous deer: an open door to hybridization?

    Directory of Open Access Journals (Sweden)

    Megan T Wyman

    Full Text Available Males of all polygynous deer species (Cervinae give conspicuous calls during the reproductive season. The extreme interspecific diversity that characterizes these vocalizations suggests that they play a strong role in species discrimination. However, interbreeding between several species of Cervinae indicates permeable interspecific reproductive barriers. This study examines the contribution of vocal behavior to female species discrimination and mating preferences in two closely related polygynous deer species known to hybridize in the wild after introductions. Specifically, we investigate the reaction of estrous female red deer (Cervus elaphus to playbacks of red deer vs. sika deer (Cervus nippon male mating calls, with the prediction that females will prefer conspecific calls. While on average female red deer preferred male red deer roars, two out of twenty females spent more time in close proximity to the speaker broadcasting male sika deer moans. We suggest that this absence of strict vocal preference for species-specific mating calls may contribute to the permeability of pre-zygotic reproductive barriers observed between these species. Our results also highlight the importance of examining inter-individual variation when studying the role of female preferences in species discrimination and intraspecific mate selection.

  10. The effect of methyl eugenol exposure on subsequent mating performance of sterile males of the oriental fruit fly, Bactrocera dorsalis

    International Nuclear Information System (INIS)

    Ji Qing'e; Guo Qingliang; Chen Jiahua

    2011-01-01

    The effect of methyl eugenol (ME) on the total times of mating, consecutive mating, mating competitiveness, multiple mating, and the incidence of wild female remating were studied in sterile males from a genetic sexing strain of Bactrocera dorsalis (Hendel). Male pupae were irradiated at dose of 100 Gy by 137 Cs at 2 d before emergence and the dose rate was 1.00 Gy/min. Sexually mature 10 day old sterile males were fed ME, while Non-ME-fed sterile males and normal wild males were used as control, and wild females as mating partners. The results showed that some ME-fed sterile males could mate continuously up to nine times, but the total times of consecutive mating and the mean value of continuous mating times were not significant (P > 0.05) compared with the control. The total mating times of ME-fed sterile males was 344.33 ± 12.55 and the mean value was 6.88 ± 0.25, but both have no significant difference compared with the control. The mating success rate of ME-fed and non-ME-fed sterile males mated with wild females were 44.67 ± 2.40% and 22.00 ± 2.31% separately. There were significant differences between them (t = -6.8, P = 0.002). The outcomes were that feeding on ME did not increase the frequency of multiple mating by sterile males, but significantly increased the mating competitiveness of sterile males against wild males. At the same time, sterile males fed ME did not significantly affect the remating of wild females 5 days after the initial mating, but increased the remating frequency of females 10 and 15 days after the initial mating. (authors)

  11. The effect of methyl eugenol exposure on subsequent mating performance of sterile males of the oriental fruit fly, bactrocera dorsalis

    International Nuclear Information System (INIS)

    Ji Qing'e; Guo Qingliang; Chen Jiaye

    2012-01-01

    The effect of methyl eugenol (ME) on the total times of mating, consecutive mating, mating competitiveness, multiple mating, and the incidence of wild female remating were studied in sterile males from a genetic sexing strain of Bactrocera dorsalis (Hendel). Male pupae were irradiated at dose of 100 Gy by 137 Cs at 2 d before emergence and the dose rate was 1.00 Gy/min. Sexually mature 10 day old sterile males were fed ME, while Non-ME-fed sterile males and normal wild males were used as control, and wild females as mating partners. The results showed that some ME-fed sterile males could mate continuously up to nine times, but the total times of consecutive mating and the mean value of continuous mating times were not significant (P> 0.05) compared with the control. The total mating times of ME-fed sterile males was 344.33±12.55 and the mean value was 6.88±0.25, but both have no significant difference compared with the control. The mating success rate of ME-fed and non- ME-fed sterile males mated with wild females were (44.67±2.40)% and (22.00±2.31)% separately. There were significant differences between them (t = -6.8, P = 0.002). The outcomes were that feeding on ME did not increase the frequency of multiple mating by sterile males, but significantly increased the mating competitiveness of sterile males against wild males. At the same time, sterile males fed ME did not significantly affect the remating of wild females 5 days after the initial mating, but increased the remating frequency of females 10 and 15 days after the initial mating. (authors)

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

    Science.gov (United States)

    Kuduk, Katarzyna; Babik, Wieslaw; Bellemain, Eva; Valentini, Alice; Zedrosser, Andreas; Taberlet, Pierre; Kindberg, Jonas; Swenson, Jon E; Radwan, Jacek

    2014-01-01

    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.

  13. 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.

  14. Reproductive behavior and physiology of Dacus oleae: egg hatch in females mated successively with normal and gamma sterilized males and vice versa

    International Nuclear Information System (INIS)

    Economopoulos, A.P.; Giannakakis, A.; Voyadjoglou, A.V.

    1976-01-01

    In Dacus oleae (Gmelin), a 2nd mating by an 8-krad gamma ray-sterilized male reduced egg hatch immediately to zero or near-zero in ca. 40-55 percent of individually-tested females. In another 50 percent of females, egg hatch was reduced to between 5 to 70 percent, while in fewer than 10 percent of females, egg hatch showed no change. The above was true for females reared on artificial diet for more than 50 generations and mated with same type males, as well as females reared on olives for 6 to 8 generations and mated first with same type males and 2nd with artificially-reared sterilized males. When the 2nd males were treated at 15 krad the effect on egg hatch was smaller. When the 2nd males were treated at 8 krad and had depleted their sperm, by repeated matings, they produced small or no-effect on egg hatch. When artificially-reared females mated first with a sterilized and second with a normal same type male, egg hatch increased from 0 to 5 percent to 70 to 100 percent in 50 to 55 percent of the cases. In another 43 percent of cases, egg hatch increased to levels between 5 to 70 percent. The combined findings from the 2 mating sequence types are as follows. After females mated first with normal males, egg hatch was above 80 percent in the population; a 2nd mating with 8-krad-sterilized males produced an immediate decrease of egg hatch to ca. 25 percent, decreasing slowly thereafter. When the 1st male was sterilized and the 2nd normal, egg hatch increased to ca. 70 percent, decreasing slowly thereafter

  15. Age-dependent male mating tactics in a spider mite-A life-history perspective.

    Science.gov (United States)

    Sato, Yukie; Rühr, Peter T; Schmitz, Helmut; Egas, Martijn; Blanke, Alexander

    2016-10-01

    Males often fight with rival males for access to females. However, some males display nonfighting tactics such as sneaking, satellite behavior, or female mimicking. When these mating tactics comprise a conditional strategy, they are often thought to be explained by resource holding potential (RHP), that is, nonfighting tactics are displayed by less competitive males who are more likely to lose a fight. The alternative mating tactics, however, can also be explained by life-history theory, which predicts that young males avoid fighting, regardless of their RHP, if it pays off to wait for future reproduction. Here, we test whether the sneaking tactic displayed by young males of the two-spotted spider mite can be explained by life-history theory. We tested whether young sneaker males survive longer than young fighter males after a bout of mild or strong competition with old fighter males. We also investigated whether old males have a more protective outer skin-a possible proxy for RHP-by measuring cuticle hardness and elasticity using nanoindentation. We found that young sneaker males survived longer than young fighter males after mild male competition. This difference was not found after strong male competition, which suggests that induction of sneaking tactic is affected by male density. Hardness and elasticity of the skin did not vary with male age. Given that earlier work could also not detect morphometric differences between fighter and sneaker males, we conclude that there is no apparent increase in RHP with age in the mite and age-dependent male mating tactics in the mite can be explained only by life-history theory. Because it is likely that fighting incurs a survival cost, age-dependent alternative mating tactics may be explained by life-history theory in many species when reproduction of old males is a significant factor in fitness.

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

    Directory of Open Access Journals (Sweden)

    Martin R Miller

    2007-07-01

    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. A character demonstrating the occurrence of mating in male Cactoblastis cactorum (Lepidoptera: Pyralidae)

    International Nuclear Information System (INIS)

    Marti, O.G.; Carpenter, J.E.

    2007-01-01

    The reproductive system of adult male Cactoblastis cactorum, the cactus moth, was examined to determine whether the mating status of males could be ascertained. In unmated males, the posterior portion of the primary ductus ejaculatorius simplex is opaque yellow in color and contains many small football-shaped hyaline granules 3-5 x 5-10 μm in size. In mated males, the posterior simplex is clear and contains no granules. The presence or absence of these characters was found to be highly reliable and should be of value in determining mating status in marked-recaptured males of this species in a sterile insect release program directed against Cactoblastis. (author)

  18. Showing Off in Humans: Male Generosity as a Mating Signal

    Directory of Open Access Journals (Sweden)

    Wendy Iredale

    2008-07-01

    Full Text Available We examined people's charity contributions while in the presence of an observer of the same sex, opposite sex, or no observer. Inspired by costly signaling theory, we hypothesized that men would be more generous in the presence of a potential mate. Men and women played a number of experimental games in which they could earn money. On completion of these games participants were asked what percentage of their earned money they would be willing to donate to charity. Our results show that men contribute more to charity when observed by a member of the opposite sex than by a member of the same sex or no observer. Conversely, female charity donations did not significantly vary across the three observer conditions. Findings support the notion that men's generosity might have evolved as a mating signal.

  19. The relevance of age and nutritional status on the mating competitiveness of medfly males (Diptera: Teprhitidae

    Directory of Open Access Journals (Sweden)

    Alzira Kelly Passos Roriz

    2013-10-01

    Full Text Available Results of previous investigations trying to ascertain which physiological factors are more important to the mating success of medfly males are controversial. In part, this controversy owes to the fact that each factor was evaluated by an independent study using different experimental designs and populations. In the present study we compare the roles of age and nutritional status (immature and adult phases on the mating competitiveness of Ceratitis capitata (Wiedemann, 1824 males. Three parameters were used to evaluate the male mating success: calling behavior (pheromone emission, lek participation and copulation (ability to be chosen by a female. Females gave preference to the males that were given a high protein diet in the larval phase. By contrast, females did not give preference to males that had been well-nourished in the adult phase only. The other parameters evaluated followed the same pattern: young males and males that had been fed a high protein diet during their immature phase had a greater participation in leks and called more often than older males and males that had been fed a diet poor in protein during their larval phase. Therefore, we conclude that the mating success of C. capitata males is determined both by age and nourishment during the immature stage.

  20. Terminal Investment Strategies and Male Mate choice: Extreme Tests of Bateman.

    Science.gov (United States)

    Andrade, Maydianne C B; Kasumovic, Michael M

    2005-11-01

    Bateman's principle predicts the intensity of sexual selection depends on rates of increase of fecundity with mating success for each sex (Bateman slopes). The sex with the steeper increase (usually males) is under more intense sexual selection and is expected to compete for access to the sex under less intense sexual selection (usually females). Under Bateman and modern refinements of his ideas, differences in parental investment are key to defining Bateman slopes and thus sex roles. Other theories predict sex differences in mating investment, or any expenditures that reduce male potential reproductive rate, can also control sex roles. We focus on sexual behaviour in systems where males have low paternal investment but frequently mate only once in their lifetimes, after which they are often killed by the female. Mating effort (=terminal investment) is high for these males, and many forms of investment theory might predict sex role reversal. We find no qualitative evidence for sex role reversal in a sample of spiders that show this extreme male investment pattern. We also present new data for terminally-investing redback spiders (Latrodectus hasselti). Bateman slopes are relatively steep for male redbacks, and, as predicted by Bateman, there is little evidence for role reversal. Instead, males are competitive and show limited choosiness despite wide variation in female reproductive value. This study supports the proposal that high male mating investment coupled with low parental investment may predispose males to choosiness but will not lead to role reversal. We support the utility of using Bateman slopes to predict sex roles, even in systems with extreme male mating investment.

  1. 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.

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

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    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.

  3. Consequences of snowy winters on male mating strategies and reproduction in a mountain ungulate.

    Science.gov (United States)

    Apollonio, Marco; Brivio, Francesca; Rossi, Iva; Bassano, Bruno; Grignolio, Stefano

    2013-09-01

    Alternative mating tactics (AMTs) are intrasexual variants in mating behaviour of several species ranging from arthropods to mammals. Male AMTs coexist between and within populations. In particular, male ungulates rarely adopt just one tactic throughout their lifetime. Tactics commonly change according to internal factors (age, body size, condition) and external conditions (weather, resources, predation, animal density). However, the influence of weather has not yet been investigated in upper vertebrates. Such influence may be relevant in species whose rutting period occurs late in fall or in winter, when environmental conditions and the snow cover in particular may vary considerably. We detected two AMTs in Alpine ibex (Capra ibex) males: older and full-grown males mainly adopted the tending tactic, while younger males usually pursued an alternative one (coursing tactic). Weather was found to influence the use of AMTs by males: in snowy mating seasons, the coursing tactic was no longer used due to difficulties in moving through deep snow. In snowy rutting periods, males appeared to delay or even avoid mating activities and a decrease of births was reported in the second part of the following birth season. Snow cover may have a negative effect on population dynamics by reducing the recruitment and on population genetic variability, as a consequence of poorer mating opportunities. Studies on factors affecting mating behaviour and leading to a reduced availability of mates and a decrease in female productivity are especially relevant in species, like Alpine ibex, whose genetic variability is low. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Sterility and mating competitiveness of male ceratitis capitata as affected by gamma radiation and di methane insecticide. Vol. 4

    Energy Technology Data Exchange (ETDEWEB)

    Wakid, A M; Fadel, A M; El-Akhdar, E A [Radiobiology Department, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); Helmy, N M [Entomology Department, Faculty of Science, Zagazig University, Benha, (Egypt)

    1996-03-01

    In the present work, the effects of pupal gamma-irradiation (50, 70, 90 Gy), or adult treatment with dimethoate insecticide (0.93 ppm) on the male sterility and mating competitiveness of the medfly, ceratitis capitata (Wied.) were studied. Results indicated that treatment of the adult medfly with dimethoate had no clear effect on male fertility whether this male mated with treated or normal females. However, gamma irradiation drastically decreased hatch ability of eggs laid by normal or treated (dimethoate) females, when mated with irradiated males all gamma doses. This reduction in egg hatch ability increased increased with increasing gamma dose. Irradiated females did not lay eggs at any of the gamma doses used. At all mating combinations, the male mating competitiveness was decreased especially when irradiated males were confined with treated males for mating with normal or treated females. Results are indicated and discussed in the text. 4 figs.

  5. Sterility and mating competitiveness of irradiated males of the large milkweed bug, Oncopeltus fasciatus

    International Nuclear Information System (INIS)

    Moursy, L.E.; Eesa, N.M.; Cutkomp, L.K.

    1991-01-01

    Low level gamma radiation adversely affected the reproductive capacity of the large milkweed bug, oncopeltus fasciatus dallas, as expressed by fecundity and fertility. Treatment was applied to late 5th instar male nymphs. Both fecundity and fertility decreased linearly with the treatment dose and complete sterility occurred when males were exposed to 6 kilorads and mated with normal females. The mating competitiveness of O. fasciatus males irradiated at late 5th instar nymphs decreased linearly with the treatment dose. A strong negative relationship existed between dose and mating competitiveness ( r = -0.93). A 3:2 ratio of irradiated males at 4 kilorads ( as late 5th instar as many progeny as normal in F 1 .2 tab.,1 fig

  6. 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...... 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...

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

    Science.gov (United States)

    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.

  9. The impact of Wolbachia, male age and mating history on cytoplasmic incompatibility and sperm transfer in Drosophila simulans.

    Science.gov (United States)

    Awrahman, Z A; Champion de Crespigny, F; Wedell, N

    2014-01-01

    Most insects harbour a variety of maternally inherited endosymbionts, the most widespread being Wolbachia pipientis that commonly induce cytoplasmic incompatibility (CI) and reduced hatching success in crosses between infected males and uninfected females. High temperature and increasing male age are known to reduce the level of CI in a variety of insects. In Drosophila simulans, infected males have been shown to mate at a higher rate than uninfected males. By examining the impact of mating rate independent of age, this study investigates whether a high mating rate confers an advantage to infected males through restoring their compatibility with uninfected females over and above the effect of age. The impact of Wolbachia infection, male mating rate and age on the number of sperm transferred to females during copulation and how it relates to CI expression was also assessed. As predicted, we found that reproductive compatibility was restored faster in males that mate at higher rate than that of low mating and virgin males, and that the effect of mating history was over and above the effect of male age. Nonvirgin infected males transferred fewer sperm than uninfected males during copulation, and mating at a high rate resulted in the transfer of fewer sperm per mating irrespective of infection status. These results indicate that the advantage to infected males of mating at a high rate is through restoration of reproductive compatibility with uninfected females, whereas uninfected males appear to trade off the number of sperm transferred per mating with female encounter rate and success in sperm competition. This study highlights the importance Wolbachia may play in sexual selection by affecting male reproductive strategies. © 2013 The Authors. Journal of Evolutionary Biology © 2013 European Society For Evolutionary Biology.

  10. Sperm Production and Mating Ability Among F1 males of Heliothis Virescens (F.)

    International Nuclear Information System (INIS)

    Ibrahim, S.M.; Sallam, H.A.

    2000-01-01

    Adult males of Heliothis Virescens (F.) less than 12 h-old were irradiated with sub sterilizing doses of 50,100 or 125 Gy then crossed with untreated virgin females. The resulted F 1 males 1-and 4-day-old were dissected to determine the production of eupyrene sperm bundles and its accumulation in the duplex region. In another test, an experiment was conducted to determine the ability of F 1 males to mate and transfer sperm to untreated females. The data show that, eupyrene sperm bundles were not found in the duplex of newly emerged males immediately after emergence Number of eupyrene sperm bundles descended to duplex was significantly affected at 125 Gy during the first dark: light cycle of sperm descended. Accumulation of eupyrene sperm bundles of unmated F 1 males was significantly reduced at 100 and 125 Gy. It is apparent that the first mating is the most important, even in the control, and the rate of females that achieved successful mating with F 1 males after the first ejaculate was markedly reduced. This reduction was directly related to the dose level of irradiation. The proportion of mated females without and sperm, with apyrene sperms only or those with reduced amount of eupyrene sperms was generally increased as the dose applied to P 1 increased

  11. 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.

  12. 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

  13. Evaluation of radiation sensitivity and mating performance of Glossina brevipalpis males.

    Directory of Open Access Journals (Sweden)

    Chantel J de Beer

    2017-03-01

    Full Text Available Area-wide integrated pest management strategies that include a sterile insect technique component have been successfully used to eradicate tsetse fly populations in the past. To ensure the success of the sterile insect technique, the released males must be adequately sterile and be able to compete with their native counterparts in the wild.In the present study the radiation sensitivity of colonised Glossina brevipalpis Newstead (Diptera; Glossinidae males, treated either as adults or pupae, was assessed. The mating performance of the irradiated G. brevipalpis males was assessed in walk-in field cages. Glossina brevipalpis adults and pupae were highly sensitive to irradiation, and a dose of 40 Gy and 80 Gy induced 93% and 99% sterility respectively in untreated females that mated with males irradiated as adults. When 37 to 41 day old pupae were exposed to a dose of 40 Gy, more than 97% sterility was induced in untreated females that mated with males derived from irradiated pupae. Males treated as adults with a dose up to 80 Gy were able to compete successfully with untreated fertile males for untreated females in walk-in field cages.The data emanating from this field cage study indicates that, sterile male flies derived from the colony of G. brevipalpis maintained at the Agricultural Research Council-Onderstepoort Veterinary Institute in South Africa are potential good candidates for a campaign that includes a sterile insect technique component. This would need to be confirmed by open field studies.

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

    Science.gov (United States)

    Keren-Rotem, Tammy; Levy, Noga; Wolf, Lior; Bouskila, Amos; Geffen, Eli

    2016-01-01

    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. PMID:27409771

  15. 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.

  16. Effects of social information on life history and mating tactics of males in the orb-web spider Argiope bruennichi.

    Science.gov (United States)

    Cory, Anna-Lena; Schneider, Jutta M

    2018-01-01

    Informed mating decisions are often based on social cues providing information about prospective mating opportunities. Social information early in life can trigger developmental modifications and influence later mating decisions. A high adaptive value of such adjustments is particularly obvious in systems where potential mating rates are extremely limited and have to be carried out in a short time window. Males of the sexually cannibalistic spider Argiope bruennichi can achieve maximally two copulations which they can use for one (monogyny) or two females (bigyny). The choice between these male mating tactics should rely on female availability that males might assess through volatile sex pheromones emitted by virgin females. We predict that in response to those female cues, males of A. bruennichi should mature earlier and at a smaller body size and favor a bigynous mating tactic in comparison with controls. We sampled spiders from two areas close to the Southern and Northern species range to account for differences in mate quality and seasonality. In a fully factorial design, half of the subadult males from both areas obtained silk cues of females, while the other half remained without female exposure. Adult males were subjected to no-choice mating tests and could either monopolize the female or leave her (bigyny). We found that Southern males matured later and at a larger size than Northern males. Regardless of their origin, males also shortened the subadult stage in response to female cues, which, however, had no effects on male body mass. Contrary to our prediction, the frequencies of mating tactics were unaffected by the treatment. We conclude that while social cues during late development elicit adaptive life history adjustments, they are less important for the adjustment of mating decisions. We suggest that male tactics mostly rely on local information at the time of mate search.

  17. Fitness of Mass-Reared Males of Anastrepha obliqua (Diptera: Tephritidae) Resulting From Mating Competition Tests in Field Cages.

    Science.gov (United States)

    Hernández, Emilio; Liedo, Pablo; Toledo, Jorge; Montoya, Pablo; Perales, Hugo; Ruiz-Montoya, Lorena

    2017-12-05

    The sterile insect technique uses males that have been mass-reared in a controlled environment. The insects, once released in the field, must compete to mate. However, the mass-rearing condition supposes a loss of fitness that will be noticeable by wild females. To compare the fitness of wild males and mass-reared males, three competition settings were established. In setting 1, wild males, mass-reared males and wild females were released in field cages. In setting 2, wild females and wild males were released without competition, and in setting 3, mass-reared males and mass-reared females were also released without competition. Male fitness was based on their mating success, fecundity, weight and longevity. The fitness of the females was measured based on weight and several demographic parameters. The highest percentage of mating was between wild males and wild females between 0800 and 0900 h in the competition condition, while the mass-reared males started one hour later. The successful wild males weighed more and showed longer mating times, greater longevity and a higher number of matings than the mass-reared males. Although the mass-reared males showed the lowest percentage of matings, their fecundity when mating with wild females indicated a high fitness. Since the survival and fecundity of wild females that mated with mass-reared males decreased to become similar to those of mass-reared females that mated with mass-reared males, females seem to be influenced by the type of male (wild or mass-reared). © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  18. Gene expression divergence and nucleotide differentiation between males of different color morphs and mating strategies in the ruff

    Science.gov (United States)

    Ekblom, Robert; Farrell, Lindsay L; Lank, David B; Burke, Terry

    2012-01-01

    By next generation transcriptome sequencing, it is possible to obtain data on both nucleotide sequence variation and gene expression. We have used this approach (RNA-Seq) to investigate the genetic basis for differences in plumage coloration and mating strategies in a non-model bird species, the ruff (Philomachus pugnax). Ruff males show enormous variation in the coloration of ornamental feathers, used for individual recognition. This polymorphism is linked to reproductive strategies, with dark males (Independents) defending territories on leks against other Independents, whereas white morphs (Satellites) co-occupy Independent's courts without agonistic interactions. Previous work found a strong genetic component for mating strategy, but the genes involved were not identified. We present feather transcriptome data of more than 6,000 de-novo sequenced ruff genes (although with limited coverage for many of them). None of the identified genes showed significant expression divergence between males, but many genetic markers showed nucleotide differentiation between different color morphs and mating strategies. These include several feather keratin genes, splicing factors, and the Xg blood-group gene. Many of the genes with significant genetic structure between mating strategies have not yet been annotated and their functions remain to be elucidated. We also conducted in-depth investigations of 28 pre-identified coloration candidate genes. Two of these (EDNRB and TYR) were specifically expressed in black- and rust-colored males, respectively. We have demonstrated the utility of next generation transcriptome sequencing for identifying and genotyping large number of genetic markers in a non-model species without previous genomic resources, and highlight the potential of this approach for addressing the genetic basis of ecologically important variation. PMID:23145334

  19. A potential mate influences reproductive development in female, but not male, pine siskins.

    Science.gov (United States)

    Watts, Heather E; Edley, Bruce; Hahn, Thomas P

    2016-04-01

    The role of photoperiod in avian reproductive timing has been well studied, and we are increasingly recognizing the roles of other environmental cues such as social cues. However, few studies have evaluated the extent to which males and females of the same species respond similarly to the same type of cue. Moreover, previous studies have rarely examined how variation in the quality or nature of a given social cue might modulate its effect. Here, we examine the sensitivity of male and female pine siskins (Spinus pinus) to a potential mate as a stimulatory cue for gonadal recrudescence, and we investigate whether variation in the relationship between a bird and its potential mate modulates the effect of that potential mate. Birds were initially housed without opposite sex birds on a 12L:12D photoperiod with ad libitum food. After gonadal recrudescence had begun males and females were randomly paired with an opposite sex bird or housed alone. An additional group of males was paired with estradiol-implanted females. In males, these social treatments had no effect on testis length, cloacal protuberance length, luteinizing hormone (LH) levels, or testosterone levels. In females, presence of a potential mate had a significant and positive effect on ovary score, defeathering of the brood patch, and LH levels. Among paired birds, the degree of affiliation within a pair corresponded to the extent of reproductive development in females, but not males. Thus, reproductive timing in females appears to be sensitive to both the presence of a potential mate and her relationship with him. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Comparative mating and reproductive performance of radiation sterilized and radiation induced F1 sterile males of Earias vittella (Fabricius)

    International Nuclear Information System (INIS)

    Shantharam, K.; Tamhankar, A.J.; Harwalkar, M.R.

    1995-01-01

    Studies were conducted on mating behaviour and reproductive performance of a) Earias vittella (F.) males rendered sterile by exposing them to 300 Gy gamma rays and b) F 1 sterile males obtained by exposing parent male to 100 Gy gamma rays. For the study, males were allowed only one mating with a normal female. Results revealed that premating period, period in copula and per cent insects mating were not adversely affected in case of both types of sterile males and fecundity also remained unaffected. However, in both types of sterile males, incidence of spermatophore transfer without sperm was very large and such an occurrence (including reduced spermatophore transfer) was significantly higher in case of radiation sterilized males compared to the F 1 sterile males. Inability to produce and transfer spermatophore and/or sperm appeared to be a major cause behind the reduced mating competitiveness of both types of males. (author). 22 refs., 2 tabs

  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. 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...

  3. Personality traits, reproductive behaviour and alternative mating tactics in male European bitterling, Rhodeus amarus

    Czech Academy of Sciences Publication Activity Database

    Řežucha, Radomil; Smith, C.; Reichard, Martin

    2012-01-01

    Roč. 149, č. 5 (2012), s. 531-553 ISSN 0005-7959 R&D Projects: GA ČR GA206/09/1163 Institutional support: RVO:68081766 Keywords : alternative reproductive behaviour * animal personality * boldness * behavioural syndrome * mating system * sperm competition * territorial males Subject RIV: EG - Zoology Impact factor: 1.661, year: 2012

  4. The mating brain: early maturing sneaker males maintain investment into the brain also under fast body growth in Atlantic salmon (Salmo salar).

    Science.gov (United States)

    Kotrschal, Alexander; Trombley, Susanne; Rogell, Björn; Brannström, Ioana; Foconi, Eric; Schmitz, Monika; Kolm, Niclas

    It has been suggested that mating behaviours require high levels of cognitive ability. However, since investment into mating and the brain both are costly features, their relationship is likely characterized by energetic trade-offs. Empirical data on the subject remains equivocal. We investigated if early sexual maturation was associated with brain development in Atlantic salmon ( Salmo salar ), in which males can either stay in the river and sexually mature at a small size (sneaker males) or migrate to the sea and delay sexual maturation until they have grown much larger (anadromous males). Specifically, we tested how sexual maturation may induce plastic changes in brain development by rearing juveniles on either natural or ad libitum feeding levels. After their first season we compared brain size and brain region volumes across both types of male mating tactics and females. Body growth increased greatly across both male mating tactics and females during ad libitum feeding as compared to natural feeding levels. However, despite similar relative increases in body size, early maturing sneaker males maintained larger relative brain size during ad libitum feeding levels as compared to anadromous males and females. We also detected several differences in the relative size of separate brain regions across feeding treatments, sexes and mating strategies. For instance, the relative size of the cognitive centre of the brain, the telencephalon, was largest in sneaker males. Our data support that a large relative brain size is maintained in individuals that start reproduction early also during fast body growth. We propose that the cognitive demands during complex mating behaviours maintain a high level of investment into brain development in reproducing individuals.

  5. Mating-induced changes in olfactory-mediated behavior of laboratory-reared normal, sterile, and wild female Mediterranean fruit flies (Diptera: Tephritidae) mated to conspecific males

    International Nuclear Information System (INIS)

    Jang, E.B.; McInnis, D.O.; Lance, D.R.; Carvalho, L.A.

    1998-01-01

    Laboratory-reared normal, sterile, and wild female Mediterranean fruit flies, Ceratitis capitata (Wiedemann), were mated with laboratory-reared normal, sterile, and wild male flies to assess the ability of males to alter olfactory-mediated behavioral responses of females to male-produced pheromone or host fruit odor. Virgin females of all 3 types showed a preferential attraction and arrestment on yellow spheres emitting male-produced pheromone in a laboratory flight tunnel. Laboratory-reared normal and wild females mated to laboratory reared normal, sterile, or wild males switched their behavior showing strong preferential attraction to, arrestment on, and egg-laying in (for laboratory-reared females) yellow spheres emitting host fruit odor (guava) over male-produced pheromone. Sterile females did not show a significant switch in behavior except when mated to sterile males. The olfactory-mediated behavioral switch was most evident in the laboratory-reared normal female × laboratory-reared normal male mating. These findings suggest that irradiation of males inducing gamete sterility does not affect the factor(s) from the male accessory gland associated with altering female olfactory behavior. The ability of sterile males to alter adequately olfactory-mediated behavior of wild females is discussed in the context of the sterile insect technique for control of Mediterranean fruit flies in the field

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

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    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.

  7. Honeybee males use highly concentrated nectar as fuel for mating flights.

    Science.gov (United States)

    Hayashi, Masaki; Nakamura, Jun; Sasaki, Ken; Harano, Ken-Ichi

    Honeybees use nectar held in the crop as their main source of energy for flight but the mass of the crop nectar load may be a cost burden. This study investigated whether males of the honeybee Apis mellifera adjust their nectar fuel load and concentration to enhance the success of mating flights. When the crop content was compared between males staying in the hive and those departing, the latter group had the larger volume (median, 5.0μl; range, 0.0-17.8μl) and higher concentration (median, 71.6%; range, 49.0%-77.6%), indicating that departing males load concentrated nectar as fuel before mating flights. Moreover, the crop nectar concentration was significantly higher in departing males than in departing workers. These results suggest that concentrated nectar is advantageous to males because it provides more sugar for energy at lower mass and secures longer or more effective mating flights for higher chance of reproductive success. No significant effect of age was detected in crop volume, and concentration and amount of dissolved sugars in the crop content. In addition, laboratory experiments showed that males had only about 5μl of nectar in the crop soon after feeding, irrespective of fed volume (5-15μl), suggesting they do not hold much nectar in the crop but send it rapidly to the midgut, unlike workers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Male mate recognition via cuticular hydrocarbons facilitates sexual isolation between sympatric leaf beetle sister species.

    Science.gov (United States)

    Zhang, Bin; Xue, Huai-Jun; Song, Ke-Qing; Liu, Jie; Li, Wen-Zhu; Nie, Rui-E; Yang, Xing-Ke

    2014-11-01

    Chemical signals in insects have been documented to play an important role in mate recognition, and divergence in chemical signals can often cause sexual isolation between closely related species or populations within species. We investigated the role of cuticular hydrocarbons (CHCs), short distance chemical signals, in male mate recognition between the two sympatric elm leaf beetles, Pyrrhalta maculicollis and Pyrrhaltaaenescens. Mating experiments demonstrated that strong sexual isolation between the two species was driven by CHCs divergence. Males preferred to mate with conspecific females with intact conspecific CHCs or conspecific CHCs reapplied after removal. Males also preferred heterospecific females that were treated with conspecific CHCs. Chemical analysis showed that the CHC profiles differ significantly between species. In P. maculicollis dimethyl-branched alkanes between C29 and C35 account for the majority of the saturated alkanes while the CHC profile of P. aenescens mostly consisted of monomethyl-branched alkanes between C22 and C29. Additionally, some compounds, such as 12,18-diMeC32, 12,18-diMeC34, are unique to P. maculicollis. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

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    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.

  10. Experience of mating rivals causes males to modulate sperm transfer in the fly Drosophila pseudoobscura.

    Science.gov (United States)

    Price, Tom A R; Lizé, Anne; Marcello, Marco; Bretman, Amanda

    2012-12-01

    Male responses to risk of sperm competition play an important role in sexual selection, sexual conflict, and the evolution of mating systems. Such responses can combine behavioural and physiological processes, and can be mediated through different components of the ejaculate such as sperm numbers and seminal proteins. An additional level of ejaculate complexity is sperm heteromorphism, with the inclusion of non-fertilising parasperm in the ejaculate. We now test the response to rivals in a sperm heteromorphic species, Drosophila pseudoobscura, measuring the behavioural response and sperm transfer and, crucially, relating these to short-term fitness. Males respond to exposure to conspecific rivals by increasing mating duration, but do not respond to heterospecific rivals. In addition, after exposure to a conspecific rival, males increased the transfer of fertilising eusperm, but not non-fertilising parasperm. Males exposed to a conspecific rival also achieve higher offspring production. This suggests that the evolution of parasperm in flies was not driven by sperm competition and adds to the increasing evidence that males can make extremely sophisticated responses to mating competition. Copyright © 2012. Published by Elsevier Ltd.

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

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    Mats Olsson

    Full Text Available 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.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.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.

  12. Mating competitiveness and the effect of X-rays and aging on males of Tetranychus urticae (Acarina, Tetranychidae) in relation to genetic control

    International Nuclear Information System (INIS)

    Feldmann, A.M.

    1977-01-01

    Males of Tetranychus urticae Koch were irradiated with X-ray doses of 4, 8, 24 and 32 krad (which were applied to 0-1 day-old adult virgin males) and tested in mating competition with one-day-old non-irradiated males. A non-significant excess of parental females were mated to the unirradiated males. This consistent trend in favour of females, mated with unirradiated males was highly significant, when the results of all the experiments were bulked. This indicated that radiation impaired the mating competitiveness of males of T. urticae. Aging of irradiated males resulted in a significant decrease of male-mating competitiveness at least within 2 days after irradiation. When 24 krad X-rays irradiated males were tested in mating competition at different ages, with unirradiated males of equal age, it was demonstrated that the reduction in mating competitiveness of aging irradiated males is caused by accelerated aging due to the irradiation treatment

  13. The evolution of strategic male mating effort in an information transfer framework.

    Science.gov (United States)

    Engqvist, L; Taborsky, M

    2017-06-01

    Sperm competition theory predicts that males should use cues indicating the risk and intensity of sperm competition to tailor their sperm investment accordingly. Rival males are an important source of social information regarding sperm competition risk. However, revealing such information may not be in the rival males' interest. Here, we use a theoretical approach based on informed and uninformed games to investigate when information transfer about sperm competition risk to competitors is beneficial for a male, and when it is not. The results show that signalling to potential future mates that a female has already mated is beneficial when the signalling male has a sperm competition disadvantage, whereas it is unfavourable when the signaller has an advantage. The reason for this counterintuitive result is that the rival males' optimal response is to reduce sperm investment when the signaller has a disadvantage and, conversely, to increase investment when the signaller has an advantage. Furthermore, we analysed scenarios where males use alternative reproductive tactics. In this situation, signalling the awareness of sperm competition risk rarely pays; instead, it is beneficial to maintain an information advantage. Thus, it may be beneficial for bourgeois males to accept cuckoldry instead of revealing their sperm competition awareness to reproductive parasites. These results provide new insight into the evolution of communication between rivals in the context of sperm competition. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  14. Hormonal contraceptive use and mate retention behavior in women and their male partners.

    Science.gov (United States)

    Welling, Lisa L M; Puts, David A; Roberts, S Craig; Little, Anthony C; Burriss, Robert P

    2012-01-01

    Female hormonal contraceptive use has been associated with a variety of physical and psychological side effects. Women who use hormonal contraceptives report more intense affective responses to partner infidelity and greater overall sexual jealousy than women not using hormonal contraceptives. Recently, researchers have found that using hormonal contraceptives with higher levels of synthetic estradiol, but not progestin, is associated with significantly higher levels of self-reported jealousy in women. Here, we extend these findings by examining the relationship between mate retention behavior in heterosexual women and their male partners and women's use of hormonal contraceptives. We find that women using hormonal contraceptives report more frequent use of mate retention tactics, specifically behaviors directed toward their partners (i.e., intersexual manipulations). Men partnered with women using hormonal contraceptives also report more frequent mate retention behavior, although this relationship may be confounded by relationship satisfaction. Additionally, among women using hormonal contraceptives, the dose of synthetic estradiol, but not of synthetic progesterone, positively predicts mate retention behavior frequency. These findings demonstrate how hormonal contraceptive use may influence behavior that directly affects the quality of romantic relationships as perceived by both female and male partners. Published by Elsevier Inc.

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

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    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.

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

    Science.gov (United States)

    Li, Xiao-Wei; Jiang, Hong-Xue; Zhang, Xiao-Chen; Shelton, Anthony M; Feng, Ji-Nian

    2014-01-01

    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.

  17. 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.

  18. Proteomic analyses of male contributions to honey bee sperm storage and mating

    OpenAIRE

    Collins, A M; Caperna, T J; Williams, V; Garrett, W M; Evans, J D

    2006-01-01

    Honey bee (Apis mellifera L.) queens mate early in life and store sperm for years. Male bees likely contribute significantly to sperm survival. Proteins were extracted from seminal vesicles and semen of mature drones, separated by electrophoresis, and analysed by peptide mass fingerprinting. Computer searches against three databases, general species, honey bees and fruit flies, were performed. Spectra were used to query the recently generated honey bee genome protein list as well as general s...

  19. Mating System Evolution under Strong Pollen Limitation: Evidence of Disruptive Selection through Male and Female Fitness in Clarkia xantiana.

    Science.gov (United States)

    Briscoe Runquist, Ryan D; Geber, Monica A; Pickett-Leonard, Michael; Moeller, David A

    2017-05-01

    Selection on floral traits in hermaphroditic plants is determined by both male and female reproductive success. However, predictions regarding floral trait and mating system evolution are often based solely on female fitness. Selection via male fitness has the potential to affect the outcomes of floral evolution. In this study, we used paternity analysis to assess individual selfing rates and selection on floral traits via male and female fitness in an experimental population of Clarkia xantiana where pollen limitation of seed set was strong. We detected selection through both female and male fitness with reinforcing or noninterfering patterns of selection through the two sex functions. For female fitness, selection favored reduced herkogamy and protandry, traits that promote increased autonomous selfing. For male fitness, selection on petal area was disruptive, with higher trait values conferring greater pollinator attraction and outcross siring success and smaller trait values leading to higher selfed siring success. Combining both female and male fitness, selection on petal area and protandry was disruptive because intermediate phenotypes were less successful as both males and females. Finally, functional relationships among male and female fertility components indicated that selfing resulted in seed discounting and pollen discounting. Under these functional relationships, the evolutionarily stable selfing rate can be intermediate or predominantly selfing or outcrossing, depending on the segregating load of deleterious mutations.

  20. 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. ©2014 The Authors Journal compliation © Insititute of Zoology, Chinese Academy of Science.

  1. Female behaviour and the interaction of male and female genital traits mediate sperm transfer during mating.

    Science.gov (United States)

    Friesen, C R; Uhrig, E J; Mason, R T; Brennan, P L R

    2016-05-01

    Natural selection and post-copulatory sexual selection, including sexual conflict, contribute to genital diversification. Fundamental first steps in understanding how these processes shape the evolution of specific genital traits are to determine their function experimentally and to understand the interactions between female and male genitalia during copulation. Our experimental manipulations of male and female genitalia in red-sided garter snakes (Thamnophis sirtalis parietalis) reveal that copulation duration and copulatory plug deposition, as well as total and oviductal/vaginal sperm counts, are influenced by the interaction between male and female genital traits and female behaviour during copulation. By mating females with anesthetized cloacae to males with spine-ablated hemipenes using a fully factorial design, we identified significant female-male copulatory trait interactions and found that females prevent sperm from entering their oviducts by contracting their vaginal pouch. Furthermore, these muscular contractions limit copulatory plug size, whereas the basal spine of the male hemipene aids in sperm and plug transfer. Our results are consistent with a role of sexual conflict in mating interactions and highlight the evolutionary importance of female resistance to reproductive outcomes. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

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

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    Hema Somanathan

    Full Text Available 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.

  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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Do male desert gobies compromise offspring care to attract additional mating opportunities?

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    Nicholas Symons

    Full Text Available Males often play a critical role in offspring care but the time and energy invested in looking after young can potentially limit their ability to seek out additional mating opportunities. Recent studies, however, suggest that a conflict between male parental effort and mating effort may not always be inevitable, especially if breeding occurs near the nest, or if parental behaviours are under sexual selection. Accordingly, we set out to experimentally investigate male care and courtship in the desert goby Chlamydogobius eremius, a nest-guarding fish with exclusive paternal care. Despite courtship occurring near the nest, we found that when egg-tending males were given the opportunity to attract additional females, they fanned their eggs less often, engaged in shorter fanning bouts, and spent more of their time outside their nests courting. Our findings highlight the importance of understanding the circumstances under which reproductive tradeoffs are expected to occur and how these, in turn, operate to influence male reproductive decisions.

  5. 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.

  6. The dynamics of male brooding, mating patterns, and sex roles in pipefishes and seahorses (family Syngnathidae).

    Science.gov (United States)

    Wilson, Anthony B; Ahnesjö, Ingrid; Vincent, Amanda C J; Meyer, Axel

    2003-06-01

    Modern theory predicts that relative parental investment of the sexes in their young is a key factor responsible for sexual selection. Seahorses and pipefishes (family Syngnathidae) are extraordinary among fishes in their remarkable adaptations for paternal care and frequent occurrences of sex-role reversals (i.e., female-female competition for mates), offering exceptional opportunities to test predictions of sexual selection theory. During mating, the female transfers eggs into or onto specialized egg-brooding structures that are located on either the male's abdomen or its tail, where they are osmoregulated, aerated, and nourished by specially adapted structures. All syngnathid males exhibit this form of parental care but the brooding structures vary, ranging from the simple ventral gluing areas of some pipefishes to the completely enclosed pouches found in seahorses. We present a molecular phylogeny that indicates that the diversification of pouch types is positively correlated with the major evolutionary radiation of the group, suggesting that this extreme development and diversification of paternal care may have been an important evolutionary innovation of the Syngnathidae. Based on recent studies that show that the complexity of brooding structures reflects the degree of paternal investment in several syngnathid species, we predicted sex-role reversals to be more common among species with more complex brooding structures. In contrast to this prediction, however, both parsimony- and likelihood-based reconstructions of the evolution of sex-role reversal in pipefishes and seahorses suggest multiple shifts in sex roles in the group, independent from the degree of brood pouch development. At the same time, our data demonstrate that sex-role reversal is positively associated with polygamous mating patterns, whereas most nonreversed species mate monogamously, suggesting that selection for polygamy or monogamy in pipefishes and seahorses may strongly influence sex

  7. Females use self-referent cues to avoid mating with previous mates.

    Science.gov (United States)

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-12-07

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that female crickets (Gryllodes sigillatus) mark males with their own unique chemical signatures during mating, enabling females to recognize prior mates in subsequent encounters and to avoid remating with them. Because self-referent chemosensory cues provide females with a simple, but reliable mechanism of identifying individuals with whom they have mated without requiring any special cognitive ability, they may be a widespread means by which females across a broad range of animal mating systems maximize the genetic benefits of polyandry.

  8. Mate choice when males are in patches: optimal strategies and good rules of thumb.

    Science.gov (United States)

    Hutchinson, John M C; Halupka, Konrad

    2004-11-07

    In standard mate-choice models, females encounter males sequentially and decide whether to inspect the quality of another male or to accept a male already inspected. What changes when males are clumped in patches and there is a significant cost to travel between patches? We use stochastic dynamic programming to derive optimum strategies under various assumptions. With zero costs to returning to a male in the current patch, the optimal strategy accepts males above a quality threshold which is constant whenever one or more males in the patch remain uninspected; this threshold drops when inspecting the last male in the patch, so returns may occur only then and are never to a male in a previously inspected patch. With non-zero within-patch return costs, such a two-threshold rule still performs extremely well, but a more gradual decline in acceptance threshold is optimal. Inability to return at all need not decrease performance by much. The acceptance threshold should also decline if it gets harder to discover the last males in a patch. Optimal strategies become more complex when mean male quality varies systematically between patches or years, and females estimate this in a Bayesian manner through inspecting male qualities. It can then be optimal to switch patch before inspecting all males on a patch, or, exceptionally, to return to an earlier patch. We compare performance of various rules of thumb in these environments and in ones without a patch structure. A two-threshold rule performs excellently, as do various simplifications of it. The best-of-N rule outperforms threshold rules only in non-patchy environments with between-year quality variation. The cutoff rule performs poorly.

  9. Selection on male size, leg length and condition during mate search in a sexually highly dimorphic orb-weaving spider.

    Science.gov (United States)

    Foellmer, Matthias W; Fairbairn, Daphne J

    2005-02-01

    Mate search plays a central role in hypotheses for the adaptive significance of extreme female-biased sexual size dimorphism (SSD) in animals. Spiders (Araneae) are the only free-living terrestrial taxon where extreme SSD is common. The "gravity hypothesis" states that small body size in males is favoured during mate search in species where males have to climb to reach females, because body length is inversely proportional to achievable speed on vertical structures. However, locomotive performance of males may also depend on relative leg length. Here we examine selection on male body size and leg length during mate search in the highly dimorphic orb-weaving spider Argiope aurantia, using a multivariate approach to distinguish selection targeted at different components of size. Further, we investigate the scaling relationships between male size and energy reserves, and the differential loss of reserves. Adult males do not feed while roving, and a size-dependent differential energy storage capacity may thus affect male performance during mate search. Contrary to predictions, large body size was favoured in one of two populations, and this was due to selection for longer legs. Male size was not under selection in the second population, but we detected direct selection for longer third legs. Males lost energy reserves during mate search, but this was independent of male size and storage capacity scaled isometrically with size. Thus, mate search is unlikely to lead to selection for small male size, but the hypothesis that relatively longer legs in male spiders reflect a search-adapted morphology is supported.

  10. 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

  11. Male mating competitiveness of a Wolbachia-introgressed Aedes polynesiensis strain under semi-field conditions.

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    Eric W Chambers

    2011-08-01

    Full Text Available 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.CP males and F1 male offspring from wild-caught A. polynesiensis females exhibit near equal mating competitiveness with F1 females under semi-field conditions.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.

  12. The influence of antibiotic treatment of bitches in oestrus on their attractiveness to males during mating.

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    Dziecioł, M; Nizański, W; Stańczyk, E; Kozdrowski, R; Najder-Kozdrowska, L; Twardoń, J

    2013-01-01

    The aim of this study was to evaluate the influence of the antibiotic treatment, including the mode of drugs administration, on bitches' attractiveness to the stud dogs during mating. Moreover, we tried to estimate the possibility of aversive effect of the drug vehicle on the male behavior. In experiment I, four bitches in oestrus without antibiotic treatment (group A), four bitches treated with intravaginal antibiotic (group B) and four bitches treated with intramuscular antibiotic (group C) were presented to four stud dogs. In experiment II, bitches in oestrus (n = 5) were presented to the males (n = 2) before and after the application to the females' vulva the antibiotic carrier--Miglyol 840 (Sasol, Germany). In both experiments the presence of the typical sexual behavior of the males (sniffing, licking the vulva and anal region, mating attempts) was evaluated. In experiment III the reaction of the males to the samples containing oestrual discharge from the bitches untreated and treated with antibiotics was evaluated. In the last part of study the aversion reaction to the samples containing antibiotic and the antibiotic carrier was evaluated. The results of experiments showed that females treated with the antibiotics were less attractive to males than untreated females, regardless of the method of administration. We did not observe adverse effect of the antibiotic carrier but samples from the bitches treated with antibiotics were significantly less attractive to the males. We concluded that the reason for reduced attractiveness of the bitches in oestrus after antibiotic treatment was the changes in semiochemical signal emitted by treated females as a consequence of elimination of the vaginal bacterial flora, which seems to be involved in creation of the typical, recognizable by the stud dogs, oestrual signal but also by the possible covering effect of used drugs.

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

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    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.

  14. 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.

  15. Colour change in a structural ornament is related to individual quality, parasites and mating patterns in the blue tit

    Science.gov (United States)

    Badás, E. P.; Martínez, J.; Rivero-de Aguilar, J.; Ponce, C.; Stevens, M.; Merino, S.

    2018-02-01

    Carry-over effects refer to processes that occur in one season and influence fitness in the following. In birds, two costly activities, namely reproduction and moult, are restricted to a small time window, and sometimes overlap. Thus, colour in newly moulted feathers is likely to be affected by the costs of reproduction. Using models of bird vision we investigated male colour change in a free-living population of blue tits ( Cyanistes caeruleus) in three sampling occasions: spring 1, winter and spring 2. We related crown, tail, breast and cheek feather colouration after the moult (winter) to the intensity of infections by blood parasites during reproduction (spring 1). In the following spring (spring 2), we explored mating patterns with respect to changes in feather colour (springs 1 vs. 2). Males that were less intensely infected by the malaria parasite Plasmodium while breeding showed purer white cheek feathers in winter, which may indicate higher feather quality. Increased brightness in the white cheek was associated with better body condition during reproduction. In the following season, males with brighter cheeks paired with females that had noticeably brighter cheek patches compared to the male's previous mate. These results suggest that the conditions experienced during reproduction are likely to affect moult and thus feather colouration, at least in the white patch. High quality individuals may allocate resources efficiently during reproduction increasing future reproductive success through variation in mating patterns. Carry-over effects from reproduction might extend not only to the non-breeding phase, but also to the following breeding season.

  16. 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.

  17. 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.

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

    Science.gov (United States)

    Iwata, Yoko; Shaw, Paul; Fujiwara, Eiji; Shiba, Kogiku; Kakiuchi, Yasutaka; Hirohashi, Noritaka

    2011-08-10

    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. 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. 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.

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

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    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.

  20. Transient population dynamics of mosquitoes during sterile male releases: modelling mating behaviour and perturbations of life history parameters.

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    Christopher M Stone

    Full Text Available The release of genetically-modified or sterile male mosquitoes offers a promising form of mosquito-transmitted pathogen control, but the insights derived from our understanding of male mosquito behaviour have not fully been incorporated into the design of such genetic control or sterile-male release methods. The importance of aspects of male life history and mating behaviour for sterile-male release programmes were investigated by projecting a stage-structured matrix model over time. An elasticity analysis of transient dynamics during sterile-male releases was performed to provide insight on which vector control methods are likely to be most synergistic. The results suggest that high mating competitiveness and mortality costs of released males are required before the sterile-release method becomes ineffective. Additionally, if released males suffer a mortality cost, older males should be released due to their increased mating capacity. If released males are of a homogenous size and size-assortative mating occurs in nature, this can lead to an increase in the abundance of large females and reduce the efficacy of the population-suppression effort. At a high level of size-assortative mating, the disease transmission potential of the vector population increases due to male releases, arguing for the release of a heterogeneously-sized male population. The female population was most sensitive to perturbations of density-dependent components of larval mortality and female survivorship and fecundity. These findings suggest source reduction might be a particularly effective complement to mosquito control based on the sterile insect technique (SIT. In order for SIT to realize its potential as a key component of an integrated vector-management strategy to control mosquito-transmitted pathogens, programme design of sterile-male release programmes must account for the ecology, behaviour and life history of mosquitoes. The model used here takes a step in this

  1. Paternal care and male mate-attraction effort in the European starling is adjusted to clutch size.

    Science.gov (United States)

    Komdeur, Jan; Wiersma, Popko; Magrath, Michael

    2002-06-22

    In facultative polygynous birds with biparental care, a trade-off may occur between male parental care and attraction of additional mates. If there is a cost associated with reduced male parental care, the relative benefit of mate attraction may be predicted to decrease as the size of a male's clutch or brood increases. We tested this prediction in monogamous pairs of facultatively polygynous European starlings (Sturnus vulgaris). The larger the clutch, the more time the male spent incubating and the less time he spent attracting an additional female (i.e. singing near and carrying green nesting material into adjacent empty nest-boxes). Reduced paternal incubation resulted in lower overall incubation (the female did not compensate) and lower hatching success. Immediately after experimental reduction of clutches, males spent significantly less time incubating and more time singing and carrying greenery, and vice versa for experimentally enlarged clutches. Males with experimentally reduced clutches attracted a second female more often than males with experimentally enlarged clutches. This is the first study, to our knowledge, to provide experimental evidence for an adjustment of paternal care and male mate-attraction effort to clutch size. However, a trade-off between paternal nestling provisioning and mate attraction was not revealed, probably due to the absence of unpaired females by that time in the breeding season. Experiments showed that the relative contribution of the male and female to nestling provisioning was unrelated to brood size.

  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. 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.

    2014-01-01

    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. PMID:25339724

  4. 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. Copyright 2001 S. Karger AG, Basel

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

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    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.

  6. The use of different concentrations of ginger root oil to improve the mating propensity of the Medfly sterile males

    International Nuclear Information System (INIS)

    Fadhl, Salma; Msaad Guerfali, M.; Kahlani, A.; Hamden, Haithem; Chevrier, C.

    2008-01-01

    The sterile insect technique in an efficient technique used to control fruit flies such as Medfly Ceratitis Capitata (Wiedemann) (Diptera : Tephritidae). Unfortunately, this technique involves mass breeding of huge quantities of target insects in the factory and sterilizing the males by exposing them to low doses of radiation. this procedure reduces the mating propensity of the sterile males which are the active agent of the technique. It was reported that the exposition of the sterile males to ginger root oil (Zingiber official Roscoe (Zingiberaceae)) improves the mating propensity of the sterile males in comparison with the non exposed ones. In this study, we exposed irradiated males at two different doses (100 and 110 Gy) to different concentrations of the ginger oil (20μl; 50μl; 80μl; 0.25 ml;0.5 ml; 1 ml) the third day after emergence. This study shows that the irradiated males at 100 Gy are more competitive in comparison with those irradiated at 110 Gy with a mating propensity percentage respectively of 60 and 35 %. regarding the exposition dose of the ginger oil, 1 ml gave the best mating propensity ( 42%) in comparison with the other concentrations

  7. 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.

  8. 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.

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

    International Nuclear Information System (INIS)

    Paranhos, Beatriz Jordao; Alves, Renata Morelli; McInnis, Donald; Damasceno, Itala; Malavasi, Aldo; Goncalves, Nilmara; Costa, Maria de Lourdes; Walder, Julio; Nascimento, Antonio

    2006-01-01

    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

  10. 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

  11. Mating systems and sexual selection in male-pregnant pipefishes and seahorses: insights from microsatellite-based studies of maternity.

    Science.gov (United States)

    Jones, A G; Avise, J C

    2001-01-01

    In pipefishes and seahorses (family Syngnathidae), the males provide all postzygotic care of offspring by brooding embryos on their ventral surfaces. In some species, this phenomenon of male "pregnancy" results in a reversal of the usual direction of sexual selection, such that females compete more than males for access to mates, and secondary sexual characteristics evolve in females. Thus the syngnathids can provide critical tests of theories related to the evolution of sex differences and sexual selection. Microsatellite-based studies of the genetic mating systems of several species of pipefishes and seahorses have provided insights into important aspects of the natural history and evolution of these fishes. First, males of species with completely enclosed pouches have complete confidence of paternity, as might be predicted from parental investment theory for species in which males invest so heavily in offspring. Second, a wide range of genetic mating systems have been documented in nature, including genetic monogamy in a seahorse, polygynandry in two species of pipefish, and polyandry in a third pipefish species. The genetic mating systems appear to be causally related to the intensity of sexual selection, with secondary sex characters evolving most often in females of the more polyandrous species. Third, genetic studies of captive-breeding pipefish suggest that the sexual selection gradient (or Bateman gradient) may be a substantially better method for characterizing the mating system than previously available techniques. Finally, these genetic studies of syngnathid mating systems have led to some general insights into the occurrence of clustered mutations at microsatellite loci, the utility of linked loci in studies of parentage, and the use of parentage data for direct estimation of adult population size.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Effect of Chocolate and Yerba Mate Phenolic Compounds on Inflammatory and Oxidative Biomarkers in HIV/AIDS Individuals

    OpenAIRE

    Petrilli, Aline A.; Souza, Suelen J.; Teixeira, Andrea M.; Pontilho, Patricia M.; Souza, Jos? M. P.; Luzia, Liania A.; Rond?, Patricia H. C.

    2016-01-01

    Flavonoids in cocoa and yerba mate have a beneficial role on inflammation and oxidative disorders. Their effect on HIV individuals has not been studied yet, despite the high cardiovascular risk of this population. This study investigated the role of cocoa and yerba mate consumption on oxidative and inflammatory biomarkers in HIV+ individuals. A cross-over, placebo-controlled, double-blind, randomized clinical trial was conducted in 92 individuals on antiretroviral therapy for at least six mon...

  14. 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.

  15. Sugar and Multivitamin Diet Effects on The Longevity and Mating Capacity of Laboratory-Reared Male Anopheline Mosquitoes.

    Science.gov (United States)

    Phasomkusolsil, Siriporn; Pantuwatana, Kanchana; Tawong, Jaruwan; Khongtak, Weeraphan; Kertmanee, Yossasin; Monkanna, Nantaporn; Khaosanorh, Sakon; Wanja, Elizabeth W; Davidson, Silas A

    2017-09-01

    Successful mating by male mosquitoes is dependent on several factors, with sugar feeding being particularly important. The effect of ingested vitamins on adult male mosquitoes is poorly understood. This laboratory study used 3 anopheline species, Anopheles campestris, An. dirus, and An. sawadwongporni, to study the effect of sugar and vitamins on male longevity, copulation, and fecundity. Males were fed 1 of 5 diets containing different combinations of sugar and vitamins: 10% glucose, 10% sucrose, 10% multivitamin syrup, 10% multivitamin syrup + 10% glucose, and 10% multivitamin syrup + 10% sucrose. The longevity of males was measured for a period of 15 days. Forced mating was used to simulate copulation, and fecundity was measured by counting the number of eggs oviposited and the hatch rate of larvae. The longevity of An. campestris and An. dirus was greatest when fed a diet of 10% multivitamin syrup + 10% glucose, and the longevity of An. sawadwongporni was greatest when fed a diet of 10% multivitamin syrup + 10% sucrose. The 1st mating routinely produced the most viable eggs when males were mated with several females. The diet of 10% multivitamin syrup + 10% sucrose produced numerically greater egg production and larval emergence for all 3 species, although this was not always statistically significant due to variability and small sample size. These results indicate that the addition of multivitamin syrup to sucrose may produce healthier and more fit male anophelines. This has potential implications for increasing insectary operations and improving the fitness of laboratory-reared male mosquitoes that will be released for mosquito and disease-pathogen control studies.

  16. 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

    2018-02-01

    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.

  17. 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.

  18. You can't always get what you want: size assortative mating by mutual mate choice as a resolution of sexual conflict

    Directory of Open Access Journals (Sweden)

    Thünken Timo

    2009-06-01

    Full Text Available Abstract Background Assortative mating patterns for mate quality traits like body size are often observed in nature. However, the underlying mechanisms that cause assortative mating patterns are less well known. Sexual selection is one important explanation for assortment, suggesting that i one (usually the female or both sexes could show preferences for mates of similar size or ii mutual mate choice could resolve sexual conflict over quality traits into assortment. We tested these hypotheses experimentally in the socially monogamous cichlid fish Pelvicachromis taeniatus, in which mate choice is mutual. Results In mate choice experiments, both sexes preferred large mates irrespective of own body size suggesting mating preferences are not size-assortative. Especially males were highly selective for large females, probably because female body size signals direct fitness benefits. However, when potential mates were able to interact and assess each other mutually they showed size-assortative mating patterns, i.e. the likelihood to mate was higher in pairs with low size differences between mates. Conclusion Due to variation in body size, general preferences for large mating partners result in a sexual conflict: small, lower quality individuals who prefer themselves large partners are unacceptable for larger individuals. Relative size mismatches between mates translate into a lower likelihood to mate, suggesting that the threshold to accept mates depends on own body size. These results suggest that the underlying mechanism of assortment in P. taeniatus is mutual mate choice resolving the sexual conflict over mates, rather than preference for mates of similar size.

  19. Drosophila male sex peptide inhibits siesta sleep and promotes locomotor activity in the post-mated female.

    Science.gov (United States)

    Isaac, R Elwyn; Li, Chenxi; Leedale, Amy E; Shirras, Alan D

    2010-01-07

    Quiescence, or a sleep-like state, is a common and important feature of the daily lives of animals from both invertebrate and vertebrate taxa, suggesting that sleep appeared early in animal evolution. Recently, Drosophila melanogaster has been shown to be a relevant and powerful model for the genetic analysis of sleep behaviour. The sleep architecture of D. melanogaster is sexually dimorphic, with females sleeping much less than males during day-time, presumably because reproductive success requires greater foraging activity by the female as well as the search for egg-laying sites. However, this loss of sleep and increase in locomotor activity will heighten the risk for the female from environmental and predator hazards. In this study, we show that virgin females can minimize this risk by behaving like males, with an extended afternoon 'siesta'. Copulation results in the female losing 70 per cent of day-time sleep and becoming more active. This behaviour lasts for at least 8 days after copulation and is abolished if the mating males lack sex peptide (SP), normally present in the seminal fluid. Our results suggest that SP is the molecular switch that promotes wakefulness in the post-mated female, a change of behaviour compatible with increased foraging and egg-laying activity. The stress resulting from SP-dependent sleep deprivation might be an important contribution to the toxic side-effects of male accessory gland products that are known to reduce lifespan in post-mated females.

  20. Effect of Chocolate and Yerba Mate Phenolic Compounds on Inflammatory and Oxidative Biomarkers in HIV/AIDS Individuals.

    Science.gov (United States)

    Petrilli, Aline A; Souza, Suelen J; Teixeira, Andrea M; Pontilho, Patricia M; Souza, José M P; Luzia, Liania A; Rondó, Patricia H C

    2016-05-23

    Flavonoids in cocoa and yerba mate have a beneficial role on inflammation and oxidative disorders. Their effect on HIV individuals has not been studied yet, despite the high cardiovascular risk of this population. This study investigated the role of cocoa and yerba mate consumption on oxidative and inflammatory biomarkers in HIV+ individuals. A cross-over, placebo-controlled, double-blind, randomized clinical trial was conducted in 92 individuals on antiretroviral therapy for at least six months and at viral suppression. Participants were randomized to receive either 65 g of chocolate or chocolate-placebo or 3 g of yerba mate or mate-placebo for 15 days each, alternating by a washout period of 15 days. At baseline, and at the end of each intervention regimen, data regarding anthropometry, inflammatory, oxidative and immunological parameters were collected. High-sensitivity C-reactive protein, fibrinogen, lipid profile, white blood cell profile and thiobarbituric acid reactive substances were assessed. There was a difference between mean concentrations of HDL-c (ANOVA; p ≤ 0.05) among the different regimens: dark chocolate, chocolate-placebo, yerba mate and mate-placebo. When a paired Student t-test was used for comparisons between mean HDL-c at baseline and after each regimen, the mean concentration of HDL-c was higher after supplementation with dark chocolate (p = 0.008).

  1. Effect of Chocolate and Yerba Mate Phenolic Compounds on Inflammatory and Oxidative Biomarkers in HIV/AIDS Individuals

    Directory of Open Access Journals (Sweden)

    Aline A. Petrilli

    2016-05-01

    Full Text Available Flavonoids in cocoa and yerba mate have a beneficial role on inflammation and oxidative disorders. Their effect on HIV individuals has not been studied yet, despite the high cardiovascular risk of this population. This study investigated the role of cocoa and yerba mate consumption on oxidative and inflammatory biomarkers in HIV+ individuals. A cross-over, placebo-controlled, double-blind, randomized clinical trial was conducted in 92 individuals on antiretroviral therapy for at least six months and at viral suppression. Participants were randomized to receive either 65 g of chocolate or chocolate-placebo or 3 g of yerba mate or mate-placebo for 15 days each, alternating by a washout period of 15 days. At baseline, and at the end of each intervention regimen, data regarding anthropometry, inflammatory, oxidative and immunological parameters were collected. High-sensitivity C-reactive protein, fibrinogen, lipid profile, white blood cell profile and thiobarbituric acid reactive substances were assessed. There was a difference between mean concentrations of HDL-c (ANOVA; p ≤ 0.05 among the different regimens: dark chocolate, chocolate-placebo, yerba mate and mate-placebo. When a paired Student t-test was used for comparisons between mean HDL-c at baseline and after each regimen, the mean concentration of HDL-c was higher after supplementation with dark chocolate (p = 0.008.

  2. Reproductive traits and number of matings in males and females of Cerambyx welensii (Coleoptera: Cerambycidae) an emergent pest of oaks.

    Science.gov (United States)

    Torres-Vila, L M; Mendiola-Diaz, F J; Conejo-Rodríguez, Y; Sánchez-González, Á

    2016-06-01

    The longhorn beetle Cerambyx welensii is an emerging pest involved in oak decline episodes, whose damage is increasingly reported in dehesa open woodlands. Knowledge of the reproductive biology of C. welensii is a crucial goal due to its new pest status. In this study, we assess the reproductive traits of both sexes in the laboratory (25°C and 60% relative humidity ). In females, body length was 44.9 ± 0.9 mm (mean ± SE), fecundity 132 ± 12 eggs, fertility 70 ± 1 %, longevity 70 ± 3 days, preoviposition period 2 ± 0.2 days, oviposition period 44 ± 3 days and postoviposition period 19 ± 3 days. Fecundity was positively correlated with female size, longevity and oviposition period. Daily fecundity was 3.0 ± 0.2 eggs/day and showed a fluctuating synovigenic pattern with a slight decreasing trend over time. Egg length was 4.24 ± 0.01 mm and egg volume 8.14 ± 0.04 mm3. Egg size was correlated with female size but the relative size of eggs was larger in smaller females. Incubation time was 13.9 ± 0.1 days and hatching did not depend on egg size. Neonate size was positively correlated with egg length. Females were polyandrous (more than 20 lifetime matings) but multiple mating did not increase fecundity, fertility or longevity. In males, body length was 43.7 ± 0.6 mm and longevity 52 ± 3 days. Unlike with females, longevity was positively correlated with male size. Males were polygynous (up to 30 lifetime matings) but mating history did not affect male longevity. Rather to the contrary, long-lived males mated more times because they had more mating chances. Lastly, C. welensii reproductive traits were compared with those other Cerambycidae species and discussed from an adaptive perspective. Our data will be useful to improve management of C. welensii in order to prevent or mitigate its impact in dehesa woodlands and other oak forests.

  3. 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.

  4. The Dynamics of Male Brooding, Mating Patterns, ad Sex Roles in Pipefishes and Seahorses (Family Syngnathidae)

    OpenAIRE

    Wilson, Anthony Bruce; Ahnesjö, Ingrid; Vincent, Amanda C. J.; Meyer, Axel

    2003-01-01

    Modern theory predicts that relative parental investment of the sexes in their young is a key factor responsible for sexual selection. Seahorses and pipefishes (family Syngnathidae) are extraordinary among fishes in their remarkable adaptations for paternal care and frequent occurrences of sex-role reversals (i.e., female-female competition for mates), offering exceptional opportunities to test predictions of sexual selection theory. During mating, the female transfers eggs into or onto speci...

  5. Male dominance, female mate choice and intersexual conflict in the rose bitterling (Rhodeus ocellatus)

    Czech Academy of Sciences Publication Activity Database

    Casalini, M.; Agbali, M.; Reichard, Martin; Konečná, Markéta; Bryjová, Anna; Smith, C.

    2009-01-01

    Roč. 63, č. 2 (2009), s. 366-376 ISSN 0014-3820 R&D Projects: GA MŠk LC06073; GA AV ČR KJB600930501 Institutional research plan: CEZ:AV0Z60930519 Keywords : female mating preference * good genes * olfactory cues * mate choice * MHC * Rhodeus ocellatus Subject RIV: EG - Zoology Impact factor: 5.429, year: 2009

  6. Mate-choice copying, social information processing, and the roles of oxytocin.

    Science.gov (United States)

    Kavaliers, Martin; Matta, Richard; Choleris, Elena

    2017-01-01

    Social and sexual behaviors, including that of mate choice, are dependent on social information. Mate choice can be modified by prior and ongoing social factors and experience. The mate choice decisions of one individual can be influenced by either the actual or potential mate choice of another female or male. Such non-independent mate choice, where individuals gain social information and socially learn about and recognizes potential mates by observing the choices of another female or male, has been termed "mate-choice copying". Here we first briefly review how, why, and under what circumstances individuals engage in mate-choice copying. Secondly, we review the neurobiological mechanisms underlying mate-choice copying. In particular, we consider the roles of the nonapeptide, oxytocin, in the processing of social information and the expression of mate-choice copying. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. 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

  8. Influence of asymmetrical mating patterns and male reproductive success on the maintenance of sexual polymorphism in Acer pictum subsp. mono (Aceraceae).

    Science.gov (United States)

    Shang, Hui; Luo, Yi-Bo; Bai, Wei-Ning

    2012-08-01

    Populations of Acer species often contain more than three sex phenotypes with complex sexual polymorphism including duodichogamy, protandry and protogyny. We identified the mechanisms that maintain sexual polymorphism in Acer pictum subsp. mono, a temperate tree from northern China, by investigating maternal mating patterns and male reproductive success. We used paternity analyses to estimate rates of outcrossing and disassortative mating, as well as male outcrossed siring success, in a population of A. pictum subsp. mono with uneven sex phenotype ratios (duodichogamous 69.1%, protandrous 19.6%, protogynous 11.3%). We used a pollen-transfer model to investigate whether the unequal ratios of sex phenotypes could be explained by the observed patterns of mating. Most progeny resulted from outcrossing, particularly disassortative among the sex phenotypes. Although the duodichogamous phenotype showed a significant amount of intraphenotypic mating, the frequency did not exceed that of disassortative mating. We detected no significant differences in male outcrossed siring success among the sex phenotypes. The pollen-transfer model demonstrated that sex phenotype ratios could be maintained by the observed mating pattern in the population. Our results indicate that disassortative mating among the sex phenotypes can maintain sexual polymorphism in A. pictum subsp. mono and that ratios biased towards duodichogamy can result from frequent intraphenotypic mating in this phenotype. © 2012 Blackwell Publishing Ltd.

  9. The effect of crowding and density on male mating behaviour in the rose bitterling (Rhodeus ocellatus)

    Czech Academy of Sciences Publication Activity Database

    Casalini, M.; Reichard, Martin; Smith, C.

    2010-01-01

    Roč. 147, č. 8 (2010), s. 1035-1050 ISSN 0005-7959 R&D Projects: GA ČR GA206/09/1163 Institutional research plan: CEZ:AV0Z60930519 Keywords : density-dependence * mating system * sexual selection * sperm competition * territoriality Subject RIV: EG - Zoology Impact factor: 1.480, year: 2010

  10. Quantitative trait locus analysis of mating behavior and male sex pheromones in Nasonia wasps

    NARCIS (Netherlands)

    Diao, Wenwen; Mousset, Mathilde; Horsburgh, Gavin J.; Vermeulen, Cornelis J.; Johannes, Frank; van de Zande, Louis; Ritchie, Michael G.; Schmitt, Thomas; Beukeboom, Leo W.

    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.

  11. Male mate location behaviour and encounter sites in a community of ...

    Indian Academy of Sciences (India)

    MADHU

    (c) Significant associations between mate location behaviours and landscape structures (landmarks and edges). Variables pairs. Kendall tau. P. Perch and Bare patch. 0.23. *. Perch and Track‡. –0.38. ***. Perch and Shrub edge‡. 0.39. ***. Perch and Wood edge. 0.22. *. Perch and Rock face‡. 0.63. ***. Perch and Stream ...

  12. 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…

  13. 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. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Alfalfa weevil male: effect of γ-radiation and weevil age on mating competitiveness and sperm transfer

    International Nuclear Information System (INIS)

    Wollam, J.D.; Hower, A.A. Jr.

    1977-01-01

    Virgin male Hypera postica (Gyllenhal) were irradiated at 1, 2, 3, 4, and 5 weeks of age. Alfalfa weevils from each age group were subjected to γ-radiation doses of 0, 2, 3, 4, 5, and 6 krads. Mating competitiveness was reduced by the 5 to 6 krad doses in all age groups except those 4 weeks old. Weevils irradiated at 1 week of age showed a reduction in competitiveness at doses above 2 krad. Radiation dose and age at irradiation had little noticeable effect on sperm transfer

  15. 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.

  16. Testing a key assumption in animal communication: between-individual variation in female visual systems alters perception of male signals

    Directory of Open Access Journals (Sweden)

    Kelly L. Ronald

    2017-12-01

    Full Text Available Variation in male signal production has been extensively studied because of its relevance to animal communication and sexual selection. Although we now know much about the mechanisms that can lead to variation between males in the properties of their signals, there is still a general assumption that there is little variation in terms of how females process these male signals. Variation between females in signal processing may lead to variation between females in how they rank individual males, meaning that one single signal may not be universally attractive to all females. We tested this assumption in a group of female wild-caught brown-headed cowbirds (Molothrus ater, a species that uses a male visual signal (e.g. a wingspread display to make its mate-choice decisions. We found that females varied in two key parameters of their visual sensory systems related to chromatic and achromatic vision: cone densities (both total and proportions and cone oil droplet absorbance. Using visual chromatic and achromatic contrast modeling, we then found that this between-individual variation in visual physiology leads to significant between-individual differences in how females perceive chromatic and achromatic male signals. These differences may lead to variation in female preferences for male visual signals, which would provide a potential mechanism for explaining individual differences in mate-choice behavior.

  17. Testing a key assumption in animal communication: between-individual variation in female visual systems alters perception of male signals.

    Science.gov (United States)

    Ronald, Kelly L; Ensminger, Amanda L; Shawkey, Matthew D; Lucas, Jeffrey R; Fernández-Juricic, Esteban

    2017-12-15

    Variation in male signal production has been extensively studied because of its relevance to animal communication and sexual selection. Although we now know much about the mechanisms that can lead to variation between males in the properties of their signals, there is still a general assumption that there is little variation in terms of how females process these male signals. Variation between females in signal processing may lead to variation between females in how they rank individual males, meaning that one single signal may not be universally attractive to all females. We tested this assumption in a group of female wild-caught brown-headed cowbirds ( Molothrus ater ), a species that uses a male visual signal (e.g. a wingspread display) to make its mate-choice decisions. We found that females varied in two key parameters of their visual sensory systems related to chromatic and achromatic vision: cone densities (both total and proportions) and cone oil droplet absorbance. Using visual chromatic and achromatic contrast modeling, we then found that this between-individual variation in visual physiology leads to significant between-individual differences in how females perceive chromatic and achromatic male signals. These differences may lead to variation in female preferences for male visual signals, which would provide a potential mechanism for explaining individual differences in mate-choice behavior. © 2017. Published by The Company of Biologists Ltd.

  18. Sex allocation predicts mating rate in a simultaneous hermaphrodite

    OpenAIRE

    Janicke, Tim; Schärer, Lukas

    2009-01-01

    Sexual selection theory for separate-sexed animals predicts that the sexes differ in the benefit they can obtain from multiple mating. Conventional sex roles assume that the relationship between the number of mates and the fitness of an individual is steeper in males compared with females. Under these conditions, males are expected to be more eager to mate, whereas females are expected to be choosier. Here we hypothesize that the sex allocation, i.e. the reproductive investment devoted to the...

  19. The mating behavior of Iguana iguana

    Science.gov (United States)

    Rodda, G.H.

    1992-01-01

    Over a 19 month period I observed the social behaviors of individually recognized green iguanas, Iguana iguana, at three sites in the llanos of Venezuela. The behavior of iguanas outside the mating season differed from that seen during the mating season in three major ways: (1) during normal waking hours outside the breeding season, adult iguanas spent the majority of time immobile, apparently resting; (2) their interactions involved fewer high intensity displays; and (3) their day to day movements were often nomadic. During the mating season, one site was watched continuously during daylight hours (iguanas sleep throughout the night), allowing a complete count of all copulation attempts (N = 250) and territorial interactions. At all sites, dominant males controlled access to small mating territories. Within the territories there did not appear to be any resources needed by females or their offspring. Thus, females could choose mates directly on the basis of male phenotype. Females aggregated in the mating territories of the largest males and mated preferentially with them. Territorial males copulated only once per day, although on several occasions more than one resident female was receptive on the same day. A few small nonterritorial males exhibited pseudofemale behavior (i.e., they abstained from sexual competition), but most nonterritorial males stayed on the periphery of mating territories and attempted to force copulations on unguarded females (peripheral male behavior). Uncooperative females were mounted by as many as three males simultaneously. Females resisted 95% of the 200 observed mating attempts by peripheral males, but only 56% of the attempts by territorial males (N = 43). The selectivity of the females probably increased the genetic representation of the territorial males in the next generation. During the mating season females maintained a dominance hierarchy among themselves. Low ranked females tended to be excluded from preferred

  20. When the ball is in the female's court: How the scramble-competition mating system of the North American red squirrel has shaped male physiology and testosterone dynamics.

    Science.gov (United States)

    Boonstra, Rudy; Dušek, Adam; Lane, Jeffrey E; Boutin, Stan

    2017-10-01

    Male reproductive success in most mammals is determined by their success in direct inter-male competition through aggression and conflict, resulting in female-defense mating systems being predominant. This is linked to male testosterone levels and its dynamics. However, in certain environments, a scramble-competition mating system has evolved, where female reproductive behavior takes precedence and male testosterone dynamics are unlikely to be related to inter-male competition. We studied the North American red squirrel (Tamiasciurus hudsonicus), a species with a well-established scramble-competition system. Using an ACTH hormonal challenge protocol as a proxy for competitive interactions, we compared the testosterone dynamics in breeding males in late winter with that in nonbreeding males in late spring in the Yukon. To gain an integrated picture of their physiological state, we also assessed changes in their stress response, body mass, energy mobilization, and indices of immune function. Testosterone levels at the base bleed were high in breeding males (2.72ng/mL) and virtually absent in non-breeding males (0.04ng/mL). Breeding males were in better condition (heavier body mass, higher hematocrit, and higher erythrocytes), had higher indices of immune function (neutrophil:lymphocyte ratio), but a similar ability to mobilize energy (glucose) compared with non-breeding males. Though total cortisol was higher in non-breeding males, free cortisol was twice as high in breeding males as their corticosteroid binding globulin levels were half as high. In response to the ACTH challenge, testosterone levels in breeding males declined 49% over the first hour and increased 36% over the next hour; in non-breeding males levels showed no change. Free cortisol increased only modestly (26% in breeding males; 23% in non-breeding males). Glucose levels changed similarly in breeding and nonbreeding males, declining for the first 30min and then increasing for the next 60min. Thus

  1. Mutual mate choice in sticklebacks : attractive males choose big females, which lay big eggs

    NARCIS (Netherlands)

    Kraak, SBM; Bakker, TCM

    1998-01-01

    Brighter red three-spined stickleback, Gasterostetus aculeatus, males have been shown to be preferred by females in the laboratory but in the field, these males did not receive more eggs. Instead, they had heavier eggs in their brood. We investigated the hypothesis that sexual selection for red

  2. 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.

  3. Mating competitiveness of irradiated males and females of the indian meal moth (Lepidoptera: Pyralidae)

    International Nuclear Information System (INIS)

    Brower, J.H.

    1978-01-01

    One-day-old adults of the Indian meal moth, Plodia interpunctella (Huebner), were irradiated (I) with either 35 krad (a partially sterilizing dose) or 50 krad (a sterilizing dose) and combined with untreated (U) adults at numbers of 1, 5, 10, 15, or 25 treated males or females per pair of untreated adults. At 25 males per pair, egg hatch was reduced to 4.8 and 22.2% at 35 and 50 krad, respectively. The calculated degree of competitiveness showed that both males and females were more competitive after treatment with 35 krad than after treatment with 50 krad and that treated females were more competitive (based on percentage egg hatch) at both doses than corresponding males. Irradiated females were fully competitive at most release ratios, but I males were not fully competitive even at the higher release ratios, although the decreases were not large enough to seriously affect their use for field control. (author)

  4. Sexy sons from re-mating do not recoup the direct costs of harmful male interactions in the Drosophila melanogaster laboratory model system.

    Science.gov (United States)

    Orteiza, N; Linder, J E; Rice, W R

    2005-09-01

    The empirical foundation for sexual conflict theory is the data from many different taxa demonstrating that females are harmed while interacting with males. However, the interpretation of this keystone evidence has been challenged because females may more than counterbalance the direct costs of interacting with males by the indirect benefits of obtaining higher quality genes for their offspring. A quantification of this trade-off is critical to resolve the controversy and is presented here. A multi-generation fitness assay in the Drosophila melanogaster laboratory model system was used to quantify both the direct costs to females due to interactions with males and indirect benefits via sexy sons. We specifically focus on the interactions that occur between males and nonvirgin females. In the laboratory environment of our base population, females mate soon after eclosion and store sufficient sperm for their entire lifetime, yet males persistently court these nonvirgin females and frequently succeed in re-mating them. Females may benefit from these interactions despite direct costs to their lifetime fecundity if re-mating allows them to trade-up to mates of higher genetic quality and thereby secure indirect benefits for their offspring. We found that direct costs of interactions between males and nonvirgin females substantially exceeded indirect benefits through sexy sons. These data, in combination with past studies of the good genes route of indirect benefits, demonstrate that inter-sexual interactions drive sexually antagonistic co-evolution in this model system.

  5. Mate-sampling costs and sexy sons.

    Science.gov (United States)

    Kokko, H; Booksmythe, I; Jennions, M D

    2015-01-01

    Costly female mating preferences for purely Fisherian male traits (i.e. sexual ornaments that are genetically uncorrelated with inherent viability) are not expected to persist at equilibrium. The indirect benefit of producing 'sexy sons' (Fisher process) disappears: in some models, the male trait becomes fixed; in others, a range of male trait values persist, but a larger trait confers no net fitness advantage because it lowers survival. Insufficient indirect selection to counter the direct cost of producing fewer offspring means that preferences are lost. The only well-cited exception assumes biased mutation on male traits. The above findings generally assume constant direct selection against female preferences (i.e. fixed costs). We show that if mate-sampling costs are instead derived based on an explicit account of how females acquire mates, an initially costly mating preference can coevolve with a male trait so that both persist in the presence or absence of biased mutation. Our models predict that empirically detecting selection at equilibrium will be difficult, even if selection was responsible for the location of the current equilibrium. In general, it appears useful to integrate mate sampling theory with models of genetic consequences of mating preferences: being explicit about the process by which individuals select mates can alter equilibria. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  6. 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.

  7. 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…

  8. Strong inbreeding depression and individually variable mating system in the narrow endemic Erodium cazorlanum (Geraniaceae

    Directory of Open Access Journals (Sweden)

    Alonso, Conchita

    2013-06-01

    Full Text Available Angiosperms evolved different systems to attract effective pollinators while reducing selfing in hermaphroditic flowers. Selfing ability can be advantageous when pollinators and/or mates are scarce, although inbreeding depression may largely reduce those advantages. Recent comparative analyses suggested endemic species tend to evolve self-compatibility but a better understanding of the associated reproductive and genetic tradeoffs is required. Experimental hand-pollinations under greenhouse conditions were conducted to investigate the selfing ability and estimate inbreeding depression up to the offspring’ first reproductive event in Ero dium cazorlanum, a narrow endemic species restricted to dolomite outcrops in SE Spanish mountains. We found autonomous selfing ineffective. Further, when experimentally applied, pollen of the same flower produced significantly fewer fruits and seeds compared to geitonogamous and cross pollinations. The number of seeds per fruit was significantly higher after cross pollinations and strong inbreeding depression accumulated through the life-cycle. Interestingly, individual plants exhibited broad variation in selfing ability with six out of 14 individuals producing no seed after geitonogamy. Understanding the consequences of individual variation in self compatibility deserves further investigation in the field now that we know that strong inbreeding depression may limit recruitment of selfed progeny.Las Angiospermas han desarrollado diversos sistemas para atraer polinizadores eficientes y al mismo tiempo reducir la posibilidad de autopolinización asociada al hermafroditismo. La capacidad de autopolinización puede ser ventajosa en situaciones de escasez de polinizadores y/o individuos reproductores, beneficios que pueden reducirse ampliamente a causa de la depresión por endogamia. Análisis filogenéticos recientes indicaron que las especies endémicas tienden a presentar sistemas de autocompatibilidad, por tanto

  9. Parameters of mating effort and success in male European ground squirrels, Spermophilus citellus

    NARCIS (Netherlands)

    Millesi, E; Dittami, J; Hoffmann, [No Value; Daan, S; Hoffmann, Ilse; Wickler, W.

    Behavioural and physiological changes during the reproductive period were documented in male European ground squirrels including: initiated conflict, scent marking, locomotion and range size, as well as testis size, scrotal pigmentation, testosterone levels and changes in body mass. Spring emergence

  10. Ephestia Kuehniella Z.: Gamma irradiation effects on the adult stage and mating competitiveness of sterile males

    International Nuclear Information System (INIS)

    Ahmed, M.Y.Y.; El-Banby, M.A.; Salem, Y.S.; Abdel-Baky, S.M.

    1985-01-01

    Effects of gamma radiation dosages from 5 to 50 Krad on the adult stage of Ephestia Kuehielia Z. were studied. Irradiated adults paired with untreated adults produced fewer eggs than pairs of unirradiated adults, and these eggs had reduced hatch. This effect was more pronounced with irradiated females or when both parents were irradiated. Radiation greatly reduced life span of treated adults. Adult females were more sensitive to the sterilizing effect of gamma radiation than were males. Males were sterilized when irradiated at 50 Krad, but females at 25 Krad. Previous studies showed that males irradiated as fully grown pupae at 45 Krad were completely sterile. When irradiated (I) males were confined with unirradiated (U) males and females (1:1:1 ratio), infertility of eggs was 48%. Increasing the ratio to 5:1:1, 10:1:1 and 15:1:1 caused 77.9, 84.6 and 94.4 percent infertility of the resulting eggs, respectively. The calculated competitiveness values for the 4 ratios were 0.55, 0.52, 0.42 and 0.88, respectively. Thus I males were only competitive at the highest flooding ration (15:1:1)

  11. Individual recognition based on communication behaviour of male fowl.

    Science.gov (United States)

    Smith, Carolynn L; Taubert, Jessica; Weldon, Kimberly; Evans, Christopher S

    2016-04-01

    Correctly directing social behaviour towards a specific individual requires an ability to discriminate between conspecifics. The mechanisms of individual recognition include phenotype matching and familiarity-based recognition. Communication-based recognition is a subset of familiarity-based recognition wherein the classification is based on behavioural or distinctive signalling properties. Male fowl (Gallus gallus) produce a visual display (tidbitting) upon finding food in the presence of a female. Females typically approach displaying males. However, males may tidbit without food. We used the distinctiveness of the visual display and the unreliability of some males to test for communication-based recognition in female fowl. We manipulated the prior experience of the hens with the males to create two classes of males: S(+) wherein the tidbitting signal was paired with a food reward to the female, and S (-) wherein the tidbitting signal occurred without food reward. We then conducted a sequential discrimination test with hens using a live video feed of a familiar male. The results of the discrimination tests revealed that hens discriminated between categories of males based on their signalling behaviour. These results suggest that fowl possess a communication-based recognition system. This is the first demonstration of live-to-video transfer of recognition in any species of bird. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male's odour

    Directory of Open Access Journals (Sweden)

    McLean Lynn

    2010-06-01

    Full Text Available Abstract Background Among invertebrates, specific pheromones elicit inherent (fixed behavioural responses to coordinate social behaviours such as sexual recognition and attraction. By contrast, the much more complex social odours of mammals provide a broad range of information about the individual owner and stimulate individual-specific responses that are modulated by learning. How do mammals use such odours to coordinate important social interactions such as sexual attraction while allowing for individual-specific choice? We hypothesized that male mouse urine contains a specific pheromonal component that invokes inherent sexual attraction to the scent and which also stimulates female memory and conditions sexual attraction to the airborne odours of an individual scent owner associated with this pheromone. Results Using wild-stock house mice to ensure natural responses that generalize across individual genomes, we identify a single atypical male-specific major urinary protein (MUP of mass 18893Da that invokes a female's inherent sexual attraction to male compared to female urinary scent. Attraction to this protein pheromone, which we named darcin, was as strong as the attraction to intact male urine. Importantly, contact with darcin also stimulated a strong learned attraction to the associated airborne urinary odour of an individual male, such that, subsequently, females were attracted to the airborne scent of that specific individual but not to that of other males. Conclusions This involatile protein is a mammalian male sex pheromone that stimulates a flexible response to individual-specific odours through associative learning and memory, allowing female sexual attraction to be inherent but selective towards particular males. This 'darcin effect' offers a new system to investigate the neural basis of individual-specific memories in the brain and give new insights into the regulation of behaviour in complex social mammals. See associated

  13. Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male's odour.

    Science.gov (United States)

    Roberts, Sarah A; Simpson, Deborah M; Armstrong, Stuart D; Davidson, Amanda J; Robertson, Duncan H; McLean, Lynn; Beynon, Robert J; Hurst, Jane L

    2010-06-03

    Among invertebrates, specific pheromones elicit inherent (fixed) behavioural responses to coordinate social behaviours such as sexual recognition and attraction. By contrast, the much more complex social odours of mammals provide a broad range of information about the individual owner and stimulate individual-specific responses that are modulated by learning. How do mammals use such odours to coordinate important social interactions such as sexual attraction while allowing for individual-specific choice? We hypothesized that male mouse urine contains a specific pheromonal component that invokes inherent sexual attraction to the scent and which also stimulates female memory and conditions sexual attraction to the airborne odours of an individual scent owner associated with this pheromone. Using wild-stock house mice to ensure natural responses that generalize across individual genomes, we identify a single atypical male-specific major urinary protein (MUP) of mass 18893Da that invokes a female's inherent sexual attraction to male compared to female urinary scent. Attraction to this protein pheromone, which we named darcin, was as strong as the attraction to intact male urine. Importantly, contact with darcin also stimulated a strong learned attraction to the associated airborne urinary odour of an individual male, such that, subsequently, females were attracted to the airborne scent of that specific individual but not to that of other males. This involatile protein is a mammalian male sex pheromone that stimulates a flexible response to individual-specific odours through associative learning and memory, allowing female sexual attraction to be inherent but selective towards particular males. This 'darcin effect' offers a new system to investigate the neural basis of individual-specific memories in the brain and give new insights into the regulation of behaviour in complex social mammals.See associated Commentary http://www.biomedcentral.com/1741-7007/8/71.

  14. 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

    We investigated the relations between female quality and ornamentation and between male breeding investment and female ornamentation in the rock sparrow, Petronia petronia, a passerine in which both sexes have a yellow breast patch. Breast patch size in females was positively correlated with body...

  15. Variation in female morph frequencies and mating frequencies : random, frequency-dependent harassment or male mimicry?

    NARCIS (Netherlands)

    Hammers, Martijn; Van Gossum, Hans

    2008-01-01

    Female-limited colour polymorphisms occur in a variety of species, where often one female morph (androchrome) resembles the body coloration of the conspecific male, whereas the other (gynochrome) does not. We tested predictions of two frequency-dependent hypotheses that are commonly invoked to

  16. Life table and male mating competitiveness of wild type and of a chromosome mutation strain of Tetranychus urticae in relation to genetic pest control

    International Nuclear Information System (INIS)

    Feldmann, A.M.

    1981-01-01

    Males of Tetranychus urticae Koch (Acarina: Tetranychidae) from a strain, homozygous for a structural chromosome mutation (T) were competed against males from a standard (wild-type) strain for mating of wild-type fermales. The T-males exhibited only a slight reduction in male mating competitiveness. The debilitating influence of ageing on male mating competitiveness was equal for males of both strains. Life-table studies on both strains showed that the net reproductive rate (R 0 ) of the T-strain was 53.3, which was higher than the R 0 -value of the standard strain (43.3). This difference was caused by the higher rate of age-dependent mortality of adult females of the standard strain. Also differences between both strains in the total sex-ratio were observed; the T-strain produced significantly fewer males and more females than the standard strain. The mean generation time of both strains was almost equal (14 days). The values of the intrinsic rate of increase (rsub(m)) for the T-strain and the standard strain were 0.286 and 0.273, respectively. The life-table data correspond well with those published elsewhere on Tetranychus urticae. The feasibility of T-strains for application in genetic pest control considering the use of structural chromosome mutations as a 'transport mechanism' for conditional lethals is discussed. (orig.)

  17. Central oxytocin receptors mediate mating-induced partner preferences and enhance correlated activation across forebrain nuclei in male prairie voles.

    Science.gov (United States)

    Johnson, Zachary V; Walum, Hasse; Jamal, Yaseen A; Xiao, Yao; Keebaugh, Alaine C; Inoue, Kiyoshi; Young, Larry J

    2016-03-01

    Oxytocin (OT) is a deeply conserved nonapeptide that acts both peripherally and centrally to modulate reproductive physiology and sociosexual behavior across divergent taxa, including humans. In vertebrates, the distribution of the oxytocin receptor (OTR) in the brain is variable within and across species, and OTR signaling is critical for a variety of species-typical social and reproductive behaviors, including affiliative and pair bonding behaviors in multiple socially monogamous lineages of fishes, birds, and mammals. Early work in prairie voles suggested that the endogenous OT system modulates mating-induced partner preference formation in females but not males; however, there is significant evidence that central OTRs may modulate pair bonding behavior in both sexes. In addition, it remains unclear how transient windows of central OTR signaling during sociosexual interaction modulate neural activity to produce enduring shifts in sociobehavioral phenotypes, including the formation of selective social bonds. Here we re-examine the role of the central OT system in partner preference formation in male prairie voles using a selective OTR antagonist delivered intracranially. We then use the same antagonist to examine how central OTRs modulate behavior and immediate early gene (Fos) expression, a metric of neuronal activation, in males during brief sociosexual interaction with a female. Our results suggest that, as in females, OTR signaling is critical for partner preference formation in males and enhances correlated activation across sensory and reward processing brain areas during sociosexual interaction. These results are consistent with the hypothesis that central OTR signaling facilitates social bond formation by coordinating activity across a pair bonding neural network. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Central oxytocin receptors mediate mating-induced partner preferences and enhance correlated activation across forebrain nuclei in male prairie voles

    Science.gov (United States)

    Johnson, Zachary V.; Walum, Hasse; Jamal, Yaseen A.; Xiao, Yao; Keebaugh, Alaine C.; Inoue, Kiyoshi; Young, Larry J.

    2016-01-01

    Oxytocin (OT) is a deeply conserved nonapeptide that acts both peripherally and centrally to modulate reproductive physiology and sociosexual behavior across divergent taxa, including humans. In vertebrates, the distribution of the oxytocin receptor (OTR) in the brain is variable within and across species, and OTR signaling is critical for a variety of species-typical social and reproductive behaviors, including affiliative and pair bonding behaviors in multiple socially monogamous lineages of fishes, birds, and mammals. Early work in prairie voles suggested that the endogenous OT system modulates mating-induced partner preference formation in females but not males; however, there is significant evidence that central OTRs may modulate pair bonding behavior in both sexes. In addition, it remains unclear how transient windows of central OTR signaling during sociosexual interaction modulate neural activity to produce enduring shifts in sociobehavioral phenotypes, including the formation of selective social bonds. Here we re-examine the role of the central OT system in partner preference formation in male prairie voles using a selective OTR antagonist delivered intracranially. We then use the same antagonist to examine how central OTRs modulate behavior and immediate early gene (Fos) expression, a metric of neuronal activation, in males during brief sociosexual interaction with a female. Our results suggest that, as in females, OTR signaling is critical for partner preference formation in males and enhances correlated activation across sensory and reward processing brain areas during sociosexual interaction. These results are consistent with the hypothesis that central OTR signaling facilitates social bond formation by coordinating activity across a pair bonding neural network. PMID:26643557

  19. Sperm length, sperm storage and mating system characteristics in bumblebees

    DEFF Research Database (Denmark)

    Baer, Boris; Schmid-Hempel, Paul; Høeg, Jens Thorvald

    2003-01-01

    -term storage of sperm, using three bumblebee species with different mating systems as models. We show that individual males produce only one size-class of sperm, but that sperm length is highly variable among brothers, among unrelated conspecific males, and among males of different species. Males of Bombus...

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

    Directory of Open Access Journals (Sweden)

    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

  1. The relationship between male moth density and female mating success in invading populations of Lymantria dispar

    Science.gov (United States)

    Patrick C. Tobin; Ksenia S. Onufrieva; Kevin W. Thorpe

    2012-01-01

    The successful establishment of non-native species in new areas can be affected by many factors including the initial size of the founder population. Populations comprised of fewer individuals tend to be subject to stochastic forces and Allee effects (positive-density dependence), which can challenge the ability of small founder populations to establish in a new area....

  2. 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.

  3. Individual and contextual variation in Thomas langur male loud calls

    NARCIS (Netherlands)

    Wich, S.A.; Koski, S.; Vries, Han de; Schaik, Carel P. van

    2003-01-01

    Individual and contextual differences in male loud calls of wild Thomas langurs (Presbytis thomasi) were studied in northern Sumatra, Indonesia. Loud calls were given in the following contexts: morning calls, vocal responses to other groups, between-group encounter calls and alarmcalls. Loud

  4. Mate choice in fruit flies is rational and adaptive.

    Science.gov (United States)

    Arbuthnott, Devin; Fedina, Tatyana Y; Pletcher, Scott D; Promislow, Daniel E L

    2017-01-17

    According to rational choice theory, beneficial preferences should lead individuals to sort available options into linear, transitive hierarchies, although the extent to which non-human animals behave rationally is unclear. Here we demonstrate that mate choice in the fruit fly Drosophila melanogaster results in the linear sorting of a set of diverse isogenic female lines, unambiguously demonstrating the hallmark of rational behaviour, transitivity. These rational choices are associated with direct benefits, enabling males to maximize offspring production. Furthermore, we demonstrate that female behaviours and cues act redundantly in mate detection and assessment, as rational mate choice largely persists when visual or chemical sensory modalities are impaired, but not when both are impaired. Transitivity in mate choice demonstrates that the quality of potential mates varies significantly among genotypes, and that males and females behave in such a way as to facilitate adaptive mate choice.

  5. Social network analysis of mating patterns in American black bears (Ursus americanus).

    Science.gov (United States)

    Moore, Jennifer A; Xu, Ran; Frank, Kenneth; Draheim, Hope; Scribner, Kim T

    2015-08-01

    Nonrandom mating can structure populations and has important implications for population-level processes. Investigating how and why mating deviates from random is important for understanding evolutionary processes as well as informing conservation and management. Prior to the implementation of parentage analyses, understanding mating patterns in solitary, elusive species like bears was virtually impossible. Here, we capitalize on a long-term genetic data set collected from black bears (Ursus americanus) (N = 2422) in the Northern Lower Peninsula (NLP) of Michigan, USA. We identified mated pairs using parentage analysis and applied logistic regression (selection) models that controlled for features of the social network, to quantify the effects of individual characteristics, and spatial and population demographic factors on mating dynamics. Logistic regression models revealed that black bear mating was associated with spatial proximity of mates, male age, the time a pair had coexisted, local population density and relatedness. Mated pairs were more likely to contain older males. On average, bears tended to mate with nearby individuals to whom they were related, which does not support the existence of kin recognition in black bears. Pairwise relatedness was especially high for mated pairs containing young males. Restricted dispersal and high male turnover from intensive harvest mortality of NLP black bears are probably the underlying factors associated with younger male bears mating more often with female relatives. Our findings illustrate how harvest has the potential to disrupt the social structure of game species, which warrants further attention for conservation and management. © 2015 John Wiley & Sons Ltd.

  6. Female preference for male color is necessary and sufficient for assortative mating in 2 cichlid sister species

    NARCIS (Netherlands)

    Selz, Oliver M.; Pierotti, Michele E. R.; Maan, Martine E.; Schmid, Corinne; Seehausen, Ole

    2014-01-01

    A critical step for speciation in the face of gene flow is the origination of reproductive isolation. The evolution of assortative mating greatly facilitates this process. Assortative mating can be mediated by one or multiple cues across an array of sensory modalities. We here explore possible cues

  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. The Possible Role of the Uropygial Gland on Mate Choice in Domestic Chicken

    Directory of Open Access Journals (Sweden)

    Atsushi Hirao

    2011-01-01

    Full Text Available In avian mating systems, male domestic fowls are polygamous and mate with a number of selected members of the opposite sex. The factors that influence mating preference are considered to be visual cues. However, several studies have indicated that chemosensory cues also affect socio-sexual behavior, including mate choice and individual recognition. The female uropygial gland appears to provide odor for mate choice, as uropygial gland secretions are specific to individual body odor. Chicken olfactory bulbs possess efferent projections to the nucleus taeniae that are involved in copulatory behavior. From various reports, it appears that the uropygial gland has the potential to act as the source of social odor cues that dictate mate choice. In this review, evidence for the possible role of the uropygial gland on mate choice in domestic chickens is presented. However, it remains unclear whether a relationship exists between the uropygial gland and major histocompatibility complex-dependent mate choice.

  9. 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

  10. To fight or mate? Hormonal control of sex recognition, male sexual behavior and aggression in the gecko lizard.

    Science.gov (United States)

    Schořálková, Tereza; Kratochvíl, Lukáš; Kubička, Lukáš

    2018-01-01

    Squamate reptiles are a highly diversified vertebrate group with extensive variability in social behavior and sexual dimorphism. However, hormonal control of these traits has not previously been investigated in sufficient depth in many squamate lineages. Here, we studied the hormonal control of male sexual behavior, aggressiveness, copulatory organ (hemipenis) size and sex recognition in the gecko Paroedura picta, comparing ovariectomized females, ovariectomized females treated with exogenous dihydrotestosterone (DHT), ovariectomized females treated with exogenous testosterone (T), control females and males. The administration of both T and DHT led to the expression of male-typical sexual behavior in females. However, in contrast to T, increased circulating levels of DHT alone were not enough to initiate the full expression of male-typical offensive aggressive behavior and development of hemipenes in females. Ovariectomized females were as sexually attractive as control females, which does not support the need for the demasculinization of the cues used for sex recognition by ovarian hormones as suggested in other sauropsids. On the other hand, our results point to the masculinization of the sex recognition cues by male gonadal androgens. Previously, we also demonstrated that sexually dimorphic growth is controlled by ovarian hormones in P. picta. Overall, it appears that individual behavioral and morphological sexually-dimorphic traits are controlled by multiple endogenous pathways in this species. Variability in the endogenous control of particular traits could have permitted their disentangling during evolution and the occurrence of (semi)independent changes across squamate phylogeny. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Sampling and assessment accuracy in mate choice: a random-walk model of information processing in mating decision.

    Science.gov (United States)

    Castellano, Sergio; Cermelli, Paolo

    2011-04-07

    Mate choice depends on mating preferences and on the manner in which mate-quality information is acquired and used to make decisions. We present a model that describes how these two components of mating decision interact with each other during a comparative evaluation of prospective mates. The model, with its well-explored precedents in psychology and neurophysiology, assumes that decisions are made by the integration over time of noisy information until a stopping-rule criterion is reached. Due to this informational approach, the model builds a coherent theoretical framework for developing an integrated view of functions and mechanisms of mating decisions. From a functional point of view, the model allows us to investigate speed-accuracy tradeoffs in mating decision at both population and individual levels. It shows that, under strong time constraints, decision makers are expected to make fast and frugal decisions and to optimally trade off population-sampling accuracy (i.e. the number of sampled males) against individual-assessment accuracy (i.e. the time spent for evaluating each mate). From the proximate-mechanism point of view, the model makes testable predictions on the interactions of mating preferences and choosiness in different contexts and it might be of compelling empirical utility for a context-independent description of mating preference strength. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. The association between personality traits, morphological traits and alternative mating behaviour in male Endler’s guppies, Poecilia wingei

    Czech Academy of Sciences Publication Activity Database

    Řežucha, Radomil; Reichard, Martin

    2016-01-01

    Roč. 122, č. 6 (2016), s. 456-467 ISSN 0179-1613 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : alternative mating tactic * animal personality * boldness * experience * sexual selection * social environment Subject RIV: EG - Zoology Impact factor: 1.398, year: 2016

  13. The effect of social environment on alternative mating tactics in male Endler’s guppy, Poecilia wingei

    Czech Academy of Sciences Publication Activity Database

    Řežucha, Radomil; Reichard, Martin

    2014-01-01

    Roč. 88, č. 2 (2014), s. 195-202 ISSN 0003-3472 R&D Projects: GA ČR GA206/09/1163 Institutional support: RVO:68081766 Keywords : alternative mating tactics * courtship * experience * Poecilia wingei * sneaking * social environment Subject RIV: EG - Zoology Impact factor: 3.137, year: 2014

  14. 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.

  15. 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.

  16. "Nice guys finish last": influence of mate choice on reproductive success in Long-Evans rats.

    Science.gov (United States)

    Winland, C; Bolton, J L; Ford, B; Jampana, S; Tinker, J; Frohardt, R J; Guarraci, F A; Zewail-Foote, M

    2012-02-01

    The present study was designed to determine if male physiology and male reproductive behavior predict reproductive success in Long-Evans rats. Mating behavior was observed in sexually naïve, naturally cycling female rats during behavioral estrous that were given the opportunity to mate with two males simultaneously. DNA analysis of offspring born following these mating encounters was used to identify the paternity of each pup. In order to assess the effect of mate choice during these mating encounters on reproductive success, one male rat in each pair was categorized as the preferred mate if the female spent more time (>50%) with him during the mating test of the present study. Furthermore, each male in the pairs was categorized as "attractive" or "non-attractive" by computing the number of females that preferred each male across many mating tests. Similar to results reported in Lovell et al. (2007), during 76% of these mating tests the same male rat in each pair was preferred by different female rats. Overall attractiveness of individual male rats predicted reproductive success in the present study. Interestingly, "attractive" males sired significantly FEWER pups than "non-attractive" males. Neither behavioral (e.g., latency to first sexual stimulation, number of sexual stimulations) nor physiological measures (e.g., body weight, urinary testosterone levels) of male rats predicted their reproductive success. In conclusion, the present results indicate that certain features of some males are more attractive to females, but attractive males are at a reproductive disadvantage (as measured by the number of pups sired). Although basal urinary testosterone levels did not differ between males that sired the majority of pups in a litter and males that sired few or none of the pups in a litter, aggression and/or other physiological measures of fertility (e.g., penile reflexes) may differ between males that are attractive to females and those that have a reproductive

  17. Mating success and sexual selection in a pelagic copepod, Temora longicornis: Evidence from paternity analyses

    DEFF Research Database (Denmark)

    Sichlau, Mie Hylstofte; Eg Nielsen, Einar; Thygesen, Uffe Høgsbro

    2015-01-01

    Knowledge about mating patterns is essential for understanding and explaining rates of reproduction and genetic potential of copepods populations. The aim of this study was to examine (1) the occurrence of multiple paternity in Temora longicornis, (2) the effect of multiple paternity (if present......) on the females reproductive output, and (3) whether mating is random or some individuals have a higher than average chance of fertilizing or being fertilized (super individuals). We show that multiple paternity is common in this copepod species, that females benefit from multiple matings by increased offspring...... production, and that a relatively small fraction of the males and females in a population account for most of the offspring production. In both males and females, mating is nonrandom. Superior individuals with a higher than average matings success were identified both among females and among males....

  18. Females use self-referent cues to avoid mating with previous mates

    OpenAIRE

    Ivy, Tracie M; Weddle, Carie B; Sakaluk, Scott K

    2005-01-01

    Females of many species mate repeatedly throughout their lives, often with many different males (polyandry). Females can secure genetic benefits by maximizing their diversity of mating partners, and might be expected, therefore, to forego matings with previous partners in favour of novel males. Indeed, a female preference for novel mating partners has been shown in several taxa, but the mechanism by which females distinguish between novel males and previous mates remains unknown. We show that...

  19. 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.

  20. The orang-utan mating system and the unflanged male: A product of increased food stress during the late Miocene and Pliocene?

    Science.gov (United States)

    Harrison, Mark E; Chivers, David J

    2007-03-01

    The orang-utan is unique among apes in having an unusually long male developmental period and two distinct adult male morphs (flanged and unflanged), which generally, but not exclusively, employ different reproductive strategies (call-and-wait vs. sneak-and-rape). Both morphs have recently been shown to have roughly similar levels of reproductive success in the one site where such a study has been conducted. This is in stark contrast to the unimale polygynous gorilla, in which dominant males sire almost all infants. Despite this, evidence on sexual dimorphism, life history, diet, and socioecology of extant and extinct apes, as well as the ontogeny, reproductive morphology, and physiology of extant apes, all indicate that the orang-utan's present-day mating system most likely evolved from a gorilla-like base, with one dominant male guarding a harem of females. The available evidence indicates that, due chiefly to the likely onset of the El Niño Southern Oscillation (generally regarded as the trigger for mast fruiting in dipterocarps) approximately 3-5Ma, southeast Asian forests would have begun to experience longer and more severe periods of low food availability. This change in food availability would have meant that full-time gregariousness was no longer energetically tolerable and, as a result, females dispersed more widely in search of food and adult/flanged males were no longer able to effectively guard a harem of females. A niche for a quiet, quick, opportunistic "sexual predator" (i.e., the unflanged male) then became available. This finding implies that, despite being anatomically quite chimpanzee-like, the ancestral hominoid probably had a social and mating system more similar to the gorilla than any other living ape.

  1. Sport participation influences perceptions of mate characteristics.

    Science.gov (United States)

    Schulte-Hostedde, Albrecht I; Eys, Mark A; Emond, Michael; Buzdon, Michael

    2012-02-22

    Sport provides a context in which mate choice can be facilitated by the display of athletic prowess. Previous work has shown that, for females, team sport athletes are more desirable as mates than individual sport athletes and non-participants. In the present study, the perceptions of males and females were examined regarding potential mates based on sport participation. It was predicted that team sport athletes would be more positively perceived than individual sport athletes and non-participants by both males and females. A questionnaire, a photograph, and manipulated descriptions were used to gauge perceptual differences with respect to team sport athletes, individual sport athletes, and extra-curricular club participants for 125 females and 119 males from a Canadian university. Both team and individual sport athletes were perceived as being less lazy, more competitive, and healthier than non-participants by both males and females. Interestingly, females perceived male athletes as more promiscuous than non-athletes, which upholds predictions based on previous research indicating (a) athletes have more sexual partners than non-athletes, and (b) females find athletes more desirable as partners than non-participants. Surprisingly, only males perceived female team sport athletes as more dependable than non-participants, and both team and individual sport athletes as more ambitious. This raises questions regarding the initial hypothesis that male team athletes would be perceived positively by females because of qualities such as the ability to cooperate, likeability, and the acceptance of responsibilities necessary for group functioning. Future studies should examine similar questions with a larger sample size that encompasses multiple contexts, taking into account the role of the social profile of sport in relation to mate choice and perception.

  2. Social structure affects mating competition in a damselfish

    Science.gov (United States)

    Wacker, Sebastian; Ness, Miriam Horstad; Östlund-Nilsson, Sara; Amundsen, Trond

    2017-12-01

    The strength of mating competition and sexual selection varies over space and time in many animals. Such variation is typically driven by ecological and demographic factors, including adult sex ratio and consequent availability of mates. The spatial scale at which demographic factors affect mating competition and sexual selection may vary but is not often investigated. Here, we analyse variation in size and sex ratio of social groups, and how group structure affects mating competition, in the site-attached damselfish Chrysiptera cyanea. Site-attached reef fishes are known to show extensive intraspecific variation in social structure. Previous work has focused on species for which the size and dynamics of social groups are constrained by habitat, whereas species with group structure unconstrained by habitat have received little attention. Chrysiptera cyanea is such a species, with individuals occurring in spatial clusters that varied widely in size and sex ratio. Typically, only one male defended a nest in multi-male groups. Nest-holding males were frequently visited by mate-searching females, with more visits in groups with more females, suggesting that courtship and mating mostly occur within groups and that male mating success depends on the number of females in the group. Male-male aggression was frequent in multi-male groups but absent in single-male groups. These findings demonstrate that groups are distinct social units. In consequence, the dynamics of mating and reproduction are mainly a result of group structure, largely unaffected short term by overall population demography which would be important in open social systems. Future studies of the C. cyanea model system should analyse longer-term dynamics, including how groups are formed, how they vary in relation to density and time of season and how social structure affects sexual selection.

  3. 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

  4. MATE standardization

    Science.gov (United States)

    Farmer, R. E.

    1982-11-01

    The MATE (Modular Automatic Test Equipment) program was developed to combat the proliferation of unique, expensive ATE within the Air Force. MATE incorporates a standard management approach and a standard architecture designed to implement a cradle-to-grave approach to the acquisition of ATE and to significantly reduce the life cycle cost of weapons systems support. These standards are detailed in the MATE Guides. The MATE Guides assist both the Air Force and Industry in implementing the MATE concept, and provide the necessary tools and guidance required for successful acquisition of ATE. The guides also provide the necessary specifications for industry to build MATE-qualifiable equipment. The MATE architecture provides standards for all key interfaces of an ATE system. The MATE approach to the acquisition and management of ATE has been jointly endorsed by the commanders of Air Force Systems Command and Air Force Logistics Command as the way of doing business in the future.

  5. Yerba Mate

    Science.gov (United States)

    ... high cholesterol who are also taking statin drugs. Obesity. Early research shows that taking yerba mate by mouth might cause weight loss when used in combination with guarana and damiana. Osteoporosis. Drinking a traditional yerba mate tea daily might ...

  6. Experimental studies on the sterile male technique of spodoptera litura (F. ) by the gamma radiation from /sup 137/Cs, 3. Experiments of the mating competitiveness between moths irradiated as pupae and unirradiated ones in the field cage

    Energy Technology Data Exchange (ETDEWEB)

    Tsukuda, R; Kiyoku, M [Okayama Univ. (Japan). Faculty of Agriculture

    1973-10-01

    Experiments of the mating competitiveness between the substerilized tobacco cutworms and the normal ones were carried out in a field cage (200 x 120 x 180 cm/plot). Pupae of seven days old reared on an artificial medium during the larval stage irradiated with 12 kR of the gamma rays to substerilize. The normal adults were cultured using leaves of cabbages. Cabbages and soybeans were planted in the purpose of egg laying for adult females mated with males in the cage. Substerilized males only or both substerilized males and females were combined with normal males and females. The mating behavior, longevity, egg deposition, percentage of egg hatch and spermatophore in a receptaculum seminis were investigated. When more than ten substerilized and one normal males were exposed to one female, or more than fourteen substerilized and two normal males were combined two normal females, the substerilized males showed high competitiveness with normal males for virgin females. When both five substerilized males and females placed together with one pair of normal male and female in the cage, or each ten substerilized males and females with each two normals, these substerilized males showed full competitiveness. In addition, it was found that offspring obtained from the combination between substerilized males and normal females were sterile.

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. 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

  9. Mating behaviour of Pseudodiaptomus annandalei (Copepoda Calanoida) with emphasis on rejection rate

    Science.gov (United States)

    Dur, G.; Souissi, S.; Schmitt, F. G.; Hwang, J. S.; Cheng, S. H.

    2009-04-01

    Mating behaviour has important consequences at both individual and population levels. Reproductive fitness is of paramount importance to sustain the success of planktonic copepod populations in aquatic environments. The calanoid copepod Pseudodiaptomus annandalei has one of the largest geographical ranges for Indo-Pacific Pseudodiaptomidae. It is also of great importance in fish culture pounds south of Taiwan. However, the mating behavior of this species has never been studied. Mating and predatory behaviour are conceptually the same. In both cases, the encounter and the interactions occur between two individuals with opposite characteristics: predator-prey for predation; male-female for mating. The mating behaviour may be defined as a sequence of encounter, pursuit, capture and copulation. Several observed behaviour suggest that both sexes asses and choose among available mates before the copulation. Pre-copulatory mate choice in copepods may manifest as mate guarding where males attached to CV females until their final moult, complicated pre-copulatory dance and escaping. During our preliminary observations, we notice that P. annandalei females escape by shaking, often violently, the males that have caught them. Consequently for such a species the act of mating may be visualized as a chain of six events (i.e. search, encounter, pursuit, capture, selective dance, copulation).Within this chain, encounter, capture and copulation are conditional events depending on the successful conclusion of their preceding events in the chain. In this study, we examined the different step in the mating behaviour of the scarcely studied sub-tropical copepod, Pseudodiaptomus annandalei, collected from the Danshuei estuary (North Taiwan). The individuals were observed using a 3D optical system to obtain simultaneous front and side views. Males, when placed in the water where females had previously swum in, showed significant increase of their swimming velocities. Additionally, their

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. Studies on the ecology of insects sterilized artificially (gamma radiation), 6. Mating competitiveness between the /sup 137/Cs gamma-substerile males reared artificially and natural ones of the tobacco cutworms

    Energy Technology Data Exchange (ETDEWEB)

    Kiyoku, M; Tsukuda, R [Okayama Univ. (Japan). Faculty of Agriculture

    1973-10-01

    Two different inbred lines of tobacco cutworms were used for the present experiments. One was a line reared on an artificial medium during the larval period, and the other was reared on leaves of the taro plants. Male pupae from the former medium were irradiated with 12 kR of gamma rays from /sup 137/Cs to substerilize. Other males and females from the latter were not irradiated. From one to four substerilized adults with one normal male were exposed to one normal female in a fixed mating-oviposition jar or cage for investigating the male mating competitiveness and mating behavior between substerilized and normal. In the experiments using substerilized adults less than two with one normal male were exposed to one female in the jar, the hatch percentages of eggs were more than 41.7%. It might not be fully competitive. When four substerile and one normal males were combined with one normal female, however, the percentage in the egg hatch was 5.6%. The value obtained was significantly lower than the theoretical estimation of hatch percentage, and this indicates that substerilized males had been mated more than normal. The result was considered to be fully competitive based on the percentage of egg hatch. Besides that, number of eggs laid in this combination showed a considerable reduction as compared with the control.

  13. 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

  14. The effects of individually ventilated cages on the respiratory systems of male and female Wistar rats from birth until adulthood

    Directory of Open Access Journals (Sweden)

    Guilherme D’Aprile Marchesi

    Full Text Available OBJECTIVE: To evaluate the respiratory systems of male and female rats maintained in individually ventilated cages (IVCs from birth until adulthood. METHODS: Female Wistar rats were housed in individually ventilated cages or conventional cages (CCs and mated with male Wistar rats. After birth and weaning, the male offspring were separated from the females and kept in cages of the same type until 12 weeks of age. RESULTS: The level of food consumption was lower in male offspring (IVC=171.7±9; CC=193.1±20 than in female offspring (IVC=100.6±7; CC=123.4±0.4, whereas the water intake was higher in female offspring (IVC=149.8±11; CC=99.2±0 than in male offspring (IVC=302.5±25; CC=249.7±22 at 11 weeks of age when housed in IVCs. The cage temperature was higher in individually ventilated cages than in conventional cages for both male (IVCs=25.9±0.5; CCs=22.95±0.3 and female (IVCs=26.2±0.3; CCs=23.1±0.3 offspring. The respiratory resistance (IVC=68.8±2.8; CC=50.6±3.0 and elastance (IVC=42.0±3.9; CC=32.4±2.0 at 300 µm/kg were higher in the female offspring housed in ventilated cages. The ciliary beat values were lower in both the male (IVCs=13.4±0.2; CC=15±0.4 and female (IVC=13.5±0.4; CC=15.9±0.6 offspring housed in individually ventilated cages than in those housed in conventional cages. The total cell (IVC=117.5±9.7; CC=285.0±22.8, neutrophil (IVC=13.1±4.8; CC=75.6±4.1 and macrophage (IVC=95.2±11.8; CC=170.0±18.8 counts in the bronchoalveolar lavage fluid were lower in the female offspring housed in individually ventilated cages than in those housed in conventional cages. CONCLUSIONS: The environmental conditions that exist in individually ventilated cages should be considered when interpreting the results of studies involving laboratory animals. In this study, we observed gender dimorphism in both the water consumption and respiratory mechanics of rats kept in ventilated cages.

  15. The effects of individually ventilated cages on the respiratory systems of male and female Wistar rats from birth until adulthood

    Science.gov (United States)

    Marchesi, Guilherme D’Aprile; de Fatima Soto, Sônia; de Castro, Isac; Rodrigues, Thiago Guimarães; Moriya, Henrique Takachi; de Almeida, Francine Maria; Pazetti, Rogerio; Heimann, Joel Claudio; Furukawa, Luzia Naôko Shinohara

    2017-01-01

    OBJECTIVE: To evaluate the respiratory systems of male and female rats maintained in individually ventilated cages (IVCs) from birth until adulthood. METHODS: Female Wistar rats were housed in individually ventilated cages or conventional cages (CCs) and mated with male Wistar rats. After birth and weaning, the male offspring were separated from the females and kept in cages of the same type until 12 weeks of age. RESULTS: The level of food consumption was lower in male offspring (IVC=171.7±9; CC=193.1±20) than in female offspring (IVC=100.6±7; CC=123.4±0.4), whereas the water intake was higher in female offspring (IVC=149.8±11; CC=99.2±0) than in male offspring (IVC=302.5±25; CC=249.7±22) at 11 weeks of age when housed in IVCs. The cage temperature was higher in individually ventilated cages than in conventional cages for both male (IVCs=25.9±0.5; CCs=22.95±0.3) and female (IVCs=26.2±0.3; CCs=23.1±0.3) offspring. The respiratory resistance (IVC=68.8±2.8; CC=50.6±3.0) and elastance (IVC=42.0±3.9; CC=32.4±2.0) at 300 µm/kg were higher in the female offspring housed in ventilated cages. The ciliary beat values were lower in both the male (IVCs=13.4±0.2; CC=15±0.4) and female (IVC=13.5±0.4; CC=15.9±0.6) offspring housed in individually ventilated cages than in those housed in conventional cages. The total cell (IVC=117.5±9.7; CC=285.0±22.8), neutrophil (IVC=13.1±4.8; CC=75.6±4.1) and macrophage (IVC=95.2±11.8; CC=170.0±18.8) counts in the bronchoalveolar lavage fluid were lower in the female offspring housed in individually ventilated cages than in those housed in conventional cages. CONCLUSIONS: The environmental conditions that exist in individually ventilated cages should be considered when interpreting the results of studies involving laboratory animals. In this study, we observed gender dimorphism in both the water consumption and respiratory mechanics of rats kept in ventilated cages. PMID:28355363

  16. Effect of chocolate and mate tea on the lipid profile of individuals with HIV/AIDS on antiretroviral therapy: A clinical trial.

    Science.gov (United States)

    Souza, Suelen J; Petrilli, Aline A; Teixeira, Andrea M; Pontilho, Patricia M; Carioca, Antonio A; Luzia, Liania A; Souza, José M; Damasceno, Nágila R; Segurado, Aluisio A; Rondó, Patricia H

    HIV/AIDS is generally associated with dyslipidemia and oxidative imbalance, which are caused by the infection itself and by antiretroviral therapy (ART). The flavonoids, found in cocoa and yerba mate, have antioxidant and hypolipidemic properties. The aim of this study was to evaluate the effects of the consumption of dark chocolate and mate tea on the lipid profiles of individuals with HIV/AIDS who are undergoing ART. A randomized, double-blind, placebo-controlled crossover clinical trial was conducted with 92 patients receiving ART for ≥6 mo and with viral suppression. The participants were randomized to receive either 65 g of chocolate (with 2148 mg polyphenols) or placebo chocolate (without polyphenols) or 3 g of mate tea (with 107 mg total phenols and 84.24 mg chlorogenic acid) or placebo mate (without polyphenols) for 15 d each, separated by a washout period of 15 d. The lipid profile, including determination of electronegative low-density lipoprotein, was determined after each intervention. The data were analyzed by analysis of variance using the pkcross procedure of the Stata 11.0 software. Analysis of variance revealed a significant overall difference in mean high-density lipoprotein cholesterol (HDL-C) between all supplements (P = 0.047). Using the paired t test, the effect was attributed to the consumption of dark chocolate (P = 0.046). The other parameters investigated were not improved. The consumption of dark chocolate for 15 d improved HDL-C concentrations of individuals with HIV/AIDS undergoing ART, possibly due to the presence of fatty acids (stearic acid), polyphenols, and theobromine. This fact is important for the cardiovascular protection of these individuals. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Habitat change influences mate search behaviour in three-spined sticklebacks

    DEFF Research Database (Denmark)

    Heuschele, Jan; Salminen, Tiina; Candolin, Ulrika

    2012-01-01

    Mate choice is one of the main mechanisms of sexual selection, with profound implications for individual fitness. Changes in environmental conditions can cause individuals to alter their mate search behaviour, with consequences for mate choice. Human-induced eutrophication of water bodies...... is a global problem that alters habitat structure and visibility in aquatic ecosystems. We investigated whether changes in habitat complexity and male cue modality, visual or olfactory, influence mate search behaviour of female three-spined sticklebacks, Gasterosteus aculeatus. We allowed gravid females...... evaluation in the absence of visual stimulation. This reduced the rate of mate encounters and probably also the opportunity for choice. Our results show that changes in habitat structure and visibility can alter female mate searching, with potential consequences for the opportunity for sexual selection....

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Sex ratios, mating frequencies and relative abundance of sympatric millipedes in the genus Chersastus (Diplopoda: Pachybolidae

    Directory of Open Access Journals (Sweden)

    Mark Ian Cooper

    2014-12-01

    Full Text Available Three hypotheses exist for explaining climbing behavior in millipedes: 1 waterlogging, 2 detritus limiting, and 3 mate avoidance. Data of sex ratios, mating frequency and relative abundance are provided to suggest an alternative explanation for the pattern in sympatric forest millipedes. Sex ratio differences - from equality - were tested using a G-test comparing millipedes on and above ground. Mating frequencies were calculated based on the percentage of paired individuals. Relative abundance may correlate with male-biases in the sex ratios. All three factors suggest Chersastus inscriptus has a higher reproductive potential than C. anulatus. This is evidence for mating hotspots.

  20. Mating flights select for symmetry in honeybee drones ( Apis mellifera)

    Science.gov (United States)

    Jaffé, Rodolfo; Moritz, Robin F. A.

    2010-03-01

    Males of the honeybee ( Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen’s visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

  1. Mating flights select for symmetry in honeybee drones (Apis mellifera).

    Science.gov (United States)

    Jaffé, Rodolfo; Moritz, Robin F A

    2010-03-01

    Males of the honeybee (Apis mellifera) fly to specific drone congregation areas (DCAs), which virgin queens visit in order to mate. From the thousands of drones that are reared in a single colony, only very few succeed in copulating with a queen, and therefore, a strong selection is expected to act on adult drones during their mating flights. In consequence, the gathering of drones at DCAs may serve as an indirect mate selection mechanism, assuring that queens only mate with those individuals having a better flight ability and a higher responsiveness to the queen's visual and chemical cues. Here, we tested this idea relying on wing fluctuating asymmetry (FA) as a measure of phenotypic quality. By recapturing marked drones at a natural DCA and comparing their size and FA with a control sample of drones collected at their maternal hives, we were able to detect any selection on wing size and wing FA occurring during the mating flights. Although we found no solid evidence for selection on wing size, wing FA was found to be significantly lower in the drones collected at the DCA than in those collected at the hives. Our results demonstrate the action of selection during drone mating flights for the first time, showing that developmental stability can influence the mating ability of honeybee drones. We therefore conclude that selection during honeybee drone mating flights may confer some fitness advantages to the queens.

  2. 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

  3. Sexual selection and physical attractiveness : Implications for mating dynamics.

    Science.gov (United States)

    Gangestad, S W

    1993-09-01

    Sexual selection processes have received much attention in recent years, attention reflected in interest in human mate preferences. Among these mate preferences are preferences for physical attractiveness. Preferences in and of themselves, however, do not fully explain the nature of the relationships that individuals attain. A tacit negotiation process underlies relationship formation and maintenance. The notion that preferences for physical attractiveness evolved under parasite-driven "good genes" sexual selection leads to predictions about the nature of trade-offs that individuals make between mates' physical attractiveness and investment potential. These predictions and relevant data are explored, with a primary emphasis on women's preferences for men's qualities. In addition, further implications of trade-offs are examined, most notably (a) the impact of environmental variations on the nature of mating and (b) some effects of trade-offs on infidelity and male attempts to control women.

  4. Efeitos da seleção individual e da seleção baseada no BLUP em populações diferentes, quanto ao tipo de acasalamento Individual selection and selection based on BLUP effects in different populations, according to mating design

    Directory of Open Access Journals (Sweden)

    E.E. Cunha

    2004-02-01

    Full Text Available Dados simulados foram utilizados para avaliar o desempenho da seleção individual e da seleção baseada no melhor preditor linear não-viesado (BLUP, em populações que diferiam entre si, quanto ao tipo de acasalamento, no decorrer de 50 gerações. Estudou-se uma característica quantitativa com herdabilidade igual a 0,10, em populações de 600 indivíduos, que apresentaram a seguinte estrutura: valores de razão sexual (d, de 10 e 50, tamanhos efetivos de população (Ne, de 36,36 e 7,84 e intensidade de seleção dos machos (i m, de 2,23 e 2,82. Em cada valor de d, formaram-se populações correspondentes ao tipo de acasalamento, em todas as gerações: acasalamentos preferenciais de meios-irmãos e irmãos completos, acasalamentos preferenciais entre meios-irmãos, acasalamentos ao acaso, exclusão de acasalamentos entre irmãos completos e exclusão de acasalamentos de meios-irmãos e irmãos completos. As características avaliadas ao longo das gerações foram: valores fenotípicos médios, consangüinidade média, perda percentual por fixação de alelos desfavoráveis e limite da seleção. Observou-se que o BLUP, o tipo de acasalamento, excluindo acasalamentos entre irmãos e a menor razão sexual, juntos, proporcionaram os melhores resultados de valores fenotípicos, durante 45 gerações de seleção. Nessa estratégia de seleção, verificou-se também atraso no número de gerações necessárias para se atingir determinado nível de consangüinidade.The performance of individual selection and of selection based on best linear unbiased prediction (BLUP for simulated data of a low heritability trait (h²=.10 selected for fifty generation in a population of 600 animals with different mating structures were evaluated. The mating structures evaluated were: mating ratio (d of 10 and 50, population size (Ne 36.36 and 7.84 and male selection intensity (i m of 2.23 and 2.82. For each d level half and full sib matings, half sib matings

  5. [Photosynthesis and transpiration characteristics of female and male Trichosanthes kirilowii Maxim individuals].

    Science.gov (United States)

    Liu, Yun; Zhong, Zhang-cheng; Wang, Xiao-xue; Xie, Jun; Yang, Wen-ying

    2011-03-01

    A field research was conducted on the photosynthesis and transpiration characteristics of dioecious Trichosanthes kirilowii individuals at four key development stages. At vegetative growth stage, the photosynthesis rate, transpiration rate, stomatal conductance, and water use efficiency of male individuals were higher than those of female individuals, and hence, male individuals entered into reproductive growth stage 22 days earlier than female individuals. After entering into reproductive growth stage, male individuals had higher photosynthesis rate, transpiration rate, and stomatal conductance, but slightly lower water use efficiency than female individuals. As the female individuals started to reproductive growth, their photosynthesis rate and water use efficiency were significantly lower, while the transpiration rate and stomatal conductance were higher than those of the male individuals. The effects of climate factors on the growth and development of T. kirilowii mainly occurred at its vegetative growth and early reproductive growth stages, and weakened at later reproductive growth stages. Higher temperature and lower relative humidity benefited the growth and development of T. kirilowii, and illumination could enhance the photosynthesis rate of T. kirilowii, especially its male individuals. After entering into reproductive growth stage, the photosynthesis rate of male individuals increased significantly with increasing illumination, but that of female individuals only had a slight increase, and the transpiration rate of male individuals as well as the photosynthesis rate of female individuals all increased significantly with increasing temperature.

  6. Self-referent phenotype matching and its role in female mate choice in arthropods

    Directory of Open Access Journals (Sweden)

    Carie B. WEDDLE, John HUNT, Scott K. SAKALUK

    2013-04-01

    Full Text Available A growing body of empirical evidence shows that females of many animal species gain benefits by mating polyandrously, and often prefer to mate with novel males over previous mates. Although a female preference for novel males has been demonstrated for multiple animal taxa, the mechanisms used by females to discriminate between novel and previous mates remain largely unknown. However, recent studies suggest that in decorated crickets Gryllodes sigillatus, females actually imbue males with their own chemical cues, known as cuticular hydrocarbons (CHCs during mating, and utilize chemosensory self-referencing to recognize recent mates. Here we review evidence that self-referent phenotype matching is a widespread mechanism of recognition in arthropods, and explore how CHCs are used to facilitate mate-choice decisions. There is substantial evidence that CHCs are used as recognition cues to discriminate between species, kin, sexes, mates, individuals, and self and non-self, and are used to facilitate mate-choice decisions in a wide range of arthropod taxa. There is also evidence that CHCs are often transferred between individuals during direct physical contact, including copulation. Chemosensory self-referencing via cuticular hydrocarbons could provide a simple, but reliable mechanism for identifying individuals from previous mating encounters. This mechanism does not require any specialized cognitive abilities because an individual’s phenotype is always available for reference. Given the ubiquitous use of CHCs among arthropods, chemosensory self-referencing may be a widespread mechanism used by female arthropods to facilitate female mate-choice decisions and to enhance opportunities for polyandry [Current Zoology 59 (2: 239-248, 2013].

  7. Choosy females and indiscriminate males: mate choice in mixed populations of sexual and hybridogenetic water frogs (Rana lessonae, Rana esculenta)

    OpenAIRE

    Engeler, B; Reyer, H U

    2001-01-01

    For several decades, behavioral ecologists have studied the effects of the environment on the behavior of individuals; but only fairly recently they have started to ask the reverse question: how do the behavioral strategies of individuals affect the composition and dynamics of populations and communities? Although intuitively obvious, this feedback from individual to higher levels is difficult to demonstrate, except in systems with exceptionally fast and marked responses of the populations to...

  8. Effect of mate size on maternal reproductive effort in the convict cichlid Amatitlania siquia

    Institute of Scientific and Technical Information of China (English)

    Ashley R. ROBART

    2012-01-01

    The differential allocation hypothesis predicts individuals will increase their reproductive investment when mated to a high quality partner.In many species of fish with biparental care females prefer large males due to the males' greater ability to raise more offspring to independence.I examined the relationship between mate quality,parental care and number of offspring in a natural population of convict cichlids Amatitlania siquia.The frequency of frontal displays by females was positively correlated with male standard length.Additionally,as males increased in length relative to their mate,females increased the frequency of chases towards predators,while males decreased the number of displays towards brood predators.This trade-off in parental effort within a pair due to mate quality is a key prediction of differential allocation.The number of offspring was correlated with male,but not female,standard length.These results support the differential allocation hypothesis in that females offered more parental care to offspring of a larger male,while their mates decreased the amount of care they provided.Additionally,females benefited in terms of number of offspring by pairing with higher quality mates.Increased female investment may provide an incentive to ensure male care and maintain pair bonding,which could lead to greater reproductive success through increased offspring survival [Current Zoology 58 (1):66-72,2012].

  9. Male Snakes Allocate Time and Energy according to Individual Energetic Status: Body Condition, Steroid Hormones, and Reproductive Behavior in Timber Rattlesnakes, Crotalus horridus.

    Science.gov (United States)

    Lind, Craig M; Beaupre, Steven J

    2015-01-01

    Life-history theory predicts that organisms will hedge current reproductive investment against potential costs in terms of survivorship and future fecundity. However, little is known regarding the endocrine mechanisms underlying bet-hedging strategies in free-ranging male vertebrates. We examined the relationships among individual energetic status, steroid hormones, mate search, and reproductive behavior in free-ranging male timber rattlesnakes. Snakes were monitored over four active seasons in order to test two hypotheses: (1) males adjust the amount of time and energy allocated toward reproduction according to the level of individual energy stores, and (2) observed condition-dependent reproductive allocation is associated with circulating concentrations of steroid hormones (testosterone and corticosterone) thought to regulate reproductive behaviors in vertebrates. A positive relationship between body condition and testosterone was observed in both the field and the laboratory. Male mate search effort was positively correlated with both body condition and testosterone. Body condition and testosterone concentrations were negatively related to time allocated toward foraging during the breeding season. A strong effect of year was observed in the analysis of testosterone and search effort, suggesting that multiple environmental factors impact hormone production and reproductive investment. Corticosterone was not related to any measured variable. Therefore, our results did not indicate a clear role of corticosterone in mediating observed relationships between energetic status and behavior. Observed relationships are consistent with the hypothesis that males allocate time and energy toward reproduction according to individual energetic status and that testosterone plays a role in mediating the trade-off between current reproductive investment and residual reproductive value.

  10. Experimental evolution reveals trade-offs between mating and immunity.

    Science.gov (United States)

    McNamara, Kathryn B; Wedell, Nina; Simmons, Leigh W

    2013-08-23

    Immune system maintenance and upregulation is costly. Sexual selection intensity, which increases male investment into reproductive traits, is expected to create trade-offs with immune function. We assayed phenoloxidase (PO) and lytic activity of individuals from populations of the Indian meal moth, Plodia interpunctella, which had been evolving under different intensities of sexual selection. We found significant divergence among populations, with males from female-biased populations having lower PO activity than males from balanced sex ratio or male-biased populations. There was no divergence in anti-bacterial lytic activity. Our data suggest that it is the increased male mating demands in female-biased populations that trades-off against immunity, and not the increased investment in sperm transfer per mating that characterizes male-biased populations.

  11. Sexual orientation related differences in cortical thickness in male individuals.

    Directory of Open Access Journals (Sweden)

    Christoph Abé

    Full Text Available Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI in order to compare regional cortical thickness (Cth and subcortical volumes of homosexual men (hoM, heterosexual men (heM and heterosexual women (heW. hoM (and heW had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.

  12. Sexual orientation related differences in cortical thickness in male individuals.

    Science.gov (United States)

    Abé, Christoph; Johansson, Emilia; Allzén, Elin; Savic, Ivanka

    2014-01-01

    Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI) in order to compare regional cortical thickness (Cth) and subcortical volumes of homosexual men (hoM), heterosexual men (heM) and heterosexual women (heW). hoM (and heW) had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.

  13. Negative Assortative Mating Based on Body Coloration in the Freshwater Platyfish (Poecillidae: Xiphophorus maculatus

    Directory of Open Access Journals (Sweden)

    Tyler E. Frankel

    2017-04-01

    Full Text Available The ability of individuals within a population to survive and thrive is highly dependent upon the maintenance of genetic variation and phenotypic diversity, thereby ensuring adaptation to dynamic environments. A fundamental method of maintaining such variation is through a negative assortative mating strategy, in which individuals would be expected to reproductively select members of the opposite sex that exhibit dissimilar phenotypes. Employing three uniform body color morphs, red, yellow and blue, of the platyfish (Xiphophorus maculatus, this study was designed to investigate whether X. maculatus females would preferentially be attracted to males exhibiting an alternative color, thereby enabling an examination of the effect of male body coloration on mate choice by adult females. Mate choice was determined based on the initial preference of each female, as well as the amount of time females spent associating with each male. Initial preferences were analyzed using a binomial distribution test, and overall preference data using Wilcoxon signed rank tests. Red females initially selected for dissimilar colored males, and spent a significantly larger amount of time associating with blue and yellow males, as did yellow females with red and blue males. Blue females initially selected and spent a significantly larger amount of time associating with red males but, interestingly, showed no selective preference between blue and yellow males. In these experimental trials, the overall strong mate selection exhibited by female platyfish for males of dissimilar coloration is suggestive of a negative assortative mating strategy and provides evidence for the maintenance of color polymorphism in nature populations.

  14. 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

  15. REINFORCEMENT OF STICKLEBACK MATE PREFERENCES: SYMPATRY BREEDS CONTEMPT.

    Science.gov (United States)

    Rundle, Howard D; Schluter, Dolph

    1998-02-01

    Detailed studies of reproductive isolation and how it varies among populations can provide valuable insight into the mechanisms of speciation. Here we investigate how the strength of premating isolation varies between sympatric and allopatric populations of threespine sticklebacks to test a prediction of the hypothesis of reinforcement: that interspecific mate discrimination should be stronger in sympatry than in allopatry. In conducting such tests, it is important to control for ecological character displacement between sympatric species because ecological character divergence may strengthen prezygotic isolation as a by-product. We control for ecological character displacement by comparing mate preferences of females from a sympatric population (benthics) with mate preferences of females from two allopatric populations that most closely resemble the sympatric benthic females in ecology and morphology. No-choice mating trials indicate that sympatric benthic females mate less readily with heterospecific (limnetic) than conspecific (benthic) males, whereas two different populations of allopatric females resembling benthics show no such discrimination. These differences demonstrate reproductive character displacement of benthic female mate choice. Previous studies have established that hybridization between sympatric species occurred in the past in the wild and that hybrid offspring have lower fitness than either parental species, thus providing conditions under which natural selection would favor individuals that do not hybridize. Results are therefore consistent with the hypothesis that female mate preferences have evolved as a response to reduced hybrid fitness (reinforcement), although direct effects of sympatry or a biased extinction process could also produce the pattern. Males of the other sympatric species (limnetics) showed a preference for smaller females, in contrast to the inferred ancestral preference for larger females, suggesting reproductive character

  16. 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.

  17. Allochronic separation versus mate choice: nonrandom patterns of mating between fall armyworm host strains

    NARCIS (Netherlands)

    Schöfl, G.; Dill, A.; Heckel, D.G.; Groot, A.T.

    2011-01-01

    Assortative mating may result from intrinsic individual mating preferences or from assortment traits not requiring expression of preferences. Assortment traits are phenotypes expressed in both sexes that enhance the probability of encountering individuals possessing similar trait values. In the

  18. The Long and the Short of Mate Attraction in a Psylloid: do Semiochemicals Mediate Mating in Aacanthocnema dobsoni Froggatt?

    Science.gov (United States)

    Lubanga, Umar K; Drijfhout, Falko P; Farnier, Kevin; Steinbauer, Martin J

    2016-02-01

    Mating is preceded by a series of interdependent events that can be broadly categorized into searching and courtship. Long-range signals convey species- and sex-specific information during searching, while short-range signals provide information specific to individuals during courtship. Studies have shown that cuticular hydrocarbons (CHCs) can be used for mate recognition in addition to protecting insects from desiccation. In Psylloidea, four species rely on semiochemicals for long-range mate attraction. Psyllid mating research has focused on long-range mate attraction and has largely ignored the potential use of cuticular hydrocarbons (CHCs) as mate recognition cues. This study investigated whether CHCs of Aacanthocnema dobsoni have semiochemical activity for long- and short-range communication prior to mating. Using a solid sampler for solvent-less injection of whole psyllids into coupled gas chromatography/mass spectrometry, we found quantitative, sex- and age-related differences in CHC profiles. Males had higher proportions of 2-MeC28, 11,15-diMeC29, and n-C33 alkanes, while females had higher proportions of 5-MeC27, 3-MeC27, 5,15-diMeC27, n-C29 and n-C30 alkanes. In males and females, 84 and 68 % of CHCs varied with age, respectively. Y-tube olfactometer bioassays provided no evidence that males or females responded to odors emanating from groups of conspecifics of the opposite sex. Tests of male and female psyllids for attraction to branchlets previously occupied by conspecifics showed no evidence of attraction to possible semiochemical residues. Our short-range chemoreception bioassay showed that males were as indifferent to freshly killed individuals of either sex with intact CHC profiles as to those treated with hexane (to remove CHCs). Aacanthocnema dobsoni utilizes substrate-borne vibrations (SBVs) for communication. Therefore, our results indicate that SBVs are probably more important than semiochemicals for long-range mate attraction. Furthermore

  19. Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male's odour

    OpenAIRE

    McLean Lynn; Robertson Duncan H; Davidson Amanda J; Armstrong Stuart D; Simpson Deborah M; Roberts Sarah A; Beynon Robert J; Hurst Jane L

    2010-01-01

    Abstract Background Among invertebrates, specific pheromones elicit inherent (fixed) behavioural responses to coordinate social behaviours such as sexual recognition and attraction. By contrast, the much more complex social odours of mammals provide a broad range of information about the individual owner and stimulate individual-specific responses that are modulated by learning. How do mammals use such odours to coordinate important social interactions such as sexual attraction while allowing...

  20. Effect of mate size on maternal reproductive effort in the convict cichlid Amatitlania siquia

    Directory of Open Access Journals (Sweden)

    Ashley R. ROBART

    2012-02-01

    Full Text Available The differential allocation hypothesis predicts individuals will increase their reproductive investment when mated to a high quality partner. In many species of fish with biparental care females prefer large males due to the males’ greater ability to raise more offspring to independence. I examined the relationship between mate quality, parental care and number of offspring in a natural population of convict cichlids Amatitlania siquia. The frequency of frontal displays by females was positively correlated with male standard length. Additionally, as males increased in length relative to their mate, females increased the frequency of chases towards predators, while males decreased the number of displays towards brood predators. This trade-off in parental effort within a pair due to mate quality is a key prediction of differential allocation. The number of offspring was correlated with male, but not female, standard length. These results support the differential allocation hypothesis in that females offered more parental care to offspring of a larger male, while their mates decreased the amount of care they provided. Additionally, females benefited in terms of number of offspring by pairing with higher quality mates. Increased female investment may provide an incentive to ensure male care and maintain pair bonding, which could lead to greater reproductive success through increased offspring survival [Current Zoology 58 (1: 66–72, 2012].

  1. Mate Value Discrepancy and Mate Retention Behaviors of Self and Partner.

    Science.gov (United States)

    Sela, Yael; Mogilski, Justin K; Shackelford, Todd K; Zeigler-Hill, Virgil; Fink, Bernhard

    2017-10-01

    This study investigated the relationship between perceived mate value discrepancy (i.e., the difference between an individual's mate value and their partner's mate value) and perceived frequency of mate retention performed by an individual relative to his or her partner. In two studies, participants in long-term, exclusive, sexual, heterosexual relationships reported their own, and their partner's, mate value and mate retention. Samples included 899 community members (Study 1) and 941 students and community members (Study 2). In Study 1, we documented that individuals with higher self-perceived short-term mate value, and who perceive their partner to have lower (vs. higher) short-term mate value, perform less frequent Benefit-Provisioning mate retention, controlling for the partner's Benefit-Provisioning mate retention. In Study 2, we documented that individuals who perceive that they could less easily replace their partner, and who perceive their partner could more (vs. less) easily replace them, perform more frequent mate retention (Benefit-Provisioning and Cost-Inflicting), controlling for the partner's mate retention. These results highlight the importance of assessing perceived discrepancies in mate value (notably, regarding the replaceability of self and partner with another long-term mate) and perceived mate retention behaviors of self, relative to partner, between men and women in long-term relationships. © 2016 Wiley Periodicals, Inc.

  2. Short-term exposure to a synthetic estrogen disrupts mating dynamics in a pipefish.

    Science.gov (United States)

    Partridge, Charlyn; Boettcher, Anne; Jones, Adam G

    2010-11-01

    Sexual selection is responsible for the evolution of some of the most elaborate traits occurring in nature, many of which play a vital role in competition over access to mates and individual reproductive fitness. Because expression of these traits is typically regulated by sex-steroids there is a significant potential for their expression to be affected by the presence of certain pollutants, such as endocrine disrupting compounds. Endocrine disruptors have been shown to alter primary sexual traits and impact reproduction, but few studies have investigated how these compounds affect secondary sexual trait expression and how that may, in turn, impact mating dynamics. In this study we examine how short-term exposure to a synthetic estrogen impacts secondary sexual trait expression and mating dynamics in the Gulf pipefish, a species displaying sex-role reversal. Our results show that only 10days of exposure to 17α-ethinylestradiol results in adult male pipefish developing female-like secondary sexual traits. While these males are capable of reproduction, females discriminate against exposed males in mate choice trials. In natural populations, this type of discrimination would reduce male mating opportunities, thus potentially reducing their long-term reproductive success. Importantly, the effects of these compounds on mating dynamics and mating opportunity would not be observed using the current standard methods of assessing environmental contamination. However, disrupting these processes could have profound effects on the viability of exposed populations. Copyright © 2010 Elsevier Inc. All rights reserved.

  3. Honey bee queens do not count mates to assess their mating success

    Science.gov (United States)

    The mating system of honey bees (genus Apis) is extremely polyandrous, where reproductive females (queens) typically mate with 12 or more males (drones) during their mating flight(s). The evolutionary implications for hyperpolyandry have been subject to considerable debate and empirical testing beca...

  4. Self-Perceived Mate Value, Facial Attractiveness, and Mate Preferences: Do Desirable Men Want It All?

    Science.gov (United States)

    Arnocky, Steven

    2018-01-01

    Ten years ago, Buss and Shackelford demonstrated that high mate value (i.e., physically attractive) women held more discerning mate preferences relative to lower mate value women. Since then, researchers have begun to consider the equally important role of men's sexual selectivity in human mate choice. Yet, little research has focused on whether high mate value men are similarly choosy in their mate preferences. In a sample of 139 undergraduate men, relationships between self-perceived mate value as well as female-rated facial attractiveness were examined in relation to men's expressed mate preferences. Results showed that self-perceived mate value was unrelated to men's facial attractiveness as rated by women. Men who believed they were of high mate value were more likely than lower mate value men to prefer to marry at a younger age; to have a spouse who was younger than them; and to have a partner who was sociable, ambitious, high in social status, with good financial prospects, a desire for children, health, good looks, and mutual attraction. Objective male facial attractiveness was generally unrelated to heightened mate preferences, with the exception of heightened preference for similar religious background and good physical health. Findings suggest that men who perceive themselves as high in overall mate value are selective in their mate choice in a manner similar to high mate value women.

  5. Sex-specific conditional mating preferences in a cichlid fish : Implications for sexual conflict

    NARCIS (Netherlands)

    Baldauf, Sebastian A.; Engqvist, Leif; Ottenheym, Tobias; Bakker, Theo C. M.; Thuenken, Timo

    Conditional mating strategies enable individuals to modulate their mating behaviour depending on 'individual status' to maximise fitness. Theory predicts that variation in individual quality can lead to differences in mating preferences. However, empirical evidence is scarce particular in terms of

  6. Vocal neighbour-mate discrimination in female great tits despite high song similarity

    DEFF Research Database (Denmark)

    Blumenrath, Sandra H.; Dabelsteen, Torben; Pedersen, Simon Boel

    2007-01-01

    Discrimination between conspecifics is important in mediating social interactions between several individuals in a network environment. In great tits, Parus major, females readily distinguish between the songs of their mate and those of a stranger. The high degree of song sharing among neighbouring...... males, however, raises the question of whether females are also able to perceive differences between songs shared by their mate and a neighbour. The great tit is a socially monogamous, hole-nesting species with biparental care. Pair bond maintenance and coordination of the pair's reproductive efforts...... are important, and the female's ability to recognize her mate's song should therefore be adaptive. In a neighbour-mate discrimination playback experiment, we presented 13 incubating great tit females situated inside nestboxes with a song of their mate and the same song type from a neighbour. Each female...

  7. Does kin recognition and sib-mating avoidance limit the risk of genetic incompatibility in a parasitic wasp?

    Directory of Open Access Journals (Sweden)

    Marie Metzger

    2010-10-01

    Full Text Available When some combinations of maternal and paternal alleles have a detrimental effect on offspring fitness, females should be able to choose mates on the basis of their genetic compatibility. In numerous Hymenoptera, the sex of an individual depends of the allelic combination at a specific locus (single-locus Complementary Sex Determination, and in most of these species individuals that are homozygous at this sexual locus develop into diploid males with zero fitness.In this paper, we tested the hypothesis of genetic incompatibility avoidance by investigating sib-mating avoidance in the solitary wasp parasitoid, Venturia canescens. In the context of mate choice we show, for the first time in a non-social hymenopteran species, that females can avoid mating with their brothers through kin recognition. In "no-choice" tests, the probability a female will mate with an unrelated male is twice as high as the chance of her mating with her brothers. In contrast, in choice tests in small test arenas, no kin discrimination effect was observed. Further experiments with male extracts demonstrate that chemical cues emanating from related males influence the acceptance rate of unrelated males.Our results are compatible with the genetic incompatibility hypothesis. They suggest that the female wasps recognize sibs on the basis of a chemical signature carried or emitted by males possibly using a "self-referent phenotype matching" mechanism.

  8. How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples.

    Science.gov (United States)

    Conroy-Beam, Daniel; Buss, David M

    2016-01-01

    Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294) we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection.

  9. How Are Mate Preferences Linked with Actual Mate Selection? Tests of Mate Preference Integration Algorithms Using Computer Simulations and Actual Mating Couples.

    Directory of Open Access Journals (Sweden)

    Daniel Conroy-Beam

    Full Text Available Prior mate preference research has focused on the content of mate preferences. Yet in real life, people must select mates among potentials who vary along myriad dimensions. How do people incorporate information on many different mate preferences in order to choose which partner to pursue? Here, in Study 1, we compare seven candidate algorithms for integrating multiple mate preferences in a competitive agent-based model of human mate choice evolution. This model shows that a Euclidean algorithm is the most evolvable solution to the problem of selecting fitness-beneficial mates. Next, across three studies of actual couples (Study 2: n = 214; Study 3: n = 259; Study 4: n = 294 we apply the Euclidean algorithm toward predicting mate preference fulfillment overall and preference fulfillment as a function of mate value. Consistent with the hypothesis that mate preferences are integrated according to a Euclidean algorithm, we find that actual mates lie close in multidimensional preference space to the preferences of their partners. Moreover, this Euclidean preference fulfillment is greater for people who are higher in mate value, highlighting theoretically-predictable individual differences in who gets what they want. These new Euclidean tools have important implications for understanding real-world dynamics of mate selection.

  10. Sharing mates and nest boxes is associated with female "friendship" in European starlings, Sturnus vulgaris.

    Science.gov (United States)

    Henry, Laurence; Bourguet, Cécile; Coulon, Marion; Aubry, Christine; Hausberger, Martine

    2013-02-01

    Breeding decisions in birds involve both mate and nest choice, and there is increasing evidence that social influences may modulate individual choices. Female preferences may be affected by other females' preferences and mutual choice cannot always be excluded, which makes the whole pattern more complex than assumed by most sexual selection models. Social transmission may be facilitated by particular social bonds, therefore prebreeding social networks may influence later mate choices. The other case where females share mate or resources is polygyny, generally viewed to only benefit males. If mutual benefits may arise then mechanisms should evolve to reduce the reproductive cost for females such as to reduce the cost of aggression by sharing their mate with a preferred same-sex social partner. We tested the hypothesis that females' mating decisions may be influenced by the prebreeding social network and that social partner relations established prior to breeding may share decisions (mate/sites) in a facultatively polygynous species, the European starling. Two experiments were designed to test the relative importance of male or nest by following the whole dynamics of the breeding cycle from the prebreeding period until mate and nest selection. In both cases socially isolated females tended to be excluded from breeding, while prebreeding social partners tended to share mates and to nest in close proximity, mate copying leading in some case to polygyny. The final pattern resulted both from female "likes and dislikes" and male preferences for some females. Aggressive interactions between females were rare. Vocal sharing between females may have been a clue for males as to the degree of social integration of these females. PsycINFO Database Record (c) 2013 APA, all rights reserved

  11. Variation in circulating testosterone during mating predicts reproductive success in a wild songbird.

    Directory of Open Access Journals (Sweden)

    Beate Apfelbeck

    2016-08-01

    Full Text Available Testosterone is an important sex hormone and mediates reproduction in male vertebrates. There is ample evidence that testosterone coordinates the expression of physiological, morphological and behavioural traits during reproduction and many of these traits are under sexual selection. However, only few studies so far have examined if individual variation in testosterone is correlated with reproductive success. Because socially monogamous bird species pass through different phases within a breeding cycle and each of these phases requires the expression of different behaviours, the relation between testosterone and reproductive success could vary with breeding stage. Here we investigate the link between reproductive success and testosterone in European stonechats – a socially monogamous songbird with biparental care. Previous studies found that territorial aggression in breeding stonechats depends on testosterone and that testosterone levels peak during the mating phase. Thus, high testosterone levels during mating may influence reproductive success by promoting territorial aggression and mate guarding. We found that males with two breeding attempts produced a similar number of fledglings as males with three breeding attempts. However, males with two breeding attempts expressed higher levels of testosterone than males with just one or those with three breeding attempts, regardless of whether testosterone was measured during the mating or the parental phase of the first brood. Furthermore, testosterone levels during mating, but not during parenting correlated with the total annual number of fledglings. Thus, individual variation in levels of plasma testosterone predicted reproductive success in stonechats.

  12. Mate replacement and alloparental care in Ferruginous Hawk (Buteo regalis)

    Science.gov (United States)

    Datta, Shubham; Inselman, Will M.; Jenks, Jonathan A.; Jensen, Kent C.; Swanson, Christopher C.; Klaver, Robert W.; Sasmal, Indrani; Grovenburg, Troy W.

    2015-01-01

    Alloparental care (i.e., care for unrelated offspring) has been documented in various avian species (Maxson 1978, Smith et al. 1996, Tella et al. 1997, Lislevand et al. 2001, Literak and Mraz 2011). A male replacement mate that encounters existing broods has options, which include alloparental care or infanticide. Infanticide may be beneficial in some species (Rohwer 1986, Kermott et al. 1990), but in long-lived avian species, like the ferruginous hawk (Buteo regalis) that do not renest within a season, infanticide might be detrimental. Adoption and rearing success likely provide direct evidence of competence of replacement mates as potential parents for future seasons, a benefit that might outweigh the investment of time and effort associated with adoption and rearing (after Rohwer 1986). Anticipated mating opportunity at the cost of adoption (Gori et al. 1996, Rohwer et al. 1999) may explain step-parental benevolence and therefore, in such a scenario would enhance individual fitness through subsequent recruitment of related young.

  13. Hormonal changes during the mating and conception seasons of wild northern muriquis (Brachyteles arachnoides hypoxanthus).

    Science.gov (United States)

    Strier, Karen B; Lynch, Jessica W; Ziegler, Toni E

    2003-10-01

    We investigated hormonal and behavioral changes in wild male and female northern muriquis (Brachyteles arachnoides hypoxanthus) at the Estação Biológica de Caratinga, Minas Gerais, Brazil, during a 6-mo period that encompassed the onset of the 1998-1999 mating and conception seasons. Individual females resumed mating with the resumption of ovarian cycling, which was not synchronized among them or related to their cortisol levels. Females experienced two to seven cycles prior to conceiving, and the first conception occurred 2 mo after the onset of the group's mating season. There were no differences in female cortisol levels across their premating, mating, and conception conditions. Cortisol levels were significantly higher in females than in males prior to the conception season, consistent with the prediction that energy reserves may be associated with breeding readiness in females, but not males, in this species. The sustained elevation in male cortisol occurred after the peak in their sexual activity, which resulted in the first conception of the year. Male cortisol levels were positively correlated between years that were similar in rainfall, but differed in the timing of sexual and reproductive events. The timing of cortisol elevations in males appears to be generally regulated by environmental cues, but is responsive to fine-tuning by social and behavioral cues related to the unpredictable timing of reproductive opportunities within their extended mating season. Copyright 2003 Wiley-Liss, Inc.

  14. 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 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.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.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.

  15. Age-related and Individual Variation in Male Piezodorus hybneri (Heteroptera: Pentatomidae Pheromones

    Directory of Open Access Journals (Sweden)

    Nobuyuki Endo

    2012-01-01

    Full Text Available Males of the Piezodorus hybneri stink bug produce a pheromone comprising β-sesquiphellandrene (Sesq, (R-15-hexadecanolide (R15, and methyl (Z-8-hexadecenoate (Z8. We collected airborne volatiles from individual P. hybneri males and analyzed them by GC-MS. Daily analysis from 1 to 16 days after adult emergence showed that pheromone emission started around 3 to 6 days after adult emergence and peaked (~1 μg/male/day on day 11. The proportion of Sesq tended to increase with age to about 80% on days 12 to 16. On the other hand, the proportion of R15 tended to decrease with age. The proportion of Z8 reached a maximum of about 34% on day 9 but otherwise remained below 20%. The total amount of pheromone emitted by individual males varied considerably: three males emitted more than 10 μg, whereas another three males emitted little or no pheromone and failed to survive by the end of the experiment. These results suggest that the amount of P. hybneri pheromone and its blend ratio could be affected by the male’s physical conditions, such as vitality and age.

  16. A Method to Test the Effect of Environmental Cues on Mating Behavior in Drosophila melanogaster.

    Science.gov (United States)

    Gorter, Jenke A; Billeter, Jean-Christophe

    2017-07-17

    An individual's sexual drive is influenced by genotype, experience and environmental conditions. How these factors interact to modulate sexual behaviors remains poorly understood. In Drosophila melanogaster, environmental cues, such as food availability, affect mating activity offering a tractable system to investigate the mechanisms modulating sexual behavior. In D. melanogaster, environmental cues are often sensed via the chemosensory gustatory and olfactory systems. Here, we present a method to test the effect of environmental chemical cues on mating behavior. The assay consists of a small mating arena containing food medium and a mating couple. The mating frequency for each couple is continuously monitored for 24 h. Here we present the applicability of this assay to test environmental compounds from an external source through a pressurized air system as well as manipulation of the environmental components directly in the mating arena. The use of a pressurized air system is especially useful to test the effect of very volatile compounds, while manipulating components directly in the mating arena can be of value to ascertain a compound's presence. This assay can be adapted to answer questions about the influence of genetic and environmental cues on mating behavior and fecundity as well as other male and female reproductive behaviors.

  17. Toward Male Individualization with Rapidly Mutating Y-Chromosomal Short Tandem Repeats

    NARCIS (Netherlands)

    K. Ballantyne (Kaye); A. Ralf (Arwin); R. Aboukhalid (Rachid); N.M. Achakzai (Niaz); T. Anjos (Tania); Q. Ayub (Qasim); J. Balažic (Jože); J. Ballantyne (Jack); D.J. Ballard (David); B. Berger (Burkhard); C. Bobillo (Cecilia); M. Bouabdellah (Mehdi); H. Burri (Helen); T. Capal (Tomas); S. Caratti (Stefano); J. Cárdenas (Jorge); F. Cartault (François); E.F. Carvalho (Elizeu); M. de Carvalho (Margarete); B. Cheng (Baowen); M.D. Coble (Michael); D. Comas (David); D. Corach (Daniel); M. D'Amato (Mauro); S. Davison (Sean); P. de Knijff (Peter); M.C.A. de Ungria (Maria Corazon); R. Decorte (Ronny); T. Dobosz (Tadeusz); B.M. Dupuy (Berit); S. Elmrghni (Samir); M. Gliwiński (Mateusz); S.C. Gomes (Sara); L. Grol (Laurens); C. Haas (Cordula); E. Hanson (Erin); J. Henke (Jürgen); L. Henke (Lotte); F. Herrera-Rodríguez (Fabiola); C.R. Hill (Carolyn); G. Holmlund (Gunilla); K. Honda (Katsuya); U.-D. Immel (Uta-Dorothee); S. Inokuchi (Shota); R. Jobling; M. Kaddura (Mahmoud); J.S. Kim (Jong); S.H. Kim (Soon); W. Kim (Wook); T.E. King (Turi); E. Klausriegler (Eva); D. Kling (Daniel); L. Kovačević (Lejla); L. Kovatsi (Leda); P. Krajewski (Paweł); S. Kravchenko (Sergey); M.H.D. Larmuseau (Maarten); E.Y. Lee (Eun Young); R. Lessig (Rüdiger); L.A. Livshits (Ludmila); D. Marjanović (Damir); M. Minarik (Marek); N. Mizuno (Natsuko); H. Moreira (Helena); N. Morling (Niels); M. Mukherjee (Meeta); P. Munier (Patrick); J. Nagaraju (Javaregowda); F. Neuhuber (Franz); S. Nie (Shengjie); P. Nilasitsataporn (Premlaphat); T. Nishi (Takeki); H.H. Oh (Hye); S. Olofsson (Sylvia); V. Onofri (Valerio); J. Palo (Jukka); H. Pamjav (Horolma); W. Parson (Walther); M. Petlach (Michal); C. Phillips (Christopher); R. Ploski (Rafal); S.P.R. Prasad (Samayamantri P.); D. Primorac (Dragan); G.A. Purnomo (Gludhug); J. Purps (Josephine); H. Rangel-Villalobos (Hector); K. Reogonekbała (Krzysztof); B. Rerkamnuaychoke (Budsaba); D.R. Gonzalez (Danel Rey); C. Robino (Carlo); L. Roewer (Lutz); A. de Rosa (Anna); A. Sajantila (Antti); A. Sala (Andrea); J.M. Salvador (Jazelyn); P. Sanz (Paula); C. Schmitt (Christian); A.K. Sharma (Anisha K.); D.A. Silva (Dayse); K.-J. Shin (Kyoung-Jin); T. Sijen (Titia); M. Sirker (Miriam); D. Siváková (Daniela); V. Škaro (Vedrana); C. Solano-Matamoros (Carlos); L. Souto (L.); V. Stenzl (Vlastimil); H. Sudoyo (Herawati); D. Syndercombe-Court (Denise); A. Tagliabracci (Adriano); D. Taylor (Duncan); A. Tillmar (Andreas); I.S. Tsybovsky (Iosif); C. Tyler-Smith (Chris); K. van der Gaag (Kristiaan); D. Vanek (Daniel); A. Völgyi (Antónia); D. Ward (Denise); P. Willemse (Patricia); E.P.H. Yap (Eric); Z-Y. Yong (Ze-Yie); I.Z. Pajnič (Irena Zupanič); M.H. Kayser (Manfred)

    2014-01-01

    textabstractRelevant for various areas of human genetics, Y-chromosomal short tandem repeats (Y-STRs) are commonly used for testing close paternal relationships among individuals and populations, and for male lineage identification. However, even the widely used 17-loci Yfiler set cannot resolve

  18. Social variables affecting mate preferences, copulation and reproductive outcome in a pack of free-ranging dogs.

    Directory of Open Access Journals (Sweden)

    Simona Cafazzo

    Full Text Available Mating and reproductive outcome is often determined by the simultaneous operation of different mechanisms like intra-sexual competition, mating preferences and sexual coercion. The present study investigated how social variables affected mating outcome in a pack of free-ranging dogs, a species supposed to have lost most features of the social system of wolves during domestication. We found that, although the pack comprised multiple breeding individuals, both male copulation success and female reproductive success were positively influenced by a linear combination of dominance rank, age and leadership. Our results also suggest that mate preferences affect mating outcome by reinforcing the success of most dominant individuals. In particular, during their oestrous period bitches clearly searched for the proximity of high-ranking males who displayed affiliative behaviour towards them, while they were more likely to reject the males who intimidated them. At the same time, male courting effort and male-male competition for receptive females appeared to be stronger in the presence of higher-ranking females, suggesting a male preference for dominant females. To our knowledge, these results provide the first clear evidence of social regulation of reproductive activities in domestic dogs, and suggest that some common organizing mechanisms may contribute to shape the social organization of both dogs and wolves.

  19. Strategies of Human Mating

    Directory of Open Access Journals (Sweden)

    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.

  20. Ant parasite queens revert to mating singly

    DEFF Research Database (Denmark)

    Sumner, Seirian; Hughes, William Owen Hamar; Pedersen, Jes Søe

    2004-01-01

    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......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...... to a dozen different males, the social parasite mates only singly. This rapid and surprising reversion to single mating in a socially parasitic ant indicates that the costs of polyandry are probably specific to a free-living lifestyle....

  1. Components of competitiveness in sterile male boll weevils (Coleoptera: Curculionidae)

    International Nuclear Information System (INIS)

    Villavaso, E.J.; McGovern, W.L.; Wagner, T.L.; Willers, J.L.

    1998-01-01

    This study examines the relative importance of age at the time of irradiation on attractiveness, mating ability, sperm transfer, prior mating, and longevity as factors of competitiveness in sterile male boll weevil, Anthonomus grandis grandis Boheman. The amount of sperm transferred by irradiated males appeared to be the most important factor in competitiveness. More sperm was transferred by virgin males irradiated on day 5 than by virgin males irradiated on day 2, and males irradiated on day 5 had greater impact on egg hatch than those irradiated on day 2. The amount of sperm in spermathecae of females mated to virgin mates irradiated on day 5 was indistinguishable from that in females mated to virgin control males. Mating ability of males of all treatments was similar. Comparable numbers of boll weevils were captured in traps baited with males irradiated at 2 or 5 d during the first 4-5 d after irradiation, but thereafter, generally more weevils were captured in traps baited with males irradiated at 2 d or with control males. Attractiveness of males irradiated at 2 d was generally comparable to that of control males. More than 91% of irradiated males individually caged on cotton, Gossypium hirsutum L., plants lived for 10 d in the field, and 40% lived for 14 d; all individually caged control males lived 14 d. When released into cotton fields, however, the numbers of both irradiated and control males declined sharply over 14 d. Thus, the potential for an effective 2-wk life span in the field suggested by the caged study did not appear to apply to laboratory-reared weevils released into cotton fields

  2. 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.

  3. Descriptive Study of Gender Dysphoria in Japanese Individuals with Male-to-Female Gender Identity Disorder

    OpenAIRE

    Shinohara, Yoshie; Nakatsuka, Mikiya

    2018-01-01

    We focus on Japanese individuals with gender identity disorder (GID), especially male-to-female (MTF) GID, who have experienced difficulty in adapting to social life. We clarify what gender dysphoria is, and we examine methods of intervention. Semi-structured interviews were conducted with 11 individuals with MTF-GID from August 2015 to April 2017. We categorized the subjects’experiences regarding dysphoria into the ‘Onset of gender dysphoria,’ ‘Experience of feeling gender dysphoria,’ and ‘C...

  4. Sensory Biology: How Female Treefrogs Pick Mates at a Noisy Party.

    Science.gov (United States)

    Taylor, Ryan C

    2017-03-06

    A recent study has found that, despite strong acoustic masking from background noise, female treefrogs are able to select among individual males advertising for mates by taking advantage of small, periodic decreases in the overall noise structure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Male Wistar rats show individual differences in an animal model of conformity.

    Science.gov (United States)

    Jolles, Jolle W; de Visser, Leonie; van den Bos, Ruud

    2011-09-01

    Conformity refers to the act of changing one's behaviour to match that of others. Recent studies in humans have shown that individual differences exist in conformity and that these differences are related to differences in neuronal activity. To understand the neuronal mechanisms in more detail, animal tests to assess conformity are needed. Here, we used a test of conformity in rats that has previously been evaluated in female, but not male, rats and assessed the nature of individual differences in conformity. Male Wistar rats were given the opportunity to learn that two diets differed in palatability. They were subsequently exposed to a demonstrator that had consumed the less palatable food. Thereafter, they were exposed to the same diets again. Just like female rats, male rats decreased their preference for the more palatable food after interaction with demonstrator rats that had eaten the less palatable food. Individual differences existed for this shift, which were only weakly related to an interaction between their own initial preference and the amount consumed by the demonstrator rat. The data show that this conformity test in rats is a promising tool to study the neurobiology of conformity.

  6. 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...

  7. The response to selection for broad male response to female sex pheromone and its implications for divergence in close-range mating behavior in the European corn borer moth, Ostrinia nubilalis.

    Science.gov (United States)

    Droney, David C; Musto, Callie J; Mancuso, Katie; Roelofs, Wendell L; Linn, Charles E

    2012-12-01

    Coordinated sexual communication systems, seen in many species of moths, are hypothesized to be under strong stabilizing natural selection. Stabilized communication systems should be resistant to change, but there are examples of species/populations that show great diversification. A possible solution is that it is directional sexual selection on variation in male response that drives evolution. We tested a component of this model by asking whether 'rare' males (ca. 5 % of all males in a population) of the European corn borer moth (ECB), Ostrinia nubilalis, that respond to the sex pheromones of both ECB and a different Ostrinia species (O. furnacalis, the Asian corn borer, ACB), might play an important role in diversification. We specifically tested, via artificial selection, whether this broad male response has an evolvable genetic component. We increased the frequency of broad male response from 5 to 70 % in 19 generations, showing that broad-responding males could be important for the evolution of novel communication systems in ECB. We did not find a broader range of mating acceptance of broad males by females of the base population, however, suggesting that broad response would be unlikely to increase in frequency without the involvement of other factors. However, we found that ECB selection-line females accepted a broader range of courting males, including those of ACB, than did females of the base population. Thus, a genetic correlation exists between broad, long-range response to female sex pheromone and the breadth of female acceptance of males at close range. These results are discussed in the context of evolution of novel communication systems in Ostrinia.

  8. Mate choice in the face of costly competition

    NARCIS (Netherlands)

    Fawcett, TW; Johnstone, RA

    2003-01-01

    Studies of mate choice commonly ignore variation in preferences and assume that all individuals should favor the highest-quality mate available. However, individuals may differ in their mate preferences according to their own age, experience, size, or genotype. In the present study, we highlight

  9. 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. PMID:22059085

  10. 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...

  11. Mate preferences do predict attraction and choices in the early stages of mate selection.

    Science.gov (United States)

    Li, Norman P; Yong, Jose C; Tov, William; Sng, Oliver; Fletcher, Garth J O; Valentine, Katherine A; Jiang, Yun F; Balliet, Daniel

    2013-11-01

    Although mate preference research has firmly established that men value physical attractiveness more than women do and women value social status more than men do, recent speed-dating studies have indicated mixed evidence (at best) for whether people's sex-differentiated mate preferences predict actual mate choices. According to an evolutionary, mate preference priority model (Li, Bailey, Kenrick, & Linsenmeier, 2002; Li & Kenrick, 2006; Li, Valentine, & Patel, 2011), the sexes are largely similar in what they ideally like, but for long-term mates, they should differ on what they most want to avoid in early selection contexts. Following this model, we conducted experiments using online messaging and modified speed-dating platforms. Results indicate that when a mating pool includes people at the low end of social status and physical attractiveness, mate choice criteria are sex-differentiated: Men, more than women, chose mates based on physical attractiveness, whereas women, more than men, chose mates based on social status. In addition, individuals who more greatly valued social status or physical attractiveness on paper valued these traits more in their actual choices. In particular, mate choices were sex-differentiated when considering long-term relationships but not short-term ones, where both sexes shunned partners with low physical attractiveness. The findings validate a large body of mate preferences research and an evolutionary perspective on mating, and they have implications for research using speed-dating and other interactive contexts. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  12. WHOQOL-100 Before and After Sex Reassignment Surgery in Brazilian Male-to-Female Transsexual Individuals.

    Science.gov (United States)

    Cardoso da Silva, Dhiordan; Schwarz, Karine; Fontanari, Anna Martha Vaitses; Costa, Angelo Brandelli; Massuda, Raffael; Henriques, Alexandre Annes; Salvador, Jaqueline; Silveira, Esalba; Elias Rosito, Tiago; Lobato, Maria Inês Rodrigues

    2016-06-01

    The 100-item World Health Organization Quality of Life Assessment (WHOQOL-100) evaluates quality of life as a subjective and multidimensional construct. Currently, particularly in Brazil, there are controversies concerning quality of life after sex reassignment surgery (SRS). To assess the impact of surgical interventions on quality of life of 47 Brazilian male-to-female transsexual individuals using the WHOQOL-100. This was a prospective cohort study using the WHOQOL-100 and sociodemographic questions for individuals diagnosed with gender identity disorder according to criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. The protocol was used when a transsexual person entered the ambulatory clinic and at least 12 months after SRS. Initially, improvement or worsening of quality of life was assessed using 6 domains and 24 facets. Subsequently, quality of life was assessed for individuals who underwent new surgical interventions and those who did not undergo these procedures 1 year after SRS. The participants showed significant improvement after SRS in domains II (psychological) and IV (social relationships) of the WHOQOL-100. In contrast, domains I (physical health) and III (level of independence) were significantly worse after SRS. Individuals who underwent additional surgery had a decrease in quality of life reflected in domains II and IV. During statistical analysis, all results were controlled for variations in demographic characteristics, without significant results. The WHOQOL-100 is an important instrument to evaluate the quality of life of male-to-female transsexuals during different stages of treatment. SRS promotes the improvement of psychological aspects and social relationships. However, even 1 year after SRS, male-to-female transsexuals continue to report problems in physical health and difficulty in recovering their independence. Copyright © 2016 International Society for Sexual Medicine. Published by Elsevier Inc

  13. No discrimination against previous mates in a sexually cannibalistic spider

    Science.gov (United States)

    Fromhage, Lutz; Schneider, Jutta M.

    2005-09-01

    In several animal species, females discriminate against previous mates in subsequent mating decisions, increasing the potential for multiple paternity. In spiders, female choice may take the form of selective sexual cannibalism, which has been shown to bias paternity in favor of particular males. If cannibalistic attacks function to restrict a male's paternity, females may have little interest to remate with males having survived such an attack. We therefore studied the possibility of female discrimination against previous mates in sexually cannibalistic Argiope bruennichi, where females almost always attack their mate at the onset of copulation. We compared mating latency and copulation duration of males having experienced a previous copulation either with the same or with a different female, but found no evidence for discrimination against previous mates. However, males copulated significantly shorter when inserting into a used, compared to a previously unused, genital pore of the female.

  14. Embryonic origin of mate choice in a lizard with temperature-dependent sex determination.

    Science.gov (United States)

    Putz, Oliver; Crews, David

    2006-01-01

    Individual differences in the adult sexual behavior of vertebrates are rooted in the fetal environment. In the leopard gecko (Eublepharis macularius), a species with temperature-dependent sex determination (TSD), hatchling sex ratios differ between incubation temperatures, as does sexuality in same-sex animals. This variation can primarily be ascribed to the temperature having direct organizing actions on the brain. Here we demonstrate that embryonic temperature can affect adult mate choice in the leopard gecko. Given the simultaneous choice between two females from different incubation temperatures (30.0 and 34.0 degrees C), males from one incubation temperature (30.0 degrees C) preferred the female from 34.0 degrees C, while males from another incubation temperature (32.5 degrees C) preferred the female from 30.0 degrees C. We suggest that this difference in mate choice is due to an environmental influence on brain development leading to differential perception of opposite-sex individuals. This previously unrecognized modulator of adult mate choice lends further support to the view that mate choice is best understood in the context of an individual's entire life-history. Thus, sexual selection results from a combination of the female's as well as the male's life history. Female attractiveness and male choice therefore are complementary. Copyright 2005 Wiley Periodicals, Inc.

  15. 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.

  16. 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.

  17. 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.

  18. Previous experiences shape adaptive mate preferences

    NARCIS (Netherlands)

    Fawcett, Tim W.; Bleay, Colin

    2009-01-01

    Existing models of mate choice assume that individuals have perfect knowledge of their own ability to attract a mate and can adjust their preferences accordingly. However, real animals will typically be uncertain of their own attractiveness. A potentially useful source of information on this is the

  19. 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. © 2013 Wiley Periodicals, Inc.

  20. Mate choice trade-offs and women's preference for physically attractive men.

    Science.gov (United States)

    Waynforth, D

    2001-09-01

    Researchers studying human sexuality have repeatedly concluded that men place more emphasis on the physical attractiveness of potential mates than women do, particularly in long-term sexual relationships. Evolutionary theorists have suggested that this is the case because male mate value (the total value of the characteristics that an individual possesses in terms of the potential contribution to his or her mate's reproductive success) is better predicted by social status and economic resources, whereas women's mate value hinges on signals conveyed by their physical appearance. This pattern may imply that women trade off attractiveness for resources in mate choice. Here I test whether a trade-off between resources and attractiveness seems to be occurring in the mate choice decisions of women in the United States. In addition, the possibility that the risk of mate desertion drives women to choose less attractive men as long-term mates is tested. The results were that women rated physically attractive men as more likely to cheat or desert a long-term relationship, whereas men did not consider attractive women to be more likely to cheat. However, women showed no aversion to the idea of forming long-term relationships with attractive men. Evidence for a trade-off between resources and attractiveness was found for women, who traded off attractiveness, but not other traits, for resources. The potential meaning of these findings, as well as how they relate to broader issues in the study of sex differences in the evolution of human mate choice for physical traits, is discussed.

  1. From preferred to actual mate characteristics: the case of human body shape.

    Directory of Open Access Journals (Sweden)

    Alexandre Courtiol

    Full Text Available The way individuals pair to produce reproductive units is a major factor determining evolution. This process is complex because it is determined not only by individual mating preferences, but also by numerous other factors such as competition between mates. Consequently, preferred and actual characteristics of mates obtained should differ, but this has rarely been addressed. We simultaneously measured mating preferences for stature, body mass, and body mass index, and recorded corresponding actual partner's characteristics for 116 human couples from France. Results show that preferred and actual partner's characteristics differ for male judges, but not for females. In addition, while the correlation between all preferred and actual partner's characteristics appeared to be weak for female judges, it was strong for males: while men prefer women slimmer than their actual partner, those who prefer the slimmest women also have partners who are slimmer than average. This study therefore suggests that the influences of preferences on pair formation can be sex-specific. It also illustrates that this process can lead to unexpected results on the real influences of mating preferences: traits considered as highly influencing attractiveness do not necessarily have a strong influence on the actual pairing, the reverse being also possible.

  2. Dynamics of testosterone concentration in male steppe lemmings (Lagurus lagurus) in the reproductive cycle reflects the species-specific mating system.

    Science.gov (United States)

    Potapova, O F; Potapov, M A; Kondratyuk, E Yu; Evsikov, V I

    2016-05-01

    In the blood of male steppe lemmings, relatively low background levels of testosterone were detected, this is characteristic of a monogamous species. A significant increase in testosterone level, more expressed in sexually active males, was observed at the initial stage of formation of reproductive couples. Apparently, in the future, the couple will exist in a stable relationship, and, hence, the maintenance of a high testosterone level becomes excessive. The decrease in, and the relative "normalization" of, the hormone level during the existence of the pair, including raising of the young, promotes higher expression of the male paternal care of the offspring at the species level.

  3. Female mating preferences determine system-level evolution in a gene network model.

    Science.gov (United States)

    Fierst, Janna L

    2013-06-01

    Environmental patterns of directional, stabilizing and fluctuating selection can influence the evolution of system-level properties like evolvability and mutational robustness. Intersexual selection produces strong phenotypic selection and these dynamics may also affect the response to mutation and the potential for future adaptation. In order to to assess the influence of mating preferences on these evolutionary properties, I modeled a male trait and female preference determined by separate gene regulatory networks. I studied three sexual selection scenarios: sexual conflict, a Gaussian model of the Fisher process described in Lande (in Proc Natl Acad Sci 78(6):3721-3725, 1981) and a good genes model in which the male trait signalled his mutational condition. I measured the effects these mating preferences had on the potential for traits and preferences to evolve towards new states, and mutational robustness of both the phenotype and the individual's overall viability. All types of sexual selection increased male phenotypic robustness relative to a randomly mating population. The Fisher model also reduced male evolvability and mutational robustness for viability. Under good genes sexual selection, males evolved an increased mutational robustness for viability. Females choosing their mates is a scenario that is sufficient to create selective forces that impact genetic evolution and shape the evolutionary response to mutation and environmental selection. These dynamics will inevitably develop in any population where sexual selection is operating, and affect the potential for future adaptation.

  4. Compatibility of Mating Preferences

    OpenAIRE

    Bingol, Haluk O.; Basar, Omer

    2016-01-01

    Human mating is a complex phenomenon. Although men and women have different preferences in mate selection, there should be compatibility in these preferences since human mating requires agreement of both parties. We investigate how compatible the mating preferences of men and women are in a given property such as age, height, education and income. We use dataset of a large online dating site (N = 44, 255 users). (i) Our findings are based on the "actual behavior" of users trying to find a dat...

  5. 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...

  6. Males collectively defend their one-male units against bachelor males in a multi-level primate society.

    Science.gov (United States)

    Xiang, Zuo-Fu; Yang, Bang-He; Yu, Yang; Yao, Hui; Grueter, Cyril C; Garber, Paul A; Li, Ming

    2014-07-01

    Group-level male-male co-operation, which has been documented in several primate and non-primate societies, may be mutualistically advantageous to the participants when confronted with threats such as takeovers and cuckoldry by external males. Co-operation among members of distinct social units-while universal among humans-is extremely rare in non-human primates. We present the first observations of collective action or co-operation among males of different one-male units (OMU) in a multi-level society of Rhinopithecus roxellana. A total of 59 instances of male co-operation were recorded. Male co-operation included coordinated chasing, joint vigilance, and patrolling behavior directed at lone adult males trying to enter an OMU. Male co-operation was significantly more frequent during the mating season when the risk of incursions and extra-group paternity was higher. Paternity of infants born in the subsequent birth season and kin relationships among resident males were identified using microsatellite genotype. All infants were sired by OMU males, which we interpret as possible evidence for their success at thwarting mating attempts by satellite males. OMU males were principally unrelated suggesting that male co-operation is best understood in terms of the mutual direct benefits individuals obtain through collective action. Our findings lend support to the bachelor threat hypothesis in which the cooperative behavior of several individuals is more effective than the lone action of a single individual in providing mate defense. Our research has implications for understanding male bonding, higher-level collective action, and the evolution of social co-operation in human societies. © 2013 Wiley Periodicals, Inc.

  7. Mate fidelity and breeding site tenacity in a monogamous sandpiper, the black turnstone

    Science.gov (United States)

    Handel, C.M.; Gill, R.E.

    2000-01-01

    We examined the relationship between mate fidelity and breeding site tenacity during a 5-year study of the black turnstone, Arenaria melanocephala, a socially monogamous sandpiper breeding in subarctic Alaska. We tested the predictions of several hypotheses regarding the incidence of divorce and the benefits of fidelity to mate and breeding site. Interannual return rates to the breeding grounds (88% for males, 79% for females) were among the highest yet recorded for any scolopacid sandpiper, and 88% of returning birds nested on their previous year's territory. The annual divorce rate was only 11%, and mate fidelity was significantly linked to fidelity to territory but independent of sex and year. Males arrived in spring significantly earlier than their mates and interannual fidelity was influenced by the relative timing of arrival of pair members. Reunited pairs had significantly higher fledging success than new pairs formed after death or divorce. The incidence of divorce was unrelated to reproductive success the previous year, although birds nested significantly further away after failure than after a successful nesting attempt. Sightings of marked individuals suggested that members of pairs do not winter together, and breeding site tenacity provides a mechanism through which pair members can reunite. We reject the 'incompatibility' hypothesis for divorce in turnstones, and our data contradict predictions of the 'better option' hypothesis. Alternatively, we propose the 'bet-hedging' hypothesis to explain the occurrence of divorce, which transpires when an individual pairs with a new mate to avoid the cost of waiting for a previous mate to return. Such costs can include remaining unmated, if the former mate has died, or experiencing lower reproductive success because of delayed breeding.

  8. Firefly Mating Algorithm for Continuous Optimization Problems

    Directory of Open Access Journals (Sweden)

    Amarita Ritthipakdee

    2017-01-01

    Full Text Available This paper proposes a swarm intelligence algorithm, called firefly mating algorithm (FMA, for solving continuous optimization problems. FMA uses genetic algorithm as the core of the algorithm. The main feature of the algorithm is a novel mating pair selection method which is inspired by the following 2 mating behaviors of fireflies in nature: (i the mutual attraction between males and females causes them to mate and (ii fireflies of both sexes are of the multiple-mating type, mating with multiple opposite sex partners. A female continues mating until her spermatheca becomes full, and, in the same vein, a male can provide sperms for several females until his sperm reservoir is depleted. This new feature enhances the global convergence capability of the algorithm. The performance of FMA was tested with 20 benchmark functions (sixteen 30-dimensional functions and four 2-dimensional ones against FA, ALC-PSO, COA, MCPSO, LWGSODE, MPSODDS, DFOA, SHPSOS, LSA, MPDPGA, DE, and GABC algorithms. The experimental results showed that the success rates of our proposed algorithm with these functions were higher than those of other algorithms and the proposed algorithm also required fewer numbers of iterations to reach the global optima.

  9. 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.

  10. Societal individualism predicts prevalence of nonhomosexual orientation in male-to-female transsexualism.

    Science.gov (United States)

    Lawrence, Anne A

    2010-04-01

    There are two distinct subtypes of male-to-female (MtF) transsexuals: homosexual and nonhomosexual. The relative prevalence of these two subtypes varies dramatically between countries, but no explanation of this variability has yet been proposed. This study examined the hypothesis that the prevalence of nonhomosexual MtF transsexualism, relative to homosexual MtF transsexualism, would be higher in individualistic countries than in collectivistic countries. I analyzed data from 22 studies of MtF transsexualism, conducted in 16 countries, examining the association between percentage of nonhomosexual participants and Hofstede's (Culture's consequences: Comparing values, behaviors, institutions, and organizations across nations, 2001) Individualism Index (IDV). IDV accounted for 77% of observed variance in the percentage of nonhomosexual MtF participants (r = 0.88, p individualistic countries for socially disruptive gender transitions by nonhomosexual gender dysphoric men, and the availability within many collectivistic countries of socially approved transgender roles for pervasively feminine homosexual gender dysphoric men, are plausible contributors.

  11. Neuroanatomy of Individual Differences in Language in Adult Males with Autism

    Science.gov (United States)

    Lai, Meng-Chuan; Lombardo, Michael V.; Ecker, Christine; Chakrabarti, Bhismadev; Suckling, John; Bullmore, Edward T.; Happé, Francesca; Murphy, Declan G. M.; Baron-Cohen, Simon

    2015-01-01

    One potential source of heterogeneity within autism spectrum conditions (ASC) is language development and ability. In 80 high-functioning male adults with ASC, we tested if variations in developmental and current structural language are associated with current neuroanatomy. Groups with and without language delay differed behaviorally in early social reciprocity, current language, but not current autistic features. Language delay was associated with larger total gray matter (GM) volume, smaller relative volume at bilateral insula, ventral basal ganglia, and right superior, middle, and polar temporal structures, and larger relative volume at pons and medulla oblongata in adulthood. Despite this heterogeneity, those with and without language delay showed significant commonality in morphometric features when contrasted with matched neurotypical individuals (n = 57). In ASC, better current language was associated with increased GM volume in bilateral temporal pole, superior temporal regions, dorsolateral fronto-parietal and cerebellar structures, and increased white matter volume in distributed frontal and insular regions. Furthermore, current language–neuroanatomy correlation patterns were similar across subgroups with or without language delay. High-functioning adult males with ASC show neuroanatomical variations associated with both developmental and current language characteristics. This underscores the importance of including both developmental and current language as specifiers for ASC, to help clarify heterogeneity. PMID:25249409

  12. 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

  13. Masculine Voices Predict Well-Being in Female-to-Male Transgender Individuals.

    Science.gov (United States)

    Watt, Seth O; Tskhay, Konstantin O; Rule, Nicholas O

    2018-05-01

    Voices convey important social information about an individual's identity, including gender. This is especially relevant to transgender individuals, who cite voice alteration as a primary goal of the gender alignment process. Although the voice is a primary target of testosterone therapy among female-to-male (FTM) trans people, little research has explored the effects of such changes on their psychological well-being. Here, we investigated how FTMs' vocal gender related to their well-being. A total of 77 FTMs (M age  = 25.45 years, SD = 6.77) provided voice samples and completed measures of their well-being and psychological health. An independent group of 32 naïve raters (M age  = 22.16 years, SD = 8.21) subsequently rated the voice samples for masculinity. We found that FTMs whose voices sounded more congruent with their experienced gender (i.e., sounded more masculine) reported greater well-being (better life satisfaction, quality of life, and self-esteem; lower levels of anxiety and depression) than FTMs with less gender congruent (i.e., more feminine) voices (β = .48). The convergence between outwardly perceived vocal gender and gender identity brought about through hormone replacement therapy may therefore support greater well-being for FTMs.

  14. Descriptive Study of Gender Dysphoria in Japanese Individuals with Male-to-Female Gender Identity Disorder.

    Science.gov (United States)

    Shinohara, Yoshie; Nakatsuka, Mikiya

    2018-04-01

    We focus on Japanese individuals with gender identity disorder (GID), especially male-to-female (MTF) GID, who have experienced difficulty in adapting to social life. We clarify what gender dysphoria is, and we examine methods of intervention. Semi-structured interviews were conducted with 11 individuals with MTF-GID from August 2015 to April 2017. We categorized the subjects'experiences regarding dysphoria into the 'Onset of gender dysphoria,' 'Experience of feeling gender dysphoria,' and 'Changes due to receiving medical care.' The subjects reported experiencing great pain and distress because they did not fully understand that they were experiencing dysphoria and could not align their gender identity and their self-identity. All subjects described their experiences of dysphoria as negative. Additionally, all said that the dysphoria was alleviated by a medical intervention such as visiting a gender clinic, receiving a diagnosis and treatment, and changing their physical sex to the sex congruent with their gender identity. The provision of information at the gender clinic and the physical changes achieved by medical intervention exerted a positive effect both mentally and socially on the subjects, who suffered various physical, mental and social problems.

  15. Dimorphic ejaculates and sperm release strategies associated with alternative mating behaviors in the squid.

    Science.gov (United States)

    Apostólico, Lígia H; Marian, José E A R

    2017-11-01

    Sperm competition is a powerful postcopulatory selective force influencing male adaptations associated with increasing fertilization success, and it is usually related to the evolution of different strategies of ejaculate expenditure between individuals. Ejaculates may also be influenced by additional selective pressures associated with sperm competition, such as timing between insemination and fertilization, female reproductive tract morphology, and fertilization environment. Also, males that adopt alternative mating tactics may face distinct sperm competition pressures, which may lead to the evolution of intraspecific diversity in ejaculates. In loliginid squids, males with alternative reproductive tactics (sneakers and consorts) differ not only in mating behavior, but also transfer spermatophores into two distinct sites within the female. Here, we compared structure and functioning of spermatophores between sneakers and consorts in the squid Doryteuthis plei applying microscopy techniques and in vitro experiments. Sneakers and consorts exhibit differences in spermatophore structure that lead to distinct spermatophoric reactions and spermatangium morphologies. Moreover, in sneakers, sperm release lasts longer and their sperm show an aggregative behavior not detected in consorts. Slow sperm release may be a strategy to guarantee longer sperm provision, given the wide interval between sneaker mating and egg release. For consorts, in turn, intense and quick sperm discharge may be advantageous, as timing between mating and egg-laying is relatively short. Within the complex squid mating system, factors such as (i) different fertilization sites and (ii) interval between mating and egg release may also influence sperm competition, and ultimately shape the evolution of divergent ejaculates between dimorphic males. © 2017 Wiley Periodicals, Inc.

  16. 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.

  17. Good vs complementary genes for parasite resistance and the evolution of mate choice

    Directory of Open Access Journals (Sweden)

    Lively Curtis M

    2004-11-01

    Full Text Available Abstract Background Female mate choice may be adaptive when males exhibit heritable genetic variation at loci encoding resistance to infectious disease. The Hamilton-Zuk hypothesis predicts that females should assess the genetic quality of males by monitoring traits that indicate health and vigor (condition-dependent choice, or CD. Alternatively, some females may employ a more direct method of screening and select mates based on the dissimilarity of alleles at the major histocompatibility loci (we refer to this as opposites-attract, or OA. Empirical studies suggest that both forms of mate choice exist, but little is known about the potential for natural selection to shape the two strategies in nature. Results We used computer simulation models to examine the evolutionary fates of the two forms of mate choice in populations at risk for infection by debilitating parasites. We found that populations exhibiting random mating (no mate choice can be invaded and replaced completely by individuals practicing CD type mate choice. We also found that an allele encoding OA choice can increase when rare in randomly mating populations, but that it does not go to fixation under selection. A similar result was obtained when the OA strategy was introduced into populations practicing CD mate choice. As before, we found that the OA choice allele will increase when rare, and that it will not go to fixation under selection. The converse however was not true, as CD individuals gain no rare advantage when introduced into an OA population. Conclusions Taken together, the results suggest that, when rare, OA is the best strategy for parasite evasion (of those considered here. The consequence of OA increasing in the population, however, is to reduce the parasite driven genotype oscillations and facilitate the breakdown of linkage disequilibrium at the disease-resistance loci. This leads to a neutrally stable situation in which different strategies have equal fitness, and

  18. The evolution of polyandry: patterns of genotypic variation in female mating frequency, male fertilization success and a test of the sexy-sperm hypothesis.

    Science.gov (United States)

    Simmons, L W

    2003-07-01

    The sexy-sperm hypothesis predicts that females obtain indirect benefits for their offspring via polyandy, in the form of increased fertilization success for their sons. I use a quantitative genetic approach to test the sexy-sperm hypothesis using the field cricket Teleogryllus oceanicus. Previous studies of this species have shown considerable phenotypic variation in fertilization success when two or more males compete. There were high broad-sense heritabilities for both paternity and polyandry. Patterns of genotypic variance were consistent with X-linked inheritance and/or maternal effects on these traits. The genetic architecture therefore precludes the evolution of polyandry via a sexy-sperm process. Thus the positive genetic correlation between paternity in sons and polyandry in daughters predicted by the sexy-sperm hypothesis was absent. There was significant heritable variation in the investment by females in ovaries and by males in the accessory gland. Surprisingly there was a very strong genetic correlation between these two traits. The significance of this genetic correlation for the coevolution of male seminal products and polyandry is discussed.

  19. Study of personality traits, individual coping resources, and their association in HIV-seropositive males

    Directory of Open Access Journals (Sweden)

    Prateek Yadav

    2017-01-01

    Full Text Available Background: HIV infection is an unfortunate consequence of a defined set of behaviors. Individuals with continued high-risk behavior either due to personality factors or due to maladaptive coping skills have higher viral loads and morbidity. Research has shown significant interactions between less effective coping styles and personality factors. Aim: This study aimed to evaluate personality traits, coping skills, and their association in male HIV-seropositive cases. Materials and Methods: This was a cross-sectional study, conducted on 86 patients. Informed consent and sociodemographic details, by a structured questionnaire, were obtained. Scales pertaining to personality factors and coping were applied. Statistical analysis was done by SPSS 16. Results: Neuroticism, extraversion, and conscientiousness traits were in the average range. Scores on openness and agreeableness were below average. The results pertaining to coping showed an overall mean score of 50.78, with the highest on physical domain and then on the philosophical domain, the lowest was in social domain. The research sample perceived their coping resources as average. Neuroticism was negatively related to all the coping styles. Extraversion showed relation with physical, emotional, social, and philosophical scales. Openness was related to philosophical and emotional scales. Agreeableness correlated with all domains of coping except the social. Conscientiousness correlated significantly with all the domains of coping. Conclusion: The various personality traits associated with male HIV-seropositive patients were identified and various coping resources used by these were also delineated. Further, the association among them was identified which can help in primary prevention and mental health professionals to have a targeted approach for counseling.

  20. Pheromonal Cues Deposited by Mated Females Convey Social Information about Egg-Laying Sites in Drosophila Melanogaster.

    Science.gov (United States)

    Duménil, Claire; Woud, David; Pinto, Francesco; Alkema, Jeroen T; Jansen, Ilse; Van Der Geest, Anne M; Roessingh, Sanne; Billeter, Jean-Christophe

    2016-03-01

    Individuals can make choices based on information learned from others, a phenomenon called social learning. How observers differentiate between which individual they should or should not learn from is, however, poorly understood. Here, we showed that Drosophila melanogaster females can influence the choice of egg-laying site of other females through pheromonal marking. Mated females mark territories of high quality food by ejecting surplus male sperm containing the aggregation pheromone cis-11-vaccenyl acetate (cVA) and, in addition, deposit several sex- and species-specific cuticular hydrocarbon (CHC) pheromones. These pheromonal cues affect the choices of other females, which respond by preferentially laying eggs on the marked food. This system benefits both senders and responders, as communal egg laying increases offspring survival. Virgin females, however, do not elicit a change in the egg-laying decision of mated females, even when food has been supplemented with ejected sperm from mated females, thus indicating the necessity for additional cues. Genetic ablation of either a female's CHC pheromones or those of their mate results in loss of ability of mated females to attract other females. We conclude that mated females use a pheromonal marking system, comprising cVA acquired from male ejaculate with sex- and species-specific CHCs produced by both mates, to indicate egg-laying sites. This system ensures information reliability because mated, but not virgin, females have both the ability to generate the pheromone blend that attracts other flies to those sites and a direct interest in egg-laying site quality.

  1. Discrete two-sex models of population dynamics: On modelling the mating function

    Science.gov (United States)

    Bessa-Gomes, Carmen; Legendre, Stéphane; Clobert, Jean

    2010-09-01

    Although sexual reproduction has long been a central subject of theoretical ecology, until recently its consequences for population dynamics were largely overlooked. This is now changing, and many studies have addressed this issue, showing that when the mating system is taken into account, the population dynamics depends on the relative abundance of males and females, and is non-linear. Moreover, sexual reproduction increases the extinction risk, namely due to the Allee effect. Nevertheless, different studies have identified diverse potential consequences, depending on the choice of mating function. In this study, we investigate the consequences of three alternative mating functions that are frequently used in discrete population models: the minimum; the harmonic mean; and the modified harmonic mean. We consider their consequences at three levels: on the probability that females will breed; on the presence and intensity of the Allee effect; and on the extinction risk. When we consider the harmonic mean, the number of times the individuals of the least abundant sex mate exceeds their mating potential, which implies that with variable sex-ratios the potential reproductive rate is no longer under the modeller's control. Consequently, the female breeding probability exceeds 1 whenever the sex-ratio is male-biased, which constitutes an obvious problem. The use of the harmonic mean is thus only justified if we think that this parameter should be re-defined in order to represent the females' breeding rate and the fact that females may reproduce more than once per breeding season. This phenomenon buffers the Allee effect, and reduces the extinction risk. However, when we consider birth-pulse populations, such a phenomenon is implausible because the number of times females can reproduce per birth season is limited. In general, the minimum or modified harmonic mean mating functions seem to be more suitable for assessing the impact of mating systems on population dynamics.

  2. Correlates of androgens in wild male Barbary macaques: Testing the challenge hypothesis.

    Science.gov (United States)

    Rincon, Alan V; Maréchal, Laëtitia; Semple, Stuart; Majolo, Bonaventura; MacLarnon, Ann

    2017-10-01

    Investigating causes and consequences of variation in hormonal expression is a key focus in behavioral ecology. Many studies have explored patterns of secretion of the androgen testosterone in male vertebrates, using the challenge hypothesis (Wingfield, Hegner, Dufty, & Ball, 1990; The American Naturalist, 136(6), 829-846) as a theoretical framework. Rather than the classic association of testosterone with male sexual behavior, this hypothesis predicts that high levels of testosterone are associated with male-male reproductive competition but also inhibit paternal care. The hypothesis was originally developed for birds, and subsequently tested in other vertebrate taxa, including primates. Such studies have explored the link between testosterone and reproductive aggression as well as other measures of mating competition, or between testosterone and aspects of male behavior related to the presence of infants. Very few studies have simultaneously investigated the links between testosterone and male aggression, other aspects of mating competition and infant-related behavior. We tested predictions derived from the challenge hypothesis in wild male Barbary macaques (Macaca sylvanus), a species with marked breeding seasonality and high levels of male-infant affiliation, providing a powerful test of this theoretical framework. Over 11 months, 251 hr of behavioral observations and 296 fecal samples were collected from seven adult males in the Middle Atlas Mountains, Morocco. Fecal androgen levels rose before the onset of the mating season, during a period of rank instability, and were positively related to group mating activity across the mating season. Androgen levels were unrelated to rates of male-male aggression in any period, but higher ranked males had higher levels in both the mating season and in the period of rank instability. Lower androgen levels were associated with increased rates of male-infant grooming during the mating and unstable periods. Our results

  3. Serum Interleukin-6, insulin, and HOMA-IR in male individuals with colorectal adenoma.

    Science.gov (United States)

    Sasaki, Yu; Takeda, Hiroaki; Sato, Takeshi; Orii, Tomohiko; Nishise, Shoichi; Nagino, Ko; Iwano, Daisuke; Yaoita, Takao; Yoshizawa, Kazuya; Saito, Hideki; Tanaka, Yasuhisa; Kawata, Sumio

    2012-01-15

    It is widely acknowledged that chronic low-grade inflammation plays a key role in the development of obesity-related insulin resistance and type 2 diabetes. The level of circulating interleukin-6 (IL-6), one of the major proinflammatory adipokines, is correlated with obesity and insulin resistance, which are known to be risk factors for colorectal adenoma. We examined the association between the circulating level of IL-6 and the presence of colorectal adenoma. In a total colonoscopy-based cross-sectional study conducted between January and December 2008, serum levels of IL-6 were measured in samples of venous blood obtained from 336 male participants attending health checkups (118 individuals with colorectal adenoma and 218 age-matched controls) after an overnight fast. In the colorectal adenoma group, the median levels of serum IL-6 (1.24 vs. 1.04 pg/mL; P = 0.01), triglyceride, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) were to be significantly higher than those in the control group. When restricted to individuals with adenoma, levels of IL-6 were positively correlated with body mass index, insulin, and HOMA-IR. Multiple logistic analyses adjusted to include insulin or HOMA-IR showed that high levels of IL-6 were associated with the presence of colorectal adenoma. There was no significant interaction of IL-6 with HOMA-IR to modify this association. Our findings suggest that increased serum levels of IL-6 are positively associated with the presence of colorectal adenoma in men, independently of insulin and HOMA-IR. ©2011 AACR.

  4. No evidence for female discrimination against male house mice carrying a selfish genetic element.

    Science.gov (United States)

    Sutter, Andreas; Lindholm, Anna K

    2016-12-01

    Meiotic drivers distort transmission to the next generation in their favor, with detrimental effects on the fitness of their homologues and the rest of the genome. Male carriers of meiotic drivers commonly inflict costs on their mates through genetic incompatibility, reduced fecundity, or biased brood sex ratios. Given these costs, evidence for female discrimination against male carriers is surprisingly rare. One of few examples is the t haplotype in house mice, a meiotic driver that shows strong transmission distortion in males and is typically homozygote lethal. As a consequence, mating between 2 t heterozygous (+/ t ) mice leads to high embryo mortality. Previous experiments showing that +/ t females avoid this incompatibility cost by preferring +/+ versus +/ t males have inferred preference based on olfactory cues or brief social interactions. Evidence from mating contexts in laboratory settings and semi-natural populations has been inconclusive. Here, we investigated female choice from a large number of no-choice mating trials. We found no evidence for discrimination against +/ t males based on mating, remating, and copulatory behavior. Further, we found no evidence for avoidance of incompatibility through selective interactions between gametes. The likelihood of mating showed significant effects of female weight and genotype, suggesting that our test paradigm enabled females to exhibit mate choice. We discuss the strengths and limitations of our approach. By explicitly considering selection at both the individual and gene level, we argue why precopulatory female discrimination by +/ t females may be less evolutionarily stable than discrimination by all females based on postcopulatory mechanisms.

  5. Asymmetric dominance and asymmetric mate choice oppose premating isolation after allopatric divergence.

    Science.gov (United States)

    Sefc, Kristina M; Hermann, Caroline M; Steinwender, Bernd; Brindl, Hanna; Zimmermann, Holger; Mattersdorfer, Karin; Postl, Lisbeth; Makasa, Lawrence; Sturmbauer, Christian; Koblmüller, Stephan

    2015-04-01

    Assortative mating promotes reproductive isolation and allows allopatric speciation processes to continue in secondary contact. As mating patterns are determined by mate preferences and intrasexual competition, we investigated male-male competition and behavioral isolation in simulated secondary contact among allopatric populations. Three allopatric color morphs of the cichlid fish Tropheus were tested against each other. Dyadic male-male contests revealed dominance of red males over bluish and yellow-blotch males. Reproductive isolation in the presence of male-male competition was assessed from genetic parentage in experimental ponds and was highly asymmetric among pairs of color morphs. Red females mated only with red males, whereas the other females performed variable degrees of heteromorphic mating. Discrepancies between mating patterns in ponds and female preferences in a competition-free, two-way choice paradigm suggested that the dominance of red males interfered with positive assortative mating of females of the subordinate morphs and provoked asymmetric hybridization. Between the nonred morphs, a significant excess of negative assortative mating by yellow-blotch females with bluish males did not coincide with asymmetric dominance among males. Hence, both negative assortative mating preferences and interference of male-male competition with positive assortative preferences forestall premating isolation, the latter especially in environments unsupportive of competition-driven spatial segregation.

  6. Effects of polygamy on the activity/rest rhythm of male fruit flies Drosophila melanogaster

    Science.gov (United States)

    Vartak, Vivek Rohidas; Varma, Vishwanath; Sharma, Vijay Kumar

    2015-02-01

    Although polygamy is common in insects, its extent varies enormously among natural populations. Mating systems influence the evolution of reproductive traits and the difference in extent of polygamy between males and females may be a key factor in determining traits which come under the influence of sexual selection. Fruit flies Drosophila melanogaster are promiscuous as both males and females mate with multiple partners. Mating has severe consequences on the physiology and behaviour of flies, and it affects their activity/rest rhythm in a sex-specific manner. In this study, we attempted to discern the effects of mating with multiple partners as opposed to a single partner, or of remaining unmated, on the activity/rest rhythm of flies under cyclic semi-natural (SN) and constant dark (DD) conditions. The results revealed that while evening activity of mated flies was significantly reduced compared to virgins, polygamous males showed a more severe reduction compared to monogamous males. In contrast, though mated females showed reduction in evening activity compared to virgins, activity levels were not different between polygamous and monogamous females. Although there was no detectable effect of mating on clock period, power of the activity/rest rhythm was significantly reduced in mated females with no difference seen between polygamous and monogamous individuals. These results suggest that courtship motivation, represented by evening activity, is successively reduced in males due to mating with one or more partners, while in females, it does not depend on the number of mating partners. Based on these results we conclude that polygamy affects the activity/rest rhythm of fruit flies D. melanogaster in a sex-dependent manner.

  7. 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

    OpenAIRE

    Chirault, Marl?ne; Lucas, Christophe; Goubault, Marl?ne; Chevrier, Claude; Bressac, Christophe; L?cureuil, 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 contro...

  8. Interchromosomal insertional translocation at Xq26.3 alters SOX3 expression in an individual with XX male sex reversal.

    Science.gov (United States)

    Haines, Bryan; Hughes, James; Corbett, Mark; Shaw, Marie; Innes, Josie; Patel, Leena; Gecz, Jozef; Clayton-Smith, Jill; Thomas, Paul

    2015-05-01

    46,XX male sex reversal occurs in approximately 1: 20 000 live births and is most commonly caused by interchromosomal translocations of the Y-linked sex-determining gene, SRY. Rearrangements of the closely related SOX3 gene on the X chromosome are also associated with 46,XX male sex reversal. It has been hypothesized that sex reversal in the latter is caused by ectopic expression of SOX3 in the developing urogenital ridge where it triggers male development by acting as an analog of SRY. However, altered regulation of SOX3 in individuals with XX male sex reversal has not been demonstrated. Here we report a boy with SRY-negative XX male sex reversal who was diagnosed at birth with a small phallus, mixed gonads, and borderline-normal T. Molecular characterization of the affected individual was performed using array comparative genomic hybridization, fluorescent in situ hybridization of metaphase chromosomes, whole-genome sequencing, and RT-PCR expression analysis of lymphoblast cell lines. The affected male carries ∼774-kb insertion translocation from chromosome 1 into a human-specific palindromic sequence 82 kb distal to SOX3. Importantly, robust SOX3 expression was identified in cells derived from the affected individual but not from control XX or XY cells, indicating that the translocation has a direct effect on SOX3 regulation. This is the first demonstration of altered SOX3 expression in an individual with XX male sex reversal and suggests that SOX3 can substitute for SRY to initiate male development in humans.

  9. Size and competitive mating success in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Smith, Carl; Pomiankowski, Andrew; Greig, Duncan

    2014-03-01

    In unicellular organisms like yeast, mating with the right partner is critical to future fitness because each individual can only mate once. Because cell size is important for viability, mating with a partner of the right size could be a significant advantage. To investigate this idea, we manipulated the size of unmated yeast cells and showed that their viability depended on environmental conditions; large cells do better on rich medium and small cells do better on poor medium. We also found that the fitness of offspring is determined by the size of their parents. Finally, we demonstrated that when a focal cell of one mating type was placed with a large and a small cell of the opposite mating type, it was more likely to mate with the cell that was closer to the optimum size for growth in a given environment. This pattern was not generated by differences in passive mating efficiency of large and small cells across environments but by competitive mating behavior, mate preference, or both. We conclude that the most likely mechanism underlying this interesting behavior is that yeast cells compete for mates by producing pheromone signals advertising their viability, and cells with the opportunity to choose prefer to mate with stronger signalers because such matings produce more viable offspring.

  10. Density-dependent selection on mate search and evolution of Allee effects.

    Science.gov (United States)

    Berec, Luděk; Kramer, Andrew M; Bernhauerová, Veronika; Drake, John M

    2018-01-01

    Sexually reproducing organisms require males and females to find each other. Increased difficulty of females finding mates as male density declines is the most frequently reported mechanism of Allee effects in animals. Evolving more effective mate search may alleviate Allee effects, but may depend on density regimes a population experiences. In particular, high-density populations may evolve mechanisms that induce Allee effects which become detrimental when populations are reduced and maintained at a low density. We develop an individual-based, eco-genetic model to study how mating systems and fitness trade-offs interact with changes in population density to drive evolution of the rate at which males or females search for mates. Finite mate search rate triggers Allee effects in our model and we explore how these Allee effects respond to such evolution. We allow a population to adapt to several population density regimes and examine whether high-density populations are likely to reverse adaptations attained at low densities. We find density-dependent selection in most of scenarios, leading to search rates that result in lower Allee thresholds in populations kept at lower densities. This mainly occurs when fecundity costs are imposed on mate search, and provides an explanation for why Allee effects are often observed in anthropogenically rare species. Optimizing selection, where the attained trait value minimizes the Allee threshold independent of population density, depended on the trade-off between search and survival, combined with monogamy when females were searching. Other scenarios led to runaway selection on the mate search rate, including evolutionary suicide. Trade-offs involved in mate search may thus be crucial to determining how density influences the evolution of Allee effects. Previous studies did not examine evolution of a trait related to the strength of Allee effects under density variation. We emphasize the crucial role that mating systems, fitness

  11. Life history changes in Trogoderma variabile and T. inclusum due to mating delay with implications for mating disruption as a management tactic

    Science.gov (United States)

    Controlling postharvest pest species is a costly process with insecticide resistance and species specific control requiring multiple tactics. Mating disruption can be used to both decrease a female’s access to males and delay timing of mating and decreases overall mating success in a population and ...

  12. Disrupting Mating Behavior of Diaphorina citri (Liviidae).

    Science.gov (United States)

    Lujo, S; Hartman, E; Norton, K; Pregmon, E A; Rohde, B B; Mankin, R W

    2016-12-01

    Severe economic damage from citrus greening disease, caused by 'Candidatus Liberibacter asiaticus' bacteria, has stimulated development of methods to reduce mating and reproduction in populations of its insect vector, Diaphorina citri (Hemiptera: Liviidae). Male D. citri find mating partners by walking on host plants, intermittently producing vibrational calls that stimulate duetting replies by receptive females. The replies provide orientational feedback, assisting the search process. To test a hypothesis that D. citri mating can be disrupted using vibrational signals that compete with and/or mask female replies, courtship bioassays were conducted in citrus trees with or without interference from female reply mimics produced by a vibrating buzzer. Statistically significant reductions occurred in the rates and proportions of mating when the buzzer produced reply mimics within 0.4 s after male courtship calls compared with undisturbed controls. Observations of courtship behaviors in the two bioassays revealed activity patterns that likely contributed to the reductions. In both disruption and control tests, males reciprocated frequently between structural bifurcations and other transition points where signal amplitudes changed. Males in the disruption bioassay had to select among vibrational signals combined from the buzzer and the female at each transition point. They often turned towards the buzzer instead of the female. There was a statistically significant reduction in the proportion of males mating if they contacted the buzzer, possibly due to its higher vibration amplitude and duration in comparison with female replies. Potential applications of D. citri mating disruption technology in citrus groves are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

  13. Semiochemical and Vibrational Cues and Signals Mediating Mate Finding and Courtship in Psylloidea (Hemiptera: A Synthesis

    Directory of Open Access Journals (Sweden)

    Umar K. Lubanga

    2014-07-01

    Full Text Available Mate finding and courtship involve complex interactions that require close coordination between individuals of the opposite gender. Well-organized signalling systems, sometimes involving a combination of signal modalities, are required to convey species-specific and individual information to members of the opposite gender. Previous studies of psyllids have focused on single-signal modalities and have largely ignored the potentially interdependent nature of different types of signals. Several studies have shown that semiochemicals play a role in psyllid mate finding. However, long-range semiochemical sex attractants, such as the highly volatile sex pheromones used by many Lepidoptera (molecular weights <300, are yet to be identified. The compounds identified thus far, namely 13-methylheptacosane (from Cacopsylla pyricola and dodecanoic acid (from Diaphorina citri, seem to have short range activity or no activity under field conditions. The possible role played by cuticular hydrocarbons in psyllid courtship remains largely ignored. Conversely, many psyllid species rely on vibrational signals for mate finding and mate assessment during courtship. This apparent disproportional reliance on vibrational rather than semiochemical signals suggests that vibrational signals have been more influential in sexual selection in psyllids. However, male fitness, female choice and benefits accrued from selecting fitter males remain poorly understood.

  14. Psychometric Evaluation and Cultural Correlates of the Mate Retention Inventory–Short Form (MRI-SF in Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Atari

    2017-02-01

    Full Text Available The current study investigated the psychometric properties of the Persian translation of the Mate Retention Inventory–Short Form (MRI-SF in Iran. We also investigated sex differences in the use of mate retention tactics and investigated the relationships between mate retention behaviors and a number of related cultural constructs. Participants (N = 308 ranged in age from 18 to 57 years. All participants were in a committed romantic relationship, with mean relationship length of 63.5 months (SD = 73.8. Participants completed the Persian translation of the MRI-SF and measures of religiosity, relationship satisfaction, self-esteem, and socioeconomic status. Cultural measures specific to Iran were also included, such as Mahr (for married individuals, self-perceived Qeiratiness (for men, and self-perceived jealousy (for women. Mahr is a mandatory amount of money or possessions paid or promised to be paid by the groom to the bride at the time of the marriage contract. Qeirati is a male-specific adjective in Persian meaning protective against unwanted attention toward a man’s romantic partner. Female jealousy is usually regarded the counterpart of male Qeiratiness in Iranian culture. The 19 mate retention tactics formed a two-component structure, consistent with previous research. Results demonstrate adequate internal consistency of 2-item assessments of mate retention tactics. Observed sex differences accorded with previous mate retention research and are discussed in reference to evolutionary perspectives on human mating. Several significant associations emerged between mate retention tactics and Iranian culture-specific variables and are discussed from a cross-cultural perspective.

  15. Toward Male Individualization with Rapidly Mutating Y-Chromosomal Short Tandem Repeats

    DEFF Research Database (Denmark)

    Ballantyne, Kaye N; Ralf, Arwin; Aboukhalid, Rachid

    2014-01-01

    diversity was increased in 86% of the populations tested and overall male relative differentiation was raised by 23.5%. Our study demonstrates the value of RM Y-STRs in identifying and separating unrelated and related males and provides a reference database. This article is protected by copyright. All...

  16. Low-impact mating system

    Science.gov (United States)

    Lewis, James L. (Inventor); Carroll, Monty B. (Inventor); Le, Thang D. (Inventor); Morales, Ray H. (Inventor); Robertson, Brandan R. (Inventor)

    2009-01-01

    An androgynous mating system for mating two exoatmospheric space modules comprising a first mating assembly capable of mating with a second mating assembly; a second mating assembly structurally identical to said first mating assembly, said first mating assembly comprising; a load ring; a plurality of load cell subassemblies; a plurality of actuators; a base ring; a tunnel; a closed loop control system; one or more electromagnets; and one or more striker plates, wherein said one or more electomagnets on said second mating assembly are capable of mating with said one or more striker plates on said first mating assembly, and wherein said one or more striker plates is comprised of a plate of predetermined shape and a 5-DOF mechanism capable of maintaining predetermined contact requirements during said mating of said one or more electromagnets and said one or more striker plates.

  17. Chemical and visual communication during mate searching in rock shrimp.

    Science.gov (United States)

    Díaz, Eliecer R; Thiel, Martin

    2004-06-01

    Mate searching in crustaceans depends on different communicational cues, of which chemical and visual cues are most important. Herein we examined the role of chemical and visual communication during mate searching and assessment in the rock shrimp Rhynchocinetes typus. Adult male rock shrimp experience major ontogenetic changes. The terminal molt stages (named "robustus") are dominant and capable of monopolizing females during the mating process. Previous studies had shown that most females preferably mate with robustus males, but how these dominant males and receptive females find each other is uncertain, and is the question we examined herein. In a Y-maze designed to test for the importance of waterborne chemical cues, we observed that females approached the robustus male significantly more often than the typus male. Robustus males, however, were unable to locate receptive females via chemical signals. Using an experimental set-up that allowed testing for the importance of visual cues, we demonstrated that receptive females do not use visual cues to select robustus males, but robustus males use visual cues to find receptive females. Visual cues used by the robustus males were the tumults created by agitated aggregations of subordinate typus males around the receptive females. These results indicate a strong link between sexual communication and the mating system of rock shrimp in which dominant males monopolize receptive females. We found that females and males use different (sex-specific) communicational cues during mate searching and assessment, and that the sexual communication of rock shrimp is similar to that of the American lobster, where females are first attracted to the dominant males by chemical cues emitted by these males. A brief comparison between these two species shows that female behaviors during sexual communication contribute strongly to the outcome of mate searching and assessment.

  18. Mutual mate choice for olorful traits in King Penguins

    NARCIS (Netherlands)

    Nolan, Paul M.; Dobson, F. Stephen; Nicolaus, Marion; Karels, Tim J.; McGraw, Kevin J.; Jouventin, Pierre

    While studies of mate choice based on male color pattern are ubiquitous, studies of mate choice based on ornamental color traits in sexually monomorphic species are less common. We conducted manipulative field experiments on two color ornaments of king penguins (Aptenodytes patagonicus), the size of

  19. Neural activity patterns in response to interspecific and intraspecific variation in mating calls in the túngara frog.

    Directory of Open Access Journals (Sweden)

    Mukta Chakraborty

    2010-09-01

    Full Text Available During mate choice, individuals must classify potential mates according to species identity and relative attractiveness. In many species, females do so by evaluating variation in the signals produced by males. Male túngara frogs (Physalaemus pustulosus can produce single note calls (whines and multi-note calls (whine-chucks. While the whine alone is sufficient for species recognition, females greatly prefer the whine-chuck when given a choice.To better understand how the brain responds to variation in male mating signals, we mapped neural activity patterns evoked by interspecific and intraspecific variation in mating calls in túngara frogs by measuring expression of egr-1. We predicted that egr-1 responses to conspecific calls would identify brain regions that are potentially important for species recognition and that at least some of those brain regions would vary in their egr-1 responses to mating calls that vary in attractiveness. We measured egr-1 in the auditory brainstem and its forebrain targets and found that conspecific whine-chucks elicited greater egr-1 expression than heterospecific whines in all but three regions. We found no evidence that preferred whine-chuck calls elicited greater egr-1 expression than conspecific whines in any of eleven brain regions examined, in contrast to predictions that mating preferences in túngara frogs emerge from greater responses in the auditory system.Although selectivity for species-specific signals is apparent throughout the túngara frog brain, further studies are necessary to elucidate how neural activity patterns vary with the attractiveness of conspecific mating calls.

  20. A Coherent Pattern Among Social Behavior, Blood Pressure, Corticosterone and Catecholamine Measures in Individual Male Rats

    NARCIS (Netherlands)

    FOKKEMA, DS; SMIT, K; VANDERGUGTEN, J; KOOLHAAS, JM

    1988-01-01

    Behavioral and physiological responses of 18 chronically cannulated male TMD-S3 rats were assessed during various social interactions with conspecifics, both with and without the possibility for physical contact (social vs. psychosocial stimulation). Response magnitudes (behavior, blood pressure,

  1. Individual variation in paternal responses of virgin male California mice (Peromyscus californicus): behavioral and physiological correlates

    NARCIS (Netherlands)

    de Jong, T.R.; Korosi, A.; Harris, B.N.; Perea-Rodriguez, J.P.; Saltzman, W.

    2012-01-01

    California mice Peromyscus californicus are a rodent species in which fathers provide extensive paternal care; however, behavioral responses of virgin males toward conspecific neonates vary from paternal behavior to tolerance to infanticide. Indirect evidence suggests that paternal responses might

  2. Individual, Family, School, and Community Predictors of High School Male Suicidal Behaviors: An Analysis of 2010 Iowa Youth Survey Data

    Science.gov (United States)

    Beck-Cross, Cathy

    2012-01-01

    Youth suicide is a public health issue and the second leading cause of death for young Iowans ages 15 to 24 years, with young males six times more likely to die than their female peers (Iowa Department of Public Health, 2009). Suicide among adolescents is a complex issue, but there are patterns of individual, family, school, and community…

  3. Low reproductive skew despite high male-biased operational sex ratio in a glass frog with paternal care.

    Science.gov (United States)

    Mangold, Alexandra; Trenkwalder, Katharina; Ringler, Max; Hödl, Walter; Ringler, Eva

    2015-09-03

    Reproductive skew, the uneven distribution of reproductive success among individuals, is a common feature of many animal populations. Several scenarios have been proposed to favour either high or low levels of reproductive skew. Particularly a male-biased operational sex ratio and the asynchronous arrival of females is expected to cause high variation in reproductive success among males. Recently it has been suggested that the type of benefits provided by males (fixed vs. dilutable) could also strongly impact individual mating patterns, and thereby affecting reproductive skew. We tested this hypothesis in Hyalinobatrachium valerioi, a Neotropical glass frog with prolonged breeding and paternal care. We monitored and genetically sampled a natural population in southwestern Costa Rica during the breeding season in 2012 and performed parentage analysis of adult frogs and tadpoles to investigate individual mating frequencies, possible mating preferences, and estimate reproductive skew in males and females. We identified a polygamous mating system, where high proportions of males (69 %) and females (94 %) reproduced successfully. The variance in male mating success could largely be attributed to differences in time spent calling at the reproductive site, but not to body size or relatedness. Female H. valerioi were not choosy and mated indiscriminately with available males. Our findings support the hypothesis that dilutable male benefits - such as parental care - can favour female polyandry and maintain low levels of reproductive skew among males within a population, even in the presence of direct male-male competition and a highly male-biased operational sex ratio. We hypothesize that low male reproductive skew might be a general characteristic in prolonged breeders with paternal care.

  4. Both male and female identity influence variation in male signalling effort

    Directory of Open Access Journals (Sweden)

    Svensson P Andreas

    2011-08-01

    Full Text Available Abstract Background Male sexual displays play an important role in sexual selection by affecting reproductive success. However, for such displays to be useful for female mate choice, courtship should vary more among than within individual males. In this regard, a potentially important source of within male variation is adjustment of male courtship effort in response to female traits. Accordingly, we set out to dissect sources of variation in male courtship effort in a fish, the desert goby (Chlamydogobius eremius. We did so by designing an experiment that allowed simultaneous estimation of within and between male variation in courtship, while also assessing the importance of the males and females as sources of courtship variation. Results Although males adjusted their courtship depending on the identity of the female (a potentially important source of within-male variation, among-male differences were considerably greater. In addition, male courtship effort towards a pair of females was highly repeatable over a short time frame. Conclusion Despite the plasticity in male courtship effort, courtship displays had the potential to reliably convey information about the male to mate-searching females. Our experiment therefore underscores the importance of addressing the different sources contributing to variation in the expression of sexually-selected traits.

  5. Studies on mating competition of irradiated melon flies

    International Nuclear Information System (INIS)

    Limohpasmanee, W.

    1994-01-01

    Mating competition is the key factor for fruit flies control by using sterile insect technique project. Mass rearing and irradiation can reduce the mating competition of fruit flies. This experiment has purpose to evaluate the mating competition of the irradiated melon fly. The results show that mating competition values of irradiated melon flies were 0.36 and 0.24 when they mated with normal and irradiated females. Both normal male and female can mate more frequency than irradiated flies. (Z=1.322, P<0.05; Z=1.851, P<0.05). The results show that quality of mass rearing and irradiated melon fly was lower than the normal flies. So that quality of irradiated fly must be improved and the number of released flies as less must be higher than natural flies 6 time

  6. Normal male childhood and adolescent sexual interactions: implications for sexual orientation of the individual with intersex.

    Science.gov (United States)

    Lee, Peter A; Houk, Christopher P

    2005-03-01

    Data provided by 24 adult men, 20 heterosexual and four homosexual, concerning parental, religious, geographic and explicit sexual innuendos, comments and childhood experiences are presented and discussed in an attempt to consider some of the multiple factors impacting the development of sexual orientation. All of the study subjects were normally developed males and were presumed to have been exposed to normal male levels of androgens prenatally. Since the experiences and perceptions reported are conditioned by a unique social environment that has been superimposed on a normal male typical prenatal CNS differentiation, the experiences of these men suggest that affirmation of masculinity, and openness in the realm of social and sexual interaction, may enhance the formation of a heterosexual orientation. Conversely, sexually explicit feedback with critical implications occurred commonly among the homosexual men, which they interpreted as implying an insufficient masculinity. Both innate factors and social influences impact sexual orientation; in some instances males appear to have been homosexual from early childhood onward, while in other cases there appears to have been some degree of conditioning and choice in sexual orientation. Regarding the intersexed male, this suggests that social interactions, particularly those provided by parents, have a major influence on the development of sexual orientation in the child, while all persons involved in these children's lives and particularly those who nurture must be prepared for any sexual orientation that develops.

  7. 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.

  8. No preference for novel mating partners in the polyandrous nuptial-feeding spider Pisaura mirabilis (Araneae: Pisauridae)

    DEFF Research Database (Denmark)

    Tuni, Cristina; Bilde, T.

    2010-01-01

    for novel partners is also expected to maximize male lifetime reproductive success by allowing males to increase the number of mates. We investigated male and female preference for novel or former mating partners in the spider Pisaura mirabilis by offering females novel males (polyandry) or the same male...

  9. Arrhenotoky and oedipal mating in the northern fowl mite (Ornithonyssus sylviarum (Acari: Gamasida: Macronyssidae

    Directory of Open Access Journals (Sweden)

    McCulloch John B

    2012-12-01

    Full Text Available Abstract Background The northern fowl mite (NFM; Ornithonyssus sylviarum is a blood-feeding ectoparasite of birds and a major pest of poultry in the United States. Mite populations spread rapidly in commercial flocks, reach peak burdens of >70,000 mites per bird and have developed resistance to many pesticides. Despite decades as a pest in the United States, the reproductive biology of NFM remains unclear. Based on karyotypes, the NFM has haplodiploid sex determination, which suggests unmated females could produce male offspring (arrhenotoky. Thus, unmated females could disseminate to a new host and initiate an infestation by producing and mating with sons (oedipal mating. Methods We used small capsules to isolate and recover NFM on host chickens. Mites in capsules could blood feed, develop and reproduce, but could not contact other mites. Individual larvae were matured in isolation to produce known, unmated females. We evaluated reproduction of (I previously mated females (i in isolation, or (ii paired with a male, and (II unmated (virgin females in isolation. In each treatment we recorded the number and sexes of offspring produced over time. Results Mated NFM produced female and male offspring in isolation, or when paired with a male. When paired with a male, females produced a female-biased sex ratio of the offspring (F:M ratio ~5:1. Unmated, female NFM produced exclusively male offspring when in isolation. When paired with their sons that had developed to maturity, the "virgin" females were able to mate and subsequently produce female offspring. Conclusions This study found that females with immediate access to sperm produced mostly female offspring. Virgin female NFM initially produced only male offspring and subsequently used oedipal mating to produce female offspring. Using this reproductive system NFM could successfully colonize new hosts as immature, or unmated females. The strong female-biased sex ratio of NFM populations suggests a

  10. Multi-year evaluation of mating disruption treatments against gypsy moth

    Science.gov (United States)

    Patrick C. Tobin; Kevin W. Thorpe; Laura M. Blackburn

    2007-01-01

    Mating disruption is the use of synthetic pheromone flakes that are aerially applied to foliage with the goal of interfering with male gypsy moths? ability to locate females and mate. Mating disruption is the primary tactic against gypsy moth used in the Gypsy Moth Slow-the-Spread Project (STS) [Tobin et al. 2004. Amer. Entomol. 50:200].

  11. Nutrition quality, body size and two components of mating behavior in Drosophila melanogaster.

    Science.gov (United States)

    Pavković-Lucić, Sofija; Kekić, Vladimir

    2010-01-01

    Two components of mating behavior, mating latency and duration of copulation, were investigated in Drosophila melanogaster males from three different "nutritional" strains, reared for more than 35 generations on banana, tomato and cornmeal-agar-yeast substrates. Males from different strains did not differ according to mating latency and duration of copulation. Also, the sizes of males from different strains did not contribute to these behavioral traits.

  12. Using Gender Role Conflict Theory in Counseling Male-to-Female Transgender Individuals

    Science.gov (United States)

    Wester, Stephen R.; McDonough, Tracy A.; White, Maureen; Vogel, David L.; Taylor, Lareena

    2010-01-01

    Ignoring gender socialization while counseling transgender clients neglects a significant aspect of the transgender experience. To address this, the authors review the literature on gender role conflict (GRC) theory as it pertains to the transgender experience of biological males whose authentic self is female. They explore the main types of…

  13. The Effects of Self-Disclosure on Male and Female Perceptions of Individuals Who Stutter.

    Science.gov (United States)

    Byrd, Courtney T; McGill, Megann; Gkalitsiou, Zoi; Cappellini, Colleen

    2017-02-01

    The purpose of this study was to examine the influence of self-disclosure on observers' perceptions of persons who stutter. Participants (N = 173) were randomly assigned to view 2 of 4 possible videos (i.e., male self-disclosure, male no self-disclosure, female self-disclosure, and female no self-disclosure). After viewing both videos, participants completed a survey assessing their perceptions of the speakers. Controlling for observer and speaker gender, listeners were more likely to select speakers who self-disclosed their stuttering as more friendly, outgoing, and confident compared with speakers who did not self-disclose. Observers were more likely to select speakers who did not self-disclose as unfriendly and shy compared with speakers who used a self-disclosure statement. Controlling for self-disclosure and observer gender, observers were less likely to choose the female speaker as friendlier, outgoing, and confident compared with the male speaker. Observers also were more likely to select the female speaker as unfriendly, shy, unintelligent, and insecure compared with the male speaker and were more likely to report that they were more distracted when viewing the videos. Results lend support to the effectiveness of self-disclosure as a technique that persons who stutter can use to positively influence the perceptions of listeners.

  14. Individual and Familial Correlates of Body Satisfaction in Male and Female College Students

    Science.gov (United States)

    Sira, Natalia; White, Carmel Parker

    2010-01-01

    Objective: This study investigates the relative contributions of global self-esteem, body mass index (BMI), dieting behaviors, and perceived parental control and care on body satisfaction among a nonclinical sample of college students. Participants and Methods: Participants (49 males and 299 females) reported weight and height (to calculate BMI)…

  15. 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.

  16. Creativity and Aggression as Ornament and Armament: Intersexual and Intrasexual Selection on Men's Mating Behaviors

    Directory of Open Access Journals (Sweden)

    Bin-Bin Chen

    2015-01-01

    Full Text Available In three studies, we tested the hypothesis that men respond to intersexual and intrasexual selection by facultatively choosing between weapon-like and ornament-like behaviors. In the first two studies, we manipulated intersexual and intrasexual selection by having male participants take part in a simulated dating game (Study 1 or imagine having a date (Study 2. In both studies, participants were told either that the target female would choose her date (intersexual or that male suitors would nominate one another (intrasexual. Under the intersexual selection condition, men demonstrated increased creativity levels and decreased aggression levels, whereas the opposite pattern was observed under the intrasexual selection condition. Study 3 showed that individual differences in creativity and aggression as personality traits similarly predicted intrasexual and intersexual mating strategies, respectively. These extend existing evolutionary mating research by specifying the mechanism of intrasexual or intersexual selection in shaping men's weapon-like or ornament-like situational response and personality development.

  17. Aphrodisiac Pheromone and its role in mating behaviour of Gamma irradiated SPODOPTERA LITTORALIS (BOISD.)

    International Nuclear Information System (INIS)

    ALM EL-DIN, M.M.S.; HAZAA, M.A.M.; EL-SHALL, S.S.A.

    2007-01-01

    The aphrodisiac pheromone in male moth of the cotton leaf worm, Spodoptera littoralis, is secreted from a scent gland that lies in the fore wings and hair pencils. The damage of the gland by gamma irradiation or elimination of the fore wings reduced mating percentage and the other related mating aspects. Multiple mating seldom was occurred in the eliminated wing males and this mean that the wing gland was effective in mating behaviour. The knowledge on pheromone glands and their role in mating behaviour have been appeared to be essential in the integrated control programmes

  18. Responses of female rock lizards to multiple scent marks of males: effects of male age, male density and scent over-marking.

    Science.gov (United States)

    Martín, José; López, Pilar

    2013-03-01

    Scent-marked substrates may inform conspecifics on the characteristics of territorial males. Scent-marks of male Carpetan rock lizards (Iberolacerta cyreni) affect space use of females, which by selecting an area may increase the probability of mating with the male that has scent-marked that area. However, males do not hold exclusive territories, and scent-marks of different individual males are often together. This may provide complex information from multiple sources on the social structure. Here, we examined female preference in response to scent marks of various males and combinations in a laboratory experiment. Females preferred areas scent-marked by territorial old males against those scent-marked by young satellite-sneaker males. This reflected the known preference of females for mating with old males. In a second experiment, females preferred areas scent-marked by two males to areas of similar size marked by a single male. This may increase the probability of obtaining multiple copulations with different males, which may favour sperm competition and cryptic female choice, or may be a way to avoid infertile males. Finally, when we experimentally over-marked the scent-marks of an old male with scent-marks of a young male, females did not avoid, nor prefer, the over-marked area, suggesting that the quality of the old male may override the presence of a satellite male. We suggest that, irrespective of the causes underlying why a female selects a scent-marked area, this strategy may affect her reproductive success, which may have the same evolutionary consequences that "direct" mate choice decisions of other animals. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Synergistic selection between ecological niche and mate preference primes diversification.

    Science.gov (United States)

    Boughman, Janette W; Svanbäck, Richard

    2017-01-01

    The ecological niche and mate preferences have independently been shown to be important for the process of speciation. Here, we articulate a novel mechanism by which ecological niche use and mate preference can be linked to promote speciation. The degree to which individual niches are narrow and clustered affects the strength of divergent natural selection and population splitting. Similarly, the degree to which individual mate preferences are narrow and clustered affects the strength of divergent sexual selection and assortative mating between diverging forms. This novel perspective is inspired by the literature on ecological niches; it also explores mate preferences and how they may contribute to speciation. Unlike much comparative work, we do not search for evolutionary patterns using proxies for adaptation and sexual selection, but rather we elucidate how ideas from niche theory relate to mate preference, and how this relationship can foster speciation. Recognizing that individual and population niches are conceptually and ecologically linked to individual and population mate preference functions will significantly increase our understanding of rapid evolutionary diversification in nature. It has potential to help solve the difficult challenge of testing the role of sexual selection in the speciation process. We also identify ecological factors that are likely to affect individual niche and individual mate preference in synergistic ways and as a consequence to promote speciation. The ecological niche an individual occupies can directly affect its mate preference. Clusters of individuals with narrow, differentiated niches are likely to have narrow, differentiated mate preference functions. Our approach integrates ecological and sexual selection research to further our understanding of diversification processes. Such integration may be necessary for progress because these processes seem inextricably linked in the natural world. © 2016 The Author(s). Evolution

  20. Experimental evidence for chemical mate guarding in a moth

    NARCIS (Netherlands)

    Hosseini, S.A.; van Wijk, M.; Ke, G.; Goldansaz, S.H.; Schal, C.; Groot, A.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

  1. Heterosexual Rejection and Mate Choice: A Sociometer Perspective

    Directory of Open Access Journals (Sweden)

    Lin eZHANG

    2015-12-01

    Full Text Available Previous studies about the effects of social rejection on individuals’ social behaviors have produced mixed results and tend to study mating behaviors from a static point of view. However, mate selection in essence is a dynamic process, and therefore sociometer theory opens up a new perspective for studying mating and its underlying practices. Based on this theory and using self-perceived mate value in the relationship between heterosexual rejection and mate choice as a mediating role, this current study examined the effects of heterosexual rejection on mate choice in two experiments. Results showed that heterosexual rejection significantly reduced self-perceived mate value, expectation, and behavioral tendencies, while heterosexual acceptance indistinctively increased these measures. Self-perceived mate value did not serve as a mediator in the relationship between heterosexual rejection and mate expectation, but it mediated the relationship between heterosexual rejection and mating behavior tendencies towards potential objects. Moreover, individuals evaded both rejection and irrelevant people when suffering from rejection.

  2. Dispersal, mating events and fine-scale genetic structure in the lesser flat-headed bats.

    Directory of Open Access Journals (Sweden)

    Panyu Hua

    Full Text Available Population genetic structure has important consequences in evolutionary processes and conservation genetics in animals. Fine-scale population genetic structure depends on the pattern of landscape, the permanent movement of individuals, and the dispersal of their genes during temporary mating events. The lesser flat-headed bat (Tylonycteris pachypus is a nonmigratory Asian bat species that roosts in small groups within the internodes of bamboo stems and the habitats are fragmented. Our previous parentage analyses revealed considerable extra-group mating in this species. To assess the spatial limits and sex-biased nature of gene flow in the same population, we used 20 microsatellite loci and mtDNA sequencing of the ND2 gene to quantify genetic structure among 54 groups of adult flat-headed bats, at nine localities in South China. AMOVA and F(ST estimates revealed significant genetic differentiation among localities. Alternatively, the pairwise F(ST values among roosting groups appeared to be related to the incidence of associated extra-group breeding, suggesting the impact of mating events on fine-scale genetic structure. Global spatial autocorrelation analyses showed positive genetic correlation for up to 3 km, indicating the role of fragmented habitat and the specialized social organization as a barrier in the movement of individuals among bamboo forests. The male-biased dispersal pattern resulted in weaker spatial genetic structure between localities among males than among females, and fine-scale analyses supported that relatedness levels within internodes were higher among females than among males. Finally, only females were more related to their same sex roost mates than to individuals from neighbouring roosts, suggestive of natal philopatry in females.

  3. Dispersal, mating events and fine-scale genetic structure in the lesser flat-headed bats.

    Science.gov (United States)

    Hua, Panyu; Zhang, Libiao; Guo, Tingting; Flanders, Jon; Zhang, Shuyi

    2013-01-01

    Population genetic structure has important consequences in evolutionary processes and conservation genetics in animals. Fine-scale population genetic structure depends on the pattern of landscape, the permanent movement of individuals, and the dispersal of their genes during temporary mating events. The lesser flat-headed bat (Tylonycteris pachypus) is a nonmigratory Asian bat species that roosts in small groups within the internodes of bamboo stems and the habitats are fragmented. Our previous parentage analyses revealed considerable extra-group mating in this species. To assess the spatial limits and sex-biased nature of gene flow in the same population, we used 20 microsatellite loci and mtDNA sequencing of the ND2 gene to quantify genetic structure among 54 groups of adult flat-headed bats, at nine localities in South China. AMOVA and F(ST) estimates revealed significant genetic differentiation among localities. Alternatively, the pairwise F(ST) values among roosting groups appeared to be related to the incidence of associated extra-group breeding, suggesting the impact of mating events on fine-scale genetic structure. Global spatial autocorrelation analyses showed positive genetic correlation for up to 3 km, indicating the role of fragmented habitat and the specialized social organization as a barrier in the movement of individuals among bamboo forests. The male-biased dispersal pattern resulted in weaker spatial genetic structure between localities among males than among females, and fine-scale analyses supported that relatedness levels within internodes were higher among females than among males. Finally, only females were more related to their same sex roost mates than to individuals from neighbouring roosts, suggestive of natal philopatry in females.

  4. Mating Success, Longevity, and Fertility of Diabrotica virgifera virgifera LeConte (Chrysomelidae: Coleoptera in Relation to Body Size and Cry3Bb1-Resistant and Cry3Bb1-Susceptible Genotypes

    Directory of Open Access Journals (Sweden)

    Bryan Wade French

    2015-11-01

    Full Text Available Insect resistance to population control methodologies is a widespread problem. The development of effective resistance management programs is often dependent on detailed knowledge regarding the biology of individual species and changes in that biology associated with resistance evolution. This study examined the reproductive behavior and biology of western corn rootworm beetles of known body size from lines resistant and susceptible to the Cry3Bb1 protein toxin expressed in transgenic Bacillus thuringiensis maize. In crosses between, and within, the resistant and susceptible genotypes, no differences occurred in mating frequency, copulation duration, courtship duration, or fertility; however, females mated with resistant males showed reduced longevity. Body size did not vary with genotype. Larger males and females were not more likely to mate than smaller males and females, but larger females laid more eggs. Moderately strong, positive correlation occurred between the body sizes of successfully mated males and females; however, weak correlation also existed for pairs that did not mate. Our study provided only limited evidence for fitness costs associated with the Cry3Bb1-resistant genotype that might reduce the persistence in populations of the resistant genotype but provided additional evidence for size-based, assortative mating, which could favor the persistence of resistant genotypes affecting body size.

  5. Only Cheap Talk after All? New Experimental Psychological Findings on the Role of Verbal Proficiency in Mate Choice

    Directory of Open Access Journals (Sweden)

    Lange Benjamin P.

    2016-10-01

    Full Text Available Recent evolutionary experimental psychological research found that high verbal proficiency (VP increased the perceived attractiveness of individuals (more so for males than females, especially in the context of a long-term relationship. Our study had the objective of replicating and extending this research. Similar to previous studies, audio files in which speakers performed scripted self-presentations that had equal content but varied on VP were used as stimuli for opposite-sex participants. VP was found to increase attractiveness ratings. The effects were mostly small for numerous variables relating to short-term mating, whereas they were moderate to large for long-term mating. Our participants attributed more future income, but not more total number of mates to speakers with higher VP. Female menstrual cycle effects on attractiveness ratings were not found. Contrary to former research, being more verbally proficient was not found to be more beneficial for one sex over the other.

  6. Estrogens can disrupt amphibian mating behavior.

    Directory of Open Access Journals (Sweden)

    Frauke Hoffmann

    Full Text Available The main component of classical contraceptives, 17α-ethinylestradiol (EE2, has high estrogenic activity even at environmentally relevant concentrations. Although estrogenic endocrine disrupting compounds are assumed to contribute to the worldwide decline of amphibian populations by adverse effects on sexual differentiation, evidence for EE2 affecting amphibian mating behaviour is lacking. In this study, we demonstrate that EE2 exposure at five different concentrations (0.296 ng/L, 2.96 ng/L, 29.64 ng/L, 2.96 µg/L and 296.4 µg/L can disrupt the mating behavior of adult male Xenopus laevis. EE2 exposure at all concentrations lowered male sexual arousal, indicated by decreased proportions of advertisement calls and increased proportions of the call type rasping, which characterizes a sexually unaroused state of a male. Additionally, EE2 at all tested concentrations affected temporal and spectral parameters of the advertisement calls, respectively. The classical and highly sensitive biomarker vitellogenin, on the other hand, was only induced at concentrations equal or higher than 2.96 µg/L. If kept under control conditions after a 96 h EE2 exposure (2.96 µg/L, alterations of male advertisement calls vanish gradually within 6 weeks and result in a lower sexual attractiveness of EE2 exposed males toward females as demonstrated by female choice experiments. These findings indicate that exposure to environmentally relevant EE2 concentrations can directly disrupt male mate calling behavior of X. laevis and can indirectly affect the mating behavior of females. The results suggest the possibility that EE2 exposure could reduce the reproductive success of EE2 exposed animals and these effects might contribute to the global problem of amphibian decline.

  7. Mating and Memory

    Directory of Open Access Journals (Sweden)

    Michael D. Baker

    2015-12-01

    Full Text Available The literature on sexual selection and the social brain hypothesis suggest that human cognition and communication evolved, in part, for the purpose of displaying desirable cognitive abilities to potential mates. An evolutionary approach to social cognition implies that proximate mating motives may lead people to display desirable mental traits. In signaling such traits, one can increase the likelihood of attracting a potential mate. Two experiments demonstrated that exposure to mating cues—highly attractive opposite-sex faces—led people to display enhancements in declarative memory—a process underlying a variety of abilities such as resource acquisition, intelligence, and creativity. Experiment 1 showed that men (but not women displayed enhanced memory for details of a story that was presented during exposure to highly attractive opposite-sex faces. Experiment 2 demonstrated that heightened displays of declarative memory reflect an enhancement in retrieval rather than in encoding. Findings contribute to the literatures on human mating and cognitive performance and provide novel insight into links between social processes and basic cognition.

  8. Site fidelity, mate fidelity, and breeding dispersal in American kestrels

    Science.gov (United States)

    Steenhof, K.; Peterson, B.E.

    2009-01-01

    We assessed mate fidelity, nest-box fidelity, and breeding dispersal distances of American Kestrels (falco sparverius) nesting in boxes in southwestern Idaho from 1990 through 2006. Seventy-seven percent of boxes had different males and 87% had different females where nest-box occupants were identified in consecutive years. High turnover rates were partly a result of box-switching. Forty-eight percent of males and 58% of females that nested within the study area in successive years used different boxes. The probability of changing boxes was unrelated to gender, nesting success in the prior year, or years of nesting experience. Breeding dispersal distances for birds that moved to different boxes averaged 2.2 km for males (max = 22 km) and 3.2 km for females (max = 32 km). Approximately 70% of birds that nested in consecutive years on the study area had a different mate in the second year. Mate fidelity was related to box fidelity but not to prior nesting success or years of nesting experience. Mate changes occurred 32% of the time when the previous mate was known to be alive and nesting in the area. Kestrels that switched mates and boxes did not improve or decrease their subsequent nesting success. Kestrels usually switched to mates with less experience and lower lifetime productivity than their previous mates. The costs of switching boxes and mates were low, and there were no obvious benefits to fidelity. The cost of "waiting" for a previous mate that might have died could be high in species with high annual mortality.

  9. Comparison of mating performance of medfly (Diptera: Tephritidae) genetic sexing and wild type strains: field cage and video recording experiments

    International Nuclear Information System (INIS)

    Calcagno, G.E.; Vilardi, J.C.; Manso, F.

    2002-01-01

    To improve the efficiency of the sterile insect technique (SIT) efforts are being devoted to obtain genetic sexing strains (GSS). The present work was carried out in order to compare the mating efficiency of flies from the GSS [(Ty34228 y + /X)sw x ] and from a wild type strain (Mendoza). Females of the GSS (T228) exhibit longer embryonic development, while males develop in a normal time period. In a field-cage experiment, mating competitiveness was compared between the T228 and the Mendoza, Argentina mass reared strain. The number and duration of matings and the location of copula in the tree were recorded. The analysis was repeated using irradiated males of T228. The results showed that mating efficiency of the GSS is good in comparison with that of the Mendoza strain. Although copulatory success in T228 is reduced by the radiation treatment, the high numbers of sterilized males released would compensate this effect in the control programs. In a second experiment, under laboratory conditions, video recording techniques were applied. In this case two virgin males, one of the GSS and one emerged from wild collected fruits, competed during 30 min for a virgin wild female. The proportion of successful males did not differ between strains, but some differences were observed between strains in the time spent in different stages of the courtship. Males of the T228 were more aggressive, and they attempted to copulate with the other male more frequently than did wild males. These differences may be due to selection for more aggressive individuals under the overcrowded laboratory breeding conditions for this strain. (author)

  10. Conceptualizing Masculinity in Female-to-Male Trans-Identified Individuals: A Qualitative Inquiry

    Science.gov (United States)

    Vegter, Vanessa

    2013-01-01

    A non-normative gender identity raises questions concerning widely accepted theories of gender that prevail in Western society. These theories are founded upon dichotomous models of gender identity that are posited as having a direct relationship to binary biological sex. The purpose of this qualitative study was to explore how individuals who…

  11. Genetic incompatibility drives mate choice in a parasitic wasp

    NARCIS (Netherlands)

    Thiel, A.; Weeda, A.C.; Boer, de J.G.; Hoffmeister, T.S.

    2013-01-01

    Introduction: Allelic incompatibility between individuals of the same species should select for mate choice based on the genetic make-up of both partners at loci that influence offspring fitness. As a consequence, mate choice may be an important driver of allelic diversity. A complementary sex

  12. How universal are human mate choices? Size does not matter when Hadza foragers are choosing a mate

    Science.gov (United States)

    Sear, Rebecca; Marlowe, Frank W.

    2009-01-01

    It has been argued that size matters on the human mate market: both stated preferences and mate choices have been found to be non-random with respect to height and weight. But how universal are these patterns? Most of the literature on human mating patterns is based on post-industrial societies. Much less is known about mating behaviour in more traditional societies. Here we investigate mate choice by analysing whether there is any evidence for non-random mating with respect to size and strength in a forager community, the Hadza of Tanzania. We test whether couples assort for height, weight, body mass index (BMI), per cent fat and grip strength. We test whether there is a male-taller norm. Finally, we test for an association between anthropometric variables and number of marriages. Our results show no evidence for assortative mating for height, weight, BMI or per cent fat; no evidence for a male-taller norm and no evidence that number of marriages is associated with our size variables. Hadza couples may assort positively for grip strength, but grip strength does not affect the number of marriages. Overall we conclude that, in contrast to post-industrial societies, mating appears to be random with respect to size in the Hadza. PMID:19570778

  13. Mate preference of female blue tits varies with experimental photoperiod.

    Directory of Open Access Journals (Sweden)

    Laura B Reparaz

    Full Text Available Organisms use environmental cues to time their life-cycles and among these cues, photoperiod is the main trigger of reproductive behaviours such as territory defence or song activity. Whether photoperiod is also important for another behaviour closely associated with reproduction, mate choice, is unknown. In many bird species, mate choice occurs at two different times during the annual cycle that strongly differ in daylength: in late winter when photoperiod is short and social mates are chosen, and again around egg-laying when photoperiod is longer and extra-pair mates are chosen. This duality makes the role that photoperiod plays on mate choice behaviours intriguing. We investigated the effect of photoperiod on mate choice using three experimental photoperiodic treatments (9 L:15 D, 14 L:10 D, 18 L:6 D, using blue tits (Cyanistes caeruleus as a biological model. We show that female choice was stronger under long photoperiods. In addition, female blue tits spent significantly more time near males with long tarsi and long wings. This latter preference was only expressed under long photoperiods, suggesting that some indices of male quality only become significant to females when they are strongly photostimulated, and therefore that females could select their social and extra-pair mates based on different phenotypic traits. These results shed light on the roles that photoperiod may play in stimulating pair-bonding and in refining female selectivity for male traits.

  14. Electrophysiological analysis of the cognitive component of social creativity in young males and females with different individual characteristics.

    Directory of Open Access Journals (Sweden)

    Saakyan, O. S.

    2015-07-01

    Full Text Available This article sets forth the problem of studying social creativity from the psychophysiological perspective. Presented here are the first experimental records of studying the cognitive component of social activity. This article describes the peculiar hemispheric activity during the resolution of interpersonal problems by students of different individual peculiarities and professional achievement levels. The author shows that when the solution to a verbal divergent task by young males and females of high creativity and professional achievement is reached, the frequency-spatial EEG indexes are higher in the parietal and frontal brain regions. In the solution of a convergent task, these indexes are higher in the frontal, central and cervical brain zones. In case of young males and females of low creativity and average and low levels of professional achievement, the solution of a convergent task is accompanied by increased EEG power in the central, frontal, parietal zones of both hemispheres. Thus, the assessment of the psychophysiological mechanisms of the cognitive component in social activity has shown that a definite picture of hemispheric activation stipulates the peculiarities of divergent and convergent thinking in young males and females of various levels of creativity and professional success. This difference, revealed at the initial stage of investigation, demands a deeper study of the phenomenon of social creativity in the professional training of a personality that is inclusive of this personality’s individual peculiarities.

  15. Beyond magic traits: Multimodal mating cues in Heliconius butterflies.

    Science.gov (United States)

    Mérot, Claire; Frérot, Brigitte; Leppik, Ene; Joron, Mathieu

    2015-11-01

    Species coexistence involves the evolution of reproductive barriers opposing gene flow. Heliconius butterflies display colorful patterns affecting mate choice and survival through warning signaling and mimicry. These patterns are called "magic traits" for speciation because divergent natural selection may promote mimicry shifts in pattern whose role as mating cue facilitates reproductive isolation. By contrast, between comimetic species, natural selection promotes pattern convergence. We addressed whether visual convergence interferes with reproductive isolation by testing for sexual isolation between two closely related species with similar patterns, H. timareta thelxinoe and H. melpomene amaryllis. Experiments with models confirmed visual attraction based on wing phenotype, leading to indiscriminate approach. Nevertheless, mate choice experiments showed assortative mating. Monitoring male behavior toward live females revealed asymmetry in male preference, H. melpomene males courting both species equally while H. timareta males strongly preferred conspecifics. Experiments with hybrid males suggested an important genetic component for such asymmetry. Behavioral observations support a key role for short-distance cues in determining male choice in H. timareta. Scents extracts from wings and genitalia revealed interspecific divergence in chemical signatures, and hybrid female scent composition was significantly associated with courtship intensity by H. timareta males, providing candidate chemical mating cues involved in sexual isolation. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  16. Are high-quality mates always attractive? State-dependent mate preferences in birds and humans

    NARCIS (Netherlands)

    Riebel, Katharina; Holveck, Marie-Jeanne; Verhulst, Simon; Fawcett, Tim W.

    2010-01-01

    Sexual selection theory posits that females should choose mates in a way that maximizes their reproductive success. But what exactly is the optimal choice? Most empirical research is based on the assumption that females seek a male of the highest possible quality (in terms of the genes or resources

  17. Influence of individual body size and variable thresholds on the incidence of a sneaker male reproductive tactic in Atlantic salmon.

    Science.gov (United States)

    Aubin-Horth, Nadia; Dodson, Julian J

    2004-01-01

    In the conditional strategy model, divergence in reproductive phenotypes depends on whether the individual's condition is above or below a genetically determined threshold. The relative contribution of the genetic and environmental components that lead to the expression of a reproductive tactic by an individual is not well understood. In the present field study, we determined when condition diverged between males that develop the mature parr phenotype and those that do not in Atlantic salmon (Salmo salar). We also investigated the uniformity of the threshold value in the population. We sampled mature parr and immature males at age one, of the same population at six different sites for four consecutive years. Our study provides an example of the interaction of genotype and environment on the expression of a reproductive tactic. Size was significantly greater for future mature parr than for future immature males as early as 20 days after hatching (emergence), suggesting that there may be a parental effect component in the tactic adopted, since no exogenous feeding takes place before this time. Size advantage at emergence was maintained through the next spring at age one to different degrees depending on the year, thus suggesting the presence of an environmental component of tactic expression. Our results support the contention that within the conditional strategy, the environment faced by a male and his condition at the moment of reproduction consistently predicts neither the environment faced by his offspring nor the fitness they will obtain by expressing the same tactic as their father. Furthermore, higher mean size at a site did not always translate into a higher proportion of mature parr, therefore supporting the hypothesis that thresholds vary across habitats within the same population.

  18. Meiotic recombination analyses of individual chromosomes in male domestic pigs (Sus scrofa domestica.

    Directory of Open Access Journals (Sweden)

    Nicolas Mary

    Full Text Available For the first time in the domestic pig, meiotic recombination along the 18 porcine autosomes was directly studied by immunolocalization of MLH1 protein. In total, 7,848 synaptonemal complexes from 436 spermatocytes were analyzed, and 13,969 recombination sites were mapped. Individual chromosomes for 113 of the 436 cells (representing 2,034 synaptonemal complexes were identified by immunostaining and fluorescence in situ hybridization (FISH. The average total length of autosomal synaptonemal complexes per cell was 190.3 µm, with 32.0 recombination sites (crossovers, on average, per cell. The number of crossovers and the lengths of the autosomal synaptonemal complexes showed significant intra- (i.e. between cells and inter-individual variations. The distributions of recombination sites within each chromosomal category were similar: crossovers in metacentric and submetacentric chromosomes were concentrated in the telomeric regions of the p- and q-arms, whereas two hotspots were located near the centromere and in the telomeric region of acrocentrics. Lack of MLH1 foci was mainly observed in the smaller chromosomes, particularly chromosome 18 (SSC18 and the sex chromosomes. All autosomes displayed positive interference, with a large variability between the chromosomes.

  19. Individual differences in the motivation to communicate relate to levels of midbrain and striatal catecholamine markers in male European starlings.

    Science.gov (United States)

    Heimovics, Sarah A; Salvante, Katrina G; Sockman, Keith W; Riters, Lauren V

    2011-11-01

    Individuals display dramatic differences in social communication even within similar social contexts. Across vertebrates dopaminergic projections from the ventral tegmental area (VTA) and midbrain central gray (GCt) strongly influence motivated, reward-directed behaviors. Norepinephrine is also rich in these areas and may alter dopamine neuronal activity. The present study was designed to provide insight into the roles of dopamine and norepinephrine in VTA and GCt and their efferent striatal target, song control region area X, in the regulation of individual differences in the motivation to sing. We used high pressure liquid chromatography with electrochemical detection to measure dopamine, norepinephrine and their metabolites in micropunched samples from VTA, GCt, and area X in male European starlings (Sturnus vulgaris). We categorized males as sexually motivated or non-sexually motivated based on individual differences in song produced in response to a female. Dopamine markers and norepinephrine in VTA and dopamine in area X correlated positively with sexually-motivated song. Norepinephrine in area X correlated negatively with non-sexually-motivated song. Dopamine in GCt correlated negatively with sexually-motivated song, and the metabolite DOPAC correlated positively with non-sexually-motivated song. Results highlight a role for evolutionarily conserved dopaminergic projections from VTA to striatum in the motivation to communicate and highlight novel patterns of catecholamine activity in area X, VTA, and GCt associated with individual differences in sexually-motivated and non-sexually-motivated communication. Correlations between dopamine and norepinephrine markers also suggest that norepinephrine may contribute to individual differences in communication by modifying dopamine neuronal activity in VTA and GCt. Copyright © 2011. Published by Elsevier Inc.

  20. Light wavelength dependency of mating activity in the drosophila melanogaster species subgroup

    International Nuclear Information System (INIS)

    Sakai, Takaomi; Tomaru, Masatoshi; Oguma, Yuzuru; Isono, Kunio; Fukatami, Akishi

    2002-01-01

    The action spectra of mating activity among the six species of the Drosophila melanogaster species subgroup were compared to understand how light wavelength affects mating activity. The species fell into three groups with respect to the action spectrum of mating activity. We chose one representative species from each of the three types for detailed study: D. melanogaster, D. sechellia and D. yakuba. The mating activities were investigated under three different light intensities of three monochromatic lights stimulus. Each species showed a unique spectral and intensity response. To know the evolutionary meaning of the light wavelength dependency of mating activity, we superimposed the type of action spectrum of mating activity in these six species on a cladogram. Mating inhibition under UV was conserved in evolution among these species. Furthermore we clarified that D. melanogaster showed low mating activity under UV because males courted less under UV. (author)

  1. Vocal performance reflects individual quality in a nonpasserine

    NARCIS (Netherlands)

    Janicke, T.; Hahn, S.M.; Ritz, M.S.; Peter, H.-U.

    2008-01-01

    Recent studies on mate-quality recognition in passerines showed that females use subtle differences in sound production to assess males. We analysed long calls of brown skuas, Catharacta antarctica lonnbergi, to test whether vocal performance could serve as an indicator of individual quality in a

  2. Mate choice and human stature: homogamy as a unified framework for understanding mating preferences.

    Science.gov (United States)

    Courtiol, Alexandre; Raymond, Michel; Godelle, Bernard; Ferdy, Jean-Baptiste

    2010-08-01

    Assortative mating for human height has long attracted interest in evolutionary biology, and the phenomenon has been demonstrated in numerous human populations. It is often argued that mating preferences generate this pattern, but other processes can also induce trait correlations between mates. Here, we present a methodology tailored to quantify continuous preferences based on choice experiments between pairs of stimuli. In particular, it is possible to explore determinants of interindividual variations in preferences, such as the height of the chooser. We collected data from a sample of 200 individuals from France. Measurements obtained show that the perception of attractiveness depends on both the height of the stimuli and the stature of the individual who judged them. Therefore, this study demonstrates that homogamy is present at the level of preferences for both sexes. We also show that measurements of the function describing this homogamy are concordant with several distinct mating rules proposed in the literature. In addition, the quantitative approach introduced here fulfills metrics that can be used to compare groups of individuals. In particular, our results reveal an important disagreement between sexes regarding height preferences in the context of mutual mate choice. Finally, both women and men prefer individuals who are significantly taller than average. All major findings are confirmed by a reanalysis of previously published data.

  3. SynchroMate

    DEFF Research Database (Denmark)

    Gibbs, M.; Vetere, F.; Bunyan, M

    2005-01-01

    ideas concerning technologies to support phatic interaction. Using the materials collected during our fieldwork as design inspirations, we developed design sketches for phatic technologies intended to support playful connection between intimates. One of these sketches – SynchroMate – is presented...

  4. Distress about mating rivals

    NARCIS (Netherlands)

    Buss, DM; Shackelford, TK; Choe, J; Buunk, BP; Dijkstra, P

    This research tested the evolutionary psychological hypothesis that men and women would be most distressed about threats from rivals who surpass them on sex-linked components of mate value. Six predictions were tested in samples from three cultures, the United States (N = 208), the Netherlands (N =

  5. Primary sex ratio adjustment by ant queens in response to local mate competition

    DEFF Research Database (Denmark)

    de Menten, Ludivine; Cremer, Sylvia; Heinze, Jürgen

    2005-01-01

    In the ant Cardiocondyla obscurior, wingless males compete with nestmate males for access to female mating partners, leading to local mate competition (LMC). Queen number varies between colonies, resulting in variation in the strength of LMC. Cremer & Heinze (2002, Proceedings of the Royal Society...

  6. Promiscuous mating in the harem-roosting fruit bat, Cynopterus sphinx.

    Science.gov (United States)

    Garg, Kritika M; Chattopadhyay, Balaji; Doss D, Paramanatha Swami; A K, Vinoth Kumar; Kandula, Sripathi; Ramakrishnan, Uma

    2012-08-01

    Observations on mating behaviours and strategies guide our understanding of mating systems and variance in reproductive success. However, the presence of cryptic strategies often results in situations where social mating system is not reflective of genetic mating system. We present such a study of the genetic mating system of a harem-forming bat Cynopterus sphinx where harems may not be true indicators of male reproductive success. This temporal study using data from six seasons on paternity reveals that social harem assemblages do not play a role in the mating system, and variance in male reproductive success is lower than expected assuming polygynous mating. Further, simulations reveal that the genetic mating system is statistically indistinguishable from promiscuity. Our results are in contrast to an earlier study that demonstrated high variance in male reproductive success. Although an outcome of behavioural mating patterns, standardized variance in male reproductive success (I(m)) affects the opportunity for sexual selection. To gain a better understanding of the evolutionary implications of promiscuity for mammals in general, we compared our estimates of I(m) and total opportunity for sexual selection (I(m) /I(f), where I(f) is standardized variance in female reproductive success) with those of other known promiscuous species. We observed a broad range of I(m) /I(f) values across known promiscuous species, indicating our poor understanding of the evolutionary implications of promiscuous mating. © 2012 Blackwell Publishing Ltd.

  7. Progressive white matter microstructure damage in male chronic heroin dependent individuals: a DTI and TBSS study.

    Directory of Open Access Journals (Sweden)

    Yingwei Qiu

    Full Text Available BACKGROUND: To investigate the WM microstructure deficits in heroin dependent individuals (HDIs with different length of heroin dependence, and to investigate whether these WM deficits can be related to the duration of heroin use and to decision-making deficits in HDIs. METHODOLOGY/PRINCIPAL FINDINGS: Thirty-six HDIs [including eighteen sHDIs (duration of heroin dependent is less than 10 years and eighteen lHDIs (duration of dependent is between 10:20 years] and sixteen healthy controls participated in this study. Whole brain voxel-wise analysis of fractional anisotropy (FA, mean diffusivity (MD, axial diffusivity (Da and radial diffusivity (Dr were performed by tract-based spatial statistics (TBSS to localize abnormal WM regions among groups. TBSS demonstrated that sHDIs had significantly lower FA than controls in right orbito-frontal WM, bilateral temporal WM and right parietal WM. The lHDIs had significantly lower FA throughout the brain compared with the controls and sHDIs. The lHDIs had significantly lower Da than controls in bilateral inferior frontaloccipital fasciculus, bilateral splenium of corpus callosum, left inferior longitudinal fasciculus, and had significantly higher Dr than controls in bilateral uncinatus fasciculus, bilateral inferior frontaloccipital fasciculus and bilateral cortical spinal fasciculus. Volume-of-interest (VOI analyses detect the changes of diffusivity indices in the regions with FA abnormalities revealed by control vs sHDIs. In most VOIs, FA reductions were caused by the increase in Dr as well as the decrease in Da. Correlation analysis was used to assess the relationship between FA and behavioral measures in HDIs and controls available. Significantly positively correlations were found between the FA values in the right orbital-frontal WM, right parietal WM and IGT performance. CONCLUSIONS: The extent and severity of WM integrity deficits in HDIs was associated with the length of heroin dependent. Furthermore

  8. Genetic and Cytogenetic Basis of Radiation-Induced Sterility in the Adult Male Cabbage Looper Trichoplusia Ni

    Energy Technology Data Exchange (ETDEWEB)

    North, D. T.; Holt, G. G. [Metabolism and Radiation Research Laboratory, Entomology Research Division, ARS, United States Department of Agriculture, Fargo, ND (United States)

    1968-06-15

    The relationship of egg hatch as a function of radiation dose is of a two-hit nature when irradiated adult males are mated to non-irradiated virgin females. Sterility as a function of dose is usually linear in insects. However, other species of moths respond similarly to irradiation, so it is indicative that the mechanism involved in producing sterility in Lepidoptera is basically different from that in other insects. The significance of the two-hit kinetics is discussed in relation to the chromosome structure and possible mechanisms for the induction of sterility in Lepidoptera. Many workers using Lepidoptera have reported that females mated to irradiated males oviposit substantially fewer eggs than normally. This response has been correlated to a lack of sperm transfer by irradiated males, even though they pass a spermatophore. The phenomenon is dose-dependent. Although Lepidoptera are far more radioresistant than other insect species when measured by the induction of sterility in the male, there appears to be very little difference when longevity is used as the criterion. The radiation dose required to reduce the lifespan of a newly emerged cabbage looper male by 50% was found to be approximately the same as that for the house fly. High doses of radiation have no immediate effect on the mating behaviour of the irradiated male. With a recessive eye-colour mutant as a sperm marker, it was determined in tests utilizing double matings that the second mating is the effective mating. Sperm mixing is not prevalent; rather it appears to be a 'sperm flushing' phenomenon in that sperm from the first mating are displaced by sperm from the second mating. Radiation studies with the cabbage looper have demonstrated that the progeny of a cross where the male parent receives a sub-sterilizing dose of gamma radiation are often semi-sterile when mated to non-irradiated individuals. The amount of inherited sterility is directly dependent on the amount of radiation given the

  9. X-linked gene transcription patterns in female and male in vivo, in vitro and cloned porcine individual blastocysts.

    Directory of Open Access Journals (Sweden)

    Chi-Hun Park

    Full Text Available To determine the presence of sexual dimorphic transcription and how in vitro culture environments influence X-linked gene transcription patterns in preimplantation embryos, we analyzed mRNA expression levels in in vivo-derived, in vitro-fertilized (IVF, and cloned porcine blastocysts. Our results clearly show that sex-biased expression occurred between female and male in vivo blastocysts in X-linked genes. The expression levels of XIST, G6PD, HPRT1, PGK1, and BEX1 were significantly higher in female than in male blastocysts, but ZXDA displayed higher levels in male than in female blastocysts. Although we found aberrant expression patterns for several genes in IVF and cloned blastocysts, similar sex-biased expression patterns (on average were observed between the sexes. The transcript levels of BEX1 and XIST were upregulated and PGK1 was downregulated in both IVF and cloned blastocysts compared with in vivo counterparts. Moreover, a remarkable degree of expression heterogeneity was observed among individual cloned embryos (the level of heterogeneity was similar in both sexes but only a small proportion of female IVF embryos exhibited variability, indicating that this phenomenon may be primarily caused by faulty reprogramming by the somatic cell nuclear transfer (SCNT process rather than in vitro conditions. Aberrant expression patterns in cloned embryos of both sexes were not ameliorated by treatment with Scriptaid as a potent HDACi, although the blastocyst rate increased remarkably after this treatment. Taken together, these results indicate that female and male porcine blastocysts produced in vivo and in vitro transcriptional sexual dimorphisms in the selected X-linked genes and compensation of X-linked gene dosage may not occur at the blastocyst stage. Moreover, altered X-linked gene expression frequently occurred in porcine IVF and cloned embryos, indicating that X-linked gene regulation is susceptible to in vitro culture and the SCNT process

  10. Sexual Cooperation: Mating Increases Longevity in Ant Queens

    DEFF Research Database (Denmark)

    Schrempf, Alexandra; Heinze, Jürgen; Cremer, Sylvia

    2005-01-01

    Divergent reproductive interests of males and females often cause sexual conflict [1] and [2] . Males of many species manipulate females by transferring seminal fluids that boost female short-term fecundity while decreasing their life expectancy and future reproductivity [3] and [4] . The life...... history of ants, however, is expected to reduce sexual conflict; whereas most insect females show repeated phases of mating and reproduction, ant queens mate only during a short period early in life and undergo a lifelong commitment to their mates by storing sperm [5] . Furthermore, sexual offspring can...... sterilized male lived considerably longer and started laying eggs earlier than virgin queens. Only queens that received viable sperm from fertile males showed increased fecundity. The lack of a trade-off between fecundity and longevity is unexpected, given evolutionary theories of aging [6] . Our data...

  11. No pain, no gain: Male plasticity in burrow digging according to female rejection in a sand-dwelling wolf spider.

    Science.gov (United States)

    Carballo, Matilde; Baldenegro, Fabiana; Bollatti, Fedra; Peretti, Alfredo V; Aisenberg, Anita

    2017-07-01

    Behavioral plasticity allows individuals to reversibly respond to short-term variations in their ecological and social environment in order to maximize their fitness. Allocosa senex is a burrow-digging spider that inhabits the sandy coasts of South America. This species shows a reversal in typical sex roles expected in spiders: females are wanderers that visit males at their burrows and initiate courtship. They prefer males with long burrows for mating, and males prefer virgin over mated females. We tested whether female sexual rejection induced males to enlarge their burrows and if female reproductive status affected males' responses. We exposed males who had constructed burrows to: a) virgin females or b) mated females, (n=16 for each category). If female rejection occurred, we repeated the trial 48h later with the same female. As control, we maintained a group of males without female exposure (unexposed group, n=32). Rejected males enlarged their burrows more frequently and burrows were longer compared to unexposed males. However, frequency and length of enlargement did not differ according to female reproductive status. Males of A. senex showed plasticity in digging behavior in response to the availability of females, as a way to maximize the possibilities of future mating. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. SEXUAL SELECTION. Irrationality in mate choice revealed by túngara frogs.

    Science.gov (United States)

    Lea, Amanda M; Ryan, Michael J

    2015-08-28

    Mate choice models derive from traditional microeconomic decision theory and assume that individuals maximize their Darwinian fitness by making economically rational decisions. Rational choices exhibit regularity, whereby the relative strength of preferences between options remains stable when additional options are presented. We tested female frogs with three simulated males who differed in relative call attractiveness and call rate. In binary choice tests, females' preferences favored stimulus caller B over caller A; however, with the addition of an inferior "decoy" C, females reversed their preferences and chose A over B. These results show that the relative valuation of mates is not independent of inferior alternatives in the choice set and therefore cannot be explained with the rational choice models currently used in sexual selection theory. Copyright © 2015, American Association for the Advancement of Science.

  13. Discrepancies between explicit and implicit self-esteem: implications for mate retention strategies and perceived infidelity.

    Science.gov (United States)

    Zeigler-Hill, Virgil; Fulton, Jessica J; McLemore, Chandler

    2012-01-01

    The purpose of the present study was to examine whether the association between explicit self-esteem and relationship outcomes was moderated by implicit self-esteem. This was accomplished by asking 210 undergraduates who were currently involved in romantic relationships to complete measures of their explicit self-esteem, implicit self-esteem, mate retention strategies, and likelihood of future infidelity. Implicit self-esteem was found to moderate the association between high explicit self-esteem and relationship outcomes for male participants such that men with discrepant high self-esteem (i.e., high explicit self-esteem but low implicit self-esteem) reported less use of mate retention strategies and perceived a greater likelihood of future infidelity in their relationships during the next year. These findings provide additional support for the idea that fragile self-esteem may have consequences for the manner in which individuals perceive their relationships.

  14. Socio-sexuality and episodic memory function in women: further evidence of an adaptive "mating mode".

    Science.gov (United States)

    Smith, David S; Jones, Benedict C; Allan, Kevin

    2013-08-01

    The functionalist memory perspective predicts that information of adaptive value may trigger specific processing modes. It was recently demonstrated that women's memory is sensitive to cues of male sexual dimorphism (i.e., masculinity) that convey information of adaptive value for mate choice because they signal health and genetic quality, as well as personality traits important in relationship contexts. Here, we show that individual differences in women's mating strategies predict the effect of facial masculinity cues upon memory, strengthening the case for functional design within memory. Using the revised socio-sexual orientation inventory, Experiment 1 demonstrates that women pursuing a short-term, uncommitted mating strategy have enhanced source memory for men with exaggerated versus reduced masculine facial features, an effect that reverses in women who favor long-term committed relationships. The reversal in the direction of the effect indicates that it does not reflect the sex typicality of male faces per se. The same pattern occurred within women's source memory for women's faces, implying that the memory bias does not reflect the perceived attractiveness of faces per se. In Experiment 2, we reran the experiment using men's faces to establish the reliability of the core finding and replicated Experiment 1's results. Masculinity cues may therefore trigger a specific mode within women's episodic memory. We discuss why this mode may be triggered by female faces and its possible role in mate choice. In so doing, we draw upon the encoding specificity principle and the idea that episodic memory limits the scope of stereotypical inferences about male behavior.

  15. Mid-arm muscle circumference as a significant predictor of all-cause mortality in male individuals.

    Directory of Open Access Journals (Sweden)

    Li-Wei Wu

    Full Text Available Emerging evidences indicate that mid-arm muscle circumference (MAMC is one of the anthropometric indicators that reflect health and nutritional status, but its correlative effectiveness in all-cause mortality prediction of United States individuals remains uncertain.We investigated the joint association between MAMC and all-cause mortality in the US general population. A population-based longitudinal study of 6,769 participants aged 40 to 90 years in the third National Health and Nutrition Examination Survey (NHANES III conducted by the National Center for Health Statistics of the Centers for Disease Control and Prevention. All participants were divided into two groups based on the gender: male and female group; each group was then divided into three subgroups depending on their MAMC level. The tertiles were as follows: T1 (18<27.3, T2 (27.3<29.6, T3 (29.6≤40.0 cm in the male group and T1 (15<22.3, T2 (22.3<24.6, T3 (24.6≤44.0 cm in the female group. Multivariable Cox regression analyses and Kaplan-Meier survival probabilities were utilized to jointly relate all-cause mortality risk to different MAMC level. For all-cause mortality in male participants, multivariable adjusted hazard ratios (HRs were 0.83 (95% confidence interval (CI: 0.69-0.98; p = 0.033 for MAMC of 27.3-29.6 cm compared with 18-27.3 cm, and 0.76 (95% CI: 0.61-0.95; p = 0.018 for MAMC of 29.6-40 cm compared with 18-27.3 cm. For all-cause mortality in female participants, multivariable adjusted hazard ratios (HRs were 0.84 (95% confidence interval (CI: 0.69-1.02; p = 0.075 for MAMC of 22.3-24.6 cm compared with 15-22.3 cm, and 0.94 (95% CI: 0.75-1.17; p = 0.583 for MAMC of 24.6-44 cm compared with 15-22.3 cm.Results support a lower MAMC is associated with a higher mortality risk in male individuals.

  16. A pair choice test to identify female mating patterns in relation to ovulation in long-tailed macaques (Macaca fascicularis)

    NARCIS (Netherlands)

    Nikitopoulos, E.; Heistermann, M.; Vries, Han de; Hooff, J.A.R.A.M. van; Sterck, E.H.M.

    2005-01-01

    Female mammals may exert choice for mates directly by mating selectively. Alternatively, females can mate promiscuously, allowing sperm competition and/or cryptic female choice to operate. Primate sexual behaviour is probably a compromise between conflicting male and female interests, so it may be

  17. Evasive mating behaviour by female nurse sharks, Ginglymostoma cirratum (Bonnaterre, 1788, in an equatorial insular breeding ground

    Directory of Open Access Journals (Sweden)

    André S. Afonso

    Full Text Available ABSTRACT Mating events and aggregations of vulnerable nurse sharks Ginglymostoma cirratum were recorded in the insular protected area of Fernando de Noronha (FEN, Brazil, between April and August 2015. Female sharks were observed clustering in groups of up to 14 individuals in shallow water adjacent to the shore. Several evasive mating behaviours in the presence of males were noticed, including shoreward movement, positioning ventral side up at the sea surface with emerged pectoral and pelvic fins, body rolling and caudal fin thrashing. Fresh bite marks indicative of male courtship and coupling attempts were visible in female's pectoral and caudal fins. Altogether, the observed behaviours match previous reports of non-cooperative female nurse sharks during mating opportunities. An extended mating season coupled with a persistent use of inshore habitats result in nurse sharks being particularly vulnerable to human pressure during a most sensitive stage of their life cycle. The effective conservation of nurse shark populations from the western South Atlantic may thus depend on the protection of critical habitats where this species aggregates to reproduce. Explicitly addressing environmental requirements by vulnerable species in local management strategies is indispensable to ensure that human pressure, including ecotourism development, does not collide with stipulated conservation aims.

  18. Females Choose Mates Based on Genetic Relatedness in a Small Dasyurid Marsupial, the Agile Antechinus (Antechinus agilis.

    Directory of Open Access Journals (Sweden)

    Marissa L Parrott

    Full Text Available Females in a variety of taxa mate with more than one male during a single oestrus and exhibit mate preferences for genetically compatible males, but the influence of female mate choice on siring success is not clearly understood. Whether females choose to mate with more than one male or endure forced copulations is also often unknown. Here, we examined the effects of genetic relatedness on female mate choice and siring success in a small semelparous carnivorous marsupial, the agile antechinus (Antechinus agilis, during two consecutive breeding seasons. Experimental trials were conducted in captivity over periods of 72 hours using interconnected enclosures in which female antechinus could choose to access any of four separated males, but males were only able to access females that entered their quarters. Females had access to two genetically similar and two genetically dissimilar males simultaneously and all behavioural interactions were observed and scored from continuous video recordings. Genetic similarity between mates and paternity of young was determined by microsatellite analyses. Some females chose to enter and mate with more than one male during a single oestrus period. Although females investigated all males, they spent significantly more time visiting, and mated more times with, genetically dissimilar males. Males that were genetically dissimilar to the female sired 88% of subsequent offspring. Whilst males mated readily with most females, they rejected the advances of some receptive females, indicating a previously unexpected level of male mate choice. The results show that genetic relatedness between mates has a significant influence on mate choice, breeding and siring success in the agile antechinus.

  19. Individual and work-related predictors of work outcomes related to sustainable employment among male shift and day workers.

    Science.gov (United States)

    van de Ven, Hardy A; Klein Hesselink, John; Bültmann, Ute; de Boer, Michiel R; de Looze, Michiel P; van der Klink, Jac J L; Brouwer, Sandra

    2014-05-01

    The aim of this study was to examine which individual and work-related characteristics predict work outcomes related to sustainable employment among male shift and day workers. Between 1 September 2005 and 31 December 2009, data on individual and work-related characteristics of N=5640 employees of Tata Steel in the Netherlands were retrieved from the Occupational Health Service and company registers. Work outcomes related to sustainable employment were (i) temporarily being placed in less strenuous work, (ii) sickness absence ≥6 weeks, and (iii) leaving the organization. Cox proportional hazard analyses were performed for all outcome measures. Similar predictors were found for shift and day workers although some differences were observed. For shift workers, high blood pressure and cardiovascular disease were important predictors for sickness absence. For day workers, insomnia was an important predictor of sickness absence ≥6 weeks. Similar predictors in magnitude and direction were found for work outcomes related to sustainable employment among shift and day workers. Interventions aimed at enhancing sustainable employability should focus on individual and work-related characteristics.

  20. A reassessment of the mating system characteristics of the army ant Eciton burchellii

    DEFF Research Database (Denmark)

    Kronauer, Daniel Jan Christoph; Berghoff, Stefanie M.; Powell, Scott

    2006-01-01

    In a recent study, Denny et al. (2004a) showed that queens of the army ant, Eciton burchellii, mate with multiple males and presented estimates suggesting that they mate with more males than queens of any other ant species so far investigated. They also inferred that data were consistent...... colonies of the same species. Mating frequencies in E. burchellii are indeed very high (mean observed and effective queen-mating frequencies of 12.9 each) but considerably lower than the previous estimates. We show that the number of patrilines represented in the first worker offspring of a young queen...

  1. Associations between age, body size and nephron number with individual glomerular volumes in urban West African males.

    Science.gov (United States)

    McNamara, Bridgette J; Diouf, Boucar; Hughson, Michael D; Hoy, Wendy E; Bertram, John F

    2009-05-01

    Glomerulomegaly has been associated with an increased risk of renal disease. Few reports have investigated the heterogeneity of glomerular size within kidneys and associated risk factors. This study measured the individual glomerular volume (IGV) of 720 non-sclerotic glomeruli in kidneys of adult West African males, and investigated associations of IGV with age, total glomerular (nephron) number and body surface area (BSA). IGVs were determined in the kidneys of 24 Senegalese males from two age groups (12 subjects aged 20- 30 years and 12 subjects aged 50-70 years). Subjects were randomly chosen at autopsies performed at Le Dantec Hospital in Dakar. Volumes of 30 glomeruli per subject were determined using the disector/Cavalieri stereological method. IGVs ranged from 1.31 x 10(6) microm3 to 12.40 x 10(6) microm3 (a 9.4-fold variation). IGV varied up to 5.3-fold within single kidneys. The trimmed range of IGV within subjects (10th to 90th percentile of IGV) was directly correlated with median glomerular size. The mean and standard deviation (SD) of IGV did not differ significantly between age groups or between subjects with higher (> or =1.78 m2) and lower BSA (IGV was significantly and directly correlated with BSA. Kidneys with less than 1 million nephrons had significantly larger mean IGV than kidneys with more than 1 million nephrons, and the trimmed range of IGVs within subjects was inversely correlated with total glomerular number. There was a considerable variation in IGV within kidneys of Senegalese males at autopsy. The heterogeneity of IGV was increased in association with low nephron number and increased BSA, with more pronounced effects in older subjects.

  2. The influence of male takeovers on female dispersal in Colobus vellerosus.

    Science.gov (United States)

    Sicotte, Pascale; Teichroeb, Julie A; Vayro, Josie V; Fox, Stephanie A; Bădescu, Iulia; Wikberg, Eva C

    2017-07-01

    Male takeovers affect male tenure, female mate choice and ultimately, individual reproductive success in group-living primates. In social systems with female philopatry and high male reproductive skew, male takeovers largely determine female mate choice, whereas in species with female dispersal, females have the option of deserting a new male. We focused on a species with facultative female dispersal to investigate which factors promote female desertion of males after takeover, using 15 cases (12 for which we have complete data on the takeover process and the female dispersal outcome). These cases took place in nine groups of Colobus vellerosus between 2001 and 2013 at the Boabeng-Fiema Monkey Sanctuary, Ghana. Quick takeovers were usually achieved by single adult males and were never followed by female dispersal. Slow takeovers involved several males, and these takeovers were regularly accompanied by female emigration. Infant attacks and infanticide by males occurred during both kinds of takeovers, but females with dependent offspring never dispersed, regardless of whether their infant was attacked or killed by the new male(s). Subadult females, who were not constrained by the presence of infants, dispersed more often after slow takeovers than after quick takeovers. Whether female dispersal post-takeover is an expression of female mate choice, or occurs to avoid the social upheaval surrounding slow takeovers, remains to be investigated. Am. J. Primatol. 79:e22436, 2017. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  3. Efficient Breeding by Genomic Mating.

    Science.gov (United States)

    Akdemir, Deniz; Sánchez, Julio I

    2016-01-01

    Selection in breeding programs can be done by using phenotypes (phenotypic selection), pedigree relationship (breeding value selection) or molecular markers (marker assisted selection or genomic selection). All these methods are based on truncation selection, focusing on the best performance of parents before mating. In this article we proposed an approach to breeding, named genomic mating, which focuses on mating instead of truncation selection. Genomic mating uses information in a similar fashion to genomic selection but includes information on complementation of parents to be mated. Following the efficiency frontier surface, genomic mating uses concepts of estimated breeding values, risk (usefulness) and coefficient of ancestry to optimize mating between parents. We used a genetic algorithm to find solutions to this optimization problem and the results from our simulations comparing genomic selection, phenotypic selection and the mating approach indicate that current approach for breeding complex traits is more favorable than phenotypic and genomic selection. Genomic mating is similar to genomic selection in terms of estimating marker effects, but in genomic mating the genetic information and the estimated marker effects are used to decide which genotypes should be crossed to obtain the next breeding population.

  4. Resources, attractiveness, family commitment; reproductive decisions in human mate choice.

    Science.gov (United States)

    Bereczkei, T; Voros, S; Gal, A; Bernath, L

    1997-08-01

    This study of reproductive decisions in human mate selection used data from "lonely hearts" advertisements to examine a series of predictions based on the mate preferences of male and females relating to age; physical appearance; financial condition and socioeconomic status; family commitment and personal traits; short- and long-term mating; and marital status and preexisting children. The sample consisted of 1000 personal advertisements (500 male) placed in two daily, national papers between February and October 1994 in Hungary. The research procedure included a pilot study of 150 advertisers (75 male) to refine the categories examined. Analysis was performed using 1) a matrix with one axis referring to offers and the other to demands of males and females separately; 2) a matrix of offers only to derive correlated traits of claims by males and females; and 3) a matrix with columns describing sex, offers, demands, advertiser's age, and required age and a row for each of the 1000 samples. It was found that men preferred younger mates, while women preferred older ones. Men were more likely to seek physical attractiveness, while women were more likely to seek financial resources (ranked 7th) and high status (ranked 6th). Women strongly preferred male domestic virtue and family commitment, and twice as many women as men demanded long-term relationships. Women more frequently declared preexisting children, and men exhibited a reluctance to accept these children. Both males and females employed "trade-off" strategies, making greater demands if they felt they had attractive offers.

  5. Lack of behavioural evidence for kin avoidance in mate choice in a hymenopteran parasitoid (Hymenoptera: Braconidae).

    Science.gov (United States)

    Bourdais, D; Hance, T

    2009-05-01

    Mechanisms for inbreeding avoidance should be prevalent in insects that reproduce by arrhenotokous haplodiploidy because of the higher potential production of unviable diploid males in inbred matings. Few studies have focused on mating strategies in insect parasitoids and even less on kinship relationships during mate choice. In this study we tested avoidance of kin as mate in the parasitic wasp Aphidius matricariae (Hymenoptera: Braconidae) using an ethological approach. Key mating parameters, such as male wing fanning, latent period before genitalia contact and duration of copulation were measured. No evidence for kin avoidance in mate choice in both A. matricariae males and females was observed in our behaviour (no choice or choice tests) tests. This lack of ethological sib mating avoidance could be due to different factors such as sex determination rule different than the single locus complementary sex determination, making lower the proportion of diploid males in case of sib matings and thus its negative consequence. The existence of other inbreeding avoidance strategies and mechanisms that reduce the probability of 2 receptive relatives meeting in nature may be common, for example, inbred mating may be rare through differential dispersal, delayed maturation, or protandry.

  6. 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.

  7. Nymphs of the common bed bug (Cimex lectularius produce anti-aphrodisiac defence against conspecific males

    Directory of Open Access Journals (Sweden)

    Harraca Vincent

    2010-09-01

    Full Text Available Abstract Background Abdominal wounding by traumatic insemination and the lack of a long distance attraction pheromone set the scene for unusual sexual signalling systems. Male bed bugs (Cimex lectularius mount any large, newly fed individual in an attempt to mate. Last instar nymphs overlap in size with mature females, which make them a potential target for interested males. However, nymphs lack the female's specific mating adaptations and may be severely injured by the abdominal wounding. We, therefore, hypothesized that nymphs emit chemical deterrents that act as an honest status signal, which prevents nymph sexual harassment and indirectly reduces energy costs for males. Results Behavioural mating assays showed that males mount nymphs significantly shorter time compared to females, although initial mounting preference was the same. In support of our hypothesis, nymphs experienced the same percentage of mating with sperm transfer as females if they were unable to emit (E-2-hexenal, (E-2-octenal 4-oxo-(E-2-hexenal and 4-oxo-(E-2-octenal, from their dorsal abdominal glands. We report that the aldehydes and 4-oxo-(E-2-hexenal are detected by olfactory receptor neurons housed in smooth and grooved peg sensilla, respectively, on the adult antennae, at biologically relevant concentrations. Behavioural experiments showed that application of 4-oxo-(E-2-hexenal or the two aldehydes at a nymph-emitted ratio, to a male/female pair during mounting initiation, decreased mating frequency to a rate comparable to that of a male/nymph pair. Conclusions By combining behavioural and sensory studies, we show that the nymph-specific alarm pheromone plays an important role in intra-specific communication in the common bed bug. Alarm pheromones are commonly looked upon as a system in predator/prey communication, but here we show that alarm pheromones may be used as multipurpose signals such as decreasing the risk of nymphal mating by males. See commentary: http

  8. Individual and seasonal variation in fecal testosterone and cortisol levels of wild male tufted capuchin monkeys, Cebus apella nigritus.

    Science.gov (United States)

    Lynch, Jessica W; Ziegler, Toni E; Strier, Karen B

    2002-05-01

    This study tested the "challenge hypothesis" and rank-based predictions for temporal steroid production in male tufted capuchin monkeys, Cebus apella. Fecal samples (n = 209) collected from six wild males were analyzed for testosterone and cortisol concentration by enzyme immunoassay. The temporal pattern in male steroid production was compared to female sexual activity and rates of male aggression. The top-ranking adult male did not differ from other adult males in testosterone or cortisol concentration. Mean adult testosterone was significantly higher than mean subadult testosterone throughout the year. There was a clear elevation of testosterone and cortisol in both adult and subadult males during the peak of adult female sexual activity after the birth season. In fact, the magnitude of increase in testosterone was higher than predicted for a species with low male-male aggression. However, there was no difference between nonbreeding baseline testosterone levels during the birth season, and the "breeding" baseline of testosterone in males found during asynchronous female sexual activity. Of all behavioral indices examined, the distribution of female-maintained consortships was the best predictor of mean adult male testosterone concentrations. Although in many species, elevated testosterone coincides with increased male-male aggression, in the present study, the sustained high-magnitude increase in steroids during the peak of adult female sexual activity was associated with a relatively low rate of male-male intragroup aggression. (c) 2002 Elsevier Science (USA).

  9. Reduced genetic variance among high fitness individuals: inferring stabilizing selection on male sexual displays in Drosophila serrata.

    Science.gov (United States)

    Sztepanacz, Jacqueline L; Rundle, Howard D

    2012-10-01

    Directional selection is prevalent in nature, yet phenotypes tend to remain relatively constant, suggesting a limit to trait evolution. However, the genetic basis of this limit is unresolved. Given widespread pleiotropy, opposing selection on a trait may arise from the effects of the underlying alleles on other traits under selection, generating net stabilizing selection on trait genetic variance. These pleiotropic costs of trait exaggeration may arise through any number of other traits, making them hard to detect in phenotypic analyses. Stabilizing selection can be inferred, however, if genetic variance is greater among low- compared to high-fitness individuals. We extend a recently suggested approach to provide a direct test of a difference in genetic variance for a suite of cuticular hydrocarbons (CHCs) in Drosophila serrata. Despite strong directional sexual selection on these traits, genetic variance differed between high- and low-fitness individuals and was greater among the low-fitness males for seven of eight CHCs, significantly more than expected by chance. Univariate tests of a difference in genetic variance were nonsignificant but likely have low power. Our results suggest that further CHC exaggeration in D. serrata in response to sexual selection is limited by pleiotropic costs mediated through other traits. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  10. Optimal mate choice patterns in pelagic copepods

    DEFF Research Database (Denmark)

    Heuschele, Jan; Eliassen, Sigrun; Kiørboe, Thomas

    2013-01-01

    The importance of sexual selection for the evolution, dynamics and adaptation of organisms is well known for many species. However, the topic is rarely studied in marine plankton, the basis of the marine food web. Copepods show behaviors that suggest the existence of sexually selected traits......, and recent laboratory experiments identified some selected morphological traits. Here, we use a ‘life history-based’ model of sex roles to determine the optimal choosiness behavior of male and female copepods for important copepod traits. Copepod females are predicted to be choosy at population densities...... typically occurring during the main breeding season, whereas males are not. The main drivers of this pattern are population density and the difference in non-receptive periods between males and females. This suggests that male reproductive traits have evolved mainly due to mate competition. The model can...

  11. Adolescents and Young Adults Mates Selection

    Directory of Open Access Journals (Sweden)

    María Martina Casullo

    2016-02-01

    Full Text Available The study sought to identify the relation between gender and age on mate pre- ferences using an intentional sample drawn in Buenos Aires city and its suburban area. A questionnaire adapted from a previous study developed by D.Buss (1990 requested subjects to rank each of 19 characteristics on its desirability in a mate. Subjects for this study were 900 adolescents and young adults aging 13 to 30 years old. Means and standard deviations were calculated as well as Spearman ́s Rho coefficients. High correlations between gender, age, and ordering were found. Mutual attraction and love, kindness and understanding and trust are cho- sen as the most important criteria. Phisically attractive is important for younger males. Similar political and religious background as well as chastity are conside- red among the less important criteria. 

  12. Social recognition is context dependent in single male prairie voles

    Science.gov (United States)

    Zheng, Da-Jiang; Foley, Lauren; Rehman, Asad; Ophir, Alexander G.

    2013-01-01

    Single males might benefit from knowing the identity of neighbouring males when establishing and defending boundaries. Similarly, males should discriminate between individual females if this leads to more reproductive opportunities. Contextual social cues may alter the value of learning identity. Knowing the identity of competitors that intrude into an animal’s territory may be more salient than knowing the identity of individuals on whose territory an animal is trespassing. Hence, social and environmental context could affect social recognition in many ways. Here we test social recognition of socially monogamous single male prairie voles, Microtus ochrogaster. In experiment 1 we tested recognition of male or female conspecifics and found that males discriminated between different males but not between different females. In experiment 2 we asked whether recognition of males is influenced when males are tested in their own cage (familiar), in a clean cage (neutral) or in the home cage of another male (unfamiliar). Although focal males discriminated between male conspecifics in all three contexts, individual variation in recognition was lower when males were tested in their home cage (in the presence of familiar social cues) compared to when the context lacked social cues (neutral). Experiment 1 indicates that selective pressures may have operated to enhance male territorial behaviour and indiscriminate mate selection. Experiment 2 suggests that the presence of a conspecific cue heightens social recognition and that home-field advantages might extend to social cognition. Taken together, our results indicate social recognition depends on the social and possibly territorial context. PMID:24273328

  13. Mating Competitiveness of Agrotis ipsilon (Hufn.) Irradiated as Parental Pupae

    International Nuclear Information System (INIS)

    El-Naggar, S.E.M.; Ibrahim, S.M.; El-Shall, S.S.A.

    1999-01-01

    Laboratory studied were carried out to evaluate the mating competitiveness of P 1 and F 1 generations of Agrotis ipsilon when irradiated as full grown pupae with 75 and 150 Gy of gamma irradiation. The mating competitiveness values showed that either males or females of P 1 or F 1 generation were full competitive after treatment with 75 or 150 Gy at all released ratios. Mating competitiveness of both irradiated males and females was also studied to avoid problems concerning mass sexing. The results revealed that confining both sexes together gave an excellent results for population suppression in both P 1 and F 1 in both tested doses and ratios. The addition of irradiated females to the release ratio make these females encountered in mating with untreated females, and possessed 78% of all matings occurred in parent generation in the two tested doses at 5:5:1 ratio and increased to reach 88% by F 1 females 75 Gy while it was reduced to only 31% at 150 Gy, but still act in mating

  14. Cognitive and biochemical effects of monosodium glutamate and aspartame, administered individually and in combination in male albino mice.

    Science.gov (United States)

    Abu-Taweel, Gasem M; A, Zyadah M; Ajarem, Jamaan S; Ahmad, Mohammad

    2014-01-01

    The present study was designed to investigate the in vivo effects of monosodium glutamate (MSG) and aspartame (ASM) individually and in combination on the cognitive behavior and biochemical parameters like neurotransmitters and oxidative stress indices in the brain tissue of mice. Forty male Swiss albino mice were randomly divided into four groups of ten each and were exposed to MSG and ASM through drinking water for one month. Group I was the control and was given normal tap water. Groups II and III received MSG (8 mg/kg) and ASM (32 mg/kg) respectively dissolved in tap water. Group IV received MSG and ASM together in the same doses. After the exposure period, the animals were subjected to cognitive behavioral tests in a shuttle box and a water maze. Thereafter, the animals were sacrificed and the neurotransmitters and oxidative stress indices were estimated in their forebrain tissue. Both MSG and ASM individually as well as in combination had significant disruptive effects on the cognitive responses, memory retention and learning capabilities of the mice in the order (MSG+ASM)>ASM>MSG. Furthermore, while MSG and ASM individually were unable to alter the brain neurotransmitters and the oxidative stress indices, their combination dose (MSG+ASM) decreased significantly the levels of neurotransmitters (dopamine and serotonin) and it also caused oxidative stress by increasing the lipid peroxides measured in the form of thiobarbituric acid-reactive substances (TBARS) and decreasing the level of total glutathione (GSH). Further studies are required to evaluate the synergistic effects of MSG and ASM on the neurotransmitters and oxidative stress indices and their involvement in cognitive dysfunctions. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Genetic determinants of mate recognition in Brachionus manjavacas (Rotifera).

    Science.gov (United States)

    Snell, Terry W; Shearer, Tonya L; Smith, Hilary A; Kubanek, Julia; Gribble, Kristin E; Welch, David B Mark

    2009-09-09

    Mate choice is of central importance to most animals, influencing population structure, speciation, and ultimately the survival of a species. Mating behavior of male brachionid rotifers is triggered by the product of a chemosensory gene, a glycoprotein on the body surface of females called the mate recognition pheromone. The mate recognition pheromone has been biochemically characterized, but little was known about the gene(s). We describe the isolation and characterization of the mate recognition pheromone gene through protein purification, N-terminal amino acid sequence determination, identification of the mate recognition pheromone gene from a cDNA library, sequencing, and RNAi knockdown to confirm the functional role of the mate recognition pheromone gene in rotifer mating. A 29 kD protein capable of eliciting rotifer male circling was isolated by high-performance liquid chromatography. Two transcript types containing the N-terminal sequence were identified in a cDNA library; further characterization by screening a genomic library and by polymerase chain reaction revealed two genes belonging to each type. Each gene begins with a signal peptide region followed by nearly perfect repeats of an 87 to 92 codon motif with no codons between repeats and the final motif prematurely terminated by the stop codon. The two Type A genes contain four and seven repeats and the two Type B genes contain three and five repeats, respectively. Only the Type B gene with three repeats encodes a peptide with a molecular weight of 29 kD. Each repeat of the Type B gene products contains three asparagines as potential sites for N-glycosylation; there are no asparagines in the Type A genes. RNAi with Type A double-stranded RNA did not result in less circling than in the phosphate-buffered saline control, but transfection with Type B double-stranded RNA significantly reduced male circling by 17%. The very low divergence between repeat units, even at synonymous positions, suggests that the

  16. The role of ego-identity status in mating preferences.

    Science.gov (United States)

    Dunkel, Curtis S; Papini, Dennis R

    2005-01-01

    This study was designed to examine the role ego-identity plays in the mating preferences of late adolescents. In addition to examining the variance in mating preferences explained by ego-identity status, it was hoped that the results could assist in testing the competing Sexual Strategies (Buss & Schmitt, 1993) and Social Role (Eagly & Wood, 1999) theories. Ego-identity and the sex of the participant accounted for a significant amount of variance in the number of sexual partners desired and the penchant for short-term mating. The sex of the participant was the lone predictor of the importance placed on the mate characteristics of physical attractiveness and earning capacity with females placing more emphasis on the former and males placing more emphasis on the latter characteristic.

  17. Sexual Dimorphism and Mating Behavior in Anomala testaceipennis

    Science.gov (United States)

    Rodrigues, Sérgio Roberto; Gomes, Elias Soares; Bento, José Maurício Simões

    2014-01-01

    Abstract The beetle, Anomala testaceipennis Blanchard (Coleoptera: Scarabaeidae), occurs in central-western Brazil where larvae feed on the roots of plants causing damage. This research aimed to study sexual dimorphism and mating behavior of A. testaceipennis . Adults of A. testaceipennis were collected with light traps in the experimental area of the State University of Mato Grosso do Sul, in Aquidauana. Laboratory experiments were performed to describe copulation behavior and adult morphology of males and females. In males the last abdominal segment has a pronounced constriction, which is absent in females, and the male’s last segment of the first pair of legs has a ventral projection, which is poorly developed in females. The mating activities of adults begin soon after sunset, when adults leave the soil and fly. When the male encounters a female, he touches her with antennae and tarsi. If accepted, the male climbs on the female and remains on her back, and soon after the copulation begins. When the female does not accept the male for mating, she moves rapidly and can roll on the ground, and by so removing the male. In the field, adults feed and mate on bloomed trees of Oiti, Licania tomentosa Benth (Malpighiales: Chrysobalanaceae) and Louro, Cordia glabrata Martius (Boraginaceae). In trees without inflorescences no adults of this species were found. PMID:25502043

  18. Direct and trans-generational effects of male and female gut microbiota in Drosophila melanogaster.

    Science.gov (United States)

    Morimoto, Juliano; Simpson, Stephen J; Ponton, Fleur

    2017-07-01

    There is increasing evidence of the far-reaching effects of gut bacteria on physiological and behavioural traits, yet the fitness-related consequences of changes in the gut bacteria composition of sexually interacting individuals remain unknown. To address this question, we manipulated the gut microbiota of fruit flies, Drosophila melanogaster , by monoinfecting flies with either Acetobacter pomorum ( AP ) or Lactobacillus plantarum ( LP ) . Re-inoculated individuals were paired in all treatment combinations. LP- infected males had longer mating duration and induced higher short-term offspring production in females compared with AP -infected males. Furthermore, females of either re-inoculation state mated with AP- infected males were more likely to have zero offspring after mating, suggesting a negative effect of AP on male fertility . Finally, we found that the effects of male and female gut bacteria interacted to modulate their daughters', but not sons' body mass, revealing a new trans-generational effect of parental gut microbiota. In conclusion, this study shows direct and trans-generational effects of the gut microbiota on mating and reproduction. © 2017 The Authors.

  19. Mate guarding in the Seychelles warbler is energetically costly and adjusted to paternity risk.

    Science.gov (United States)

    Komdeur, J

    2001-10-22

    Males may increase their fitness through extra-pair copulations (copulations outside the pair bond) that result in extra-pair fertilizations, but also risk lost paternity when they leave their own mate unguarded. The fitness costs of cuckoldry for Seychelles warblers (Acrocephalus sechellensis) are considerable because warblers have a single-egg clutch and, given the short breeding season, no time for a successful replacement clutch. Neighbouring males are the primary threat to a male's genetic paternity. Males minimize their loss of paternity by guarding their mates to prevent them from having extra-pair copulations during their fertile period. Here, I provide experimental evidence that mate-guarding behaviour is energetically costly and that the expression of this trade-off is adjusted to paternity risk (local male density). Free-living males that were induced to reduce mate guarding spent significantly more time foraging and gained significantly better body condition than control males. The larger the reduction in mate guarding, the more pronounced was the increase in foraging and body condition (accounting for food availability). An experimental increase in paternity risk resulted in an increase in mate-guarding intensity and a decrease in foraging and body condition, and vice versa. This is examined using both cross-sectional and longitudinal data. This study on the Seychelles warbler offers experimental evidence that mate guarding is energetically costly and adjusted to paternity risk.

  20. Home ranges and satellite tactics of male green swordtails (Xiphophorus helleri) in nature.

    Science.gov (United States)

    Franck, D; Klamroth, B; Taebel-Hellwig, A; Schartl, M

    1998-05-01

    Dominance relationships were studied between marked or otherwise individually recognizable male green swordtails in a creek at Lake Catemaco and in a tributary of the Rio Atoyac (Veracruz, Mexico). The Atoyac population is unique because of a high degree of polymorphism, including both macromelanophore spotting and a micromelanophore tailspot pattern. During the dry season males living in the same area maintained a linear social hierarchy for periods of many days. The subordinate males settled down either in the same home ranges or in home ranges largely overlapping with that of dominant males. Although dominant males untiringly chased the subordinate males away, they returned persistently and achieved the status of non-tolerated satellites. Females were less stationary and presumably passed through many male home ranges during their feeding activities. The data clearly demonstrate that green swordtails live in complex social systems in which male-male competition and probably also female mate choice are likely to be essential factors for individual reproductive success.

  1. Personality and mate preferences: five factors in mate selection and marital satisfaction.

    Science.gov (United States)

    Botwin, M D; Buss, D M; Shackelford, T K

    1997-03-01

    Although personality characteristics figure prominently in what people want in a mate, little is known about precisely which personality characteristics are most important, whether men and women differ in their personality preferences, whether individual women or men differ in what they want, and whether individuals actually get what they want. To explore these issues, two parallel studies were conducted, one using a sample of dating couples (N = 118) and one using a sample of married couples (N = 216). The five-factor model, operationalized in adjectival form, was used to assess personality characteristics via three data sources-self--report, partner report, and independent interviewer reports. Participants evaluated on a parallel 40-item instrument their preferences for the ideal personality characteristics of their mates. Results were consistent across both studies. Women expressed a greater preference than men for a wide array of socially desirable personality traits. Individuals differed in which characteristics they desired, preferring mates who were similar to themselves and actually obtaining mates who embodied what they desired. Finally, the personality characteristics of one's partner significantly predicted marital and sexual dissatisfaction, most notably when the partner was lower on Agreeableness, Emotional Stability, and Intellect-Openness than desired.

  2. The atypical presence of the paternal mitochondrial DNA in somatic tissues of male and female individuals of the blue mussel species Mytilus galloprovincialis

    Directory of Open Access Journals (Sweden)

    Rodakis George C

    2010-08-01

    Full Text Available Abstract Background In animals mtDNA inheritance is maternal except in certain molluscan bivalve species which have a paternally inherited mitochondrial genome (genome M along with the standard maternal one (genome F. Normally, the paternal genome occurs in the male gonad, but it can be often found, as a minority, in somatic tissues of males and females. This may happen in two ways. One is through "sperm mtDNA leakage" into somatic tissues, a deviation from the normal situation in which the sperm mtDNA vanishes in females or ends up exclusively in the germ line of males. The other is through "egg heteroplasmy", when the egg contains, in small quantities, the paternal genome in addition to maternal genome. Findings To test the two hypotheses, we compared the sequences of one of the most variable domains of the M molecule in a somatic tissue (foot and in the sperm of ten male and in the foot of ten female individuals of M. galloprovincialis. Presence of the M genome was rarer in the foot of females than males. The M genome in the sperm and in the foot of males was identical. Conclusions Given that the surveyed region differs from individual to individual, the identity of the M genome in the foot and the sperm of males supports strongly the hypothesis that, at least for the tissue examined, the presence of the M genome is due to sperm mtDNA leakage.

  3. Are human mating preferences with respect to height reflected in actual pairings?

    Science.gov (United States)

    Stulp, Gert; Buunk, Abraham P; Pollet, Thomas V; Nettle, Daniel; Verhulst, Simon

    2013-01-01

    Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the actual partner. People value height in their partner and we investigated to what extent preferences for height are realised in actual couples. We used data from the Millennium Cohort Study (UK) and compared the distribution of height difference in actual couples to simulations of random mating to test how established mate preferences map on to actual mating patterns. In line with mate preferences, we found evidence for: (i) assortative mating (r = .18), (ii) the male-taller norm, and, for the first time, (iii) for the male-not-too-tall norm. Couples where the male partner was shorter, or over 25 cm taller than the female partner, occurred at lower frequency in actual couples than expected by chance, but the magnitude of these effects was modest. We also investigated another preference rule, namely that short women (and tall men) prefer large height differences with their partner, whereas tall women (and short men) prefer small height differences. These patterns were also observed in our population, although the strengths of these associations were weaker than previously reported strength of preferences. We conclude that while preferences for partner height generally translate into actual pairing, they do so only modestly.

  4. Are human mating preferences with respect to height reflected in actual pairings?

    Directory of Open Access Journals (Sweden)

    Gert Stulp

    Full Text Available Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the actual partner. People value height in their partner and we investigated to what extent preferences for height are realised in actual couples. We used data from the Millennium Cohort Study (UK and compared the distribution of height difference in actual couples to simulations of random mating to test how established mate preferences map on to actual mating patterns. In line with mate preferences, we found evidence for: (i assortative mating (r = .18, (ii the male-taller norm, and, for the first time, (iii for the male-not-too-tall norm. Couples where the male partner was shorter, or over 25 cm taller than the female partner, occurred at lower frequency in actual couples than expected by chance, but the magnitude of these effects was modest. We also investigated another preference rule, namely that short women (and tall men prefer large height differences with their partner, whereas tall women (and short men prefer small height differences. These patterns were also observed in our population, although the strengths of these associations were weaker than previously reported strength of preferences. We conclude that while preferences for partner height generally translate into actual pairing, they do so only modestly.

  5. The evolution of sex roles in mate searching.

    Science.gov (United States)

    Fromhage, Lutz; Jennions, Michael; Kokko, Hanna

    2016-03-01

    Searching for mates is a critical stage in the life cycle of most internally, and many externally, fertilizing species. Males usually invest more in this costly activity than females, but the reasons for this are poorly understood. Previous models have shown that female-biased parental investment, including anisogamy, does not by itself select for male-biased mate searching, so it requires additional explanations. Here, we correct and expand upon earlier models, and present two novel hypotheses that might explain the evolution of male-biased mate searching. The "carry-over hypothesis" states that females benefit less from searching if the associated costs affect other stages of the life cycle, rather than arising only while searching. It is relevant to the evolution of morphological traits that improve searching efficiency but are also expressed in other contexts. The "mating window hypothesis" states that females benefit less from searching if their life cycle includes intervals during which the exact timing of mating does not matter for the appropriate timing of reproduction (e.g., due to sperm storage or delayed embryo implantation). Such intervals are more likely to exist for females given the general pattern of greater female parental investment. Our models shed new light on classic arguments about sex role evolution. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  6. Personality may confound common measures of mate-choice.

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    Morgan David

    Full Text Available The measurement of female mating preferences is central to the study of the evolution of male ornaments. Although several different methods have been developed to assess sexual preference in some standardized way, the most commonly used procedure consists of recording female spatial association with different males presented simultaneously. Sexual preference is then inferred from time spent in front of each male. However, the extent to which the measurement of female mate-choice is related to exploration tendencies has not been addressed so far. In the present study we assessed the influence of variation in exploration tendencies, a trait closely associated to global personality, on the measurement of female mating preference in the zebra finch (Taeniopygia guttata using the widely used four-chamber choice-apparatus. The number of movements performed within both exploration and mate-choice apparatus was consistent within and across the two contexts. In addition, personality explained variation in selectivity, preference strength and consistency. High-exploratory females showed lower selectivity, lower preference scores and displayed more consistent preference scores. Our results suggest that variation in personality may affect the measurement of female mating preference and may contribute to explain existing inconsistencies across studies.

  7. Differences in Attack Avoidance and Mating Success between Strains Artificially Selected for Dispersal Distance in Tribolium castaneum.

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    Kentarou Matsumura

    Full Text Available Individuals of both dispersal and non-dispersal types (disperser and non-disperser are found in a population, suggesting that each type has both costs and benefits for fitness. However, few studies have examined the trade-off between the costs and benefits for the types. Here, we artificially selected for walking distance, i.e., an indicator of dispersal ability, in the red flour beetle Tribolium castaneum and established strains with longer (L-strains or shorter (S-strains walking distances. We then compared the frequency of predation by the assassin bug Amphibolus venator and the mating frequency of the selected strains. L-strain beetles suffered higher predation risk, than did S-strain beetles. L-strain males had significantly increased mating success compared to S-strain males, but females did not show a significant difference between the strains. The current results showed the existence of a trade-off between predation avoidance and mating success associated with dispersal types at a genetic level only in males. This finding can help to explain the maintenance of variation in dispersal ability within a population.

  8. Sexual Selection on male cuticular hydrocarbons via male-male competition and female choice.

    Science.gov (United States)

    Lane, S M; Dickinson, A W; Tregenza, T; House, C M

    2016-07-01

    Traditional views of sexual selection assumed that male-male competition and female mate choice work in harmony, selecting upon the same traits in the same direction. However, we now know that this is not always the case and that these two mechanisms often impose conflicting selection on male sexual traits. Cuticular hydrocarbons (CHCs) have been shown to be linked to both social dominance and male attractiveness in several insect species. However, although several studies have estimated the strength and form of sexual selection imposed on male CHCs by female mate choice, none have established whether these chemical traits are also subject to sexual selection via male-male competition. Using a multivariate selection analysis, we estimate and compare sexual selection exerted by male-male competition and female mate choice on male CHC composition in the broad-horned flour beetle Gnatocerus cornutus. We show that male-male competition exerts strong linear selection on both overall CHC abundance and body size in males, while female mate choice exerts a mixture of linear and nonlinear selection, targeting not just the overall amount of CHCs expressed but the relative abundance of specific hydrocarbons as well. We discuss the potential implications of this antagonistic selection with regard to male reproductive success. © 2016 The Authors. Journal of Evolutionary Biology published by John Wiley & Sons Ltd on behalf of European Society for Evolutionary Biology.

  9. The role of impulsivity in self-mutilators, suicide ideators and suicide attempters - a study of 1265 male incarcerated individuals.

    Science.gov (United States)

    Carli, Vladimir; Jovanović, Nikolina; Podlesek, Anja; Roy, Alec; Rihmer, Zoltan; Maggi, Stefania; Marusic, Dragan; Cesaro, Caterina; Marusic, Andrej; Sarchiapone, Marco

    2010-06-01

    We explored differences between high and low-impulsive incarcerated individuals in the context of lifetime self-mutilation, suicide ideation and suicide attempt. A total of 1265 males detained in Italian penitentiary institutions were studied between January 2006 and December 2008. The study raters were specifically trained to discriminate between suicide attempters, ideators and self-mutilators. Participants completed the Barratt Impulsivity Scale, Childhood Trauma Questionnaire (CTQ), Eysenck Personality Questionnaire (EPQ), Connor-Davidson Resilience Scale (CD-RISC), Brown-Goodwin Assessment for Lifetime History of Aggression (BGLHA) and Buss and Durkee Hostility Inventory (BDHI). Based on BIS 7 total score distribution, two extreme quarters - high-impulsive group (n=306) and low-impulsive group (n=285) - were compared. Over 42% of participants had lifetime suicide ideation, 13% attempted suicide and 17% were self-mutilators. High-impulsive subjects were younger, more often single and with more prominent psychoticism, extraversion, aggression, hostility and resilience capacity. They were more frequently diagnosed with substance use disorders and engaged in self-mutilating behaviour. There was no difference in the rate of suicide attempts between the two groups. Although high-impulsive subjects were more prone to suicidal behaviour, it was not predicted by higher impulsivity when other psychological variables were accounted for. Copyright 2010 Elsevier B.V. All rights reserved.

  10. Factors associated with health care discrimination experiences among a national sample of female-to-male transgender individuals.

    Science.gov (United States)

    Shires, Deirdre A; Jaffee, Kim

    2015-05-01

    Transgender individuals experience harassment, violence, and discrimination in a number of settings. Although health care discrimination against transgender people has been documented, this issue is understudied. Using a national cross-sectional survey data set (N = 1,711), the authors sought to determine how gender identity and presentation predict health care discrimination experiences among female-to-male (FTM) transgender people after demographic and socioeconomic characteristics are controlled. Analyses were conducted using chi-square tests and a two-step logistic regression. The majority of participants were white (73.9 percent) and between 25 and 44 years old (65.2 percent). Overall, 41.8 percent of FTM participants reported verbal harassment, physical assault, or denial of equal treatment in a doctor's office or hospital. When other factors were controlled, being Native American or multiracial, identifying as queer or asexual/other, having a graduate degree, living full-time as nonbirth gender, using hormones or surgery for medical transition, and having identification documents that list one's preferred gender were associated with increased reporting of health care discrimination experiences; being 45 years or older and reporting an annual income of $60,000 or more were associated with decreased risk. The study's findings can be useful to social workers, who play a role in educating health care providers and advocating for policies that improve health care experiences for FTM and other transgender patients.

  11. Paternity of offspring in multiply-mated, female crickets: the effect of nuptial food gifts and the advantage of mating first

    Science.gov (United States)

    Calos, J. B.; Sakaluk, S. K.

    1998-01-01

    The spermatophore transferred by male decorated crickets (Gryllodes sigillatus) includes a large gelatinous mass, the spermatophylax, that is consumed by the female after mating. This nuptial gift preoccupies the female while sperm are discharged from the remaining portion of the spermatophore, the sperm ampulla, into her reproductive tract. There is considerable variation in the mass of the spermatophylax, and about half of all males produce spermatophylaxes that are too small to ensure complete sperm transfer. We tested two hypotheses concerning the maintenance of this variation: (i) males trade-off investment in spermatophylaxes against copulation frequency; and (ii) males synthesize the largest spermatophylaxes of which they are physiologically capable. Males synthesizing large and small food gifts were permitted multiple mating opportunities with the same females, and allozyme markers were used to establish the paternity of offspring. There was a significant advantage to those males that mated first irrespective of gift size. This advantage probably arose, in part, because the sperm of first males would have had exclusive access to females' eggs during the first 24 hours of oviposition, and underscores the benefits of matings with virgin females. The paternity of 'small-gift' males increased with gift mass, but there was no such increase in 'large-gift' males. This difference probably stems from the relationship between gift mass and sperm transfer: most of the gifts of the large-gift males would have been above the threshold needed to achieve complete inseminations, whereas those of small-gift males would have been below the threshold. Within mating-order positions, there was no significant difference in the paternity of large-gift and small-gift males, a result seemingly consistent with the 'trade-off' hypothesis. However, there was no correlation between spermatophylax mass and male mating frequency, so that the mechanism by which small-gift males offset

  12. The evolution of sex differences in mate searching when females benefit: new theory and a comparative test.

    Science.gov (United States)

    McCartney, J; Kokko, H; Heller, K-G; Gwynne, D T

    2012-03-22

    Sexual selection is thought to have led to searching as a profitable, but risky way of males obtaining mates. While there is great variation in which sex searches, previous theory has not considered search evolution when both males and females benefit from multiple mating. We present new theory and link it with data to bridge this gap. Two different search protocols exist between species in the bush-cricket genus Poecilimon (Orthoptera): females search for calling males, or males search for calling females. Poecilimon males also transfer a costly nuptial food gift to their mates during mating. We relate variations in searching protocols to variation in nuptial gift size among 32 Poecilimon taxa. As predicted, taxa where females search produce significantly larger nuptial gifts than those where males search. Our model and results show that search roles can reverse when multiple mating brings about sufficiently strong material benefits to females.

  13. Corticosterone Concentrations Reflect Parental Expenditure in Contrasting Mating Systems of Two Coucal Species

    Directory of Open Access Journals (Sweden)

    Wolfgang Goymann

    2017-03-01

    Full Text Available The period of parental care can be a demanding life-history stage because parents need to find sufficient resources to feed themselves and their offspring. Often, this is reflected by elevated baseline levels of glucocorticoids—hormones that regulate metabolism and energy allocation. During 10 breeding seasons, we studied plasma corticosterone (the major avian glucocorticoid concentrations as a physiological correlate of parental expenditure in two closely related coucal species with fundamentally different mating systems: the sex-role reversed black coucal (Centropus grillii with female competition and male-only care and the socially monogamous and biparental white-browed coucal (C. superciliosus. The two species live in the same habitat and share a similar breeding biology. However, female black coucals aggressively defend a territory and produce many eggs for their various male partners, and male black coucals feed their offspring much more frequently and rest less often than female and male white-browed coucals. These differences were reflected in baseline and stress-induced concentrations of corticosterone: male black coucals had higher baseline and stress-induced corticosterone concentrations when they were feeding young than outside a feeding context, and also the concentrations of female black coucals were higher during the main period of breeding when they defended territories and produced multiple clutches. In contrast, baseline and stress-induced concentrations of corticosterone in female and male white-browed coucals did not differ between periods when they were feeding young and periods without dependent offspring. Paradoxically, on an individual basis feeding effort was negatively related to baseline corticosterone in male black coucals and female white-browed coucals. In conclusion, corticosterone concentrations of coucals reflected differences in competition and parental roles and support the notion that a switch from

  14. Does the contraceptive pill alter mate choice in humans?

    Science.gov (United States)

    Alvergne, Alexandra; Lummaa, Virpi

    2010-03-01

    Female and male mate choice preferences in humans both vary according to the menstrual cycle. Women prefer more masculine, symmetrical and genetically unrelated men during ovulation compared with other phases of their cycle, and recent evidence suggests that men prefer ovulating women to others. Such monthly shifts in mate preference have been suggested to bring evolutionary benefits in terms of reproductive success. New evidence is now emerging that taking the oral contraceptive pill might significantly alter both female and male mate choice by removing the mid-cycle change in preferences. Here, we review support for such conclusions and speculate on the consequences of pill-induced choice of otherwise less-preferred partners for relationship satisfaction, durability and, ultimately, reproductive outcomes.

  15. Identifying the Transition between Single and Multiple Mating of Queens in Fungus-Growing Ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R.

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...

  16. Revisiting telegony : Offspring inherit an acquired characteristic of their mother's previous mate

    NARCIS (Netherlands)

    Crean, Angela J.; Kopps, Anna M.; Bonduriansky, Russell

    2014-01-01

    Newly discovered non-genetic mechanisms break the link between genes and inheritance, thereby also raising the possibility that previous mating partners could influence traits in offspring sired by subsequent males that mate with the same female (‘telegony’). In the fly Telostylinus angusticollis,

  17. Identifying the transition between single and multiple mating of queens in fungus-growing ants

    DEFF Research Database (Denmark)

    Villesen, Palle; Murakami, Takahiro; Schultz, Ted R

    2002-01-01

    Obligate mating of females (queens) with multiple males has evolved only rarely in social Hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. The monophyletic tribe of ('attine') fungus-growing ants...

  18. Do pheromones reveal male immunocompetence?

    Science.gov (United States)

    Rantala, Markus J; Jokinen, Ilmari; Kortet, Raine; Vainikka, Anssi; Suhonen, Jukka

    2002-01-01

    Pheromones function not only as mate attractors, but they may also relay important information to prospective mates. It has been shown that vertebrates can distinguish, via olfactory mechanisms, major histocompatibility complex types in their prospective mates. However, whether pheromones can transmit information about immunocompetence is unknown. Here, we show that female mealworm beetles (Tenebrio molitor) prefer pheromones from males with better immunocompetence, indicated by a faster encapsulation rate against a novel antigen, and higher levels of phenoloxidase in haemolymph. Thus, the present study indicates that pheromones could transmit information about males' parasite resistance ability and may work as a reliable sexual ornament for female choice. PMID:12204128

  19. Cotton Leaf worm: Inherited Effects of Low Doses of Gamma Radiation on The Progeny of Irradiated Males. Vol. 4

    Energy Technology Data Exchange (ETDEWEB)

    Sallam, H A; El-Naggar, S M; Shible, M M [Plant Protection Department, Faculty of Agriculture, Al-Azhar University, Cairo, (Egypt); El-Dessouki, S A; El-Awady, S M [Biological Applications Department, Nuclear Research Center, Atomic Energy Authority, Cairo, (Egypt)

    1996-03-01

    Full grown male pupae of the cotton leaf worm, Spodoptera Littoralis (Boisd.) were gamma irradiated with low doses of 25, 50,75, and 100 Gy. The effects on reproduction, development and sex ratio were the biological aspects studied among P{sub 1}, F{sub 1}, F{sub 2}, F{sub 3} generations. Fecundity of normal females mated with F{sub 1} or F{sub 2} males was significantly reduced for all doses. The F{sub 1} males were more sterile than their irradiated parental males, while F{sub 2} males were more fertile F{sub 1} males. Irradiation of P{sub 1} males did not clearly affect neither the percentage of mated females nor the average number of spermatophores per mated females among the individuals of P{sub 1}, F{sub 1}, F{sub 2}, F{sub 3} generations. The percent of larvae surviving to the adult stage was gradually decreased by increasing dose to P{sub 1} male throughout the first three filial generation. The average larval and pupal durations were not affected among the progeny of P{sub 1} males for both males and females. The sex ratio among the progeny of irradiated males was nearly 1:1. 3 tabs.

  20. Cotton Leaf worm: Inherited Effects of Low Doses of Gamma Radiation on The Progeny of Irradiated Males. Vol. 4

    International Nuclear Information System (INIS)

    Sallam, H.A.; El-Naggar, S.M.; Shible, M.M.; El-Dessouki, S.A.; El-Awady, S.M.

    1996-01-01

    Full grown male pupae of the cotton leaf worm, Spodoptera Littoralis (Boisd.) were gamma irradiated with low doses of 25, 50,75, and 100 Gy. The effects on reproduction, development and sex ratio were the biological aspects studied among P 1 , F 1 , F 2 , F 3 generations. Fecundity of normal females mated with F 1 or F 2 males was significantly reduced for all doses. The F 1 males were more sterile than their irradiated parental males, while F 2 males were more fertile F 1 males. Irradiation of P 1 males did not clearly affect neither the percentage of mated females nor the average number of spermatophores per mated females among the individuals of P 1 , F 1 , F 2 , F 3 generations. The percent of larvae surviving to the adult stage was gradually decreased by increasing dose to P 1 male throughout the first three filial generation. The average larval and pupal durations were not affected among the progeny of P 1 males for both males and females. The sex ratio among the progeny of irradiated males was nearly 1:1. 3 tabs

  1. Socioeconomic Development and Shifts in Mate Preferences

    Directory of Open Access Journals (Sweden)

    Emily A. Stone

    2008-07-01

    Full Text Available Mate preferences shift according to contexts such as temporal duration of mateship sought and ecological prevalence of parasites. One important cross-cultural context that has not been explored is a country's socioeconomic development. Because individuals in less developed countries are generally less healthy and possess fewer resources than those in more developed countries, displays of health and resources in a prospective long-term partner were hypothesized to be valued more in populations in which they are rare than in populations in which they are more common. We also predicted negative correlations between development and preferences for similar religious background and a desire for children. We found strong support for the health hypothesis and modest support for the resource acquisition potential hypothesis. We also found an unpredicted positive correlation between development and importance ratings for love. Discussion addresses limitations of the current research and highlights directions for future cross-cultural research on mating psychology.

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Individual and combined (Plus-hybrid effect of cytoplasmic male sterility and xenia on maize grain yield

    Directory of Open Access Journals (Sweden)

    Sofija Bozinovic

    2015-06-01

    Full Text Available Plus-hybrid effect refere to a combined effect of cytoplasmic male sterility (CMS and xenia in maize (Zea mays L. It could be used in commercial production by growing a mixture of 80% CMS hybrid and 20% of another fertile hybrid. The aim of this research was to examine individual and combined CMS and xenia effects on two hybrids widely grown in Serbia. Sterile and fertile versions of ZP 1 and ZP 2 hybrids (three-way; Iodent x Lancaster dents were used as females, while ZP 1, ZP 2, ZP 3, ZP 4, and ZP 5 (three-way or single cross; Iodent (BSSS x Lancaster dents were used as pollinators. All of them belong to medium maturity group. The trial was set up at one location in Serbia (Zemun Polje in 2009, 2010, and 2011. Molecular analysis of the five genotypes was done using simple sequence repeat (SSR primers. Plus-hybrid effect on grain yield ranged from -6.2% to 6.2%; on thousand kernel weight from -1.7% to 5.2%; on number of kernels per area from -1.0% to 8.0%. The poor response could be due to a use of three-way instead of single cross hybrids in S type of sterility. Modified Rogers' distance between hybrids was in the range 0.211 to 0.378 and was not relevant for the effect, which depended mostly on the sterile hybrid genotype and the fertile hybrid pollinator ability. This approach should be more suitable for female hybrids with slightly poorer performance, already being produced on a sterile base.