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Summary While animals navigating the real world face a barrage of complex sensory input, their brains have evolved to perceptually compress multidimensional information by selectively extracting the features relevant for survival. For instance, communication signals supporting social interactions in several mammalian species consist of acoustically complex sequences of vocalizations, however little is known about what information listeners extract from such time-varying sensory streams. Here, we utilize female mice’s natural behavioural response to male courtship songs to evaluate the relevant acoustic dimensions used in their social decisions. We found that females were highly sensitive to disruptions of song temporal regularity, and preferentially approached playbacks of intact male songs over rhythmically irregular versions of the songs. In contrast, female behaviour was invariant to manipulations affecting the songs’ sequential organization, or the spectrotemporal structure of individual syllables. The results reveal temporal regularity as a key acoustic cue extracted by mammalian listeners from complex vocal sequences during goal-directed social behaviour. Highlights - Natural behaviour is used to probe how mouse listeners encode vocal sequences - Listeners are highly sensitive to disruptions of the songs’ rhythmic regularity - Female behaviour is invariant to changes in song sequence - Approach behaviour is robust to the removal of syllable spectrotemporal dynamics

Biologists have long been fascinated by the elaborate courtship displays performed by diverse organisms throughout the animal kingdom. The evolution of courtship behaviour often requires specializations of neural, sensory and motor systems. In addition, physically impressive displays may also require optimized metabolic, respiratory and cardiovascular systems to sustain the neuromuscular demands. Hormonal signalling can reach all of these tissues simultaneously to prepare them for use in courtship. Studies of male golden-collared manakins, Manacus vitellinus, a small bird of the Neotropics with a physically intense and noisy courtship display, have uncovered numerous androgen-dependent neuromuscular and metabolic specializations that enable not only the performance of elaborate courtship routines, but also their evolutionary exaggeration. However, physiological specializations for one function can create limits on their use for other purposes. Such trade-offs may influence the way courtship develops but may also provide information used by females for mate choice. We review this body of work with an eye towards expanding our appreciation of the evolution of widespread tissue hormone sensitivity and hormone action as the system through which elaborate courtship behaviours evolve.

Animals perform a series of actions in a fixed order during ritualistic innate behaviors. Although command neurons and sensory pathways responding to external stimuli that trigger these behaviors have been identified, how each action is induced in a fixed order in response to multimodal sensory stimuli remains unclear. Here, the sexually dimorphic lateral antennal lobe tract projection neuron 4 (lPN4) in maleDrosophila melanogastermediates the expression of a fixed behavioral action pattern at the beginning of the courtship ritual, in which a male taps a female body and then extends a wing unilaterally to produce a courtship song. We found that blocking the synaptic output of lPN4 caused an increase in the ratio of male flies that extended a wing unilaterally without tapping the female body, whereas excitation of lPN4 suppressed the transition from the tapping phase to the unilateral wing extension phase. Real-time calcium imaging showed that lPN4 is activated by a volatile pheromone, palmitoleic acid, whose responses were inhibited by simultaneous gustatory stimulation with female cuticular hydrocarbons, showing the existence of an “AND-gate” for multimodal sensory inputs during male courtship behaviors. These results suggest that the function of lPN4 is to suppress unilateral wing extension while responding to a female smell, which is released by appropriate contact chemosensory inputs received when tapping a female. As the female smell also promotes male courtship behaviors, the olfactory system is ready to simultaneously promote and suppress the progress of courtship actions while responding to a female smell.SIGNIFICANCE STATEMENTAlthough it has been 80 years since Konrad Lorenz and Niko Tinbergen introduced how multiple acts comprising separate innate behaviors are released in a fixed order according to external stimuli, the neural circuits responsible for such fixed action patterns remain largely unknown. The male courtship behavior ofDrosophila melanogasteris a good model to investigate how such a fixed behavioral sequence is determined in the brain. Here, we show that lateral antennal lobe tract projection neuron 4 (lPN4) inD. melanogasterfunctions as an “AND-gate” for volatile and contact chemosensory inputs, mediating the expression of tapping behaviors before unilateral wing extension during male courtship rituals.

Incorporating microsatellite techniques to determine parentage is a powerful addition to behavioral mating system studies in wild animals. Nonetheless, in some tetrapod taxa such as lizards, there are relatively few direct comparisons of individual reproductive success measured genetically versus estimates based on behavioral interactions, especially in species where males and females do not maintain prolonged social contact. We combined observations of behavior with microsatellite analysis of parentage over ten seasons in male Collared Lizards, (Crotaphytus collaris), to test the extent to which the proportion of each female’s total courtship interactions with different males predicted the proportion of total offspring sired by those males (proportion of paternity). Territorial males (T-males) court females frequently. Non-territorial (NT) males on the other hand behave stealthily. This allows them to court females, albeit less frequently, while limiting attacks by T-males. Both T- and NT-males occupied habitats that varied in structural complexity which might influence which males court and sire offspring with individual females, therefore we included habitat type (simple vs. complex) and male social tactic as possible predictors in our test. Proportion of courtship by NT-males did not predict their proportion of paternity in either habitat type. Courtship by T-males was a strong predictor of paternity in simple habitats but not complex habitats. Our findings support the hypothesis that courtship is a more accurate predictor of T-male mating success in simple habitats, which is consistent with previous findings suggesting that reduced area and topographical heterogeneity, especially the absence of subsurface crevices in simpler habitats, makes it more economical for T-males to prevent surreptitious mating by NT-males. Our study, therefore, highlights the importance of considering possible effects of alternative social tactics and variation in environmental conditions when testing the accuracy of behaviorally based estimates of breeding relationships, especially in polygamous species with multiple paternity.

Sexual signal evolution is shaped by whether only one or both sexes execute mate choice. When mate choice by both sexes is considered, the same signalling modality is generally inferred for males and females. In the noctuid moth Chloridea (Heliothis) virescens (Lepidoptera: Noctuidae), both sexes may be signallers and responders, as both emit a sex-specific pheromone. Male mate choice is based on the female sex pheromone, perceived via the antennae, and has been well documented. However, whether females choose partners and whether their choice is based on the male pheromone are unknown. Since female mate choice is expected when males vary in quality, we reared males on two different larval diets that affected their size, which correlated positively with their fitness. When given a choice, more females mated with larger than with smaller males, and these females produced more eggs and larvae. Female choice was not affected by the absolute amount or composition of the male pheromone. Moreover, we found that antennaless females mated as readily as intact females, indicating that antennal sensory input is not required for females to mate. To determine whether females make an active choice, we studied courtship behaviour in detail and observed that females determined the outcome of courtship by moving away from the male (avoidance) or by facilitating copulation with an abdominal bend (acceptance). Additionally, we discovered that tactile sensory stimuli may be involved during courtship. Because tactile interactions may mediate contact-based (chemical) communication, we also investigated putative pheromone components on moth legs, but found no differences between the sexes. Together, our study is the first comprehensive investigation of female mate choice in a heliothine moth.

Reproductive behaviour is often targeted by behavioural parasitism due to its high energy costs and direct relationship with fitness. Courtship behaviour represents a substantial amount of the investment in reproduction, as it usually requires conspicuous movements that are energetically demanding and increase predation risk. Here, we present an alternative reproductive tactic in which dominant male sailfin tetra, Crenuchus spilurus Gunther 1863, parasitize the courtship behaviour of subordinate males. By conducting field observations and controlled experiments in laboratory, we show that, under low availability of nesting sites, dominant males favour a close-range defence of nesting sites, while subordinate males invest more in courtship activities. However, subordinate males often directed courtship movements towards a nesting site dominated by a concealed dominant male, who subsequently took over the female and resumed courtship. Our laboratory experiment also showed that only dominant males obtained spawning success regardless of the amount of effort allocated to courtship behaviour, circumventing the initial female preference for the subordinate male. Subordinate males were more likely to initiate contests and ceased courtship upon losing aggressive contests. In such instances, the courtship effort of dominant males was higher, suggesting that dominant males modulate their courtship effort according to the effort of subordinate males. We refer to this tactic as courtship piracy. For being dependent on resource defence, the effectiveness of courtship piracy is contingent on the defendability of nesting sites. In a follow-up experiment, we show that dominant males invest more in nesting site defence only when nesting sites are scarce. Since rainfall controls the amount of nesting sites in the natural habitat, we suggest that seasonality modulates the relative contribution of courtship piracy and female mate choice to reproductive success.

Across animal taxa, individuals eavesdrop upon courting conspecific males, often in an attempt to steal mating opportunities. While multimodal signals can increase the likelihood that choosers respond to courters, such multimodal signals might also attract the unwanted attention of conspecific eavesdroppers. Previous studies of the brush-legged wolf spider, Schizocosa ocreata, demonstrate that field-experienced males court in response to visual displays of conspecific male courtship more than do laboratory-raised males. Furthermore, other studies demonstrate that males can learn to associate visual signals with the presence of a nearby female. Male S. ocreata, however, use a combination of vibratory and visual signals in their multimodal courtship display. Whether such associative learning varies based on which signal modality is experienced or whether multimodal signals result in enhanced learning remains unknown. Consequently, we examined eavesdropping on courtship behaviours of S. ocreata, with added emphasis on learning to respond to unimodal versus multimodal playback. We used vibratory and video playback techniques to test whether associative learning results in varied courtship levels when males associate unimodal or multimodal courtship signals with the presence of a nearby female. Results show that male S. ocreata associated courtship playback with the presence of a nearby female (i.e. courted at higher levels), regardless of whether courtship playback was unimodal or multimodal, demonstrating that male S. ocreata are capable of learning in multiple modalities. Multimodal playback, however, did not appear to enhance males’ ability to associate conspecific courtship signals with female cues. Courtship behaviours were greater in response to vibratory playback, though, suggesting that male S. ocreata weight modalities differently than females do. We further discuss the implications of this result regarding the communication network of S. ocreata.

Reproductive behaviour is generally under strong natural and sexual selection, meaning that variation in mate attraction investment reveals important fitness trade-offs. Nevertheless, in many taxa with sex-specific displays, individuals differ considerably in such investment. Male white-ruffed manakins, Corapipo altera (Pipridae), exhibit dramatic variation in display investment, despite having a mating system shaped by strong sexual selection. We tested three alternative hypotheses that could explain this variation: (1) individual quality and condition, (2) competition or (3) cooperation. We manipulated the social environment of male manakins at display sites in two experiments. First, we increased the acoustic signalling around focal males’ display sites by broadcasting the sounds of other displaying males to simulate elevated display of neighbouring males. Second, we temporarily prevented neighbouring males from using their display sites, thereby increasing the competition at focal display sites. Males reduced rates of vocalization in response to elevated acoustic signalling, suggesting that males may cooperate with neighbours to advertise the locations of leks, minimizing their individual effort when possible. The number of individuals at the focal display site and the number of silent displays increased when neighbours were prevented from displaying nearby, consistent with the competition hypothesis. However, the constancy in time investment and rates of other display behaviours throughout both manipulations suggests that male quality or condition underlies much of the individual variation in behaviour at display sites. Overall, our results are consistent with cooperation and individual quality mediating individual investment in display site advertisement. While manipulations created opportunities for competition, the responses of focal males were not consistent with antagonist social interactions affecting investment in display. This work demonstrates the importance of both intrinsic and social drivers shaping investment in courtship behaviour and highlights the potential for multimodal displays to facilitate cooperation.

Pair formation in ducks is thought to be influenced by the acquisition of breeding plumage, the occurrence of courtship display, or both. We examined the frequency of pair formation in Mallard (Anas platyrhynchos), Green-winged Teal (Anas crecca carolinensis), and Northern Shoveler (Spatula clypeata) in the central valley of California in relation to the frequencies of male attainment of breeding plumage and courtship display. Predictions related to two hypotheses are: (1) the timing of pair formation is directly related to the attainment of breeding (definitive alternate) plumage by males, and (2) frequencies of courtship display are highest during pair formation. Most female Mallard were paired by the end of October, with >80% in pairs by early December. Of Northern Shoveler, 90% were paired by early January and 90% of female Green-winged Teal were paired by early February. The highest rates of courtship display by Mallard were observed during October through November, by Northern Shoveler in November, and by Green-winged Teal in November through January. Courtship display was, therefore, relatively frequent at the same time as pair formation for all three species. Northern Shoveler spent less time in courtship display than the other two species. Most (90%) male Mallard had acquired alternate plumage by mid-November, Northern Shoveler by early February, and Green-winged Teal by mid-December. Thus, timing of pair formation coincided with timing of attainment of breeding plumage in Mallard and Green-winged Teal but not Northern Shoveler.

The Northern chamois (Rupicapra rupicapra) is a weakly polygynous species widely distributed in the mountain regions of Europe and the Near East. The Balkan chamois (R. r. balcanica) occurs in the mountain regions of southeastern Europe, and its ecology and behavior during the rut are largely unknown, making it one of the most understudied subspecies of chamois. Despite the scarce body mass dimorphism, males display a developed behavioral polymorphism that affects the mating success and possibly survival. Here, we provide the first quantitative analysis of the behavioral repertoire and activity budget of rutting male Balkan chamois and compare frequencies of different behavioral categories (i.e., courtship and direct and indirect aggression) with those observed in Alpine (R. r. rupicapra) and Tatra (R. r. tatrica) chamois. Male Balkan chamois have a rich behavioral repertoire (24 different behavioral patterns) with a prevalence of courtship behaviors and a higher frequency of indirect than direct forms of aggression. Compared with Alpine and Tatra chamois, no significant difference in the frequency of different behavioral categories was detected. The activity budget showed that when not rutting, males spent ~ 41% of their time foraging and ~ 59% lying down. Time spent rutting was negatively correlated with time spent foraging and time spent lying down, suggesting that time spent for mating activities increased at the expense of foraging and resting. In dominant males, the frequency of courtship behavior was higher than the frequency of aggressive behaviors, whereas in subordinate males, no differences were detected among behavioral patterns. Furthermore, no significant differences in activity budgets were detected between male types. This is the first report of Balkan chamois rutting behavior and provides important insights into the ecology of a poorly known subspecies.

Mating in ants often occurs on the wing during nuptial flights or on the ground when scattered female sexuals attract males by pheromones. In both scenarios, there is little opportunity for males to engage in prolonged aggressive competition or elaborate courtship displays. Male morphology is therefore adapted to locating female sexuals and mating, and it lacks specific weapons or other traits associated with courtship. In contrast, sexuals of the ant genus Cardiocondyla typically mate in their natal nests. As a consequence, in many species winged males have been replaced by wingless fighter or territorial males, which kill or expel rival males with their strong mandibles and show complex mating behavior. However, no wingless males are known from Cardiocondyla zoserka from West Africa, and instead, winged males have evolved a bizarre secondary sexual trait: uniquely shaped antennae with spoon‐like tips that show heavily sculptured ventral surfaces with numerous invaginations. We here report on the courtship behavior of C. zoserka males and describe antennal glands with class 3 gland cells, which presumably secrete a close range sex pheromone. Antennal glands have not yet been found in males of other ant species, including a close relative of C. zoserka, suggesting that in ants with intranidal mating sexual selection can rapidly lead to highly divergent adaptations and the evolution of novel structures.

Although reproductive behavior is of general interest in evolutionary studies, ecology, and conservation of biodiversity, there are relatively few records on courtship behavior for several animal groups, which include birds, one of the most well-studied vertebrates. Herein we report novel information on a poorly known Neotropical owl species, by reporting courtship displays of the Black-banded Owl (Strix huhula), registered in the Brazilian western Amazon. We describe two events of courtship exhibited by a pair of S. huhula, including vocalization patterns, body movements, and courtship feeding, which suggests that this species possess complex social behavior. Our study provides pivotal information to the understanding of the reproductive biology of the Black-banded Owl and others owl species with similar patterns of reproduction and courtship behavior.

For drug resistance patients, removal of a portion of the brain as a cause of epileptic seizures is a surgical remedy. However, before surgery, the detailed analysis of the epilepsy localization area is an essential and logical step. The Electroencephalogram (EEG) signals from these areas are distinct and are referred to as focal, while the EEG signals from other normal areas are known as nonfocal. The visual inspection of multiple channels for detecting the focal EEG signal is time-consuming and prone to human error. To address this challenge, we propose a novel method based on differential operator and Tunable Q-factor wavelet transform (TQWT) to distinguish the focal and nonfocal signals. For this purpose, first, the EEG signal was differenced and then decomposed by TQWT. Second, several entropy-based features were derived from the TQWT subbands. Third, the efficacy of the six binary feature selection algorithms, binary bat algorithm (BBA), binary differential evolution (BDE) algorithm, firefly algorithm (FA), genetic algorithm (GA), grey wolf optimization (GWO), and particle swarm optimization (PSO), was evaluated. In the end, the selected features were fed to several machine learning and neural network classifiers. We observed that the PSO with neural networks provides an effective solution for the application of focal EEG signal detection. The proposed framework resulted in an average classification accuracy of 97.68%, a sensitivity of 97.26%, and a specificity of 98.11% in a tenfold cross-validation strategy, which is higher than the state of the art used in the public Bern-Barcelona EEG database.

We investigated the significance of sexual maturity, courtship behaviour and mating refusals in an aphidophagous ladybird, Coccinella transversalis Fabricius using four mating combinations, viz. virgin couple, previously mated couple, virgin male x mated female, and mated male x virgin female. Adult females and males attained sexual maturity at a very early age of 3.47 ± 0.32 and 4.02 ± 0.75 days after emergence respectively revealing slight protogyny. Early sexual maturity trait enables early initiation of sexual activities leading to increase in its population dynamics. The male courtship displays were prominent in virgins than in the non-virgins, which indicate that males perhaps resort to courtship when they are mating for the first time. The duration of copula (24.70 ± 4.50 min) and the number of bouts (343.60 ± 56.53) were greater in the copulation of non-virgins than that of the virgins (17.19 ± 5.19 min of copulation with 265.90 ± 79.73 bouts). The female mating refusals were higher in mated females than in virgins suggesting that females resist to re-mate due to probable sufficiency of single mating for their progeny. Both early sexual maturity and increased incidences of mating refusals by the mated females seemingly are traits that favour sexual selection. Attainment of early sexual maturity and offspring production might help mass-rearing of C. transversalis for the aphid biocontrol programme.

Thomas Hardwicke's acquisition of drawings of the lesser bird of paradise ( Paradisaea minor) and the subsequent publication of his painting of the male bird performing its elaborate courtship ritual in J. E. Gray's Illustrations of Indian zoology are described.

Previous research on non-verbal courtship behavior (flirting) has been conducted almost exclusively with heterosexual participants and has relied upon an evolutionary-based, reproduction driven framework. This study extended beyond a reductionist perspective to examine the differential contributions of gender identity, traditional masculinity-femininity, gender role ideology, and sexual orientation in predicting flirting behavior. Results from 626 participants revealed that, across all participants, gender, masculinity-femininity, and gender role ideology were predictive of flirting techniques, while sexual orientation was not. Among self-identified men only, sexual orientation was predictive, until the introduction of masculinity-femininity into the model nullified the effect. Among self-identified women, only masculinity-femininity and gender role ideology predicted flirting behavior. The negligible predictive role of sexual orientation suggests that existing paradigms of flirting research may be adequate to capture experiences of flirtatious behavior among sexual minority individuals.

Insects are exposed to cadmium stress since cadmium pollution has increasingly become a serious global environmental issue. However, until now few studies have paid attention to the effect of heavy metals on insect reproductive behaviors. In our study, the courtship behaviors, mating behaviors and fecundity of beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) exposed to different concentrations of cadmium in artificial diets at larval stage were studied. The results showed that cadmium stress changed the courtship rhythm by significantly advancing or delaying the courtship starting time. Low dose of cadmium (0.2 mg/kg) increased the courtship frequency in the first two scotophases, but in the fourth phase, the two cadmium treatments reduced the frequency. The total courtship duration was significantly shortened in the first six scotophases except high dose of cadmium treatment (51.2 mg/kg) in the sixth dark phase. Paired adults did not mate after the seventh scotophase under low cadmium exposure, while high cadmium stress made the paired adults just copulate in the first four scotophases. The daily mating rate and total mating rate decreased with the increase in cadmium concentration. The number of eggs of low cadmium treatment was higher than that of control, but the difference was not significant; the number of eggs in high cadmium treatment was lower than that of control and low cadmium treatment. Our results indicate that cadmium exposure can disrupt the courtship rhythm for females and has negative influences on copulation behavior and high cadmium stress can reduce fecundity. Hence, the insect population increase will be affected by heavy metal pollution. Our study will provide scientific reference for environmental risk assessment of heavy metal pollution.

Drosophila melanogaster males reduce courtship behaviour after mating failure. In the lab, such conditioned courtship suppression, aka 'courtship conditioning', serves as a complex learning and memory assay. Interestingly, variations in the courtship conditioning assay can establish different types of memory. Here, we review research investigating the underlying cellular and molecular mechanisms that allow male flies to form memories of previous mating failures.

Bristle patches on the carapace behind the eyes were found for the first time in both males and females of the four species of mud crab Scylla spp. Electrocardiography revealed that the bristle patches of Scylla paramamosain were sensitive to touch (with a glass capillary) but not to chemical stimulation (with sugarcane juice). To elucidate the function of these touch signals, the courtship behaviour of S. paramamosain was video-recorded in a broodstock tank. A male approached a female, extended a walking leg over her carapace, touched her bristle patches with a dactyl, mounted her, and probed the bristle patches further with the third maxillipeds. Touch stimulus may be a signal for courtship in Scylla and one of the chain stimuli for the completion of mating behaviour.

Behavioural thermoregulation can ameliorate thermal stress but is costly. For species that court in a thermally stressful microhabitat, sexual selection via endurance rivalry favours individuals that are able and willing to endure harsh conditions in the courtship habitat, as retreats to a thermal refuge will reduce mating opportunities. The relative costs and benefits of refuge use versus continued courtship in the face of thermal risk, which vary across abiotic and biotic contexts, determine the optimal behavioural strategy. We examined the social and abiotic factors driving behavioural decisions related to thermoregulatory retreat in the fiddler crab Austruca mjoebergi. Male fiddler crabs perform a courtship display on the thermally stressful intertidal sediment surface. Time on the surface, and thus time available for display, was limited by high temperatures; as temperature increased, surface time decreased. Yet when presented with a stimulus female, males were more likely to perform the courtship display, displayed at a higher rate and increased time spent on the surface. These results demonstrate that behavioural decisions related to thermal retreat depend both on the abiotic conditions that influence the degree of thermal stress and on the social conditions that influence the reproductive prospects of the individual.

A new species of Alavesia (Empidoidea: Atelestidae), Alavesia wimpala sp. nov. is described from the mid-Cretaceous amber of Myanmar. Together with the recently described Alavesia longistylata H. Zhang & Wang in Zhang et al. 2020 and A. longicornuta Sinclair & Grimaldi, 2020 the herein described species Alavesia wimpala sp. nov. forms a distinct group of Alavesia Waters & Arillo, 1999 which we consider deserving a subgeneric level. Subgenus Pennonalavesia subgen. nov. is introduced here comprising three species. Males of these species have a very prolonged third segment of stylus bearing a long-oval pennon. The palpus is prolonged and blade- or ribbon-shaped. A catalogue to all 19 species of the genus is given as well as a key to Alavesia (Pennonalavesia subgen. nov.). The function of the prolonged antenna in display and courtship is discussed. Most probably the triangular shape of the wings with its broad base allows a hovering flight in these species to present the pennons at the end of stylus. These characters indicate a high derived courtship behaviour in these flies in the Cretaceous period. On the other hand a possible raptorial behaviour of the new species is suggested.

Within populations, individual males adopt different courtship tactics due to differences in their competitive ability, which may vary depending on the animal’s age and size. To test the hypothesis that mule deer (Odocoileus hemionus) and white-tailed deer (O. virginianus) males vary their courtship behavior based on their size, we conducted focal observations of 144 mule deer and 85 white-tailed males that varied in size, at a large grassland site in southern Alberta. The smallest mule deer males devoted more time to feeding, were less likely to engage in late-stage courtship than larger males and were less likely to move among female groups. Other males, including small white-tailed males, appeared to use a roving strategy to search for estrous females in different groups, which is consistent with recent research on male movements. Both medium and large males increased the time they spent in one-male groups, and specifically isolated pairs, as courtship advanced, presumably to reduce competition with other males. However, this trend was most pronounced for medium mule deer males, and for all size classes of white-tailed deer. In contrast, large mule deer males spent a similar proportion of time tending females in all group types. Our results identified potential size-dependent tactics for mule deer males. In contrast, white-tailed males of all sizes appeared to rely on a tactic of finding and tending estrous females in isolation from other males.

Sexual signals are often elaborate, even spectacular, behaviours. The reproductive rewards for successful display are great, but so are the potential costs. These costs include not only the resources needed to produce a display, but also resources required if the display evokes attack from a rival or predator. To maximize payoff, individuals must monitor both internal and external cues to adjust display effort. We know surprisingly little about how these competing demands are balanced. Leptin, a hormone secreted by adipose tissue, regulates energy allocation to functions as diverse as feeding, sleep, reproduction and immunity. Despite evidence that leptin influences reproductive trade-offs, its role as a putative regulator of courtship display is poorly understood. Here we examine the use of interoceptive and exteroceptive cues to modulate display effort in Alston's singing mouse, Scotinomys teguina. We manipulated individual perception of energy balance through intraperitoneal injection of exogenous leptin, and we manipulated social context through playback of conspecific song. Leptin-injected mice responded with song to playback more frequently and more quickly than saline-injected controls. Although leptin seems to promote increased song effort, we found that leptin also reduced song duration. Song effort increased after leptin injection and playback of conspecific songs. Understanding the mechanisms by which animals respond to internal and external cues broadens our understanding of context-dependent display as well as behavioural plasticity more generally.

Courtship displays have been traditionally considered stereotyped behaviours. Many elaborate courtships are displayed in specific locations or in courts prepared by the displaying individuals. Sudden environmental events may alter the spatial structure of the displaying site, and individuals should be able to cope with such disruptions. In some mating systems, courtship is the only or main trait used in mate choice. This is the case in lek mating systems where male mating success is highly skewed and intense sexual selection may drive the evolution of elaborate courtship. The golden-collared manakin is a lekking species of the Neotropical forests. Males have an elaborate courtship display that includes a series of acrobatic jumps within a court delimited by small saplings. The courtship ends with a jump on one of the saplings, called the mating sapling, which invites the female to copulate. The display of each male follows a consistent routine that males establish at the beginning of the reproductive season. We hypothesized that males possess behavioural flexibility to adapt their courtship behaviour to unpredictable environmental changes. We investigated the effects of a sudden disruption of the court configuration by placing a piece of bark on the mating sapling. Males gradually established a new display sequence with an alternative mating sapling, demonstrating a high level of behavioural flexibility that suggests the involvement of motor learning. When the bark was removed, some males reverted to the original sequence, showing retention of the original display sequence. Our study provides evidence for the involvement of motor learning in the establishment and adjustment of elaborate courtship displays.

Courtship and mating behavior were investigated in four species, representing three different genera, in the family Pachytroctidae. All exhibited a lengthy courtship in the male-above position followed by brief copulation in the female-above position with both facing in the same direction. This courtship behavior has not previously been observed in ‘Psocoptera’ and may be unique to Pachytroctidae. In three of the species in this study, the spermatophore remnant protruded from the tip of the male’s abdomen after copulation, and was immediately deposited on the surface of the experimental enclosure. Differences in courtship behavior of the two closely related and sympatric Tapinella species, described in this report, may represent reproductive isolating mechanisms. Under experimental conditions, we observed a male of each Tapinella species mount, court, and attempt to mate with a virgin female of the other species. In each case the female rejected the male and failed to mate. Implications relative to these behaviors are discussed. DOI links to videos are provided for easy access.

Females of the sevenspine goby Gymnogobius heptacanthus are more colorful and active in courtship display than males. Females tend to exhibit agonistic behavior in female-female competition reaching its highest level in their completed readiness to spawn. In addition, females are sex-role reversed, performing courtship displays. Fish behavioral patterns are rather simple. Thus, the level of male aggression is very low. They do not initiate any courtship display. The spawning ground is not a strictly-guarded site of importance. A small number of male spawners can be a key factor for the sex-role reversal occurrence.

Characterisation of distance sex pheromones in decapods is challenging, although great efforts have been made in this field in the past 50 yr. In a previous study, we identified a component of the distance (soluble) sex pheromone bouquet of the peppermint shrimp Lysmata wurdemanni as being a uridine-5’-di-phosphate (UDP)-like chemical. However, UDP itself does not elicit the full pre-copulatory ‘approach and follow’ behaviour in peppermint shrimp. Here, we tested the hypothesis that the UDP-like chemical is uridine-5’-tri-phosphate (UTP), a metabolic product of chitin synthesis, and that this is the component of the distance sex pheromone of L. wurdemanni. We ran a series of bioassays to examine whether UDP, UTP or mixtures of the 2 compounds elicit male mating behaviour. Our results showed that male L. wurdemanni responded to UTP by displaying stereotyped courtship behaviour—the same behaviour elicited from males when exposed to water that previously contained moulting females. Combining UTP and UDP did not enhance the intensity of this courtship behaviour. The minimum effective concentration of UTP found to elicit courtship behaviour in the male shrimp was between 10-6 and 10-7 M. HPLC analysis showed the presence of UTP in the moulting water of female shrimp and also the partial conversion of UTP to UDP during the sample preparation procedure. Both the bioassay and chemical analysis results presented in this study suggest that UTP is a component of the distance sex pheromone in L. wurdemanni, and that the major peak in the chromatogram of a L. wurdemanni pheromone identified in previous studies might be a breakdown product of UTP.

The existence of ovulatory-cycle shifts in women’s mate preferences has been a point of controversy. There is evidence that naturally cycling women in their fertile phase, compared with their luteal phase, evaluate specific behavioral cues in men as more attractive for sexual relationships. However, recent research has cast doubt on these findings. We addressed this debate in a large, preregistered, within-participants study using salivary-hormone measures and luteinizing-hormone tests. One hundred fifty-seven female participants rated the sexual and long-term attractiveness of 70 men in dyadic intersexual interactions in natural videos. Multilevel comparisons across two ovulatory cycles indicated that women’s mate preferences for men’s behaviors did not shift across the cycle for either competitive or courtship behavior. Within-women hormone levels and relationship status did not affect these results. Hormonal mechanisms and implications for estrus theories are discussed.

Background The hybridizing field crickets, Gryllus firmus and Gryllus pennsylvanicus have several barriers that prevent gene flow between species. The behavioral pre-zygotic mating barrier, where males court conspecifics more intensely than heterospecifics, is important because by acting earlier in the life cycle it has the potential to prevent a larger fraction of hybridization. The mechanism behind such male mate preference is unknown. Here we investigate if the female cuticular hydrocarbon (CHC) profile could be the signal behind male courtship. Results While males of the two species display nearly identical CHC profiles, females have different, albeit overlapping profiles and some females (between 15 and 45%) of both species display a male-like profile distinct from profiles of typical females. We classified CHC females profile into three categories: G. firmus-like (F; including mainly G. firmus females), G. pennsylvanicus-like (P; including mainly G. pennsylvanicus females), and male-like (ML; including females of both species). Gryllus firmus males courted ML and F females more often and faster than they courted P females (p Gryllus pennsylvanicus males were slower to court than G. firmus males, but courted ML females more often (p p G. firmus males). Conclusions Our results suggest that male mate preference is at least partially informed by female CHC profile and that ML females elicit high courtship behavior in both species. Since ML females exist in both species and are preferred over other heterospecific females, it is likely that this female type is responsible for most hybrid offspring production.

The red-sided garter snake exhibits a dissociated reproductive pattern, mating at a time when their gonads are quiescent and circulating sex steroids, initially reported to be low, have been found to be elevated during the breeding season. However, the only cue identified that initiates courtship behavior and mating in the red-sided garter snake is an extended period of low-temperature dormancy (LTD) followed by exposure to warm temperatures. In this study, we examined a possible association between winter dormancy, sex steroid hormone metabolism, and initiation of reproductive behavior in the male red-sided garter snake. Upon emergence from winter dormancy, courtship behavior was assessed using attractive females as stimuli. Animals receiving implants containing 1,4,6-androstatriene-3,17-dione (ATD), an aromatase inhibiter, showed little or no courtship behavior, while animals implanted with ATD + 17β estradiol (E2 ) or blank implants exhibited normal courtship. In addition, neurons in the pathways critical in the control of reproductive behavior were examined using the Golgi method. Examination of brains collected upon emergence revealed animals implanted with ATD had a significantly reduced number of dendritic spines compared to controls and animals treated with ATD + E2 . This study provides the first documentation that courtship behavior and mating in the male red-sided garter snake appears to be controlled not by LTD alone, but in conjunction with sex steroid hormones. Moreover, behavioral data suggest that the aromatization of androgens during LTD appears to be critical for the initiation of reproductive behavior in the male red-sided garter snakes.

Previously, we described gene factor of interpulse interval (fipi, aka CG15630), whose decreased expression in the nervous system led to the changes in the parameters of a pulse song—a component of courtship in Drosophila males, in particular, to the reduction of the interpulse interval (Fedotov et al. 2014). In this study, we describe the structures of the nervous system, where the fipi gene is expressed. We also examine the role of this gene in courtship behavior, including its modification as a result of previous experience of a male courting a non-receptive fertilized female. It is known that such experience (learning) reduces the intensity of subsequent courtship of a male as regards other females. The expression of the GFP marker protein under control of the fipi gene promoter was detected in local interneurons of the antennal lobes, in Kenyon gamma-neurons, and in visual neurons of the optical lobes. The blocking of synaptic transmission from fipi-neurons reduced the efficiency of courtship suppression, and increased the excitability of these neurons, which resulted in a longer retention of the suppression effect. The knockdown of the fipi gene did not cause abnormalities in the courtship suppression, instead, it increased courtship intensity in males with no experience. The results show that fipi neurons are involved in the regulation of courtship behavior, and suggest that the expression of the fipi gene in gamma-neurons of mushroom bodies is involved in the formation of a short-term memory in this form of learning.

Motivational states are important determinants of behavior. InDrosophila melanogaster, courtship behavior is robust and crucial for species continuation. However, the motivation of courtship behavior remains unexplored. We first find the phenomenon that courtship behavior is modulated by motivational state. A male fly courts another male fly when it first courts a decapitated female fly however, male– male courtship behavior rarely occurs under normal conditions. Male flies that have satisfied the need for sexual behavior show a decreased male–female sex drive. Therefore, in this phenomenon, the male fly’s courtship motivational state is induced by its exposure to female flies. Blocking dopaminergic neurons by expressing TNTe decreases motivational state-induced male–male courtship behavior without affecting male–female courtship behavior. Vision cues are another key component in sexually driven male–female courtship behavior. Here, we identify a base theory that the inner motivational state could eventually decide fly behavior.

In a few species, males invest more than females in parental care while the females invest in mating competition and producing multiple broods for several mates. Species in the family Jacanidae are commonly used for studying this type of breeding system (called sex-role reversal), and previous studies found discrepancies and variation between species in the expected characteristics of reversed sex roles. Yet, a better understanding of sex role differences in breeding behavior in such species is crucial for disentangling possible evolutionary mechanisms leading to this peculiar breeding system. Sex-role reversal in the pheasant-tailed jacana Hydrophasianus chirurgus has been documented long time ago. Since the very early observation of this species, however, there was no attempt to provide a comprehensive and quantitative description of their breeding. This study aims to fill these knowledge gaps by investigating the sex role differences in the breeding behavior of pheasant-tailed jacanas, by observing and monitoring a breeding population in Taiwan. We focused on three main characteristics of sex-role reversal: (1) competition between females for access to males, such as agonistic and courtship behaviors, (2) polyandrous mating, and (3) male-only care. As expected, we found that females provide most of the territory defense toward conspecifics. Males also participated in agonistic behaviors, although less frequently than females. Furthermore, contrary to what was expected, we found that males spent more time than females on courtship behavior. Polyandrous females performed mating and laying sequentially with different mates but maintained the pair bonds simultaneously with multiple males. For the first time for the species, we could estimate that the average number of mates per female (i.e., degree of polyandry) was 2.4 and that at least 81.8% of the females in the population were polyandrous. Finally, our observations corroborated that brood care is predominantly provided by males, nevertheless females were also participating to some degree in brood attendance but never in direct care (i.e., brooding). This study highlights that some aspects of polyandrous breeding might deviate from stereotyped view on sex-role reversal, and stress the importance of further within species and comparative studies in order to fully understand the mechanisms leading to sex-role reversal.

An individual’s decision to engage in courtship depends on external cues from potential mates and internal cues related to maturation, health, and experience. Hormones allow such information to be conveyed to distal tissues in a coordinated fashion. Here, we show Ecdysis-Triggering Hormone (ETH) is a regulator of male courtship in Drosophila melanogaster, and critical for mate choice and courtship inhibition after the completion of copulation. Preventing ETH release increases male-male courtship and decreases post-copulation courtship inhibition (PCCI). Such aberrant male courtship behavior in ETH-deficient males appears to be the consequence of inabilityto integrate pheromone cues into decision making. Silencing of ETH receptor (ETHR) in GR32A-expressing neurons leads to reduced ligand sensitivity and elevated male-male courtship. We find OR67D is critical for suppression of courtship after mating, and ETHR silencing in OR67D-expressing neurons, and GR32A-expressing neurons to a lesser degree, elevates post-copulation courtship. Finally, ETHR silencing in the corpus allatum increases post-copulation courtship; treatment of with juvenile hormone analog partially restores normal post-mating behavior. ETH, a stress-sensitive reproductive hormone, appears to coordinate multiple sensory modalities to guide Drosophila male courtship behaviors, especially after mating.

Male sexual behavior in Drosophila melanogaster, largely controlled by the fruitless (fru) gene encoding the male specific FruM protein, is among the best studied animal behaviors. Although substantial studies suggest that FruM specifies a neuronal circuitry governing all aspects of male sexual behaviors, recent findings show that FruM is not absolutely necessary for such behaviors. We propose that another regulatory gene doublesex encoding the male-specific DsxM protein builds a core neuronal circuitry that possesses the potential for courtship, which could be either induced through adult social experience or innately manifested during development by FruM expression in a broader neuronal circuitry. FruM expression levels and patterns determine the modes of courtship behavior from innate heterosexual, homosexual, bisexual, to learned courtship. We discuss how FruM expression is regulated by hormones and social experiences and tunes functional flexibility of the sex circuitry. We propose that regulatory genes hierarchically build the potential for innate and learned aspects of courtship behaviors, and expression changes of these regulatory genes among different individuals and species with different social experiences ultimately lead to behavioral diversification.

Animals often exhibit conspicuous, and sometimes curious, courtship traits, such as nestling-like courtship display in birds, though modern studies of nestling-like courtship display (and calls) are virtually lacking. An exception is previous experiments on the barn swallow Hirundo rustica, demonstrating that females are equally attracted to playback of two structurally similar calls, nestling-like male courtship calls and nestling food-begging calls. The experiments support the sensory trap hypothesis, i.e., that male signals mimic nestling stimuli to exploit female parental care for nestlings. However, female attraction might not be the sole function of nestling-like traits, and males might also have a sensory bias toward nestling-like traits, in which males would be less aggressive toward characteristics typical of immature individuals. Here, I conducted playback experiments to study the function of nestling-like male courtship calls in the context of male–male interactions. Playback of male courtship songs induced frequent approaches by neighbouring males, while nestling-like male courtship calls or nestling food-begging calls induced fewer approaches, though male responses to the latter two vocalisations increased when approaching the nestling period. The observed pattern indicates that, by mimicking immature individuals, males attract intended signal receivers (i.e., females) while avoiding interference from eavesdroppers (i.e., neighbouring males). This unique function can explain why species with parental care exhibit immature-like behaviour.

International audience; Reproductive success can improve with experience, which increases with age in many long-lived species. Signals that provide reliable information about age are therefore of importance for mate choice and consequently are under sexual selection. In birds, these are often vocal signals as well as visual signals in the form of plumage coloration. King penguins, Aptenodytes patagonicus, are sexually monomorphically ornamented seabirds that perform a complex visual and acoustic courtship display. Coloured beak spots and ear patches contain information about the condition and physiological status of adult males and females, but their role as a signal of age has previously only been studied in young birds. Vocalizations have mainly been studied as signals of individuality and not in the context of courtship. We investigated two multicomponent signals in the context of mate choice by analysing beak spot, ear patch and call parameters of wild king penguins. We explored the relation between these signals and age as well as age classes (chicks, juveniles, adults). Ornament parameters were weakly correlated with in males, but not in females, while acoustic parameters were highly correlated with age in both sexes. The calls' fundamental frequency and energy parameters and all the beak spot parameters reliably classified individuals into their age class. Since age class was redundantly encoded in both acoustic and colour parameters, we hypothesize that calls and ornaments function as back-up signals that increase the chance of accurately conveying the age class of the sender to receivers. King penguins might sequentially analyse age class signals during courtship, where acoustic signals serve as long-range communication when sender and receiver are out of sight, and ornamentation signals become important at close range. We show the importance of considering bimodal, multicomponent signals when studying complex behaviour and discuss how signalling environment, the species' life history and mating system influence the evolution of communication signals.

Insect courtship parades consist of series of innate and stereotyped behaviours that become hardwired-in during the development of the nervous system. As such, insect courtship behaviour provides an excellent model for probing the principles of neuronal assembly, which underlie patterns of behaviour. Here, we present the main advances of recent studies - in species all the way from flies to planthoppers - and we envisage how these could lead to further propitious findings.

Alar (Daminozide), a plant growth retardant, is used in different fruit orchards especially of apples and mangoes to increase the production by preventing pre harvest fruit drop, promoting colour development and increasing the storage life. In an earlier study we have demonstrated both neurotoxic and teratogenic effects of Alar in a model organism Drosophila melanogaster. As an extension of the previous work, the present study is designed to investigate the effects of Alar on larval and adult behaviour of the fly. The Results demonstrated no significant alteration in feeding rate of treated larvae, but their foraging path length was shortened considerably, indicating impaired locomotion. Moreover, the onset of their specific courtship behavior like orientation, tapping and wing vibration was significantly delayed which suggest that the treated males were less vigorous and females were less receptive than the controls. In addition, Alar treatment was associated with reduction in copulation duration and subsequent decline in Courtship Index indicating lower reproductive fitness. Collectively, the findings suggest that Alar is ethotoxic for D. melanogaster.

The mating behavior of the moth Atheloca subrufella Hulst, 1887 (Lepidoptera: Pyralidae) was investigated in laboratory arenas. The descriptions of courtship and copulation in males and females were based on direct observations of virgin couples. The courtship and copulation bioassays results comprise several behavior patterns such as antennation, female searching (walking and/or flying); female encounter; female calling behavior; exhibition of pheromone gland; male approach and copulation. For that, courtship and copulation behavior ethograms were presented. The results also suggest that the mating behavior in A. subrufella is mediated by a long-range pheromone and the presence of a short-range pheromone. In overall, this research presents itself as a basis study to further investigations upon A. subrufella sex pheromone and to improve the development of new strategies of behavioral control techniques. O comportamento de acasalamento da mariposa Atheloca subrufella Hulst, 1887 (Lepidoptera: Pyralidae) foi investigado em arenas de laboratório. As descrições de corte e cópula em machos e fêmeas foram baseadas em observações diretas de casais virgens. Os resultados dos bioensaios de corte e cópula compreendem diversos padrões comportamentais tais como, antenação, busca pela fêmea (caminhando e/ou voando), encontro da fêmea, comportamento de chamamento da fêmea, exibição da glândula de feromônio, tentativa de cópula e cópula. Para isso, foram apresentados etogramas comportamentais de corte e cópula. Os resultados também sugerem que o comportamento de acasalamento em A. subrufella é mediado por um feromônio de longa distância e pela presença de um feromônio de curta distância. De maneira geral, esta pesquisa apresenta-se como estudo base para futuras investigações sobre o feromônio sexual de A. subrufella e desenvolvimento de novas estratégias de controle comportamental.

Understanding patterns of diversity in sexual signals can give insight into processes initiating, mediating or following from species diversification. Here we focus on female sex pheromones, which are widespread among animals, where some taxa show phylogenetic patterns of variation, but for others, ecological factors better explain pheromone diversity. Causes of differences in these patterns are unclear, and general insights require studying a broader range of taxa. Here we examined variation in the responses of male redback spiders, Latrodectus hasselti, to sex pheromones produced by three allopatric female congeners with different degrees of phylogenetic relatedness (from the same clade: Latrodectus mirabilis, Latrodectus hesperus; and from a different clade: Latrodectus geometricus) to infer pheromone divergence. We examined variation in male responses to conspecific and heterospecific females’ airborne and contact pheromones, which attract males and elicit courtship behaviour, respectively. We measured male courtship responses to extracted contact pheromones in isolation and male preferences in response to airborne pheromones and combined cues (pheromones, silk) in a two-choice maze. Male responses to airborne chemicals, contact chemicals and combined cues suggested variation in species specificity, with L. hasselti males showing strong discrimination against airborne pheromones of L. hesperus females (same clade), moderate evidence for discrimination based on contact cues of L. geometricus, but only when multiple sources of information were available (different clade), and no discrimination of L. mirabilis females (same clade) relative to conspecifics, regardless of the types of information available. Thus, male responses were not consistent with a phylogenetic pattern. Moreover, airborne pheromones can apparently diverge relatively rapidly, but airborne and contact pheromones may remain similar across long evolutionary timescales. We propose that differential responses to L. hesperus may arise from selection for population-level pheromone divergence within that species and that, in general, pheromones and male responses may be evolutionarily conserved across Latrodectus.

To better understand the social monogamy in decapod crustaceans, individual recognition in a socially monogamous shrimp, Lysmata debelius, was investigated. We hypothesized that chemical cues play an important role in mediating monogamy, because chemical cues is the primary form of communicaition. To test this, we first examined mate recognition and second tested the presence of chemical cues in individual recognition. The individual recognition to conspecifics of different reproductive statuses was tested in a Y-maze excluding visual cues and tactile cues. Inter-molt and pre-molt euhermaphrodite-phase shrimps served as males and females, respectively. A focal male (cue detector) was placed in the bottom chamber, and two shrimps (cue releasers) of different statuses were placed in the upper two champers, respectively. We find that the focal male spent more time in the front of the chamber holding the paired partner when the other shrimp was not female, and prefered to the female stranger rather than its male partner. Interestingly, when both stranger and partner were females, the focal male actually spent more time in the chamber holding the female stranger. The results indicate that olfactory chemical cues mediate monogamy in L. debelius in place of visual cues, and the chemical cues are probably individual specific (i.e. identification odor). The courtship and mating behaviors of L. debelius were also reported for the first time. During mating, L. debelius displayed no courtship behavior, differing from its sister species, L. wurdemanni which live in aggregation, and L. amboinensis which live in low denstiy. Combining the previous results in L. wurdemanni and L. amboinensis, we can conclude that L. wurdemanni has the most elaborate precopulatory courtship rituals, L. amboinesis has less, and L. debelius has none, i.e. the behavioral activity between male and pre- and post-molt female decreases with the population intensity. This behavioral pattern should be sexually selected in different social systems. The present study would enrich our understanding of the evolution of social-dependent behaviors in crustaceans.

While the mate choice literature has focused primarily on the choices that females make, under certain circumstances males are expected to make mating decisions as well. Such circumstances include when males provide a significant energetic investment in a female or her offspring. Male orthopterans can invest considerable resources in females and have been studied for their mating investment decisions. However, while males provide acoustic information to females, females do not provide reciprocal acoustic information to males. Here, we tested the hypothesis that Laupala males use chemical signals to make mating decisions. We found that males and females have discernable differences in cuticular lipid expression when considering both whole-body and antennae-only extracts. Furthermore, access to the antennae alone resulted in males showing more courtship towards females and more aggressive behaviours towards males. Finally, males showed higher levels of association and courtship behaviour near female-exposed filter paper than they did near male-exposed and control filter paper. These results suggest that Laupala males use chemical signals when deciding whether to initiate courtship and open the possibility that chemical communication has played a role in the diversification of this genus.

SYW is funded by the National Scientific Foundation of China (31372187). MGR is funded by the NERC, UK (grants NE/E015255/1 and NE/J020818/1). Changes in elements of courtship behaviour can influence sexual isolation between species. Large‐scale analyses of changes, including loss and gain of courtship elements, across a relatively complete phylogenetic group are rare but needed to understand the significance of such changes, for example whether the gain and loss of courtship elements are essentially arbitrary or equally reversible. In most species of Drosophila, courtship, including singing, mainly occurs before mounting as pre‐mounting courtship. The Drosophila montium species group is unusual because loss of pre‐mounting courtship and gain of post‐mounting one has been detected in this group. Here we provide an extensive analysis on the courtship repertoire and songs of 42 species in this group. Synchronously captured video and audio recordings were analysed to describe courtship patterns and male courtship songs and changes were analysed in a phylogenetic context. Ancestral state reconstruction suggests that a gain of post‐mounting courtship singing at the ancestor of this species group has been accompanied with a concurrent decrease in the incidence of pre‐mounting courtship singing and has led to subsequent further decrease and eventually complete loss of pre‐mounting courtship song in several lineages. Alongside this evolutionary trend towards post‐mounting courtship, sine song and a special type of “high pulse repetition song” have become more widely used for courtship during species diversification in the montium group. It is likely that the elaboration of post‐mounting courtship behaviours is associated with changes in the relative importance of pre‐ and post‐mounting components of mating systems, such as sperm competition or cryptic female choice. Postprint

Songbirds hold a prominent role in the fields of neurobiology, evolution, and social behavior. Many of these fields have assumed that females lacked the ability to produce song and have therefore treated song as a male-specific behavior. Consequently, much of our understanding regarding the evolution and neural control of song behavior has been driven by these assumptions. Here we review literature from diverse fields to provide a broader perspective of the role of females in vocal communication and courtship. Recent evidence indicates that song evolved in both males and females and instances of female song are still common. The specialized neural circuit known as the "song system," which is necessary for singing in males, is also present in females, including those that do not sing, implying broader functions that include evaluating male song and controlling courtship behavior. In addition to having flexible, individualized preferences, females actively shape their social network through their interactions with males, females, and juveniles. We suggest that by developing more accurate hypotheses concerning the role of females we may better understand the evolution and neural mechanisms of song production and courtship behavior.

Reinforcement signals such as food reward and noxious punishment can change diverse behaviors. This holds true in fruit flies, Drosophila melanogaster, which can be conditioned by an odor a...

This work was supported by Portuguese National Funds through FCT (Fundação para a Ciência e a Tecnologia), within the cE3c Unit FCT funding (grant number UID/BIA/00329/2013), IO PhD grant (SFRH/BD/90686/2012) and SAMV (SFRH/BPD/66042/2009 and PTDC/BIA‐ANM/0810/14) and MB (SFRH/BPD/82259/2011) Post‐Doctoral research grants. This work was also supported by the ERC (European Research Council) AdG BioTIME (250189) to AEM. Sexual selection theory suggests that males need to constantly reappraise their mating decisions to take account of the presence and the phenotypes of their rivals. Here we examine this expectation by asking: (i) If the presence of a rival influences male mating behaviour; (ii) How important is the attractiveness of the rival (absolute attractiveness) in shaping male behaviour; and (iii) How does a male's attractiveness in comparison to his rival (relative attractiveness) influence a male's mating decisions. Using the Trinidadian guppy, a species in which female mate choice (based on males’ attractive traits) plays an important role in male mating outcomes, we recorded the frequency of courtship displays and unsolicited attempts by focal males. First, we quantified focal male mating behaviour with and without a rival. Since the probability of a successful mating is, on average, halved by the presence of a rival, we predicted that under competition the focal male would invest more in less costly mating tactic—unsolicited attempts. Second, we examined how the rival's standard length and area of orange coloration mediated focal male mating behaviour. We found that rival presence influenced how focal males responded to females in terms of both mating tactics. However, the rival attractiveness elicited changes only in male courtship display. Focal males increased courtship display rate if his rival was small or if possessed large amounts of orange, regardless of considering rival absolute or relative attractiveness. Our results show that males invest in the costlier mating tactic when there is no rival or in the presence of a smaller rival. Interestingly, they make a similar investment in the presence of an attractive orange rival. Overall, this study highlights the importance of fine‐grained male decisions in mating encounters and shows that mating tactics are differentially shaped by multiple competition risk cues. Postprint

金沢大学理工学研究域生命理工学系, Males of Drosophila melanogaster exhibit stereotypic courtship behavior through which they assess potential mates by processing multimodal sensory information. Although previous studies revealed important neural circuits involved in this process, the full picture of circuits that participate in male courtship remains elusive. Here, we established a genetic tool to visualize or optogenetically reactivate neural circuits activated upon specific behavior, exploiting promoter activity of a neural activity-induced gene Hr38. With this approach, we visualized neural circuits activated in the male brain and the ventral nerve cord when a male interacted with a female. The labeling of neural circuits was additively dependent on inputs from antennae and foreleg tarsi. In addition, neural circuits that express the sex-determining gene fruitless or doublesex were extensively labeled by interaction with a female. Furthermore, optogenetic reactivation of the labeled neural circuits induced courtship posture. With this mapping system, we found that a fruitless-positive neural cluster aSP2 was labeled when a male interacted with a female, in addition to previously characterized neurons. Silencing of neurons including aSP2 led to frequent interruption of courtship and significant reduction of mating success rate without affecting latency to start courtship, suggesting that these neurons are required for courtship persistency important for successful copulation. Overall, these results demonstrate that activity-dependent labeling can be used as a powerful tool not only in vertebrates, but also in invertebrates, to identify neural circuits regulating innate behavior. © 2019 National Academy of Sciences. All Rights Reserved., Embarogo Period 6 months

1. In treehoppers in which courtship has been studied, males initiate the search for females by periodically emitting a vibrational signal. The responses by the female are used by males as a beacon and give rise to a duet. 2. Courtship and mating of the treehopper Ennya maculicornis were characterised through the simultaneous recording of vibrational signals and the behaviour of males and females in an arena. 3. In E. maculicornis, female initiated mate searching. Females produced two types of signals during the this process: (i) a signal that preceded the approach by the male and (ii) a signal that preceded mating. Males emitted two signals associated with two stereotyped body movements: (i) a signal produced as a response to the first signal emitted by the female, involving a change in the male's locomotory mode and the approach to the female, and (ii) a signal produced after finding and holding on to the female, involving simultaneous abdomen raising and wing fluttering. These signals were repeated several times before the female emitted the second signal. The four signalling patterns were observed in all recordings in which mating was observed. When any of the signals was missing, mating did not occur. 4. Female‐biased sex ratios in E. maculicornis, along with iteroparity, are suggested to explain the initiation of mate searching behaviour by females. A comparison of data with that from other treehoppers indicates that vibrational signals and their associated behaviour are more diverse among treehoppers than has been appreciated previously.