Previous Mating Research Articles

Trial marriage model-Female mate choice under male interference.

In sexually reproducing animals, the process of mate choice by females is often mixed with the process of male-male competition. Current models of female male choice focus mainly on how females identify the higher quality of males, but neglect the effect of male-male competition on the mate choice of females. Therefore, it remains controversial what is the relative importance of two processes in forming a social bond. We propose a new 'trial marriage' model for females' mate choice. The model assumes that females unconditionally accept any male they first encounter as their mating partner, and then conditionally switch mates to a new male of higher quality than their current partner when male-male competition occurs. This model was tested in the green weevil Hypomeces squamosus by exploring how females switched mates when males' mating interference was experimentally induced. The likelihood that females switched mates, as well as their conditional acceptance criteria of a new mate, was both raised with the intensity of males' mating interference that was manipulated in an enhanced encounter rate experiment, and in male introduction or stepwise removal experiments. These experimental findings confirm that a 'trial marriage' strategy occurs during females' mate choice. Compared with other strategies, it is more beneficial for females to choose a better mate without paying the costs of identifying males as suggested by the 'trial marriage' strategy. More importantly, using the current partner quality as the conditional acceptance threshold of new mates, females can choose better males in future encounters with potential mates. In the green weevils, males' preference for larger females and the higher possibility of the largest male winning an interference are mixed together when males' mating interference reaches a higher intensity. Therefore, the consequence of a male interference will determine which male could be chosen by a female. Under this condition, conditional acceptance of the winner becomes the most beneficial strategy of females in choosing their mates. We thus suggest that the 'trial marriage' strategy would be more efficient when males' mating interference becomes the determinant factor of females' mate choice.

An experimental test of the role of male mating history on paternal effects in the livebearer fish Gambusia holbrooki.

Studies often show that paternal age affects offspring fitness. However, such effects could be due either to age, or to a male's previous mating effort (which is necessarily confounded with age). We experimentally tested whether differences in the mating history of old males affect offspring performance in the mosquitofish Gambusia holbrooki. Upon maturation, males were housed for a duration of the natural field-breeding season (23 weeks) either with mating access to females (lifetime-mating), or with visual but no physical access to females (no-mating). We then paired these males with a female to test whether male mating history had a significant effect on their mate's breeding success or offspring performance. The daughters, but not the sons, of 'no-mating' treatment males matured significantly sooner, and at a significantly smaller size, than those of 'lifetime-mating' treatment males. There was, however, no effect of male mating history on their daughters' initial fecundity, or on proxy measures of their sons' reproductive success. These results, when combined with earlier studies showing effects of male mating history on sperm quality, growth and immunity, suggest that variation in paternal effects currently attributed to male age could partly arise because older males have usually mated more often than younger males.

Bodyweight-Related Polyandry in the Tobacco Cutworm Moth Spodoptera litura (Lepidoptera: Noctuidae)

Recent studies on polyandry evolution have revolutionized our understanding of sexual selection. Therefore, study on traits in females, such as sensory perception and remating strategies, is expected to disclose a greater role of sexual selection in female evolution. Here, we tested how bodyweights of both sexes affected female and male remating behavior in Spodoptera litura (Fabricius, 1775) (Lepidoptera: Noctuidae). Results show most (74.4%; unmated virgin females may be sexually immature) females and males mated the first time in the second scotophase after eclosion. In the subsequent scotophase, 41.9% once-mated females and 94.1% once-mated males mated the second time with a novel virgin mate. Analyses indicate that female remating probability significantly increased with the increase of her own and the second male’s bodyweight but decreased with the increase of the first male’s bodyweight, while bodyweights of both sexes have no significant effect on male remating probability. Considering the nature of the low level of polyandry (two times on average) and last male precedence in S. litura, we propose that 1) females are more choosy when remating, from which females will benefit indirectly by sequential mate comparison and remate to replace sperm from the previous mates with those from higher quality mates, and 2) males will generally like to remate with any possible females, from which males will gain direct benefit by siring more offspring. The outcome of polyandry rate is likely to be the result of male investment × female choice interactions.

The adaptive role of a species-specific courtship behaviour in coping with remating suppression of mated females

Three-way interactions consisting of a female and her current and previous mates have been studied intensively in the context of sperm competition involving male manipulation of female remating rate but have rarely been documented in a broader context involving classical premating male display and stimulatory traits such as courtship behaviour. This is surprising because premating traits influence the intensity of postmating competition, which occurs only when a mated female consecutively accepts another male. In Drosophila fruit flies, the subsequent male has an advantage over the previous male in sperm competition. However, the ejaculate of the previous male changes the female's behaviour to refuse remating for several days (remating suppression), reducing the potential advantage of the subsequent male. Under such conditions, the evolution of any means that counteract remating suppression is thought to be adaptive for the subsequent male. Males of the fruit fly Drosophila prolongata perform a unique courtship behaviour called ‘leg vibration’. Although leg vibration increases female receptivity, it is not always required for mating with virgin females, raising a question of why it evolved in the first place. In this study, the role of leg vibration in remating was examined, using leg amputation to manipulate the efficiency of leg vibration and an eye colour mutation to detect remating events. Leg vibration had a profound effect on mated females: the remating rate was extremely low with leg-amputated males, indicating that leg vibration was almost indispensable for remating of recently mated females. Our results demonstrated that single courtship behaviour has different levels of importance or necessity for the first male and the subsequent males, providing an example of the evolution of courtship behaviour that was possibly driven by postmating competition.

High regenerative capacity of the liver and irreversible injury of male reproductive system in carbon tetrachloride-induced liver fibrosis rat model.

Liver fibrosis (LF) is a chronic disease, associated with many collateral diseases including reproductive dysfunction. Although the normal liver has a large regenerative capacity the complications of LF could be severe and irreversible. Hormone and sex-related issues of LF development and interactions with male reproductive have not been finally studied. The aim was to study the reproductive function of male rats in experimental CCl4-induced liver fibrosis rat model, and the capability for restoration of both the liver and male reproduction system. Studies were conducted on 20 3-month old Wistar male rats. The experimental animals were injected with freshly prepared 50% olive oil solution of carbohydrate tetrachloride (CCl4). On the 8th week after injection we noted the manifestations of liver fibrosis. The rats were left to self-healing of the liver for 8weeks. All male rats underwent ultrasound and biopsy of the liver and testes on the 8th and 16th weeks. The male rats were mated with healthy females before CCl4 injection, after modeling LF on the 8th week, and after self-healing of the liver. Pregnancy was monitored on ultrasound. On the 8th week of experiment we observed ultrasound manifestation of advanced liver fibrosis, including hepatosplenomegaly, portal hypertension. Ultrasound exam of the rat testes showed testicular degeneration, hydrocele, fibrosis, scarring, petrifications, size reduction, and restriction of testicular descent; testes size decreased from 1.24±0.62ml to 0.61±0.13, p<0.01. Liver histology showed granular dystrophy of hepatocytes, necrotic areas, lipid inclusions in parenchyma. Rats with liver fibrosis demonstrated severe injury of the reproductive system and altering of fertility: the offspring of male rats with advanced LF was 4.71±0.53 born alive vs 9.55±0.47 born from mating with healthy males, p<0.001. Eightweeks after last CCl4 injection, we revealed signs of liver regeneration, significant recovery of its structure. The ALT and AST levels significantly decreased and reached background measurements. As a result of the second interbreeding after liver self-healing no significant difference was found vs previous mating. Carbohydrate tetrachloride induces injury of liver parenchyma evoking fast and severe liver fibrosis, and is associated with irreversible structural and functional changes in testes, reducing fertility, decreasing potential pregnancy rate, and affecting its development. Liver showed high potential to regenerate, however the self-restoring after liver fibrosis was not accompanied with recovery of the reproductive system.

Do males choose their mates in the lekking moth Achroia grisella? Influence of female body mass and male reproductive status on male mate choice.

Lekking males aggregate to attract females and contribute solely to egg fertilization, without any further parental care. Evolutionary theory therefore predicts them to be nonchoosy toward their mates, because any lost mating opportunities would outweigh the benefits associated with such preferences. Nevertheless, due to time costs, the production of energetically costly sexual displays, and potential sperm limitation, the mating effort of lekking males is often considerable. These factors, combined with the fact that many females of varying quality are likely to visit leks, could favor the evolution of male mate preferences. Here, we show that males of the lekking lesser wax moth, Achroia grisella, were indeed more likely to mate with heavier females in choice experiments, even at their virgin mating (i.e., when their reproductive resources have not yet been depleted by previous matings). This differential female mating success could not be attributed to female behavior as heavy and light females showed similar motivation to mate (i.e., latency to approach the males) and time to copulate. Males seem to benefit from mating with heavier females, as fecundity positively correlated with female mass. This new empirical evidence shows that male mate choice may have been underestimated in lekking species.

Phenotypic plasticity in female mate choice behavior is mediated by an interaction of direct and indirect genetic effects in Drosophila melanogaster.

Female mate choice is a complex decision‐making process that involves many context‐dependent factors. In Drosophila melanogaster, a model species for the study of sexual selection, indirect genetic effects (IGEs) of general social interactions can influence female mate choice behaviors, but the potential impacts of IGEs associated with mating experiences are poorly understood. Here, we examined whether the IGEs associated with a previous mating experience had an effect on subsequent female mate choice behaviors and quantified the degree of additive genetic variation associated with this effect. Females from 21 different genetic backgrounds were housed with males from one of two distinct genetic backgrounds for either a short (3 hr) or long (48 hr) exposure period and their subsequent mate choice behaviors were scored. We found that the genetic identity of a previous mate significantly influenced a female's subsequent interest in males and preference of males. Additionally, a hemiclonal analysis revealed significant additive genetic variation associated with experience‐dependent mate choice behaviors, indicating a genotype‐by‐environment interaction for both of these parameters. We discuss the significance of these results with regard to the evolution of plasticity in female mate choice behaviors and the maintenance of variation in harmful male traits.

Sexual conflict over remating interval is modulated by the sex peptide pathway.

Sexual conflict, in which the evolutionary interests of males and females diverge, shapes the evolution of reproductive systems across diverse taxa. Here, we used the fruit fly to study sexual conflict in natural, three-way interactions comprising a female, her current and previous mates. We manipulated the potential for sexual conflict by using sex peptide receptor (SPR) null females and by varying remating from 3 to 48 h, a period during which natural rematings frequently occur. SPR-lacking females do not respond to sex peptide (SP) transferred during mating and maintain virgin levels of high receptivity and low fecundity. In the absence of SPR, there was a convergence of fitness interests, with all individuals gaining highest productivity at 5 h remating. This suggests that the expression of sexual conflict was reduced. We observed an unexpected second male-specific advantage to early remating, resulting from an increase in the efficiency of second male sperm use. This early window of opportunity for exploitation by second males depended on the presence of SPR. The results suggest that the SP pathway can modulate the expression of sexual conflict in this system, and show how variation in the selective forces that shape conflict and cooperation can be maintained.

金乌贼繁殖行为与交配策略

PDF HTML阅读 XML下载 导出引用 引用提醒 金乌贼繁殖行为与交配策略 DOI: 10.5846/stxb201510232145 作者: 作者单位: 中国海洋大学,中国海洋大学,中国海洋大学,中国海洋大学,中国水产科学研究院黄海水产研究所 作者简介: 通讯作者: 中图分类号: 基金项目: 国家海洋公益性行业科研专项资助项目（201405010，201305043） Reproductive behavior and mating strategy of Sepia esculenta Author: Affiliation: ocean university of china,ocean university of china,ocean university of china,ocean university of china,Yellow Sea Fisheries Research Institute, Chinese Academy of Fisheries Science Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:2014年6月于室内大型水槽使用摄像系统对金乌贼繁殖过程进行连续观察与记录，通过定性和定量比较分析，解析其繁殖过程中游泳、捕食、求偶、争斗、交配及产卵等行为特征。结果显示：金乌贼游泳主要依靠漏斗喷水的反作用力，持续游泳能力较弱；繁殖期的金乌贼继续摄食，能发现周围20-38 cm范围内的凡纳滨对虾，攻击距离为7-24 cm，能在2.1-6.1 s内完成对对虾的捕获且成功率极高，外源营养为卵（精）巢不同步发育、分批产卵和复杂的繁殖行为继续提供能量支持；金乌贼具明显的求偶行为，规格差异是影响求偶的重要因素，其中雄性亲本更倾向选择与自身规格相当或略小的雌性，而雌性亲本则更倾向于选择大规格（较大规格争斗易获胜）的雄性；金乌贼一次交配持续125-398 s，雄性有明显的精子移除行为和领域性，交配后雄性伴游在雌性周围3-24 cm范围内，不允许其他乌贼靠近，平均伴游61 min后会再次交配。精子移除、伴游以及多次交配是雄性金乌贼有效提高父权贡献率的关键行为基础；研究结果表明，金乌贼采取"多夫多妻"的混交婚配策略，两性亲本均存在多次交配现象，这能有效提高雌雄的生殖成功率和受精卵的遗传多样性。 Abstract:Sepia esculenta Hoyle is widely distributed in Chinese coastal waters, and the taste and the highly value of nutrients make it one of the most important economical species in China. This organism can grow up to 200 mm in mantle length during its short lifespan of 1 year or less. Mature S. esculenta individuals migrate to inshore areas to mate and spawn during the breeding period, which is from June to July in Xuejiadao, Qingdao in China. The reproductive behavior and mating strategy, which include mate selection and sperm competition, determine the quality (e.g. dorsal mantle length or body weight of newly hatched larvae) and quantity of offspring, and play an important role in generating genetic diversity. Here, sexually mature S. esculenta were captured using a basket trap off the coast of Xuejiadao, Qingdao, China, between May and June of 2014. The reproductive behaviors of S. esculenta, including swimming, predation, courtship, battle, mating, and egg-laying were analyzed using both qualitative and quantitative comparisons after observation in an indoor pool with an image pickup system. The results revealed that the swimming power of S. esculenta was mainly linked to the funnel and could not be sustained for long periods of time. S. esculenta continued to feed on Litopenaeus vannamei ((10.4±0.6) cm in total length) within a distance ranging from 20 to 38 cm and could rapidly catch prey (in 2.1-6.1 s), illustrating that it utilized the energy from feeding for the non-synchronous ovarian (testicular) development, batch spawning, and complex reproductive behaviors. Before mating, S. esculenta demonstrated obvious courtship behavior. The males tended to choose females of similar or slightly smaller sizes, whereas the females tended to choose larger males. The males competed for females and the winner had an opportunity to mate with female. The male would begin by lightly touching the cheek of the female, and also maintained a head-to-head position during the mating. Before ejaculation, the males moved arm III to remove the sperm masses attached to the residual buccal membranes from previous matings. After sperm removal, the male held spermatophores ejected through its funnel with the base of hectocotylized left arm IV and then pressed the coiled arm on the ventral portion of the female's buccal membrane. A successful mating lasted a relatively long time (125-398 s), but the mating process could easily be interrupted by interference from other individuals nearby, especially other males. The male continued to guard the spawning female (staying 3-24 cm from the female), and repeated matings occurred at an average interval of 61 min during the mate guarding process. Fertilized female S. esculenta individuals began to lay eggs approximately 4.5 min after mating. The eggs were relatively large (long axis diameter: 16.4-20.0 mm; short axis diameter: 10.5-12.6 mm). Although males involved in guarding females delayed their search for other mates, they may have reduced the probability that the female would remate with other males. Sperm removal, guarding, and repeated mating could effectively improve the male success rate. The mating strategy of S. esculenta was promiscuity, and repeated instance of mating, in both males and females, could effectively improve the reproductive success rate and level of genetic diversity. 参考文献 相似文献 引证文献

Mating behaviour and its relationship with morphological features in the millipede Pachyiulus hungaricus (Karsch, 1881) (Myriapoda, Diplopoda, Julida)

Although millipedes (Diplopoda) represent one of the most diverse classes of arthropods, data concerning details of their mating behaviour are very scarce. In this work, we explored mating behaviour of the European millipede Pachyiulus hungaricus under laboratory conditions, and its relationship with the size and shape of certain morphological traits. We conducted 3 types of behavioural tests: a mating arena test, a female choice test, and a male choice test. Premating behaviour was sequenced in 5 behavioural steps and, together with the duration of copulation, scored in all mating assays. Males were the more active sex in searching for mates, while females were the choosier sex. Furthermore, in the choice tests, previous mating partners had significantly more copulations than new ones, thus raising questions about postcopulatory sexual selection in this species. On the other hand, our results indicate that size and/or shape of the tested morphological traits, except for the shape of the male walking legs, were not subject to precopulatory sexual selection. Other sensory domains known to influence courtship behaviour need to be investigated in this regard in P. hungaricus.

Relative Amplitude of Courtship Song Chirp and Trill Components Does Not Alter Female Teleogryllus oceanicus Mating Behavior

AbstractLow‐amplitude acoustic signals intended for short‐range communication, often called soft songs, remain poorly studied, especially among acoustically communicating invertebrates. Some insects do employ low‐amplitude acoustic signals, but it remains unclear what the specific function, if any, is of quietness per se. Male Teleogryllus oceanicus, or Pacific field crickets, produce a two component, short‐distance courtship song consisting of a high‐amplitude series of chirps followed by a lower‐amplitude trill. We investigated whether female T. oceanicus prefer to mate with males that sing courtship songs containing trill components that are equally as loud as (−0 dB) or quieter than (−3 dB and −10 dB) the loudest chirp (90 dB). We found no evidence that modifying trill amplitude affects female mate preference. We did, however, find that previously unmated females were faster to mount males than were females that had mated once before. Previous mating status showed no significant interaction with trill amplitude. What, if any, function of low‐amplitude components of field cricket courtship song remains to be determined.

Lifetime changes in phenotypic expression and evolutionary potential of female mating traits in Drosophila melanogaster

Recognition of the ubiquity of female multiple mating has caused an important shift in sexual selection research, emphasizing the adaptive nature of female mating strategies. While phenotypic changes in female mating traits have been previously studied, little is known about the genetic basis of female mating behaviour and its potential to respond to selection at different stages throughout an individual's life. Using a large quantitative genetic breeding design, we observed lifetime female mating behaviour in Drosophila melanogaster to examine the effect of female age and mating history on three key mating traits: courtship latency, mating latency and copula duration. Courtship latency (time until males initiate courtship) decreased with the cumulative number of females' previous matings. Mating latency (defined here as the time between the beginning of courtship and the start of copulation) increased with female age, and copula duration was found to decrease as females aged. We calculated quantitative genetic estimates for mating traits in virgin females and at the females' third mating to examine changes in the evolutionary potential of mating traits. We found considerable additive genetic variation in courtship latency and mating latency measured in virgin females. Copula duration displayed no heritable variation among females across sire families, but male effects were consistent with the idea that this trait is under male control. Heritability estimates differed significantly from zero in virgin females for courtship latency and mating latency but not when females were mating for the third time. However, overlapping 84% confidence intervals between heritability estimates obtained from virgin and mated females suggest that female mating strategies may have the potential to respond to selection at these different life stages.

The male ejaculate as inhibitor of female remating in two tephritid flies

The inhibition of female receptivity after copulation is usually related to the quality of the first mating. Males are able to modulate female receptivity through various mechanisms. Among these is the transfer of the ejaculate composed mainly by sperm and accessory gland proteins (AGPs). Here we used the South American fruit fly Anastrepha fraterculus (where AGP injections inhibit female receptivity) and the Mexican fruit fly Anastrepha ludens (where injection of AGPs failed to inhibit receptivity) as study organisms to test which mechanisms are used by males to prevent remating. In both species, neither the act of copulation without ejaculate transfer nor sperm stored inhibited female receptivity. Moreover, using multiply mated sterile and wild males in Mex flies we showed that the number of sperm stored by females varied according to male fertility status and number of previous matings, while female remating did not. We suggest female receptivity in both flies is inhibited by the mechanical and/or physiological effect of the full ejaculate. This finding brings us closer to understanding the mechanisms through which female receptivity can be modulated.

The time interval between sequential mating affects the response of male meadow voles to previous mates

Male meadow voles differed in their copulatory behaviour, mating and reproductive success, and odour preferences for successively encountered mates, when the interval between pairing with two females was 1 h, 1 day, 4 days, 7 days or 10 days. Male voles had shorter latencies to first ejaculation with female 2 than with female 1 when the interval was 1 h, which may be attributed to heightened sexual arousal in males for female 2. Males also had shorter copulatory bouts with female 2 than with female 1 when the intervals between pairings were 1 h and 1 day. Shorter copulation bouts may allow more mating opportunities for both sexes and encourage multiple mating. Male voles also preferred the scent marks of female 2 to those of female 1 when the interval between pairing was 7 or 10 days, suggesting that these females were treated as distinct entities.

Male Success in Intrasexual Contests Extends to the Level of Sperm Competition in a Species of Dung Roller Beetle

Contests between males fighting over limited resources often determine the reproductive success of the contestants. It is possible that the outcomes of such contests are affected by traits that also contribute to the likelihood of males achieving paternity when sperm from multiple males compete to fertilize the ova of a single female; however, this relationship has been poorly characterized. In dung and carrion roller beetles, contests among males for the possession of a food ball – a vital resource for nesting – are frequent in nature. However, females that roll and nest with a male often store the sperm of previous mates, forcing males to engage in sperm competition. We analyzed the relationship between wins and losses in contests between food ball owner males and subsequent paternity success in the carrion roller beetle Canthon cyanellus using both naive (virgin) and experienced (previously mated) males. Owner males that initiated contests were more likely to win, and contest durations were longer between experienced owner males than between naive owners. The paternity of the winner owner males nesting with a female that had previously mated with another male was higher than for loser owner males, and the paternity of experienced owners also tended to be higher than for virgin owners. Our results indicate that winning and being an experienced male are associated with greater success at fighting and sperm competition than losing and being a naive male.

Using local dispersal data to reduce bias in annual apparent survival and mate fidelity

ABSTRACT In mark–recapture studies conducted on fixed-area study sites, apparent (or “local”) survival (ϕ) is the product of the probabilities of true survival (S) and site fidelity to the sampling area (F). If marked individuals permanently emigrate from the study site, apparent survival will be biased low relative to true survival. Similarly, estimates of mate fidelity will be biased high because site fidelity is typically higher for individuals that reunite with their previous mates than among pairs that divorce. Here, we develop a method for calculating site fidelity that takes plot boundaries into account, based on a dispersal model estimated from local movements within a fixed study site. We use dispersal estimates to adjust apparent survival and mate fidelity for the effects of short-distance movements out of a fixed area. We demonstrate our method with a retrospective analysis of a published study of 2 species of sandpipers breeding sympatrically at a field site in western Alaska. Estimates of sur...

Role of Large Cabbage White butterfly male-derived compounds in elicitation of direct and indirect egg-killing defenses in the black mustard.

To successfully exert defenses against herbivores and pathogens plants need to recognize reliable cues produced by their attackers. Up to now, few elicitors associated with herbivorous insects have been identified. We have previously shown that accessory reproductive gland secretions associated with eggs of Cabbage White butterflies (Pieris spp.) induce chemical changes in Brussels sprouts plants recruiting egg-killing parasitoids. Only secretions of mated female butterflies contain minute amounts of male-derived anti-aphrodisiac compounds that elicit this indirect plant defense. Here, we used the black mustard (Brassica nigra) to investigate how eggs of the Large Cabbage White butterfly (Pieris brassicae) induce, either an egg-killing direct [i.e., hypersensitive response (HR)-like necrosis] or indirect defense (i.e., oviposition-induced plant volatiles attracting Trichogramma egg parasitoids). Plants induced by P. brassicae egg-associated secretions expressed both traits and previous mating enhanced elicitation. Treatment with the anti-aphrodisiac compound of P. brassicae, benzyl cyanide (BC), induced stronger HR when compared to controls. Expression of the salicylic (SA) pathway- and HR-marker PATHOGENESIS-RELATED GENE1 was induced only in plants showing an HR-like necrosis. Trichogramma wasps were attracted to volatiles induced by secretion of mated P. brassicae females but application of BC did not elicit the parasitoid-attracting volatiles. We conclude that egg-associated secretions of Pieris butterflies contain specific elicitors of the different plant defense traits against eggs in Brassica plants. While in Brussels sprouts plants anti-aphrodisiac compounds in Pieris egg-associated secretions were clearly shown to elicit indirect defense, the wild relative B. nigra, recognizes different herbivore cues that mediate the defensive responses. These results add another level of specificity to the mechanisms by which plants recognize their attackers.

Switching tactics: phenotypic plasticity in the alternative mate-finding tactics of burying beetles

Male Nicrophorus burying beetles utilize two alternative mate-finding tactics: searching and signalling. The searching tactic involves flying in search of a carcass on which to mate, while the signalling tactic involves emitting pheromone in the absence of a carcass to attract females. All males use both tactics, but the amount of time spent using each tactic differs between individuals. Because all males are phenotypically plastic in the time spent using alternative behaviours, the expression is likely to be condition dependent on some environmental cue, such as the availability of reproductive resources (i.e. females and carcasses). We tested how the expression of alternative tactics is influenced by previous mating experience and the perceived availability of females versus carcasses by using a repeated measures design in which mate-finding behaviour of males was observed before and after exposure to: (1) multiple females but no carcasses, (2) multiple females and multiple carcasses, (3) multiple carcasses but no females, or (4) no females or carcasses (control). Males in the multiple-female group (but lacking a carcass) allocated significantly more time to signalling, as did males in the control group lacking both mating and carcass experience. Thus, males that did not encounter carcasses during the treatment period increased pheromone emission thereafter. In the two groups that were given carcasses, however, investment in signalling was not altered. With respect to time allocated to searching, control, multiple-female and multiple-carcass groups all significantly decreased time spent searching, whereas males in the female-and-carcass group did not alter time allocated to searching. Our results demonstrate that environmental cues do influence which alternative tactic male burying beetles use, and that the chosen tactic is influenced by the availability of both receptive females and carcasses on which to breed. • Experience with females and carcasses influences mating tactics in male burying beetles. • Low availability of carcasses leads to increased signalling. • Experience with both females and carcasses is necessary to maintain investment in searching.

Females of the Cellar Spider Discriminate Against Previous Mates

AbstractMate choice for novel partners should evolve when remating with males of varying genetic quality provides females with fitness‐enhancing benefits. We investigated sequential mate choice for same or novel mating partners in females of the cellar spider Pholcus phalangioides (Pholcidae) to understand what drives female remating in this system. Pholcus phalangioides females are moderately polyandrous and show reluctance to remating, but double‐mated females benefit from a higher oviposition probability compared to single‐mated females. We exposed mated females to either their former (same male) or a novel mating partner and assessed mating success together with courtship and copulatory behaviours in both sexes. We found clear evidence for mate discrimination: females experienced three‐fold higher remating probabilities with novel males, being more often aggressive towards former males and accepting novel males faster in the second than in the first mating trial. The preference for novel males suggests that remating is driven by benefits derived from multiple partners. The low remating rates and the strong last male sperm precedence in this system suggest that mating with novel partners that represent alternative genotypes may be a means for selecting against a former mate of lower quality.

Previous mating experience increases fighting success during male-male contests in the hermit crab Pagurus nigrofascia

Prior social experience often affects subsequent competitive interactions and their outcomes. Although the effects of prior contest experience have been widely examined, effects of mating experience remain less well examined. We examined, in males of the hermit crab Pagurus nigrofascia, whether males successively copulated with more than one female and whether males with copulation experience differed in their subsequent contest behaviors and probability of winning in male-male contests compared to males without copulation experience. The copulation experience of intruders was manipulated and the contest behaviors compared between mated and unmated groups. Males mated with several females regardless of the male body size. Compared with unmated intruders, intruders with mating experience succeeded more often in taking over females and did so within a shorter period particularly when the male-male contests occurred over females with a long time to molt. These results suggest that mated males of P. nigrofascia overestimate the female quality and/or enhance the competitive performance similar to the “winner effect” that is a positive feedback from prior winning experience to future contests.