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

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

The Influence of Pedipalp Autotomy on the Courtship and Mating Behavior of Pardosa milvina (Araneae: Lycosidae)

Male Pardosa milvina wolf spiders use their pedipalps both for copulation and courtship. Pedipalp loss is significantly more common among adult males compared to females. We measured the courtship and mating effects associated with the loss of one or both pedipalps among adult male P. milvina. Pedipalp loss significantly reduced courtship intensity, but had no influence on mounting success. Intact males were less likely to be cannibalized and suffered fewer predatory attacks by females than autotomized males. Loss of the left pedipalp resulted in significantly less intense courtship, higher female aggression levels, and delayed onset of courtship whereas loss of the right pedipalp minimally affected male and female behavior relative to intact males. Pedipalp displays may function in reducing female aggression rather than increasing female receptivity.     

Condition‐dependent male copulatory courtship and its benefits for females

Postcopulatory sexual selection has shaped the ornaments used during copulatory courtship. However, we know relatively little about whether these courtship ornaments are costly to produce or whether they provide indirect benefits to females. We used the mealworm beetle, Tenebrio molitor, to explore this. We challenged males using an entomopathogenic fungus and compared their courtship (frequency of leg and antennal contacts to the female), copulation duration, number of eggs laid, and hatching rate against control males. Infected males copulated for longer yet they reduced their leg and antennal contacts compared to control males. However, there was no obvious relation between infection, copulation duration, and courtship with egg production and hatching success. In general, our results indicate that the ornaments used during postcopulatory courtship are condition‐dependent. Moreover, such condition dependence cannot be linked to male fitness.     

Male dwarf chameleons assess risk of courting large, aggressive females

Conflict between the sexes has traditionally been studied in terms of costs of mating to females and female resistance. However, courting can also be costly to males, especially when females are larger and aggressively resist copulation attempts. We examined male display intensity towards females in the Cape dwarf chameleon, Bradypodion pumilum, in which females are larger than males and very aggressive. We assessed whether aggressive female rejection imposes potential costs on males and whether males vary their display behaviour with intensity of female rejection, female size or relative size differences. Males persisted in courtship after initial female rejection in 84% of trials, and were bitten in 28% of trials. Attempted mounts were positively associated with males being bitten. Males reduced courtship with increased intensity of female rejection. Male courtship behaviour also varied with female size: males were more likely to court and approach smaller females, consistent with the hypothesis that larger females can inflict more damage. These results suggest that, in addition to assessing female willingness to mate, male dwarf chameleons may use courtship displays to assess potential costs of persistence, including costs associated with aggressive female rejection, weighed against potential reproductive pay-offs associated with forced copulation.     

Visual and Olfactory Female-Borne Cues Evoke Male Courtship in the Aphid Parasitoid Aphidius colemani Viereck (Hymenoptera: Braconidae)

We investigated the courtship and mating behavior of the pan-tropical polyphagous endoparasitoid Aphidius colemani Viereck. The courtship and mating displays, the magnitude of male-male sexual approaches and the role of female-borne cues evoking male courtship behavior were quantified. The sequence of events leading to copulation in this parasitoid did not differ from that found for other braconids. Females refused to copulate more than once. Same-sex courtships were observed among males and their possible role in an adaptive context is discussed. Olfactory female-borne cues played a key role in eliciting the courtship responses of males. Males were attracted by freshly dead females, but not by dead females soaked in hexane, nor by visual cues from females alone. Intense male wing fanning behavior was elicited by crushed abdomens of virgin females, suggesting that the female abdomen is the source of a short-distance pheromone crucial in evoking male courtship. Further studies are required to clarify the exact nature of the chemicals involved.     

Reproductive behaviour of the white-tailed zygaenid moth,Elcysma westwoodii (Lepidoptera,Zygaenidae). II. Female mating strategy

Male white-tailed zygaenid moths.Elcysma westwoodii, often gather to a female to mate her. One of the factors that seems to cause male gathering is the females' tendency to refuse males. Field observations indicated that there was a relationship between the courtship duration, the copulation duration and egg fertilization: short courtship was followed by long copulation and oviposition of fertile eggs in the same day, while long courtship was followed by short copulation and failure of oviposition. This phenomenon may be the result of differences in male activity. More “fertile” males can reach copulation more quickly and continue it longer than males by limiting receptivity. This “passive female choice” seems to function in high male density. Long copulation usually continued until the female began oviposition.     

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

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

Do Male Veiled Chameleons,Chamaeleo calyptratus,Adjust their Courtship Displays in Response to Female Reproductive Status?

Variation in male courtship behavior may be due to inherent differences among males or may arise from males adjusting their courtship displays according to female responsiveness. Female veiled chameleons, Chamaeleo calyptratus , exhibit two distinctive suites of body coloration and behavior patterns that vary according to receptive and non-receptive stages of their reproductive cycle. We presented male chameleons with both receptive and non-receptive females, and recorded differences in their mating frequency, courtship intensity and courtship behavior patterns. As expected, males were more likely to court and attempt mating with receptive females. Although fewer males courted non-receptive females, their courtship displays were significantly longer than those directed towards receptive females. Males also adjusted the contents of their displays according to female reproductive condition. Certain behavior patterns were unique to courtship displays directed towards each class of females. Males exhibited the behavior pattern `head roll' only when paired with receptive females, and `chin rub' was displayed only during courtship of non-receptive females. We hypothesize that these differences in male courtship frequency, intensity and content reflect differences in female reproductive value. Although males may benefit from mating with both receptive and non-receptive females, the costs associated with courtship may depend on female responsiveness. Thus, males adjust their courtship tactics accordingly.     

Male Courtship Behavior and Weapon Trait as Indicators of Indirect Benefit in the Bean Bug,Riptortus pedestris

Females prefer male traits that are associated with direct and/or indirect benefits to themselves. Male–male competition also drives evolution of male traits that represent competitive ability. Because female choice and male–male competition rarely act independently, exploring how these two mechanisms interact is necessary for integrative understanding of the evolution of sexually selected traits. Here, we focused on direct and indirect benefits to females from male attractiveness, courtship, and weapon characters in the armed bug Riptortus pedestris. The males use their hind legs to fight other males over territory and perform courtship displays for successful copulation. Females of R. pedestris receive no direct benefit from mating with attractive males. On the other hand, we found that male attractiveness, courtship rate, and weapon size were significantly heritable and that male attractiveness had positive genetic covariances with both courtship rate and weapon traits. Thus, females obtain indirect benefits from mating with attractive males by producing sons with high courtship success rates and high competitive ability. Moreover, it is evident that courtship rate and hind leg length act as evaluative cues of female choice. Therefore, female mate choice and male–male competition may facilitate each other in R. pedestris. This is consistent with current basic concepts of sexual selection.     

Multiple male traits interact: attractive bower decorations facilitate attractive behavioural displays in satin bowerbirds

Sexually selected male courtship displays often involve multiple behavioural and physical traits, but little is known about the function of different traits in mate choice. Here, we examine female courtship behaviours to learn how male traits interact to influence female mating decisions. In satin bowerbirds (Ptilonorhynchus violaceus), successful males give highly aggressive, intense behavioural displays without startling females. Males do this by modulating their displays in response to female crouching, which signals the display intensity that females will tolerate without being startled. Females typically visit multiple males for multiple courtships before choosing a mate, and females show differing tolerance for intense displays during their first courtship with each male. We test three hypotheses that may explain this: (i) familiarity with the courting male; (ii) the order of the courtship in mate-searching; and (iii) the attractiveness of the courting male. We found that females are more tolerant of intense displays during first courtships with attractive males; this increased female tolerance may allow attractive males to give higher intensity courtship displays that further enhance their attractiveness. We then examined why this is so, finding evidence that females are less likely to be startled by males with better physical displays (bower decorations), and this reduced startling then contributes to male courtship success. This role of physical displays in facilitating behavioural displays suggests a novel mechanism by which multiple physical and behavioural traits may influence female choice.     

Males mate guard in absentia through extended effects of postcopulatory courtship in the parasitoid wasp Spalangia endius (Hymenoptera: Pteromalidae)

The proximal mechanisms leading to monandry have been little studied in most insect orders, including Hymenoptera. In the parasitoid wasp Spalangia endius, mated females are less attractive (less often mounted) than virgins and are unreceptive (unlikely to allow copulation). Which aspects of mating are responsible was tested by observing male responses toward females whose mating had been interrupted at various stages. All females were allowed to receive precopulatory courtship and to open their genital aperture to copulate. Then some were interrupted before copulation, some after copulation but before postcopulatory courtship, and some were allowed to complete postcopulatory courtship. Females that had copulated were not less attractive than females that had not. In contrast, females that had received postcopulatory courtship were clearly both less attractive and less receptive. Thus, postcopulatory courtship functions as extended mate guarding, by making the female less attractive and less receptive to subsequent males even after the original male is no longer present. The effect of postcopulatory courtship on female attractiveness was persistent but imperfect: when males were presented sequentially to mated females, most but not all males retreated without mounting, and a female could repulse more than twenty males in succession.     

The Effect of Limb Loss on the Courtship and Mating Behavior of the Wolf Spider Pardosa milvina (Araneae: Lycosidae)

Limb loss is common in the wolf spider Pardosa milvina, appearing in nearly one third of adult males but occurring less frequently among adult females and juveniles. Since males wave their first pair of legs during courtship displays, the reproductive consequences of limb loss may be significant. We measured the courtship and mating effects of the loss of one, two, or four legs among adult male P. milvina. Missing one or two legs did not significantly reduce a male's ability to mate, but missing four legs was detrimental to mating success, reduced both courtship intensity and copulation duration, and increased cannibalism frequency. Results suggest behavioral flexibility in compensating for limited leg loss and a defensive function of the anteriormost legs to thwart female cannibalism attempts.     

Mating behavior ofPhytoecia rufiventris Gautier (Coleoptera: Cerambycidae)

Sexual behavior between males and females, as well as between males, is described and discussed for the cerambycid beetlePhytoecia rufiventris. The beetles' taxis toward plants taller than average height brings the sexes together from a distance. A male may mount another individual (male or female) and attempt copulation without sex discrimination. The male can discern the sex of another individual only when the terminal part of his abdomen touches the ventral surface of the fifth visible sternite of the latter. No evidence of a sex pheromone is found in this species. Within 1.5–5.5 cm the substrateborne vibrations produced by a moving individual may be the important factor which elicits males to approach a moving individual and attempt copulation. If a female is receptive when a male touches her, he can copulate with her without any courtship display. However, if the female runs away and appears unreceptive, the male will perform courtship displays. Copulation is usually terminated by males. Homosexual behavior between males is discussed.     

The mating behaviour of the egyptian cotton leafworm moth, spodoptera littoralis (Boisd.)

A detailed study of courtship in Spodoptera littoralis showed that there were four significant behaviour patterns. The male flew to a calling female and hovered above her with his brushes fully extended. In response, the female lifted her wings, curved her abdomen and withdrew her pheromone gland. The male settled beside the female to pair and then moved to hang head downwards during copulation. Thirty percent of successful courtships lacked one of the main behaviour patterns. Nearly half the courtships observed did not end in copulation: none of these included all of four major behaviour patterns and the majority lacked two or three. Females often rejected males with a rapid flick of the wings. Antennaless males did not mate or extend the brushes in response to a calling female. Just over half of the antennaless females observed during 135-min tests mated with normal males, but courtship was abnormal. Olfactory cues appeared to be important to females in recognizing the courting male, since antennaless females did not wing flick, were significantly more likely to take to flight as the result of the male brush display and frequently failed to retract the pheromone gland during the latter states of courtship. The courtship behaviour of S. littoralis is compared with published accounts for other Noctuids.     

Complex Courtship Behavior in the Striped Ground Cricket, Allonemobius socius (Orthoptera: Gryllidae): Does Social Environment Affect Male and Female Behavior?

Complex courtship in the striped ground cricket, Allonemobius socius, involves a series of behaviors alternating between the sexes. We examined if complex courtship allows either or both genders to evaluate their mate and how mating behavior changes in different social environments. While complex courtship may allow discrimination by both sexes, here only females exhibited a preference. Males did not alter their courtship behavior or change spermatophore size for different size females. In contrast, females initiated copulation more quickly with bigger males possessing bigger spermatophores. In a different social environment (additional male, female, or both), males were less likely to omit courtship songs and female discrimination of mates changed. The distinct differences in male and female behavior suggest that subtle changes in social environment can have important consequences in structuring courtship and mating behavior.     

Genetic difference in female choice between two guppy populations

The pattern of mating preferences of female guppies, Poecilia reticulata, differs genetically between two Trinidadian populations. Males from the Aripo and Paria rivers of Trinidad differ in the extent and intensity of orange pigment in their colour patterns. The relative area of orange in Paria colour patterns was nearly twice that in Aripo colour patterns. To test the hypothesis that a difference in female mating preferences could have contributed to the difference in colour patterns, patterns of female choice between laboratory-reared Paria and Aripo females were compared. The frequency of sexual responses to male courtship displays was used to measure the average preference of females for individual males. Paria females discriminated significantly between Paria males based upon differences in the extent of orange in the colour pattern. Aripo females showed no evidence of discrimination between Paria males, and thus differed significantly from Paria females in choice behaviour. Neither group of females discriminated between Aripo males. These results are evidence that female choice behaviour can vary genetically within a species and suggest that differences in preferences may have contributed to divergence in colour patterns among guppy populations.     

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.     

同种雄性竞争对手的存在对星豹蛛雄蛛求偶和交配行为的影响

越来越多的研究发现,雄性产生精子(精液)也需付出代价。雄性除了依据配偶质量和竞争对手的竞争强度适应性调整生殖投入外,雄性在求偶和交配行为上也相应产生适应性反应,求偶和交配行为具有可塑性。目前雄性求偶和交配行为可塑性研究主要集中于雌性多次交配的类群中,在雌性单次交配的类群中研究甚少。以雌蛛一生只交配一次而雄蛛可多次交配的星豹蛛为研究对象,比较:(1)前一雄性拖丝上信息物质对后续雄蛛求偶和交配行为的影响,(2)雌雄不同性比对雄蛛求偶和交配行为的影响。研究结果表明,星豹蛛前一雄蛛拖丝上的信息物质对后续雄蛛求偶潜伏期、求偶持续时间和交配持续时间都没有显著影响,但前一雄蛛拖丝上的信息物质对后续雄蛛求偶强度有显著抑制作用。同时,性比对星豹蛛雄蛛求偶和交配行为都没有显著影响。可见,星豹蛛雄蛛对同种雄性拖丝上的化学信息可产生求偶行为的适应性调整,而对性比不产生适应性反应。     

Pheromonal inhibition of male courtship behaviour in the brown tree snake, Boiga irregularis: a mechanism for the rejection of potential mates

Pheromones play a central role in coordinating the events leading up to copulation in snakes. We report here a novel pheromone system in the brown tree snake in which females release a pheromone that inhibits male courtship behaviour. In a previous study, we made observations of female brown tree snakes releasing cloacal secretions (CS) during courtship that appeared to cause courting males to cease courtship. All snakes have glands that release CS through ducts located along the cloacal orifice. Although CS have been studied for many years, their function in the mediation of snake behaviour has not been experimentally well determined. We examined the role of CS in the reproductive behaviour of male and female brown tree snakes. We conducted four experiments to test the effect of both male and female CS on brown tree snake behaviour under two behavioural contexts, courtship and male-male ritualized combat. Within each experiment, we compared the effects of CS to a control. Female CS caused a decrease in the time that males spent courting females and a decrease in the intensity of courtship compared with the control treatment. Male CS did not, however, affect the time that males spent displaying courtship or the intensity of that courtship. Neither male nor female CS had significant effects on male ritualized combat behaviour, including time that males spent in combat or the intensity of combat behaviours displayed. Furthermore, neither female nor male CS had an effect on female courtship versus controls. The inhibition of brown tree snake reproductive behaviours is specific to female CS inhibiting male courtship behaviour. This pheromone acts in concert with the female sex pheromone to regulate the events leading to copulation.Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.      

Female and male interactions during courtship in Calopteryx maculata and C. dimidiata (Odonata: Calopterygidae): Influence of oviposition behaviour

Calopteryx maculata and C. dimidiata damselfly females respond to male courtship with specific displays which signal differences in their receptivity. These include a rejection (wing spreading) and an invitation (wing-flipping) display, as well as a neutral (sit still) response. There are interspecific differences in the likelihood of each female display and in male responses to these displays. C. maculata males persist in courtship irrespective of female response, while C. dimidiata males generally stop courting when the female's response is rejection or neutrality. I suggest that these differences result from interspecific differences in oviposition behaviour. Female C. maculata oviposit at the water surface, which exposes them to disturbance by males attempting to mate. Females are therefore likely to remate to secure postcopulatory guarding when changing oviposition sites and males are expected to be persistent in courtship. Female C. dimidiata submerge to oviposit, which frees them from male disturbance and means that males have less control over female access to oviposition sites. Males therefore have less influence on mating by females and are expected not to persist in courtship of non-receptive females.