Copulatory vocalizations of female macaques (Macaca fascicularis): Variability factors analysis

In 234 copulations, male and female behavioural patterns were collected, especially the vocal pattern for the female. Moreover quantitative structural analysis was performed on 38 of these female copulatory vocalizations. A multifactorial analysis, ANAFAC, was performed to seek relations between (1) utterance of female copulatory call and male and female copulatory behaviour and (2) these patterns and the great variability of female calls. Utterance of female copulatory vocalizations is essentially due to the female’s own copulatory behaviour in periods of intense sexual activity. Long female calls are related to male ejaculation, and those “rich” in harmonics are related to visual and tactile communicatory signals exchanged by the male and the female during a mount. This analysis strongly confirms the tied bond between quality of a call and internal state of the emitter. Long calls, rich in harmonics, may serve as signals maintaining or strengthening the possibly temporary preferential relation between male and sexually receptive female.     

Female aggression predicts mode of paternity acquisition in a social lizard

Individual differences in behaviour are ubiquitous in nature. Despite the likely role of selection in maintaining these differences, there are few demonstrations of their fitness consequences in wild populations and, consequently, the mechanisms that link behavioural variation to variation in fitness are poorly understood. Specifically, the consequences of consistent individual differences in behaviour for the evolution of social and mating strategies have rarely been considered. We examined the functional links between variation in female aggression and her social and mating strategies in a wild population of the social lizard Egernia whitii. We show that female Egernia exhibit temporally consistent aggressive phenotypes, which are unrelated to body size, territory size or social density. A female''s aggressive phenotype, however, has strong links to her mode of paternity acquisition (within- versus extra-pair paternity), with more aggressive females having more offspring sired by extra-pair males than less aggressive females. We discuss the potential mechanisms by which female aggression could underpin mating strategies, such as the pursuit/acceptance of extra-pair copulations. We propose that a deeper understanding of the evolution and maintenance of social and mating systems may result from an explicit focus on individual-level female behavioural phenotypes and their relationship with key reproductive strategies.     

Mating behavior of Pine Sawyer,Monochamus saltuarius Gebler (Coleoptera: Cerambycidae)

Mating behavior of the pine sawyer, Monochamus saltuarius Gebier (Cerambycidae: Lamiinae) was observed on pine trees in an outdoor net cage kept in one healthy pine tree and a cluster of pinelogs (cut over one month) to attract the beetles. When sawyer adult pairs released into net cage, they all moved to the pinelogs. And then the male was staying motionless with his antenna outstretched while the female was actively moving in his vicinity. The mating behavioral reactions were followed by the next steps: The first phase of courtship was initiated by the female approach toward the male. Second, male dashed, contacted antenna and mounted female's back. Third, female carried the male on her back and walked around and then male began to lick. Fourth, male inserted his penis into the female's genitalia when female stopped walking. While a long pairbond, the mating pair repeated copulations, lastly, when mating is over, male and female stayed separately. The mating began on sunset and resting of both male and female began at the temperature below about 20 °C. Substantially straightforward mate searching by female indicates the presence of a male sex pheromone.     

The copulatory plug delays ejaculation by rival males and affects sperm competition outcome in house mice

Females of many species mate with multiple males (polyandry), resulting in male–male competition extending to post‐copulation (sperm competition). Males adapt to such post‐copulatory sexual selection by altering features of their ejaculate that increase its competitiveness and/or by decreasing the risk of sperm competition through female manipulation or interference with rival male behaviour. At ejaculation, males of many species deposit copulatory plugs, which are commonly interpreted as a male adaptation to post‐copulatory competition and are thought to reduce or delay female remating. Here, we used a vertebrate model species, the house mouse, to study the consequences of copulatory plugs for post‐copulatory competition. We experimentally manipulated plugs after a female's first mating and investigated the consequences for rival male behaviour and paternity outcome. We found that even intact copulatory plugs were ineffective at preventing female remating, but that plugs influenced the rival male copulatory behaviour. Rivals facing intact copulatory plugs performed more but shorter copulations and ejaculated later than when the plug had been fully or partially removed. This suggests that the copulatory plug represents a considerable physical barrier to rival males. The paternity share of first males increased with a longer delay between the first and second males' ejaculations, indicative of fitness consequences of copulatory plugs. However, when males provided little copulatory stimulation, the incidence of pregnancy failure increased, representing a potential benefit of intense and repeated copulation besides plug removal. We discuss the potential mechanisms of how plugs influence sperm competition outcome and consequences for male copulatory behaviour.     

Recognition of Individual Males' Songs by Female Dunnocks: a Mechanism Increasing the Number of Copulatory Partners and Reproductive Success

Previous studies have shown that a female dunnock Prunella modularis increases her reproductive success on average by copulating with more than one male resident on her territory and thereby obtaining extra help in raising offspring. Here we document behavior by females that affects which males copulate with them. During her period of receptivity to copulation, a female in a territory shared by two males often left the dominant (or alpha) male, which guarded her most of the time, and approached the subordinate (or beta) male when he sang. A female's responses to individual males thus tend to increase her own reproductive success by increasing her chances for copulation with both males sharing her territory. Playbacks of tape-recorded songs in the field showed that females approached only songs of resident males, not neighbors. They can therefore discriminate individual males by their songs alone, a capability not previously established for female songbirds. Despite intensive guarding of females by males, mating success among male dunnocks depends in part on female choice.     

Rhesus macaque copulation calls: Re-evaluating the “honest signal” hypothesis

Male rhesus macaques sometimes give loud calls while thrusting or dismounting during multi-mount copulations.Hauser (1993) has proposed that these calls (1) impose a cost (increased risk of aggression) on calling males, and (2) increase callers' copulation frequencies, supporting the hypothesis that calls function as honest signals (handicaps) that females use to evaluate male quality during mate choice. This hypothesis was re-examined using data collected at Cayo Santiago, Puerto Rico on 40 focal females and their 56 observed copulatory partners. Although attacks by males against copulating pairs were frequent, they were usually directed only against the female of the pair. Males that called were no more likely than silent males to suffer male escalated attack during or immediately following mount series. Male-female dyads in which the male called during copulation were significantly more likely than non-calling dyads to complete the most copulations observed for any given female. Males that called at least once were significantly more likely than non-calling males to complete at least one copulation with a peri-ovulatory female. A log-linear model revealed that male rank and calling were both associated with likelihood of experiencing at least one peri-ovulatory copulation. However, calling was not associated with reception of demonstrated female mate choice behaviors. Controlling for dominance rank, callers did not experience more female proximity maintenance than non-callers. Nor were callers' hip-grasps refused less frequently than non-callers' hip-grasps. These results cast doubt on the hypothesis that rhesus macaque copulation calls are costly, honest indicators of intrinsic male quality. A contrasting alternative hypothesis, that a male's copulatory calls advertise relative immunity from attacks against his copulatory partners, was not supported either. Thus, the function of rhesus macaque copulatory calls remains unknown. The unusually high rate of copulations amongHauser's (1993) subjects may explain the discrepancy in results, but it is unclear how high copulation rates would increase the cost of copulatory calling to males.     

Multi-male mating and female choice increase offspring growth in the spiderNeriene litigiosa(Linyphiidae)

The purpose of this controlled-breeding study was to investigate the viability consequences of female choice and sequential polyandry for offspring in a way that would separate the influences of these two aspects of female sexual behaviour. Female sierra dome spiders,Neriene litigiosa(=Linyphia litigiosa) typically mate two to three times before production of their first batch of eggs, although some females (ca 16%) mate only once. Strong fighters are preferred as first mates and principal sires. Large males that give a vigorous performance during copulatory courtship are preferred as sires among a female's secondary mates. In this study, the number of matings by free-living females was experimentally controlled and the size and copulatory vigour of all the females’ mates were recorded. At the end of the breeding season, the females were collected and their broods were obtained in captivity. Randomly chosen subsets of 28 female's offspring were reared under standard conditions during the following spring. The spiderlings were reared for 27 days in the company of siblings under conditions that would encourage the expression of genetic variation in viability, and growth and survivorship were monitored. After controlling for maternal effects (i.e. female size and oviposition date) and variance in feeding opportunities among rearing groups, both mate number and mate size were positively and independently related to offspring growth rates and the size of offspring attained after emergence from the natal cocoon. The results support the hypotheses that the preference for large males yields viability benefits to offspring and that polyandry can augment the benefits of selective mating.     

Female genital morphology and mating behavior of Orchestina (Arachnida: Araneae: Oonopidae)

The unusual reproductive biology of many spider species makes them compelling targets for evolutionary investigations. Mating behavior studies combined with genital morphological investigations help to understand complex spider reproductive systems and explain their function in the context of sexual selection. Oonopidae are a diverse spider family comprising a variety of species with complex internal female genitalia. Data on oonopid phylogeny are preliminary and especially studies on their mating behavior are very rare. The present investigation reports on the copulatory behavior of an Orchestina species for the first time. The female genitalia are described by means of serial semi-thin sections and scanning electron microscopy. Females of Orchestina sp. mate with multiple males. On average, copulations last between 15.4 and 23.54 min. During copulation, the spiders are in a position taken by most theraphosids and certain members of the subfamily Oonopinae: the male pushes the female back and is situated under her facing the female's sternum. Males of Orchestina sp. possibly display post-copulatory mate-guarding behavior. The female genitalia are complex. The genital opening leads into the uterus externus from which a single receptaculum emerges. The dorsal wall of the receptaculum forms a sclerite serving as muscle attachment. A sclerotized plate with attached muscles lies in the posterior wall of the uterus externus. The plate might be used to lock the uterus during copulation. The present study gives no direct evidence for cryptic female choice in Orchestina sp. but suggests that sexual selection occurs in the form of sperm competition through sperm mixing.     

Repeatability of Host Female and Male Aggression Towards a Brood Parasite

Current research on behavioural consistency showed that various types of animal behaviour are highly repeatable in the context of mate choice, exploration and parental care, including nest protection. However, the repeatability of aggressive nest defence has not yet been studied in hosts of brood parasites, although host aggression against adult parasites represents a crucial line of antiparasitic defences. Here, we investigated the between‐season repeatability of the great reed warbler (Acrocephalus arundinaceus) aggression towards a stuffed dummy of the brood parasitic common cuckoo (Cuculus canorus). We found that under the relatively stable risk of brood parasitism across breeding seasons, female responses to the cuckoo were highly repeatable, whereas male responses were variable. We suggest that the potential explanation for the observed patterns of female and male behaviours may lie in female's prominent roles in offspring care and nest protection, and in her lower renesting potential in comparison with that of males. However, further studies on the relationship between host aggression and other types of behaviours (host personality) and their fitness consequences under the fluctuating parasitism pressures are required to clarify the adaptive significance of aggressive behaviour observed in hosts of brood parasites.     

Sexual Behaviour of Sumatran Long-tailed Macaques (Macaca fascicularis)

The sexual behaviour of wild long-tailed macaques (Macaca fascicularis) was studied in the Gunung Leuser National Park, Sumatra, Indonesia. All females showed some swelling of the sexual skin, but the frequency and maximum size of the swelling decreased with age. The frequency of copulations and consortships for a given female increased with increasing degree of swelling or coloration. No regular cycles could be found in the occurrence of swellings, copulations and consortships. Periods for which a female had consortships tended to be long (up to 5–6 weeks on end). These two results suggest that in the wild the predictability of the moment of ovulation is very low. The consortships were not exclusive: both the male and the female occasionally copulated with others. All females had many different male partners and, as ovulation signalling was not clear, none of these males could have any certainty about paternity of a female's offspring. Yet, the highest-ranking males probably had the best chances to father children because they were more often involved in sexual interaction (both copulations and consortships), especially around the estimated date of conception. This does not hold for the nulliparous females who were virtually ignored by the higher-ranking males. Consortships were occasionally actively maintained by the female, for whom a direct advantage of consorting might be an increased safety against conspecifics and predators. One advantage of mating with many different males might be a reduced risk of infanticide.     

Do Female Red-winged Blackbirds Engage in a Mixed Mating Strategy?

Parentage analyses of broods of nestling red-winged blackbirds (Agelaius phoeniceus) revealed that extra-pair fertilizations (EPFs) accounted for 24% of the offspring. 8% of attempted copulations and 13% of male courtship displays during observations of focal females were by extra-pair males. In addition, mates and non-mates often chased and occasionally made physical contact with females; 34% of those chases in which contact was made were extra-pair chases. Females behaved variably during both within-pair and extra-pair events; females crouched less and resisted more frequently during extra-pair courtship than during within-pair courtship. All extra-pair events, whether natural or induced by male removal, were either resisted or accepted by the female. In 318 focal female-hours of observation during the fertilizable period, no female was ever seen in another male's territory soliciting a copulation. In addition, removal of females' mates resulted in frequent extra-pair courtship and copulation; all of these occurred on the removed male's territory. Some females left their mates' territories on occasion — these forays were nearly always off the study area, no female was ever seen copulating with an extra-pair male while on these forays, and neither the frequency nor the duration of female forays correlated with the frequency of extra-pair fertilizations within broods. There were no associations between extra-pair fertilizations and female age, settlement order, nest order, or clutch size. The number of fledglings produced from a nest was significantly positively associated with the number of sires of the brood. Fewer offspring apparently starved in broods that were multiply sired, yet males did not provide courtship feedings during either within-pair or extra-pair copulations, nor was any paternal care provided to young sired through extra-pair matings. The frequency of infertile eggs was low (< 1%); in those instances of infertile eggs the territory owner sired some young in the same nest or another nest on his territory. Fewer broods were a mixture of within-pair and extra-pair paternity than expected by chance. Clear evidence implicating a mixed strategy on the part of females could not be gathered. Because females behaved variably and because not all costs and benefits to females of extra-pair copulations could be measured, it remains possible that female behavior patterns are either (1) part of a mixed strategy, or (2) part of a strategy minimizing the costs of copulation.     

Indirect partner choice through manipulation of male behaviour by female fowl, Gallus gallus domesticus

The direct and indirect consequences of female copulatory behaviour for copulation success have seldom been quantified. In feral fowl, most copulations were forced by males and copulation success was determined by two factors. First, female differential resistance and solicitation directly affected copulation success and were displayed non-randomly with respect to male social status. Second, another female copulatory behaviour, the distress call, had an indirect effect on both copulation success and the quality of copulation partners. Distress calls triggered male attention to a copulation, which increased the probability of higher-ranking males than the copulating male disrupting the copulation and inseminating the calling female. Females preferentially uttered distress calls when mounted by low-ranking males. Both copulation resistance and distress calling influenced copulation success, but only distress calling increased the probability of copulation disruption by other males. Consistent with the effect of direct selection, differential distress calling indirectly biased copulation success in favour of dominant males. Female fowl may thus ameliorate the effect of male sexual coercion by manipulating male behaviour.     

Copulation in free-ranging black-handed spider monkeys (Ateles geoffroyi)

I report ad libitum data on 18 copulations involving free-ranging black-handed spider monkeys (Ateles geoffroyi) on Barro Colorado Island, Panama. All copulations were performed in a dorsoventral position, as is typically reported for this genus. Intromission often appeared difficult to achieve, possibly as a result of the large size of the glans penis in these animals. The average length from intromission to termination of thrusting exceeded 17 min, followed by an average period of almost 2 min before separation occurred, which suggests the possibility of a copulatory lock. Offspring of the female participant were almost always in close proximity to or in contact with the pair, and harassment by the offspring was observed only during the final stages of the copulation. All but one copulatory event occurred in complete seclusion from other adult males, and sexual behavior was not limited to any one adult male in the group.     

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.     

Patterns of extrapair mating in relation to male dominance status and female nest placement in black-capped chickadees

In sexually promiscuous animals, females may benefit by nestingclose to the edge of their partner's territory to facilitateextrapair copulations. In the present study, we describe theextrapair mating system of black-capped chickadees, Poecileatricapillus, and test whether nest locations are influencedby conspecific attraction to extrapair partners. We conducteda spatial analysis of female mating strategies by using microsatellitepaternity analysis in conjunction with geographic informationsystem (GIS) analysis of nest and territory locations. Extrapairoffspring comprised 52 of 351 offspring (14.8%) and were presentin 19 of 57 broods (33.3%). Females paired to males with lowdominance status in the previous winter's flock hierarchy weremore likely to engage in a mixed reproductive strategy thanwere females paired to males with high dominance status. Femaleshad extrapair copulations and extrapair fertilizations withhigh-ranking males more often than with low-ranking males. Notall extrapair copulations resulted in extrapair fertilizations.Females constructed their nests within 16.8 ± 1.0 m ofthe edge of their partner's territory, significantly closerto the edge of their nearest neighbor's territory than to thecenter of their own partner's territory. Extrapair males usuallyshared territory boundaries with cuckolded males. Females pairedto low-ranking males constructed nests near the territory edgesof neighboring high-ranking males. However, females did nothave extrapair copulations with the neighbor nearest to theirnest or even with the high-ranking neighbor nearest to theirnest. We conclude that conspecific attraction to neighbors mayinfluence nesting location in black-capped chickadees; however,it does not operate by facilitating extrapair copulations.     

Sperm Competition and Copulation Intervals of the White Spoonbill (Platalea leucorodia,Aves, Threskiornithidae)

Some aspects of sperm competition were studied in the white spoonbill (Platalea leucorodia) breeding in Doñana National Park (SW Spain). Shorter pair copulation intervals occurred during the prelaying period, when females were subjected to a relatively high frequency of extra-pair copulations. Pair copulation intervals with an intermediate extra-pair copulation by the male mate were longer than those without extra-pair copulation. This result indicates that males need a time of recovery between copulations before they can perform another. Extra-pair copulations by the females did not affect the length of intervals between pair copulations. There were no differences between the lengths of the intervals between an extra-pair copulation by the female and the following pair copulation for cases in which the male mate detected an intruder male attempting copulation with his mate and those in which the intruder remained undetected. However, the correlations obtained between copulatory intervals for detected and undetected cases suggest a copulatory response by their mates, although affected by the required recovery time between copulations by the males. Finally, since extra-pair copulations mainly occurred while male mates were collecting nest material, they engaged in this activity shortly after pair copulations, probably to avoid a last-male advantage under the sperm competition pressure.     

Reproductive Behaviour in Zonocerus elegans (Orthoptera: Pyrgomorphidae) with Special Reference to Nuptial Gift Guarding

Egglaying aggregations, mate fidelity and male and female mate choice and mating behaviour of the African pyrgomorphid grasshopper Zonocerus elegans are described from the field. Several hundred males and females were individually marked at oviposition sites. Pairs remained stable over days, during egglaying and presumably also over the weeks prior to egglaying. In addition to long-term consorting with a female, males may try to obtain inseminations by “footpad”–tactics at oviposition sites. It is suggested that prolonged consorting and repeated copulations increase the female's reproductive output as well as the male's share in it. Our data and the literature indicate that males are involved not only in rival competition but also in a “battle of the sexes” which females are likely to win. The intra– and intersexual “war on two fronts” results behaviourally in elaborate mating tactics and anatomically in highly developed internal female genitalia and male copulatory organs (well known taxonomic characters). This applies not only to grasshoppers but also to other insects and arthropods.     

Female resistance and male force: context and patterns of copulation in the New Zealand stitchbird Notiomystis cincta

The New Zealand stitchbird or hihi Notiomystis cincta is unique in that it has two distinct mating positions, in addition to the male standing on the female's back, as is seen in all other birds, it also copulates face‐to‐face. In this study, 43 male stitchbirds first attracted a female to their territory and supplemented their within‐pair matings by intruding into other territories and attempting forced copulations – often resulting in high levels of female harassment. I recorded the temporal variation of both attempted and successful copulations relative to the female's fertile period in order to understand the function of copulation variation in this species. Each of 105 observed copulations were classified according to whether they were: (1) within‐pair or extra‐pair, (2) forced or unforced, and (3) face‐to‐face or standing. Two copulation categories ‘within‐pair unforced standing’ (50%) and ‘extra‐pair forced face‐to‐face’ (27%) accounted for the majority of all observed copulations, and this supported the previous categorisation of face‐to‐face copulation being forced by extra‐pair males in this species. However, in 10% of copulations the female conceded to copulate with an extra‐pair male in a standing position while displaying only subtle signs of resistance, thus, female stitchbirds may show convenience polyandry when the costs of resistance are high. The peak in copulation frequency centred on two days prior to the laying of the first egg and occurred within a period of six days before and seven days after the first egg was laid. Unsuccessful extra‐pair forced copulation attempts closely followed the distribution of all copulations. Male age and morphometrics did not predict whether a female would resist or accept extra‐pair copulation attempts, and female resistance did not appear to depend on male quality. Despite the current trend focussing on female fitness benefits associated with EPCs, it appears that male stitchbirds gain EPCs through forced copulation and females gain no apparent benefit.     

Sperm competition and diversity in rodent copulatory behaviour

The copulatory behaviour of male mammals is characterized by striking diversity in patterns of copulatory stimulation and ejaculation frequency. We conducted comparative analyses of rodents to investigate the potential influence of sperm competition in the evolution of copulatory behaviour. We found that increasing sperm competition is associated with faster rates of stimulation and earlier ejaculation among species in which males perform multiple intromissions prior to ejaculation, but with no overall change in the number of intromissions per ejaculation. Increasing sperm competition is also associated with a higher frequency of repeated ejaculations with the same female, and with shorter refractory periods between repeated copulations. Increasing sperm competition level thus appears to select for male ability to ejaculate more rapidly and more frequently with each female mated. As prolonged copulations are known to reduce female remating rates, these findings indicate that males may experience opposing selection pressures on copulatory behaviour with respect to offensive and defensive aspects of sperm competition. We conclude that sperm competition is likely to be an important selection pressure explaining diversity in mammalian copulatory behaviour.     

The combined effects of pre‐ and post‐copulatory processes are masking sexual conflict over mating rate in Gerris buenoi

In polygynandrous animals, post‐copulatory processes likely interfere with precopulatory sexual selection. In water striders, sexual conflict over mating rate and post‐copulatory processes are well documented, but their combined effect on reproductive success has seldom been investigated. We combine genetic parentage analyses and behavioural observations conducted in a competitive reproductive environment to investigate how pre‐ and post‐copulatory processes influence reproductive success in Gerris buenoi Kirkaldy. Precopulatory struggles had antagonistic effects on male and female reproductive success: efficiently gaining copulations was beneficial for males, whereas efficiently avoiding copulations was profitable for females. Also, high mating rates and an intermediate optimal resistance level of females supported the hypothesis of convenience polyandry. Contrary to formal predictions, high mating rates (i.e. the number of copulations) did not increase reproductive success in males or decrease reproductive success in females. Instead, the reproductive success of both sexes was higher when offspring were produced with several partners and when there were few unnecessary matings. Thus, male and female G. buenoi displayed different interests in reproduction, but post‐copulatory processes were masking the effects of copulatory mating success on reproductive success. Given the high mating rates observed, sperm competition could easily counter the effect of mating rates, perhaps in interaction with cryptic female choice and/or fecundity selection. Our study presents a complex but realistic overview of sexual selection forces at work in a model organism for the study of sexual conflict, confirming that insights are gained from investigating all episodes in the reproduction cycle of polygynandrous animals.