Courtship Activity Research Articles

Dominant males exploit the courtship effort of subordinate males in an Amazonian fish

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 Günther 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. • Dominant males defend nesting sites, while subordinate males engage in courtship. • Only dominant males obtained spawning success, regardless of effort in courtship. • Dominant males parasitize the courtship behaviour of subordinate males. • Effectiveness of courtship piracy depends on the defendability of nesting sites. • Seasonality may control the contribution of courtship piracy to reproductive success.

Ecology and behavioral response of Ruddy Shelduck (Tadorna ferruginea) in the wetland complex of Oued Righ valley (Algerian Sahara).

The wetland complex of Oued Righ valley accommodates a population of Ruddy Shelduck (Tadorna ferruginea) between 2012 and 2014, the total reached 80 individuals in the Lake Hamraia where the species wintering. The analysis of the diurnal time budget of wintering populations revealed the role of feeding area delivery for this species and they devoted their day time to feeding (51.2%), sleeping (18.8%), followed by swimming activity (6.3 %), and courtship activities with flying (2.03%) which often occurs after disturbances caused by human or by Marsh harrier (Circus aeruginosus). It is interesting to study the behavior of these ducks in Saharan bioclimatic area and follow the phenology and characteristics in order to preserve the biodiversity in this region.

To hum or not to hum: Neural transcriptome signature of male courtship vocalization in a teleost fish.

For many animal species, vocal communication is a critical social behavior and often a necessary component of reproductive success. Additionally, vocalizations are often demanding motor acts. Wanting to know whether a specific molecular toolkit might be required for vocalization, we used RNA-sequencing to investigate neural gene expression underlying the performance of an extreme vocal behavior, the courtship hum of the plainfin midshipman fish (Porichthys notatus). Single hums can last up to 2 h and may be repeated throughout an evening of courtship activity. We asked whether vocal behavioral states are associated with specific gene expression signatures in key brain regions that regulate vocalization by comparing transcript expression levels in humming versus non-humming males. We find that the circadian-related genes period3 and Clock are significantly upregulated in the vocal motor nucleus and preoptic area-anterior hypothalamus, respectively, in humming compared with non-humming males, indicating that internal circadian clocks may differ between these divergent behavioral states. In addition, we identify suites of differentially expressed genes related to synaptic transmission, ion channels and transport, neuropeptide and hormone signaling, and metabolism and antioxidant activity that together may support the neural and energetic demands of humming behavior. Comparisons of transcript expression across regions stress regional differences in brain gene expression, while also showing coordinated gene regulation in the vocal motor circuit in preparation for courtship behavior. These results underscore the role of differential gene expression in shifts between behavioral states, in this case neuroendocrine, motor and circadian control of courtship vocalization.

Understanding sociality and behavior change associated with a nesting event in a captive flock of great white pelicans

Zoo-housed pelicans are commonplace, but their breeding record is poor and little research is published on the activity patterns, as potential predictors of nesting, of captive flocks. Existing literature shows that comparative research can provide useful information for husbandry and conservation planning for pelican populations. The opportunity arose to investigate the time-activity budget and social network of a breeding flock of captive great white pelicans. Three chicks were hatched in June and July 2016 and one in March 2017. Data on state behaviors, space use, and association preferences were collected around these nesting events, from October 2016 to February 2017 and July to October 2017. Results suggest that pre-nesting periods were associated with heightened flock-wide vigilance, suggesting that vigilance may be a precursor for courtship or nesting activity. Social network analysis revealed nonrandom associations between birds and a social structure across the flock, in which subadults seemed to associate more with each other than with adult birds. A limited visitor effect was noted; whilst no overall behavior change was apparent with different numbers of visitors, pelicans did widen their enclosure usage with increased visitor presence. These data are relevant to those attempting to breed this pelican, who wish to know more about the daily behavior patterns of this species across the season and physiological state, and who wish to understand pelican social structure, which is useful to the planning and implementation of bird moves or changes to the social environment of the flock. Further extending such research to include uninterrupted observation over a successful breeding event is recommended.

Flexibility of nuptial colouration in a unique ecotype of threespine stickleback (Gasterosteus aculeatus)

Nuptial colouration in animals may serve as a signal of competitor and (or) mate quality during breeding. In many temperate fishes, nuptial colouration develops during discrete breeding seasons and is a target of sexual selection. We examine nuptial colouration and behaviour of a unique ecotype of threespine stickleback (Gasterosteus aculeatus Linnaeus, 1758), wherein males turn from dull brown-grey to pearlescent white during the breeding season. The main goal of this work was to determine the relative role of white colouration in intersexual competition and mate choice. In a combination of field and laboratory work, we found that males are brightest white when engaging in courtship activities in the presence of a female; this indicates that white colouration may be primarily related to enhancing signalling during mate attraction. White colouration intensity increased as the breeding season progressed and may be related to an influx of conspecifics. Colour change from cryptic grey to bright white occurred rapidly (<90 s) and may be deployed to enhance behavioural signals. We conclude that bright white colouration in the white ecotype is a potential signal of mate quality and may have evolved from a previously existing capacity for colour plasticity in common threespine stickleback.

Narrow‐spectrum artificial light silences female fireflies (Coleoptera: Lampyridae)

AbstractThe rapid spread of artificial light at night (ALAN) poses myriad problems for nocturnal biodiversity.Bioluminescent taxa that communicate via glowing lures, warning signals, or courtship advertisements may have their signals obscured by artificial illumination, unless the added light is spectrally tuned to reduce its impact.Previous research has demonstrated that broad‐spectrum white light inhibits the production of courtship advertisements by male firefly beetles, yet the impact of varying wavelengths of artificial light on both members of the courtship dialogue is largely unknown.We exposed courting pairs ofPhotinus obscurellusfireflies to five colours of downwelling illumination, at two intensities, and recorded changes in male flash rate and flash intensity, female responsiveness, and the flash pattern composition of both sexes.All artificial light treatments significantly suppressed courtship activity.Bright amber light had the greatest impact, suggesting that ALAN which most overlaps the spectrum of firefly bioluminescence will most disrupt firefly courtship.Our findings contradict similar investigations of non‐bioluminescent taxa and raise concerns about the possibility of a universal standard for ecologically sustainable ALAN.

How do adults of the critically endangered hermit butterfly (Chazara briseis) utilise their habitat? (Lepidoptera, Satyrinae)

Effective conservation of specialised, endangered species depends on the knowledge of all vital resources they require within species’ lifetime. The butterfly Chazara briseis is endangered throughout Europe, especially so in all states north from the Alps. It depends on large areas of open steppe grassland with short and sparse turf. To identify resource use by adult C. briseis butterflies in relation to vegetation structure within its sites. We re-analysed mark-recapture data from the last Czech metapopulation, inhabiting a chain of volcanic hills in Ceske Stredohori highlands and hosting 2000 adults in 2006. We related adult activities observed prior to captures to visually assessed vegetation structures and land cover types obtained from aerial photographs. Additionally, we used land cover types to explore the adults’ home ranges and to compare capture points with randomly selected points. The butterflies displayed clearly structured diurnal activity with nectaring from morning to noon and courtship activities and egg-laying in the afternoons. Both sexes used short-sward patches (egg laying, patrolling), but also patches with taller, flower-rich vegetation (mating, nectaring). These results were corroborated using land cover types, however, with much lower explanatory power. Lifetime utilisation of land cover types (home ranges) differed between sexes, females utilised more shrubby and longer-sward areas than males. Randomly selected points within the sites significantly differed from capture points, the latter contained more open, either short or tall grassland patches. Management of inhabited sites must provide open, short-sward patches alternating with flower-rich taller sward and shrubby patches.

Excreta grooming behavior in a litter-dwelling scorpion species (Scorpiones: Buthidae) from Brazil

Behavioral studies of scorpions mainly focus on hunting and courtship activity. Few studies have focused on the cleaning processes that these arachnids invest in. This work aims to describe the first report of excreta grooming behavior for Brazilian scorpions. Excreta cleaning behavior was recorded in 37 specimens of Tityus pusillus Pocock, 1893 with the behavior lasting around 80 sec. The paste-like nature of the scorpion excreta suggests that it could easily obstruct their anus when dry, so the excreta cleaning behavior may mitigate this probability and further contact with the nitrogenous compounds.

Flypub To Study Ethanol Induced Behavioral Disinhibition and Sensitization.

Alcohol use disorder (AUD) remains a serious problem in our society. To develop effective interventions for addiction, it is important to understand the underlying neurobiological mechanisms, for which diverse experimental approaches and model systems are needed. The main ingredient of alcoholic beverages is ethanol, which causes adaptive changes in the central nervous system and behavior upon chronic intake. Behavioral sensitization (i.e., escalated responses) in particular represents a key adaptive change underlying addiction. Most ethanol-induced behavioral sensitization studies in animal models have been conducted on the locomotor activating effect of ethanol. A prominent effect of ethanol is behavioral disinhibition. Behavioral sensitization to the disinhibition effect of ethanol, however, is underrepresented. To address this issue, we developed the Flypub assay that allows measuring the escalated increase in disinhibited courtship activities upon recurring ethanol exposure in Drosophila melanogaster.Here, we report the step-by-step Flypub assay including assembly of ethanol exposure chambers, setup of the assay station, criteria for fly care and collection, ethanol delivery, quantification of disinhibited courtship activities, data processing and statistical analysis. Also provided are how to troubleshoot critical steps, overcome limitations and expand its utility to assess additional ethanol-induced behaviors. The Flypub assay in combination with powerful genetic tools in Drosophila melanogaster will facilitate the task of discovering the mechanism underlying ethanol-induced behavioral sensitization.

Temperature‐related breakdowns in the coordination of mating in Enchenopa binotata treehoppers (Hemiptera: Membracidae)

AbstractTemperature influences the expression of a wide range of behavioral traits in ectotherms, including many involved in the initiation of pair formation and mating. Although opportunities to mate are thought to be greatest when male and female activity overlap, sex‐specific behaviors and physiology could result in mismatched thermal optima for male and female courtship. Here, we investigate how conflicts in the thermal sensitivity of male and female courtship activity affect patterns of mating across temperatures in Enchenopa binotata treehoppers (Hemiptera: Membracidae). These plant‐feeding insects coordinate mating with plant‐borne vibrational signals exchanged in male–female duets prior to pair formation. We manipulated temperature across an ecologically relevant range (18–36ºC) and tested the likelihood of individual male and female E. binotata to engage in courtship activity using vibrational playbacks. We then staged male–female mating interactions across the same temperature range and quantified the thermal sensitivity of mating‐related behaviors across stages of mating. Specifically, we measured the timing of duetting, the likelihood for key pre‐copulatory behaviors to occur, whether the pair mated, and copulation duration. We found sex‐specific thermal sensitivity in courtship activity: Males showed a clear peak of activity at intermediate temperatures (27–30ºC), while females showed highest activity at the hotter thermal extreme. Mating rates, courtship duets, and copulatory attempts were less likely to occur at thermal extremes. Also, duetting occurred earlier and copulation was shortest at higher temperatures. Overall, our data suggest that sexes differ in how temperature affects mating‐related activity and some processes involved in mate coordination may be more sensitive than others across variable thermal environments.

Reduction of spermatophore melanization in Litopenaeus vannamei shrimp fed Ulva clathrata during a commercial hatchery production

Male broodstock (Litopenaeus vannamei, 36 ± 7 g, n = 600) reproductive performance, spermatophores and reproductive tract melanization, prostaglandin concentrations and biochemical composition were evaluated after including 3.8% Ulva clathrata meal in the diet (dry base) of a commercial hatchery during 45 days. Males fed Ulva had less melanized spermatophores (120 compared with 233, P < 0.01), less bacteria in the ductus deferens (P < 0.01), more sperm cells in testicles (P < 0.05), and increased courtship activity (839 compared with 689, P < 0.01), with no effect on mortality. Ulva-fed males had more arachidonic acid (20:4n-6) in the spermatophores (P < 0.05) but this did not affect the prostaglandin concentrations in response to diet. Males fed Ulva had more carotenoids in the hepatopancreas (0.08 ± 0.02 compared with 0.01 ± 0.01 mg/g, P < 0.05), and phenolic compounds in hepatopancreas (6.1 ± 0.7 compared with 1.8 ± 0.7 mg eq. phloroglucinol/g, P < 0.05) and muscle (0.4 ± 0.3 compared with 0.2 ± 0.1 mg eq. phloroglucinol/g, P < 0.05). Males fed the Ulva also had a lesser carbohydrate content in the hepatopancreas (P < 0.01) and muscle (P < 0.01). In conclusion, supplementing fresh maturation diets with a small dose of dried Ulva allowed for improvement of reproductive performance and to decrease melanization in spermatophores and the male reproductive tract.

Sex Mysteries of the Fly Courtship Master Regulator Fruitless.

The fruitless (fru) gene of Drosophila melanogaster generates two groups of protein products, the male-specific FruM proteins and non-sex-specific FruCOM proteins. The FruM proteins have a 101 amino acids (a.a.)-long extension at the N-terminus which is absent from FruCOM. We suggest that this N-terminal extension might confer male-specific roles on FruM interaction partner proteins such as Lola, which otherwise operates as a transcription factor common to both sexes. FruM-expressing neurons are known to connect with other neurons to form a sexually dimorphic circuit for male mating behavior. We propose that FruM proteins expressed in two synaptic partners specify, at the transcriptional level, signaling pathways through which select pre- and post-synaptic partners communicate, and thereby pleiotropic ligand-receptor pairs for cell-cell interactions acquire the high specificity for mutual connections between two FruM-positive cells. We further discuss the possibility that synaptic connections made by FruM-positive neurons are regulated by neural activities, which in turn upregulate Fru expression in active cells, resulting in feedforward enhancement of courtship activities of the male fly.

Семья и брак в жизненных ориентирах молодежи Оренбургской области

&lt;p&gt; На основе результатов социологического исследования 2018 г. анализируются предпочтения в семейно-брачных и сексуальных отношениях молодежи Оренбургской области России. Наиболее предпочтительным и подходящим для современной региональной российской молодежи установлен официальный брак, подразумевающий традиционные семейные ценности; брачный контракт как вид «страховки»; рождение двоих детей в возрасте от 25 до 30 лет; любовь как главная причина заключения брака. Большинство из опрошенной молодежи Оренбургской области к альтернативным формам брака (однополый брак, открытый брак, свингерство, коммунальный брак, Годвин-брак, виргинальный брак, сезонный брак и брак Childfree) чаще относятся отрицательно, чем нейтрально или положительно. Наиболее лояльное отношение проявлено к фиктивному браку и браку по расчету. Сексуальное поведение региональной молодежи характеризуется равноправной инициацией ухаживаний и сексуальных действий. Определяющую роль в сексуальной близости для молодых женщин играет установление тесного эмоционального контакта, для молодых мужчин — получение удовольствия. Ответственность за вопросы, связанные с использованием контрацептивов, как правило, несет юноша. Социальное конструирование сексуального поведения происходит на фоне принятия традиционных ролей и сценариев.&lt;/p&gt;

Zingerone improves mating performance of Zeugodacus tau (Diptera: Tephritidae) through enhancement of male courtship activity and sexual signaling

Certain male fruit flies from the genera Bactrocera and Zeugodacus (Diptera: Tephritidae) actively forage for floral semiochemicals produced by some endemic Bulbophyllum orchids found in tropical and subtropical forests. These floral semiochemicals are largely classified as either phenylbutanoids (e.g., raspberry ketone (RK)) or phenylpropanoids (e.g., methyl eugenol (ME)). Zingerone (ZN) is a phenylbutanoid recently found that structurally resembles ME and RK, both of which are phytochemicals commonly used as male attractants in fruit fly control programmes. It was previously shown that feeding on ME and RK increased the mating success of certain tephritid fruit flies, specifically in B. dorsalis and B. tryoni males, respectively, through enhancement of sexual signaling. However, ZN, which acts as a metabolic enhancer to increase male courtship activity in B. tryoni, did not show the same effect. As fruit fly-phytochemical lure interactions are unique and species-specific phenomena, this study seeks to elucidate the ecological significance of ZN feeding to Zeugodacus tau in terms of sexual signaling. We demonstrate here that ZN feeding by Z. tau males enhanced female attraction and subsequent mating success by increasing male courtship, and the attractiveness of the sexual signals in both wind tunnel and semi-field cage bioassays. In addition, we also demonstrated temporal effects on male behaviour in relation to the amount of lure intake. However, feeding on ZN did not appear to affect the total time spent in copula for Z. tau. This is the first report showing an important role of ZN in increasing courtship activity as well as enhancement of sexual signaling in Z. tau males.

Patterns of Thermal Sensitivity and Sex-Specificity of Courtship Behavior Differs Between Two Sympatric Species of Enchenopa Treehopper

Predicting how insects will react to future thermal conditions requires understanding how temperature currently affects insect behavior, from performance traits to those involved in mating and reproduction. Many reproductive behaviors are thermally-sensitive, but little is known how temperature affects the behaviors used to find mates and coordinate mating. Here, we investigate how temperature influences courtship activity in two sympatric species of Enchenopa treehoppers (Hemiptera: Membracidae). Enchenopa use substrate-borne vibrational signals exchanged in male-female duets to facilitate pair formation prior to mating. In a controlled laboratory setting, we assessed the likelihood of males and females to produce courtship signals across a range of ecologically relevant temperatures. We found that changes in courtship activity across temperatures differed between the two species. We also found sex differences within species: in one species males were more likely to signal at higher temperatures, while in the other species females were more likely to signal at higher temperatures. Our results suggest that sex-specific responses to temperature may constrain mating to narrower ranges of temperatures. Furthermore, sympatric species may respond differently to changes in thermal variation despite sharing similar climactic history.

Choosy Gulf pipefish males ignore age but prefer active females with deeply keeled bodies

Within Syngnathidae (pipefish, seadragons and seahorses), male pregnancy often results in choosy males and competitive females. Females in these species often evolve secondary sexual traits and engage in courtship displays that make their ornaments more noticeable to males. Most syngnathids probably continue to grow larger throughout their lives, but we know little about the relationship between age and mating competition in these taxa. Here, we use the Gulf pipefish, Syngnathus scovelli, to investigate the roles of ornament size, courtship activity level, age and fecundity in female mating competition. We conducted male choice trials that allowed males to choose between similarly sized females of different ages. We also measured age and size at maturity. We found that females with larger ornaments were deeper bodied and engaged in longer courtship displays, yet males chose females based on body depth and display rather than ornamentation. This result suggests that ornamentation serves to help males assess female quality. Female age plays no role in male choice or in female ornamentation. Our finding that males care more about female phenotype than female age considerably simplifies the interpretation of mating patterns in natural populations of Gulf pipefish, which are characterized by considerable age structure.

A single male auditory response test to quantify auditory behavioral responses in Drosophila melanogaster

Many animals utilize auditory signals to communicate with conspecific individuals. During courtship, males of the fruit fly Drosophila melanogaster and related species produce a courtship song comprised of sine and pulse songs by vibrating their wings. The pulse song increases female receptivity and male courtship activity, indicating that it functions as a sexual signal. One song parameter, interpulse interval (IPI), varies among closely related species. In D. melanogaster, a song with a conspecific IPI induces a stronger behavioral response than heterospecific songs, indicating the ability of the flies to discriminate conspecific IPI. Traditionally, the fly’s response to the song is measured under grouped conditions, in which the effect of sensory modalities other than audition cannot be excluded. Here, to quantify the individual ability to discriminate a conspecific song, we systematically analyzed the auditory response of single male flies to sound with various parameters. Moreover, we applied this method, termed SMART (Single Male Auditory Response Test), to two sister species for potential application in a comparative approach. By quantifying the locomotor activity of single D. melanogaster males during sound exposure, we detected increased locomotor activity in response to pulse songs, but not to white noise or pure tone. The conspecific song evoked stronger response than the heterospecific songs, and ablation of their antennal receivers severely suppressed the locomotor increase. A pulse song with a small IPI variation evoked a continuous response, while the response to songs with highly variable IPIs tends to be rapidly decayed. This provides the first evidence that fruit flies discriminate IPI variations, which possibly inform the age and social contexts of the singer. Sister species, D. sechellia, exhibited a locomotor response to pulse song, while D. simulans exhibited no behavioral response. This suggests that auditory and other stimuli that elicit this behavioral response are diversified among Drosophila species.

Australia’s engagement with China: From fear to greed and back again

This paper examines how Australia has managed its relationship with China. It looks at the broad trends in the relationship, with a focus on the decades after recognition in 1972. The second part examines the recent past, and particularly the ways in which Australia’s active courtship of China has begun to be tempered by concerns about the destabilizing security and strategic consequences of the country’s return to power. It assesses the options Australia faces and the growing polarization of opinion between security “hawks” and economic “doves” in public debate about Australia’s future, and then charts where Australian policy is currently placed. The paper concludes by explaining why Australia finds taking a nuanced position in relation to its engagement with China so difficult.

Courtship and mating behaviour of manta rays Mobula alfredi and M. birostris in the Maldives.

The aim of this 14 year study was to elucidate the entire courtship and mating behaviour of manta rays Mobula alfredi and M. birostris using behavioural observations, video and photographic records. From 2003 to 2016, over 11,000 surveys were undertaken at known manta ray aggregation sites in the Maldives to record any observed manta rays reproductive activity. From 47,591 photo-ID sightings, 4,247 individual M. alfredi were identified and 226 individual M. birostris from 229 photo-ID sightings, all recorded at 22 atolls across 265 different sites. Courtship activity was observed on 206 surveys at 30 different sites. A total of 229 courtship events were recorded, with 90% (n = 205) of them occurring at cleaning sites. The observed courtship activity was categorised into seven distinct stages which are described in detail: initiation, endurance, evasion, pre-copulatory positioning, copulation, post-copulatory holding and separation. Photographs provide the first scientific record of the entirety of manta rays courtship and mating. Both M. alfredi and M. birostris appear to engage in the same elaborate courtship rituals, exhibiting the same behaviours during all stages of the courtship and mating process.

Life‐history and demographic traits of the marula fruit fly Ceratitis cosyra: potential consequences of host specialization

AbstractLife‐history strategies are diverse both across and within species, although the factors shaping this diversity are not fully understood. In the present study, we investigate the life‐history strategies of the marula fruit fly Ceratitis cosyra (Walker) (Diptera: Tephritidae) and how they differ between the sexes. We measure lifespan and age‐dependent reproductive effort in both sexes. In females, reproductive effort is measured as fecundity (egg counts) and for males, courtship behaviour, mating propensity and sperm transfer at ages 5, 15 and 25 days are assayed. Mean ± SE lifespan of flies is 104.6 ± 2.8 days, with females living on average 9 days longer than males. Total female fecundity and time until peak egg production both positively correlate with lifespan. The proportion of males courting and mating is similar at 5 and 15 days, although courtship activity increases and mating success decreases significantly by 25 days. The number of sperm transferred and sperm storage asymmetry are highest at 15 days, with 12 173 ± 826 sperm being stored per female after mating. We also compare life‐history traits in C. cosyra with other tephritids, aiming to determine how niche breadth might contribute to life‐history evolution. In comparison with other tephritids, C. cosyra has a long lifespan and a relatively low lifetime fecundity, although males transfer particularly large numbers of sperm during copulation. These life‐history traits may be associated with the seasonal availability of marulas, which are its preferred native host.