Male displays and female preferences in the courtship of a gregarious cricket

The courtship of males of the gregarious cricket Amphiacusta maya involves a variety of signals. The quantitative aspects of both successful and unsuccessful courtship sequences were examined to determine whether certain aspects of male displays were correlated with female mating preferences regardless of which male performed them. Although variability among males was high for most courtship components measured, I found no evidence of female choice with respect to the courtship variables studied. About 35% of the duration of each male courtship sequence is devoted to chirping, but there were no differences in either the likelihood of copulation or the latency to copulation between normal males and experimentally silenced males. The possibility that intrinsic differences in male quality explained the variability in courtship duration was examined with a two-way analysis of variance. The variance in courtship duration was attributable to variance among females, not to variance among males. Thus the courtship behaviour of male A. maya is variable enough to allow females to exert stabilizing or disruptive selection on displays, but there is no evidence that females use the available information.     

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.     

Courtship in two species of periodical cicadas, Magicicada septendecim and Magicicada cassini

Courtship behaviour of two species of periodical cicadas, Magicicada septendecim and M. cassini, was studied in the field during the 1970, 1973, and 1974 emergences of these insects. In areas where both species were courting there were differences in both male and female courtship patterns, both in acoustic and behavioural components. Experiments with models showed that male M. septendecim were more likely to court crude models of females than were M. cassini males. When females were ‘courted’ with models that could imitate some of male courtship, they were more receptive when the models' ‘songs’ were those of conspecific males. Acoustic differences between species are probably used by females in mate selection, maintaining species separation even in areas where the two species overlap in both space and time.     

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.      

Reproductive behaviour of female Chorthippus biguttulus grasshoppers

Female grasshoppers of acoustically communicating species assume series of reproductive states that are associated with particular behaviours. Studies on laboratory populations of Chorthippus biguttulus (L.) revealed that females of this species lack the period of ‘passive copulatory readiness’, increase their attractiveness to males by sound production and mate multiple times before their first oviposition. In particular, female Ch. biguttulus display a period of ‘primary rejection’ after their imaginal moult during which they reject male mating attempts followed by a period of ‘active copulatory readiness’ in which they produce acoustic signals and may copulate with courting males. Female stridulation generally stimulated male mating activity and stridulating females attracted more male mating attempts than mute females in the same cage, indicating that males preferentially court females that signal ‘active copulatory readiness’. After receipt of a spermatophore, Ch. biguttulus females displayed periods of ‘secondary rejection’ followed by re-establishment of ‘active copulatory readiness’. Acoustic responses of females to male songs, an indicator of reproductive readiness, were significantly reduced until 2 days after mating and remained slightly reduced in comparison to pre-mating levels. Some females mated multiple times before their first oviposition and cycled between ‘secondary rejection’ and ‘active copulatory readiness’.     

The chemical basis for sex recognition in Drosophila melanogaster

Chemical cues were recognized to play a predominant role in initiating male courtship behaviour in Drosophila melanogaster as measured by the number and duration of wing-vibration responses elicited in test males. The effect was associated with compounds specific to the female cuticle, for which we describe a simple extraction procedure. Female active extracts were compared with behaviourally non-active extracts from males, using gas-liquid and thin-layer chromatography. Using these preparative methods, long-chain hydrocarbons were isolated and activity was found only among unsaturated molecules. One, heptacosadiene, inducing the highest level of courtship, appears to be the main aphrodisiac pheromone of the female D. melanogaster. This compound is specific to females of the species and is the most abundant of their cuticular hydrocarbons.     

Effects of male paragonial gland secretion on sexual receptivity and courtship behaviour of female Drosophila melanogaster

Female Drosophila melanogaster show a switch-off in sexual receptivity and an increase in oviposition rate following impregnation. These effects are also observed in unfertilized virgin females which receive transplants of intact male paragonia into the abdominal body cavity. Virgin Amherst wildtype females show a repertoire of responses to male courtship characterized by high rates of kicking and fending and a low rate of genital extrusion. Fertilized females show low rates of kicking and fending but a high rate of genital extrusion. Virgin female hosts receiving paragonial gland implants show an altered pattern of courtship rejection with low rates of kicking and fending. Studies on these host females, and on females homozygous for the mutant allele female-sterile, suggest that the expression of genital extrusion depends, in addition to the paragonial gland substance, upon additional information input from abdominal stretch receptors or from the ovary.     

The Role of Males in Host-Fruit Selection by Females of a Walnut Infesting Tephritid (Diptera) <Emphasis Type="Italic">Rhagoletis zoqui</Emphasis>

Rhagoletis zoqui Bush flies have a mating system in which males guard and defend walnut fruit-hosts from other males and mate, apparently without courtship, with females as they arrive to oviposit. Hypothetically, female selection of a particular fruit may be due to the quality of fruit for larval development (previously determined by guarding males), the quality of the male upon the fruit as a mate, or both, but this is not clear. We performed an experiment to determine if R. zoqui females or males select the fruit to oviposit or guard based on its quality for larval development (i.e., size, sugar-content [brix] or hardness), or following male-mediated cues such as chemical residues, related to prior fruit occupation by the male during guarding. Fruit choice by R. zoqui females and males were examined under semi-natural conditions on caged branches of English walnut trees, Juglans regia L., growing in the highlands of south-central Mexico. A single male or female was allowed to select a fruit and was then removed. An individual of the opposite sex was then introduced to the same branch and presented with the opportunity to choose among the same array of hosts. The pattern of fruit choice was consistent, with female choice on the basis of male presence, suggesting that males left a chemical cue that persisted in their absence. No fruit quality differences were detected between selected and non-selected fruit. Fruit features selected by females and males matched almost exactly, although males rarely select the same fruit as females. We conclude that females preferentially selected fruit previously occupied by males although additional studies are required to determine the cues used by R. zoqui for oviposition resource selection by both females and resource guarding males.     

Eavesdropping in crabs: an agency for lady detection

Although conspicuous courtship displays are an effective way of attracting the attention of receptive females, they could provide valuable information to rival males on the location of these females. In fiddler crabs, males that see a receptive female wave their single, greatly enlarged claw in a highly conspicuous courtship display. We test whether other males use this courtship display to alert them to the presence of receptive females that they cannot directly see. We show that male fiddler crabs (Uca mjoebergi) eavesdrop on the courtship displays of nearby males to detect mate-searching females. This allows males to begin waving before a female becomes visible. Furthermore, males appear to adjust their waving according to the information available: eavesdropping males wave 12 times faster than non-courting males but only 1.7 times slower than males in full visual contact with the female.     

Drosophila Ovipositor Extension in Mating Behavior and Egg Deposition Involves Distinct Sets of Brain Interneurons

Oviposition is a female-specific behavior that directly affects fecundity, and therefore fitness. If a fertilized female encounters another male that she has evaluated to be of better quality than her previous mate, it would be beneficial for her to remate with this male rather than depositing her eggs. Females who decided not to remate exhibited rejection behavior toward a courting male and engaged in oviposition. Although recent studies of Drosophila melanogaster identified sensory neurons and putative second-order ascending interneurons that mediate uterine afferents affecting female reproductive behavior, little is known about the brain circuitry that selectively activates rejection versus oviposition behaviors. We identified the sexually dimorphic pC2l and female-specific pMN2 neurons, two distinct classes of doublesex (dsx)-expressing neurons that can initiate ovipositor extension associated with rejection and oviposition behavior, respectively. pC2l interneurons, which induce ovipositor extrusion for rejection in females, have homologues that control courtship behavior in males. Activation of these two classes of neurons appears to be mutually exclusive and each governs hierarchical control of the motor program in the VNC either for rejection or oviposition, contributing centrally to the switching on or off of the alternative motor programs.     

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.     

Inhibition of female mating receptivity by male-derived extracts in two Callosobruchus species: Consequences for interspecific mating

We investigated the effects of injecting male-derived extracts on congeneric female receptivity in two species of Callosobruchus beetle, C. chinensis and C. maculatus. We also examined the influence of interspecific mating on female remating behaviour in these two species. Male-derived extracts reduced congeneric female receptivity in both species. As quick-acting components, extracts of C. chinensis male seminal vesicles reduced the receptivity of C. maculatus females, whereas extracts of C. maculatus male testes reduced the receptivity of C. chinensis females. As slow-acting components, extracts of male accessory glands of other species reduced the receptivity of both C. maculatus and chinensis females. After interspecific mating, the sperm of C. maculatus males were transferred to the reproductive organs of C. chinensis females, thereby reducing their receptivity. In contrast, no C. chinensis sperm were transferred to the reproductive organs of C. maculatus females; accordingly, the latter's receptivity was not reduced. Furthermore, the survival rate of C. chinensis females decreased markedly after interspecific mating. These results raise the possibility that under circumstances where populations of these two species share the same habitat, reproductive interference would occur only in the interactions between C. maculatus males and C. chinensis females.     

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.     

Wing pigmentation in territorial male damselflies, Calopteryx haemorrhoidalis: a possible relation to sexual selection

One striking characteristic in adult males of some odonate species is the presence of wing pigmentation. In Calopteryx species, males show a series of pre- and postcopulatory behavioural displays during which they face females while showing their pigmented wings. One hypothesis to explain the precopulatory flying displays and the associated wing pigmentation is that they may serve a sexual selection function. I investigated this in the territorial damselfly Calopteryx haemorrhoidalis. Males of this species defend aquatic substrates that females use for oviposition. Observational evidence indicated that males with a higher proportion of wing pigmentation were more likely to defend a territory, obtained more matings, had fewer gut parasites, survived in the study site and stayed in territories for longer. Experimental evidence suggested that the relationship mating success and wing pigmentation still held when controlling for the size of the substrate defended by territorial males. Similar to other studies in the Calopterygidae, these results suggest that wing pigmentation may be favoured by sexual selection. I discuss, however, whether an alternative function for male copulatory courtship displays and wing pigmentation, as sexual and/or species recognition, may also explain the evolution of these traits. Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved.     

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.     

Differential responses of yellow-breasted chats, Icteria virens, to male and female conspecific model presentations

A detailed understanding of the behavioural interactions between males and females is crucial for elucidating the selection pressures shaping mating system evolution; however, these interactions are often difficult to observe, particularly in free-living populations. We simulated extraterritorial intrusions by presenting conspecific models on to territories of a Neotropical migratory passerine, the yellow-breasted chat, Icteria virens. Simulated intrusions elicited different responses based on the sex of the focal individual and the sex and species of the model. Behavioural responses of the focal individuals were largely directed towards conspecific models, whereas simulated heterospecific intrusions, using a Carolina wren, Thryothorus ludovicianus, model, elicited minimal response. Male song was not related to any particular model presentation. Males directed mating behaviours, including courtship displays and copulations, exclusively towards the female conspecific model. Males behaved aggressively towards the conspecific male model. In contrast, females never showed any courtship behaviour towards the male model and showed significant aggression towards the conspecific female model. The results of this study reveal that territorial aggression in yellow-breasted chats is strongly intrasexual. Additionally, simulated female extraterritorial intrusions, but not male intrusions, resulted in extrapair courtship and copulation. This pattern is likely to be typical of many socially monogamous species and points to the behavioural mechanisms underlying both monogamy and extrapair mating systems.     

Physiological regulation of long-term oviposition in the house cricket, Acheta domesticus

In house crickets [Acheta domesticus (L.)] a single mating early in adult life sufficed to induce egg laying for the duration of the life of a female. Female house crickets mated readily shortly after adult emergence but oviposition did not commence until about 12–14 days after emergence, even though females matured eggs by 7 days. The egg-laying factor associated with mating remained active during prolonged periods of substrate deprivation during which the female did not oviposit. If the spermatophore was removed prematurely shortly after a mating, the long-term, egg-laying response was truncated and was correlated with a dramatic decline in the fertility of eggs which were oviposited. The egg-laying stimulus appeared to act in the spermatheca, apparently through neural means, since denervation of the spermatheca abolished mating-induced oviposition. These results indicate that the oviposition factor found in the testes is able to act for long periods of time and has to be present continually in order to be effective. Furthermore, the long-term oviposition stimulus in the house cricket may be different from prostaglandin E2 which induces a prompt ovipositional response.     

Decapitated females as a tool in the analysis of Drosophila behaviour

Decapitated females provide a method of arranging variable stimulus environments to evaluate components of behaviour involved in sexual and frequency dependent selection. Conspecific matings are bypassed via male preference for normal females per se. Presence of conspecific decapitatated females induces male to increase insemination of alien females. Discrimination mechanisms, including sign stimuli, are the least labile, and excitability is the most labile component of courtship. D. subpalustris males with abnormal stimulation use a qualitatively different courtship element not present in their normal repertoire. An efficiency index (courtship/insemination) shows D. palustris males, with more heterogenous stimulation in their courtship, more effective in overcoming female reluctance. Sexual isolation may differ operationally from sexual selection in the necessity for particular stimuli rather than more stimulation.     

Male singing behaviour and female presence in the territory in whitethroats Sylvia communis

Unmated male songbirds usually change their vocal behaviour when females enter their territories. Either the males court the females by changing the rate or pattern with which their normal long-ranging full songs are emitted, or they shift to special displays and long- or short-ranging vocalisations. In this study we quantified how female presence and behaviour affect the singing behaviour of male whitethroats. In the presence of a female the male frequently performed song flights, maybe to locate the female before it was courted, with sequences of diving-song displays. The courtship was interrupted by periods of perch songs. Female dscharp calls and short movements made the males initiate or resume courtship, whereas short horizontal jumps made the males intensify their courtship. Overall, the males changed their dual-function song activity in females' presence by emitting fewer perch songs and more flight songs. The quiet diving songs were only emitted during direct courtship of a female. The song types emitted immediately before, during, and after courtship are all highly variable, thus allowing for a quick assessment of the male's song repertoire. The courtship was also interrupted by periods of male woid calling, a call that is known to have a deterring effect on rival males. Bouts of woid calls were usually followed by song flights, again probably to locate the female that might have moved out of sight, or maybe to locate potential rival intruders. The latter was supported by an increased intrusion rate during female presence. Communicated by P. McGregor