The effect of male mating history on paternal investment, fecundity and female remating in the seed beetle Callosobruchus maculatus

1. In many organisms, males provide nutrients to females via ejaculates that can influence female fecundity, longevity and mating behaviour. The effect of male mating history on male ejaculate size, female fecundity, female longevity and female remating behaviour in the seed beetle Callosobruchus maculatus was determined.
2. The quantity of ejaculate passed to females declined dramatically with successive matings. Despite the decline, a male's ability to fertilize a female fully did not appear to decline substantially until his fourth mating.
3. When females multiply mated with males of a particular mated status, the pattern of egg production was cyclic, with egg production increasing after mating. Females multiply mated to virgins had higher fecundity than females mated to non-virgins, and females mated to twice-mated males had disproportionately increased egg production late in their life.
4. Females that mated to multiple virgins, and consequently laid more eggs, experienced greater mortality than females mated only once or mated to non-virgins, suggesting that egg production is costly, and rather than ameliorating these costs, male ejaculates may increase them by allowing or stimulating females to lay more eggs.
5. Females mating with non-virgin males remated more readily than did females mated to virgins. Females given food supplements were less likely to remate than females that were nutritionally stressed, suggesting that females remate in part to obtain additional nutrients.     

Effects of multiple mating and male eye span on female reproductive output in the stalk-eyed fly, Cyrtodiopsis dalmanni

Females of the stalk-eyed fly, Cyrtodiopsis dalmanni, mate repeatedly during their lifetime and exhibit mating preferencefor males with large eye span. How these mating decisions affectfemale fitness is not fully understood. In this study, we examinedthe effects of multiple mating and male eye span on short-termreproductive output in this species. Experiments that manipulatedthe number of copulations and partners a female received suggested that obtaining a sufficient sperm supply is an important benefitassociated with multiple mating. The average percentage offertile eggs laid by females increased as a function of matingfrequency and ranged from 40% for females mated once, to 80%for females mated continuously. In addition, a high proportionof copulations in this species appeared to be unsuccessful. One-third of all females mated once laid less than 10% fertileeggs. There was no significant difference in reproductive performancebetween females mated to multiple partners and females matedto a single partner. There was also no indication that femalesreceived any short-term reproductive benefits from mating withmales with large eye span. In fact, females mated to males with short eye span laid a higher percentage of fertile eggs thanfemales mated to large eye span males.     

Courtship and copulation, but not ejaculates, reduce the longevity of female field crickets (Gryllus bimaculatus)

Females of many taxa incur fitness costs from male sexual coercion and harassment leading to mating. Although male crickets cannot force copulations on females, female Gryllus bimaculatus in this study incurred significant reductions in longevity through being exposed to different levels of male courtship. Virgin females kept in isolation had the longest life spans. Reductions in longevity applied to females in sensory contact with males (without the opportunity to mate), females that courted and mated and females that mated but with fertilization being prevented. Females also incurred significant reductions in longevity when kept with other females, which may have been due to high levels of cannibalism. Consistent with previous studies, females appeared to incur no cost to longevity from receiving sperm or seminal fluid. It is known that female G. bimaculatus benefit genetically from multiple mating. However, this benefit could possibly be offset by the negative effect that male courtship and mating behaviour has on female longevity.     

Male Performance and Body Size Affect Female Re-Mating Occurrence in the Orb-Web Spider Leucauge mariana (Araneae, Tetragnathidae)

Females can affect male probabilities of paternity success through behavioural, morphological and/or physiological processes occurring during or after copulation. These processes under female-control include the acceptance or rejection of mating attempts by subsequent males. Leucauge mariana is an orb weaving spider that shows male mate guarding of penultimate females, male–male competition on female webs and copulatory plugs, suggesting a polyandric mating system. The aim of the present study was to ascertain whether male behaviour during courtship and copulation in L. mariana relate with female re-mating decisions. Forty-three virgin females were exposed to up to three males until they mated. In 24 cases, the copulatory plug was absent after mating and females were exposed the next day to up to three other males. Eighteen females accepted a second mating. Relatively larger females were more receptive to second matings and were more likely to copulate if the second male was smaller. Longer duration of female tapping and abdominal bobbing during courtship, and first copulations with less short insertions and more flubs, were associated with increased female acceptance to second matings. The results indicate cryptic female choice on male courtship and copulatory performance and suggest female-control over the determination of male mating success in this spider species.     

Multi-male mating, probability of conception, and litter size in the prairie vole (Microtus ochrogaster)

We conducted a mating experiment in the laboratory using prairie voles, Microtus ochrogaster, to document that multi-male mating (MMM) can occur in this supposedly monogamous species and to test two hypotheses for the advantages of MMM in female mammals. The two hypotheses are that MMM (1) increases the probability of pregnancy and (2) increases litter size. We also tested the hypothesis that multiple copulations, rather than multiple partners, increases litter size and/or probability of pregnancy. Females were given a choice of mating with any of three males, each of which was tethered in a separate compartment. The mate choice bouts were recorded on videotape. We recorded the number of copulations and number of males with which females mated over a 24 h period. Litter size and probability of pregnancy were not significantly different for females that mated with one, two or three males. Increasing numbers of copulations, independent from the number of males, also did not increase litter size but did significantly increase the probability of pregnancy. MMM, at least in prairie voles, must serve some function other than increasing litter size and probability of conception.     

Male mate choice in the chameleon grasshopper (Kosciuscola tristis)

In many species, males can increase their fitness by mating with the highest quality females. Female quality can be indicated by cues, such as body size, age and mating status. In the alpine grasshopper Kosciuscola tristis, males can be found riding on subadult females early in the season, and as the season progresses, males engage in fights over ovipositing females. These observations suggest that males may be competing for females that are either unmated (early season) or sperm‐depleted (late season). We thus hypothesised that male K. tristis may be choosy in relation to female mating status, and specifically, we predicted that males prefer females that are unmated. We conducted behavioural experiments in which males were given the choice of two females, one mated and one unmated. Contrary to our prediction, males did not mate preferentially with unmated females. However, copulation duration with unmated females was, on average, 24 times the length of copulation with mated females. While female K. tristis can reject mates, we did not observe any evidence of overt female choice during our trials. Females may gain additional benefits from mating multiply and may therefore not readily reject males. While our experiment cannot definitively disentangle female from male control over copulation duration, we suggest that males choose to invest more time in copula with unmated females, perhaps for paternity assurance, and that male mate assessment occurs during copulation rather than beforehand.     

Postcopulatory female choice increases the fertilization success of novel males in the field cricket, Gryllus vocalis

Although recent studies have demonstrated that female crickets prefer novel males to previous mates, the relative contribution of pre- and postcopulatory behaviors to this advantage remain unknown, as do the reproductive consequences to males. I paired females either with previous or novel mates, and recorded the latency to mating and the time after mating at which the female removed the male's spermatophore, terminating sperm transfer. Females that mated with familiar males removed their spermatophores sooner than females that mated with novel males. Females paired with novel males also mated more quickly than females paired with familiar males, but this difference was not statistically significant. A molecular-based paternity analysis was used to determine whether the postcopulatory preference of females for novel males influences a male's fertilization success. Females were assigned to either mate three times with the same male and then once with a novel male, or four times with four different males. The paternity of the last male was higher when the female previously had mated repeatedly with the same male than when she had mated previously with different males. These results suggest that female spermatophore removal behavior influences male paternity such that novel males receive a fertility benefit.     

Multiple mating and repeated copulations: effects on male reproductive success in red flour beetles

In many insects, both sexes mate multiple times and females use stored sperm for fertilizations. While males frequently engage in two distinct behaviours, multiple mating (with different females) and repeated copulations (with the same female), the reproductive consequences of these behaviours for males have been quantified for only a few species. In this study, males of the red flour beetle, Tribolium castaneum, were found to be capable of mating with as many as seven different virgin females within 15 min. Across sequential copulations with virgin females, there was no decline in either male insemination success or average female progeny production over 48 h. However, when males copulated with previously mated females, there was a significant decline in male paternity success across sequential copulations, possibly due to male sperm depletion. In separate experiments, T. castaneum males were found to engage in two to six repeated copulations with the same, individually marked female. These repeated copulations did not increase male insemination success, short-term female fecundity, or male paternity success. Repeated copulations may possibly play a role in sperm defence. This study indicates that males may frequently engage in multiple matings, but these additional matings may lead to diminishing male reproductive returns.     

FEMALES RECEIVE A LIFE-SPAN BENEFIT FROM MALE EJACULATES IN A FIELD CRICKET

Abstract.— Mating has been found to be costly for females of some species because of toxic products that males transfer to females in their seminal fluid. Such mating costs seem paradoxical, particularly for species in which females mate more frequently than is necessary to fertilize their eggs. Indeed, some studies suggest that females may benefit from mating more frequently. The effect of male ejaculates on female life span and lifetime fecundity was experimentally tested in the variable field cricket, Gryllus lineaticeps. In field crickets, females will mate repeatedly with a given male and mate with multiple males. Females that were experimentally mated either repeatedly or multiply lived more than 32% longer than singly mated females. In addition, multiply mated females produced 98% more eggs than singly mated females. Because females received only sperm and seminal fluid from males in the experimental matings, these life‐span and fecundity benefits may result from beneficial seminal fluid products that males transfer to females during mating. Mating benefits rather than mating costs may be common in many animals, particularly in species where female mate choice has a larger effect on male reproductive success than does the outcome of sperm competition.     

Factors affecting female sexual receptivity in the planthopper, Prokelisia dolus

Abstract. The mating system of Prokelisia dolus Wilson (Homoptera: Delphacidae) was characterized by determining: if males and females multiply mate; when transitions occur in female sexual receptivity, what triggers sexual refractoriness; and what behaviours characterize unreceptive virgins, receptive virgins, and unreceptive mated females. Males copulated with up to six females in less than 1 h, but completely inseminate, on average, only the first four females. Females rarely mated more than once, unless males were depleted of sperm due to previous copulations or if copulation was interrupted (if duration was<2 min). Male and female calling was associated (100% and 91%, respectively) with sexual receptivity and resultant matings. The transition from unreceptive virgin to receptive (calling) mature virgin occurred 48 h posteclosion, and all were mated by day 4. Females that were sexually immature and those completely inseminated did not call. Rejection of males by females included walking away from approaching males (65%), female kicking (7%), and abdominal lifting (5%). Rejection of males was observed by immature, mature and calling, and mated females. Sexual refractoriness was not triggered by acoustic and visual stimuli or mechanical stimulation of genitalia. Refractoriness was also not triggered by reception of small quantities of sperm because some females laid a few viable eggs yet calling was not terminated. Sexual refractoriness was activated by a substance in the ejaculate as demonstrated by injection into the haemocoel of male accessory glands or testes and homogenates of seminal vesicles. This is the first study that documents the role of male ejaculate in inhibiting female sexual receptivity in Hemiptera (Homoptera).     

Copulation patterns in the golden orb-web spider Nephila madagascariensis

A consequence of multiple mating by females can be that the sperm of two or more males directly compete for the fertilisation of ova inside the female reproductive tract. Selection through sperm-competition favours males that protect their sperm against that of rivals and strategically allocate their sperm, e.g., according to the mating status of the female and the morphology of the spermatheca. In the majority of spiders, we encounter the otherwise unusual situation that females possess two independent insemination ducts, both ending in their own sperm storage organ, the spermatheca. Males have paired mating organs, but generally can only fill one spermatheca at a time. We investigated whether males of the African golden orb-web spider Nephila madagascariensis can prevent rival males from mating into the same spermatheca and whether the mating status of the female and/or the spermatheca causes differences in male mating behaviour. There was no significant difference in the duration of copulations into unused spermathecae of virgin and mated females. We found that copulations into previously inseminated spermathecae were generally possible, but shorter than copulations into the unused side of mated females or with virgins. Thus, male N. madagascariensis may have an advantage when they mate with virgins, but cannot prevent future males from mating. However, in rare instances, parts of the male genitals can completely obstruct a female genital opening.     

Male Mate Choice in the Guppy (Poecilia reticulata): Do Males Prefer Larger Females as Mates?

Although females are the choosier sex in most species, male mate choice is expected to occur under certain conditions. Theoretically, males should prefer larger females as mates in species where female fecundity increases with body size. However, any fecundity‐related benefits accruing to a male that has mated with a large female may be offset by an associated fitness cost of shared paternity if large females are more likely to be multiply mated than smaller females in nature. We tested the above hypothesis and assumption using the Trinidadian guppy (Poecilia reticulata) by behaviourally testing for male mate choice in the laboratory and by ascertaining (with the use of microsatellite DNA genotyping) patterns of male paternity in wild‐caught females. We observed significant positive relationships between female body length and fecundity (brood size) and between body length and level of multiple paternity in the broods of females collected in the Quaré River, Trinidad. In laboratory tests, a preference for the larger of two simultaneously‐presented virgin females was clearly expressed only when males were exposed to the full range of natural stimuli from the females, but not when they were limited to visual stimuli alone. However, as suggested by our multiple paternity data, males that choose to mate with large females may incur a larger potential cost of sperm competition and shared paternity compared with males that mate with smaller females on average. Our results thus suggest that male guppies originating from the Quaré River possess mating preferences for relatively large females, but that such preferences are expressed only when males can accurately assess the mating status of encountered females that differ in body size.     

Paternity and kinship patterns in polyandrous moustached tamarins (Saguinus mystax)

We studied patterns of genetic relatedness and paternity in moustached tamarins, small Neotropical primates living in groups of 1–4 adult males and 1–4 adult females. Generally only one female per group breeds, mating with more than one male. Twin birth are the norm. In order to examine the genetic consequences of this mating pattern, DNA was extracted from fecal samples collected from two principal and six neighboring groups. DNA was characterized at twelve microsatellite loci (average: seven alleles/locus). We addressed the following questions: Do all adult males have mating access to the reproductive female of the group? How is paternity distributed across males in a group? Can polyandrous mating lead to multiple paternity? Are nonparental animals more closely related to the breeders than to the population mean? And, are mating partners unrelated? Breeding females mated with all nonrelated males. In at least one group the father of the older offspring did not sire the youngest infant although he was still resident in the group. We also found evidence for multiple paternity in a supposed twin pair. Yet, within each group the majority (67–100%) of infants had the same father, suggesting reproductive skew. Relatedness within groups was generally high (average R = 0.31), although both nonrelated males and females occurred, i.e., immigrations of both sexes are possible. Mating partners were never found to be related, hence inbreeding seems to be uncommon. The results suggest that while the social mating system is polyandry, paternity is often monopolized by a single male per group. Am J Phys Anthropol, 2005. © 2004 Wiley-Liss, Inc.     

Socio-sexual behavior of female northern muriquis (Brachyteles hypoxanthus)

Female northern muriquis (Brachyteles hypoxanthus) are known to engage in frequent copulations with multiple partners, a pattern that in other primates has been attributed to various functions such as confusing paternity, reducing male aggression, or ensuring fertilization. However, in some female primates, promiscuity is restricted to times when conceptions are unlikely. We investigated whether female northern muriquis might exhibit a similarly mixed strategy by examining their mating, social, and activity patterns during their conception cycles versus other times. Systematic behavioral data were collected during an 18-month period between August 2001 and February 2003 on 13 adult females in a well-studied group at the RPPN-Feliciano Miguel Abdala, Minas Gerais, Brazil. Females mated on an average of 12.5+/-7.9 days during the study period, and spent significantly less time resting and engaging in non-sexual social behaviors, and significantly more time in sexual behaviors on days that they copulated than on days they did not. Three of the eight females for which sufficient data were available copulated significantly more often with their spatially closest non-kin associates, and four of five females that could be analyzed copulated significantly more often with their most frequent non-kin embrace partners. Comparisons between conception and non-conception periods revealed no differences in female activity budgets or in either the number of copulations or the number of different mating partners per female. Our results suggest that some females mate preferentially with close associates and social partners, but there is no indication that females alter their behavior during the cycles in which they conceive.     

Influence of male mating history on female reproductive success among monandrous Naryciinae (Lepidoptera: Psychidae)

1. Multiple male copulations can have detrimental effects on female fitness due to sperm limitation. 2. Monandrous Naryciinae females are immobile while the males are short‐lived and do not feed. Multiple male mating is therefore expected to lead to sperm limitation in females. Sperm limitation and male limitation are hypothesised as causes of the repeated evolution of parthenogenetic reproduction in the Psychidae. 3. In this study, the effects of multiple male mating on female reproduction are investigated in several species of Naryciinae by allowing males multiple copulations. The results for two species, Siederia listerella and Dahlica lichenella, are compared. The sex ratios of 53 natural populations are examined for indications of male limitation. 4. Previous copulations by the male increased the female's risk of remaining unfertilised. However, contrary to expectations, those unfertilised females were capable of successful re‐mating. 5. In S. listerella, the number of previous copulations of males negatively influenced female fitness. Females produced 30% fewer offspring if they mated with a previously mated male. In D. lichenella, the older the male and the lower its number of total lifetime copulations, the higher the female's reproductive success. 6. Only a fraction of the investigated populations had a female‐skewed sex ratio, but differences in development time between males and females could lead to reproductive asynchrony. 7. In conclusion, male mating history did not lead to strong sperm limitation in Naryciinae as had been suggested by their life history.     

Multiple Mating Increases Fecundity, Fertility and Relative Clutch Mass in the Female Leopard Gecko (Eublepharis macularius)

Females across many taxa may mate with several males or mate more than once with the same male within one reproductive event. Although many researchers have discussed the effects of multiple mating on reproductive success of females, few studies have attempted to disentangle whether the reproductive success of females differs with respect to whether females mate with multiple males or mate more than once with one male. In this study, we hypothesized that female leopard geckos (Eublepharis macularius) increase aspects of their reproductive success, such as fecundity, fertility and relative clutch mass, by mating more than once within one reproductive event, either by mating repeatedly with the same male or multiply mating with different males. We controlled for the potentially confounding variables of mating frequency and mate number by allowing females to mate once with one male, twice with the same male, or twice with two different males. We found that females that mated with more than one male laid more clutches, exhibited increased egg fertility and invested more in clutches relative to females that mated only once with one male, whereas females that mated twice to the same male were intermediate for these variables. Thus, reproductive success is higher among female leopard geckos that mated with more than one male compared to female leopard geckos that mated only once.     

Factors influencing paternity success in Antechinus agilis: last‐male sperm precedence,timing of mating and genetic compatibility

We describe the patterns of paternity success from laboratory mating experiments conducted in Antechinus agilis, a small size dimorphic carnivorous marsupial (males are larger than females). A previous study found last‐male sperm precedence in this species, but they were unable to sample complete litters, and did not take male size and relatedness into account. We tested whether last‐male sperm precedence regardless of male size still holds for complete litters. We explored the relationship between male mating order, male size, timing of mating and relatedness on paternity success. Females were mated with two males of different size with either the large or the small male first, with 1 day rest between the matings. Matings continued for 6 h. In these controlled conditions male size did not have a strong effect on paternity success, but mating order did. Males mating second sired 69.5% of the offspring. Within first mated males, males that mated closer to ovulation sired more offspring. To a lesser degree, variation appeared also to be caused by differences in genetic compatibility of the female and the male, where high levels of allele‐sharing resulted in lower paternity success.     

Strategic ejaculation in the common dung fly Sepsis cynipsea

Sperm competition has been a major selective force acting on male and female behaviour. Theory predicts that when sperm compete numerically, selection will favour males that vary the number of sperm they transfer with sperm competition risk. This often leads to increased copula duration when sperm competition risk is high, the selective advantage of which is increased paternity. We investigated the copulatory behaviour of the common dung fly Sepsis cynipsea in relation to male and female size, female mating status, age, and presence or absence of dung. This fly is unusual in that males mate-guard before copula while females use the sperm of previous males for their current clutch. Body size had no effect on copula duration, but duration of first copulations depended on female age, with older females having longer copulations. For females that copulated twice, there was an interaction between female age and mating status influencing copula duration: old females had longer copulations than young females, but second copulas were longer for young females. Residual testis size of nonvirgin males was smaller than for virgins, and testis shrinkage was significantly associated with copula duration, which indicates that males transfer more ejaculate with longer copulations. We therefore conclude that copulation duration and ejaculate transfer vary in accordance with sperm competition theory.     

Polyandry enhances offspring viability with survival costs to mothers only when mating exclusively with virgin males in Drosophila melanogaster

A prominent hypothesis for polyandry says that male–male competitive drivers induce males to coerce already‐mated females to copulate, suggesting that females are more likely to be harassed in the presence of multiple males. This early sociobiological idea of male competitive drive seemed to explain why sperm‐storing females mate multiply. Here, we describe an experiment eliminating all opportunities for male–male behavioral competition, while varying females’ opportunities to mate or not with the same male many times, or with many other males only one time each. We limited each female subject's exposure to no more than one male per day over her entire lifespan starting at the age at which copulations usually commence. We tested a priori predictions about relative lifespan and daily components of RS of female Drosophila melanogaster in experimental social situations producing lifelong virgins, once‐mated females, lifelong monogamous, and lifelong polyandrous females, using a matched‐treatments design. Results included that (1) a single copulation enhanced female survival compared to survival of lifelong virgins, (2) multiple copulations enhanced the number of offspring for both monogamous and polyandrous females, (3) compared to females in lifelong monogamy, polyandrous females paired daily with a novel, age‐matched experienced male produced offspring of enhanced viability, and (4) female survival was unchallenged when monogamous and polyandrous females could re‐mate with age‐ and experienced‐matched males. (5) Polyandrous females daily paired with novel virgin males had significantly reduced lifespans compared to polyandrous females with novel, age‐matched, and experienced males. (6) Polyandrous mating enhanced offspring viability and thereby weakened support for the random mating hypothesis for female multiple mating. Analyzes of nonequivalence of variances revealed opportunities for within‐sex selection among females. Results support the idea that females able to avoid constraints on their behavior from simultaneous exposure to multiple males can affect both RS and survival of females and offspring.     

Reproductive Behavior of Female Propithecus verreauxi at Beza Mahafaly,Madagascar

Prosimian and anthropoid females are generally thought to have divergent reproductive patterns, characterized by circumscribed and situation-dependent receptivity. This dichotomy underpins the traditional view that nonreproductive mating serves a social function in anthropoid females, distinguishing them from prosimians which, like most other mammals, mate only when conception is most probable. Circumscribed estrous cycles differ from anthropoid menstrual cycles by the presence of menstruation, and greater flexibility in timing and longer duration of receptivity in the latter. The degree to which sexual behavior is tightly synchronized to periovulatory events in Propithecus verreauxi was assessed via the behavioral, hormonal, and social correlates of reproduction in a free-ranging population. I collected data from two social groups before and during the 1990–1991 and 1991–1992 breeding seasons at Beza Mahafaly, Madagascar. I also conducted 644 focal-animal hours and collected 485 fecal samples from five marked females in the Vaovao and Vavy Masiaka social groups. Estrus was behaviorally characterized by 0.5–96-h periods of receptivity when females were motivated and willing to mate, the latter not always coincident with periovulatory events. Females exhibited age- and rank-related asynchronous receptivity, and in some cases, periovulatory synchrony within groups. Sifaka were not pair-bonded. Most females mated with multiple males, temporally ordering partners based on male residence and age. Mating was limited by male mate-guarding and sexual aggression by males, female mate competition, and aversions to mating with certain partners. It was facilitated by surreptitious copulations, positive mate choice, and the availability of non-resident mating partners.