Male-female Interactions Research Articles

Male–female interactions and ultrasonic vocalization in three sympatric species of voles during conspecific and heterospecific encounters

Using ultrasonic vocalization, the present study examined the behaviour of three sympatrically living species of voles: common voles, field voles and bank voles during heterosexual encounters both within and between species. Voles were trapped in south-eastern Poland and their behaviour and vocalization investigated using 10-min open field tests. Conspecific heterosexual pairs of all three species of voles presented high social activity but the kind of behaviour was different. Bank vole male–female interactions were more agonistic than those of common voles and of field voles as seen in the number of aggressive approaches and latency to the first attack. Common voles and field voles emitted significantly more ultrasounds and spent longer time on the production of ultrasonic calls than bank voles. The duration of sounds was similar but the frequency of calls emitted by field voles was higher than those of common voles and bank voles. Voles in heterospecific encounters of male with female showed shorter duration of sniffing and emitted very few ultrasounds. The current work has shown that ultrasounds are part of male–female behaviour in common voles, field voles and bank voles and could play a significant role in vole communication.

A THEORETICAL PROPOSAL FOR LATE LUTEAL PHASE BEHAVIOURAL CHANGES IN AN EVOLUTIONARY CONTEXT

Late luteal phase behavioural changes (LLBC) have been reported for humans and some other primates, and encompass a wide spectrum of behaviours. Several studies have estimated that a majority of women manifest some LLBC. At a more extreme end of the spectrum, in a small minority of women, LLBC have been classified as major emotional disturbances or medical conditions (although not without controversy), for example, as part of premenstrual dysphoric disorder. In this report, an attempt is made to place LLBC in an evolutionary context; some of these behaviours, in particular at a less extreme end of the spectrum, may have co-evolved with reproductive physiology. Evolutionary perspectives upon human reproductive behaviour are often complex (and controversial) issues; in this context, specific and more isolated mechanisms for possible evolutionary stability of some LLBC—e.g., related to male-female behavioural interactions—are suggested for further discussion. Overall, it is proposed that qualitative and quantitative changes in hormones and hormonal activities during the menstrual cycle evolved to optimize reproductive success through neurophysiological responses that include behavioural components, perhaps some LLBC.

The Mechanistic Basis of a Large Male Mating Advantage in Two Freshwater Amphipod Species

AbstractIn many animals, body size plays an important role in determining both ecological success and mating success. Thus, the expression of body size within a population is often the result of the interaction between natural selection and sexual selection. Here, I examine the mechanistic basis for a large male mating advantage in two freshwater amphipod species that differ ecologically. Traditionally, size‐biased mating patterns in amphipods have been attributed to the advantage of large size in male–male competition for females. In this study, when direct male–male interactions were eliminated (via tethering), large males had a mating advantage similar to that observed under control conditions (males free to interact) and in previous field and laboratory studies. These results suggest that male–female interactions play an important role in selecting for large male size. There was, however, some evidence for male takeovers in the species that shows the stronger size‐based mating bias. Takeovers occurred in 33% of trials when smaller males were in the position of defender, i.e. paired with the female. Therefore, takeovers by larger males may also contribute to the strong size‐based mating biases observed in this species.

Female-limited polymorphism in a widespread damselfly: morph frequencies, male density, and phenotypic similarity of andromorphs to males

In several animal species, one male type coexists with two to several female types, a polymorphism often explained in the context of sexual selection. Where it occurs, one female morph typically resembles the conspecific male phenotype, but the degree of resemblance varies across species. Here, we question whether the degree of phenotypic similarity between male-like females and males varies within species. Phenotypic resemblance is hypothesized to depend on the potential for frequency- and density-dependent selection on male and (or) female phenotypes. We studied six populations of the damselfly Nehalennia irene (Hagen, 1861) that differed widely in estimates of morph frequency and male density. Male-like females resemble males more than another female type resembles males, across populations, when comparisons are based on abdominal patterns. Abdomen phenotype does matter in male–female interactions of damselflies. Furthermore, male-like females were more similar to males at low and high density sites compared with sites with intermediate densities, contrary to the hypothesis that the potential for male harassment influences the degree of phenotypic similarity. Additionally, male-like females of most populations converged on the abdominal phenotype of males of one population rather than on that of syntopic males; a problem that has not received any attention.

Social Context Influences Chemical Communication in D. melanogaster Males

Chemical communication mediates social interactions in insects. For the fruit fly, D. melanogaster, the chemical display is a key fitness trait because it leads to mating. An exchange of cues that resembles a dialogue between males and females is enacted by pheromones, chemical signals that pass between individual flies to alter physiology and behavior. Chemical signals also affect the timing of locomotor activity and sleep. We investigated genetic and environmental determinants of chemical communication. To evaluate the role of the social environment, we extracted a chemical blend from individual males selected from groups composed of one genotype and compared these extracts to those from groups of mixed genotypes. To evaluate the role of the physical environment, these comparisons were performed under a light-dark cycle or in constant darkness. Here, we show that chemical signaling is affected by the social environment, light-dark cycle, and genotype as well as the complex interplay of these variables. Gene-by-environment interactions produce highly significant effects on chemical signaling. We also examined individual responses within the groups. Strikingly, the response of one wild-type fly to another is modulated by the genotypic composition of his neighbors. Chemical signaling in D. melanogaster may be a "fickle" trait that depends on the individual's social background.

Behavioral predictors of copulation in captive Key Largo woodrats (Neotoma floridana smalli)

The development of a captive breeding program for the endangered Key Largo woodrat (Neotoma floridana smalli) presents special challenges due to aggressive behavior toward conspecifics, a low reproductive rate, and limited information on estrous cycles. In an effort to identify behavioral predictors of copulation, we observed 17 Key Largo woodrats prior to and during 267 male-female pairing events, 76 of which resulted in copulation. Predictors of copulation include male-female interactions at the door of the tube connecting their enclosures, raspy vocalizations, pre-mounting lordosis, and chasing. A binary logistic regression model based on pre-pairing behaviors correctly predicted the outcome of 78.7% of observed pairing events, and a similar model based on intra-pairing behaviors correctly predicted the outcome of 86.1% of observed pairing events. Behavior-based models may be useful in the management of captive breeding programs for this and other endangered species.

Of Men and Mice: C. S. Lewis on Male-Female Interactions

Questions of gender are frequently bracketed when discussing C. S. Lewis's life and works. Perhaps most evade the issue because the distinctions are so sharply drawn—either Lewis is a misogynist or he is a product of his time. The issue of women in Lewis's works, however, should not be ignored. In this article, I focus both on Lewis's portrayals of the emancipated woman in his nonfiction writing (particularly ‘Modern Man and His Categories of Thought’, The Four Loves, and ‘Priestesses in the Church?’) and in his fictional writing (particularly ‘The Shoddy Lands’, That Hideous Strength, and Till We Have Faces). I argue that Lewis's frequently problematic portrayals of women in his fiction grow not only out of his theoretical dislike of the emancipated woman but also out of his theological understanding of gender. Building on the biblical image of the relationship of God and humanity as one of a marriage, Lewis casts his fictional couples as representations of the relationship between the masculine divine and the feminine mortal. While focusing on communicating spiritual truths, however, Lewis loses sight of social realities. In his final novel, Till We Have Faces, Lewis is able to get at the theological level by moving away from social context into the realm of myth.

Relationships Between Exposure to Rap Music Videos and Attitudes Toward Relationships Among African American Youth

The purpose of the study is to (a) predict adversarial attitudes toward male-female relationships and (b) explore the relationships between traditional agents of socialization and personal acceptance of negative images in rap videos by African American adolescents. Participants completed psychosocial measures, viewed videos, and completed surveys about the videos. Higher levels of adversarial attitudes toward male-female relationships and exposure to rap videos were associated with acceptance of negative images of women in the videos. Participants who reported watching rap videos because their friends watched them held less adversarial attitudes toward male-female relationships than did those who reported watching because they were fun to watch or to find out the latest trends. Furthermore, higher levels of spiritual or religious coping and higher socioeconomic status were associated with rejection of negative images of women in rap videos. Last, higher levels of spiritual or religious coping were associated with the rejection of negative images of men and male-female interactions in rap videos. Implications for clinicians and parents are outlined, and recommendations for future research are provided.

Choice of Female Groups by Male Mosquitofish (Gambusia holbrooki)

AbstractEven though females are usually more selective in choosing their mates, males are also capable of exercising mate choice. Despite the large body of evidence on the individual features preferred in sexual selection, little attention has been devoted to the first stage of male–female interaction. As poeciliid fish are known to be social, in the wild, initially mate choice may concern a preliminary selection among shoals. Only after this primary choice, males may subsequently direct their attention to a specific mate. We observed spontaneous preference of male mosquitofish (Gambusia holbrooki) when choosing between groups differing in size and sex ratio. In partial agreement with our predictions, males preferred to join a group of females rather than an isolated one (expt 1) and the larger group when two female groups were presented (expt 2). An all‐female group was preferred to a mixed‐sex group (expt 3), whereas no preference was observed when the two mixed‐sex groups differed in the number of males (expt 4) or in the size of the males (expt 5). These results suggest that male mosquitofish are capable of discriminating among different quantities of individuals within a group and use such information to select among groups in order to optimize the likelihood of successful matings.

Ultrasonic Vocalizations Induced by Sex and Amphetamine in M2, M4, M5 Muscarinic and D2 Dopamine Receptor Knockout Mice

Adult mice communicate by emitting ultrasonic vocalizations (USVs) during the appetitive phases of sexual behavior. However, little is known about the genes important in controlling call production. Here, we study the induction and regulation of USVs in muscarinic and dopaminergic receptor knockout (KO) mice as well as wild-type controls during sexual behavior. Female mouse urine, but not female rat or human urine, induced USVs in male mice, whereas male urine did not induce USVs in females. Direct contact of males with females is required for eliciting high level of USVs in males. USVs (25 to120 kHz) were emitted only by males, suggesting positive state; however human-audible squeaks were produced only by females, implying negative state during male-female pairing. USVs were divided into flat and frequency-modulated calls. Male USVs often changed from continuous to broken frequency-modulated calls after initiation of mounting. In M2 KO mice, USVs were lost in about 70–80% of the mice, correlating with a loss of sexual interaction. In M5 KO mice, mean USVs were reduced by almost 80% even though sexual interaction was vigorous. In D2 KOs, the duration of USVs was extended by 20%. In M4 KOs, no significant differences were observed. Amphetamine dose-dependently induced USVs in wild-type males (most at 0.5 mg/kg i.p.), but did not elicit USVs in M5 KO or female mice. These studies suggest that M2 and M5 muscarinic receptors are needed for male USV production during male-female interactions, likely via their roles in dopamine activation. These findings are important for the understanding of the neural substrates for positive affect.

Previous Motor Experience Enhances Courtship Behavior in Male Cricket Gryllus bimaculatus

In crickets Gryllus bimaculatus, flight has been shown to be able to promote aggressive encounters between males and to suppress escape behavior. The aim of this study was to examine the influence of flight on male behavior in male–female interactions. We found that flown males demonstrate enhanced courtship behavior. The latency of calling song was significantly shorter, while the relative total duration of singing as well as the duration of singing episodes longer in flown males than in the control. Mating rate was also significantly higher in the experimental group containing flown males. The results suggest that, in addition to previously reported effects on aggressiveness and escape, flying has a profound accelerating effect on male courtship behavior.

Ni Ennemie, Ni Rivale: Female Friendship in Works by Alice Rivaz, Anne-Lise Grobety and Noelle Revaz

This article studies the theme of female friendship in work by three women writers from French-speaking Switzerland: La Paix des ruches by Alice Rivaz (1947), Pour mourir en fevrier by Anne-Lise Grobety (1969) and Rapport aux betes (2002) by Noelle Revaz. The writers chosen for this study represent three generations, having been born in 1901, 1949 and 1968 respectively. The article compares and contrasts their different representations of friendships between women. Rivaz, writing before Le Deuxieme sexe and the modern women's movement, has a very idealistic view of relations between women, which she contrasts strongly with male-female interaction; Grobety, writing in the wake of 1968 and during the early days of modern feminism, is perhaps more realistic but again sees men as potential threats to relationships between women; finally, Revaz is completely different since her female character is isolated from other women, dominated by the male narrator and sidelined. This article thus seeks to show how, over a period of sixty years, the theme of female friendship has been dealt with in different ways by women writers, and establishes links with changing attitudes to the women's movement.

Males of a subsocial spider choose among females of different ages and the same reproductive status

Most sexual preference studies test female choice between different males or test male choice between females with different reproductive status, but few studies test male preference towards females of different ages within the same reproductive status. In subsocial spiders, males can share the nest with subadult and adult females of different ages. We exposed a male of Anelosimus cf. studiosus to three kinds of females simultaneously: a subadult female, a recently moulted female and a mature adult female (both virgins) comparing male preferences and female interactions. Males courted mature and recently moulted females indiscriminably, but preferentially mated with mature females, while subadult females were not courted. Mature females did not interfere with male courtship towards other females whereas some recently moulted females unsuccessfully attempted to interfere with male courtship towards mature females. In spite of these interferences, no female-female fighting was observed. Taking into account the fact that males court and pseudocopulate with subadult females in uni-female nests, this research using multi-female nests suggests that male preferences show plasticity according to the social context. The preference for copulation with mature females could be due to possible mechanical problems associated to the moult, constraining attempts by males to mate with recently moulted females. This hypothesis and our findings suggest that male may recognize female state and age of adulthood.

Predator upon a flower: life history and fitness in a crab spider

1. Introduction 2. Some Basic Biology 3. Foraging Strategies 4. Fitness Payoffs 5. Constraints on Success 6. Experience, Learning, and Innate Behavior 7. Some Sensory Aspects of Substrate Choice 8. Morphological Variation 9. Male-female Interactions 10. Misumena as Part of the Community 11. Xysticus emertoni, a Cohabiting Crab Spider 12. Conclusions and Future Directions References Index

Matchmaking in Plants

In plants, as in animals, fertilization requires male and female gametes selectively and exclusively to meet and fuse. In plants, unlike in animals, it is not the actual gametes that participate in this dance, but rather the gametophytes, which carry immotile gametes. Escobar-Restrepo et al . (see the Perspective by McCormick) have now identified one of the molecules by which the female gametophyte (the embryo sac) recognizes the male gametophyte (the pollen). A receptor kinase, FER, is situated at cell surfaces within the female gametophyte. As the pollen tube approaches, a signaling cascade is initiated in the embryo sac that closes the door to late-arriving pollen tubes and halts further growth of the successful pollen tube, which then releases the male gamete. A good match between FER and its presumed ligand from the pollen tube appears to form the basis of reproductive compatibility. J.-M. Escobar-Restrepo, N. Huck, S. Kessler, V. Gagliardini, J. Gheyselinck, W.-C. Yang, U. Grossniklaus, The FERONIA receptor-like kinase mediates male-female interactions during pollen tube reception. Science 317 , 656-660 (2007). [Abstract] [Full Text] S. McCormick, Reproductive dialog. Science 317 , 606-607 (2007). [Summary] [Full Text]

Male signaling behavior and sexual selection in a wolf spider (Araneae: Lycosidae): a test for dual functions

Male signaling behaviors are often studied in a single context but may serve multiple functions (e.g., in male–male competition and female mate choice). We examined the issue of dual function male signals in a wolf spider species Schizocosa ocreata (Hentz) that displays the same species-specific signaling behaviors in both male–male and male–female contexts. These signaling behaviors have been described as either aggression or courtship according to the context observed. We tested the possibility of dual functions by comparing the relationship between behaviors and outcome of male–male contests (winner/loser) and male–female mating encounters (mating success). Frequency, rate, and mean duration of signaling behaviors did not vary with outcome of male–male contests, which appears instead to be based upon relative size and body mass. Winners of contests had significantly greater body mass than losers, and greater mass relative to opponents was significantly associated with probability of winning. Overall, signaling rates were much higher in male–female interactions than in male–male contests and were higher for males that successfully mated than for those that did not mate. Mean duration of some male displays was also greater for males that successfully mated. However, male size was not associated with probability of mating. Taken together, results suggest an intersexual selection context for the current function of male signals in these wolf spiders and that increased display vigor is associated with male mating success.

Female–female aggression: structure of interaction and outcome in loggerhead sea turtles

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 336:267-274 (2007) - doi:10.3354/meps336267 Female–female aggression: structure of interaction and outcome in loggerhead sea turtles Gail Schofield1,2,*, Kostas A. Katselidis1,3, John D. Pantis4, Panayotis Dimopoulos1, Graeme C. Hays2 1Department of Environmental & Natural Resources Management, University of Ioannina, G. Seferi 2, 30100 Agrinio, Greece 2Department of Biological Sciences, Institute of Environmental Sustainability, University of Wales Swansea, Singleton Park, Swansea SA2 8PP, UK 3National Marine Park of Zakynthos, 1 El. Venizelou Street, 29100 Zakynthos, Greece 4Department of Ecology, School of Biology, UP Box 119, Aristotle University of Thessaloniki, 54006 Thessaloniki, Greece *Email: g.schof@freemail.gr ABSTRACT: Aggressive behaviour between females of the same species is not widely documented, particularly in marine vertebrates. During a 3 yr in-water survey at the temperate loggerhead sea turtle Caretta caretta breeding area of Zakynthos, Greece, female–female interactions comprised 4% of all female loggerhead sighting events (n = 60 out of 1449 events). Male–female interactions comprised an additional 4% of sighting events, while 92% were of solitary females. The structure of interactions was analysed for 58 of these sighting events, each lasting an average of 3.4 min (SD ± 1) and comprising a total of 3.1 h observation time. We found that interactions involved ritualized escalation in behaviour from passive threat displays (e.g. head–tail circling) to aggressive combat (e.g. sparring). We suggest that circling individuals evaluate opponent size, sparring individuals test opponent strength, and that the positioning of the prehensile tail signals motivational intent to either escalate or abort. The presence of intruder females triggered a passive response in 100% of events involving basking and swimming turtles (n = 19); although residents resting on the seabed only responded on 69% of occasions (n = 27), their response was almost 4 times more likely to escalate to one of aggression. Our results suggest that certain sites may be preferentially sought after and defended by sea turtles. KEY WORDS: Caretta caretta · Sequential assessment · Evolutionary stable strategy · Territory · Marine · Vertebrate · Reptile Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 336. Online publication date: April 27, 2007 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2007 Inter-Research.

Sexual behavior in ewes and other domestic ruminants

Similarities as well as differences across species in the control of sexual behavior are helping to fully understand the subtle relations between physiology and eco-ethological constraints and how the brain integrates such information. We will illustrate this with sexual behavior in domestic ruminants and especially ewes. Females of these species like humans, but unlike rodents, have a long luteal phase. A prolonged exposure to progesterone (Pg) before the preovulatory estradiol rise is necessary for estrous behavior to be displayed. Estradiol action and receptor localization is very similar to that observed in other species. But not too surprisingly, the role of Pg is rather different with a priming effect not observed in rodents. However, as in rodents, Pg also has an inhibitory effect, is necessary for the display of proceptivity and is responsible for the timing of the different periovulatory events. These steroids act on the central nervous system in similar areas across mammalian species to regulate estrous behavior. Steroid fluctuations during the estrous cycle cause changes in catecholaminergic activity in the hypothalamus. Interestingly, these neurotransmitters seem to have very similar effects in ewes and rats as illustrated by the norepinephrine rise after male–female interactions observed in both species. Similar comparisons can be made regarding the action of some neuropeptides, including oxytocin and GnRH, and more integrative processes like sexual differentiation and modulation of reproduction by social interactions. Data on sheep, goats and cows will be compared with those of rodents.

The Payoff of Fighting in House Crickets: Motivational Asymmetry Increases Male Aggression and Mating Success

AbstractMotivational asymmetry caused by differences in subjective resource value is a key component of strategic models of aggression. We study the role of motivational asymmetry in determining differential aggression and mating success of male house crickets, Acheta domesticus. We also assess the extent to which mating differences associated with motivational asymmetry are due to direct male–male fighting vs. male–female interactions. We manipulated male motivation to compete for a mating opportunity by providing males with either no access or nightly access to females for 4 d prior to the experiment. As predicted, when males from each treatment had to compete for the female, those with lower prior access were more aggressive and mated more often. In contrast, when males from each treatment were paired individually with females, there was no significant difference in the frequencies with which they pursued, courted or mated with females. We also found no evidence for female choice based on motivational asymmetry; the rate of successful courtship did not differ between treatments. We conclude that prior mate encounter rate can generate motivational asymmetry, leading to differential mating success mediated by direct male–male aggression.

Mating Behavior and Species Status of Host-Associated Populations of the Polyphagous Thrips, Frankliniella schultzei

The thrips taxon, Frankliniella schultzei Trybom, could possibly comprise a complex of unrecognised cryptic species. We therefore made a range of reproductive behavioral observations on F. schultzei individuals from different host-associated populations to investigate their species status. We first described the mating behavior of F. schultzei taken from flowers of a primary host species, Malvaviscus arboreus. The pattern of male-female interaction was complex and protracted, with several behavioral steps being performed. These steps were similar for all mating pairs. Most females responded to male presence before physical contact, suggesting that male pheromones may be involved. We then compared mating behaviors, brood sizes and sex ratios of F. schultzei pairs derived from different host plant species. All pairs in crosses regardless of their original host plant species produced female offspring, indicating successful mating. Frequencies of behaviors were similar for all pairs. Only those crosses involving F. schultzei individuals from Erythrina crista-galli flowers differed from the general pattern in pre-copulation and copulation times. The females from E. crista-galli also produced significantly fewer offspring than females from other crosses. Finally we used traps baited with males from two populations, but set among flowers of one host plant species, to test for differential attraction of females. We found no evidence that the different host-associated populations investigated differ from one another functionally in their sex pheromone system. However, these results do not yet discount the possibility of cryptic species within the taxon F. schultzei. Populations of F. schultzei on many other host species need to be investigated from this perspective.