Female Aggression Research Articles

Condition‐Dependent Female Aggression and Its Effects on Mating Success and Sexual Cannibalism in Jumping Spiders

ABSTRACTPre‐copulatory sexual cannibalism is an extreme form of aggression toward potential mates. In this study, we examined condition‐dependent female aggression and its effects on mating success and frequency of pre‐copulatory sexual cannibalism in the jumping spider Phidippus audax Hentz 1845. We examined two of the leading hypotheses of why sexual cannibalism may occur, (1) female mate choice and (2) adaptive female foraging. We separated 137 adult virgin female P. audax into three feeding treatments: (1) well‐fed spiders, (2) 14‐day food deprived, and (3) 28‐day food deprived. We recorded weight loss (14‐ and 28‐day treatments) and survival rates. We conducted mating trials to measure the proportion of non‐aggressive and aggressive male and female behaviors, male mating success, and pre‐copulatory sexual cannibalism. Females deprived of food had higher weight loss and lower survival rates than well‐fed females. In addition, food deprived female spiders exhibited higher proportions of aggressive behaviors and pre‐copulatory sexual cannibalism, and lower mating success compared to well‐fed spiders. We found that as male size increased females were less likely to cannibalize males, but we found no effect of male body condition on whether a male mated with or was cannibalized by a female. Our results are consistent with the adaptive foraging hypothesis and corroborates prior research on pre‐copulatory sexual cannibalism.

Males discriminate between substrate-borne cues of conspecific females based on age and mating status in the jumping spider, Habronattus brunneus.

Sexual selection is often studied with a focus on female mate choice, wherein females evaluate male signals to select an optimal mate. However, in some systems, males should also make careful decisions about the females they choose to court, particularly when faced with the risk of precopulatory sexual cannibalism. Here, we explore the idea that male jumping spiders (Habronattus brunneus) may mitigate this risk by responding to female cues probably associated with female aggression and/or receptivity. We tested mature male spiders' ability to discriminate between substrate-borne cues (i.e. silk and excreta) produced by conspecific females of different ages and mating statuses. We found that males spent more time exploring cues produced by mature, non-mated females compared with either immature females or mated females. Heightened interest in cues produced by females that are sexually mature but not yet mated may allow males to reduce cannibalism risk, reduce wasted courtship effort and increase their reproductive success. The use of chemical and/or tactile cues in jumping spider courtship behaviour has been vastly understudied compared with the ways they use vision; this study provides the groundwork for understanding how these sensory modalities interact.

Neurons Underlying Aggression-Like Actions That Are Shared by Both Males and Females in Drosophila.

Aggression involves both sexually monomorphic and dimorphic actions. How the brain implements these two types of actions is poorly understood. We found that in Drosophila melanogaster, a set of neurons, which we call CL062, previously shown to mediate male aggression also mediate female aggression. These neurons elicit aggression acutely and without the presence of a target. Although the same set of actions is elicited in males and females, the overall behavior is sexually dimorphic. The CL062 neurons do not express fruitless, a gene required for sexual dimorphism in flies, and expressed by most other neurons important for controlling fly aggression. Connectomic analysis in a female electron microscopy dataset suggests that these neurons have limited connections with fruitless expressing neurons that have been shown to be important for aggression and signal to different descending neurons. Thus, CL062 is part of a monomorphic circuit for aggression that functions parallel to the known dimorphic circuits.

Does female control and male mating system predict courtship investment and mating outcomes? A comparative study in five widow spider species (genus Latrodectus) tested under similar laboratory conditions

BackgroundMale courtship investment may evolve in response to the male’s expectation of future mating opportunities or the degree of female control during mating interactions. We used a comparative approach to test this hypotheses by assessing the courtship and mating behaviors of five widow spider species (genus Latrodectus) under common laboratory conditions. We predicted male investment in courtship would be higher in species where males mate only once because of high cannibalism rates (monogyny, L. geometricus, L. hasselti, L. mirabilis), compared to species with rare cannibalism (L. mactans, L. hesperus) in which males should reserve energy for future mating opportunities. Increased male investment, measured as courtship duration, might also evolve with increased female control over mating outcomes if females prefer longer courtships. We tested this by assessing the frequency of copulations, timing of sexual cannibalism, and the degree of female-biased size dimorphism, which is expected to be negatively correlated with the energetic cost of rebuffing male mating attempts.ResultsCopulation frequency was consistently lower in species with extreme female-skewed size dimorphism, and where sexual cannibalism was more prevalent, suggesting the importance of female control for mating outcomes. We confirmed significant interspecific variation in average courtship duration, but contrary to predictions, it was not predicted by male mating system, and there was no consistent link between courtship duration and sexual size dimorphism.ConclusionWe show that the degree of sexual dimorphism is not only correlated with sexual cannibalism, but also with mating success since restriction of male copulation frequency by female Latrodectus affects paternity. However, predictions about male mating system or female control affecting courtship duration were not supported. We propose that the form of female control over mating and cannibalism, and male responses, might be more informative for understanding the evolution of courtship duration. For example, male tactics to avoid female aggression may drive lower courtship duration in species like L. mirabilis. Nonetheless, our results differ from inferences based on published studies of each species in isolation, illuminating the need for standardized data collection for behavioural comparative studies.

Evidence for female dominance in the Milne-Edwards' sportive lemur (Lepilemur edwardsi).

Female dominance over males is more frequent in Malagasy lemurs than in other primate clades, but patterns of female-male dominance vary among species, and few data are available for one particularly species-rich genus, Lepilemur. We investigated the types, temporal distribution, and outcome of female-male agonistic conflicts in the Milne-Edwards' sportive lemur (Lepilemur edwardsi). Ten L. edwardsi belonging to five social units were equipped with radio collars and observed during 79 focal follows between May and November 1998. We quantified agonistic conflicts, monthly conflict rates, and documented the winner and context for all conflicts. Female-male agonistic conflicts (N = 162) occurred at a mean rate of 0.21 conflicts/hour within groups. Agonistic conflicts peaked during the birth season and occurred mostly in unknown or infant proximity contexts. Females won 96% of all decided agonistic conflicts (N = 154). Other outcomes occurred only when females were with infants during the birth season. In that context, one female sometimes withdrew from her pair partner, and another female withdrew or fled from an extra-group male whose attacks eventually led to infanticide. Our results suggest female dominance in pair-living L. edwardsi. We hypothesize that elevated female aggression may convey fitness benefits to female Lepilemur because it generally allows females to intervene quickly and efficiently on behalf of their infants against nonfather males who may approach the newborn infants when they are parked in vegetation.

Sexually dimorphic control of aggression by androgen signaling in a cichlid

Innate social behaviors like aggression are modulated by sex steroid hormones such as androgens and estrogens. However, we know little about how the same hormone regulates similar behaviors in both sexes. We investigated the role of androgenic signaling in the regulation of aggression in Astatotilapia burtoni, a social fish in which males and females perform similar aggressive behaviors. We used androgen receptor (AR) α knockout (KO) animals for this study since this gene was recently shown to be required for male-typical aggression and mating. Surprisingly, ARα KO females did not show deficits in aggression. We also determined that females lacking the other AR, ARβ, showed normal levels of aggression. Blocking both ARs pharmacologically confirmed that neither AR is necessary for aggression in females. However, ARα KO males showed clear deficits in attacks. Thus, in A. burtoni there appears to be a sexual dimorphism in the role of ARα in the control of aggression.

Testing the Associations Between Attachment Anxiety, Relational Aggression and Depressive Symptoms in Romantic Relationships: Actor-Partner Interdependence Model and Actor-Partner Interdependence Mediator Model.

Emerging adulthood is a pivotal period for romantic relationships, yet the specific mechanisms through which attachment anxiety influences relationship dynamics and psychological outcomes in this phase are poorly understood. Particularly, in the context of romantic dyads, understanding how partners' behaviors and emotional patterns reciprocally influence each other remains underexplored. This study utilizes the Actor-Partner Interdependence Model and Actor-Partner Interdependence Mediator Model to explore the relationship between attachment anxiety,relational aggression (both perpetration and victimization), and depressive symptoms among emerging adults. A sample of 138 mixed-sex emerging adulthood couples from China, was recruited (Mage = 21.40, SD = 2.54; 50% female, 62.6% reporting that this relationship was ongoing for more than a year). Attachment anxiety significantly predicted relational aggression in both partners, with male attachment anxiety also significantly predicted female relational aggression. Significant indirect effects of both partners' relational aggression perpetration and victimization on their own and each other's relationship between attachment anxiety and depressive symptoms. These findings contribute to understanding the intricate dynamics of attachment anxiety and relational aggression in romantic relationships during emerging adulthood, emphasizing the need for targeted interventions to mitigate these risks.

Exploring relational aggression and gender dynamics: a global and Indonesian perspective

Girls generally use less physical aggression than boys. However, does this mean that girls are more likely to use relational aggression. With this question in mind, our study aims to analyze the relational aggression of students in Indonesia based on gender. This type of research used is comparative research. The sample in this study was 510 respondents consisting of 19.6% male and 80.4% female. The relational aggression scale (RAS) was used to collect data on student relational aggression in various regions in Indonesia. The analysis technique used is descriptive and differences with the Welch test. The results show that there are significant differences in male and female relational aggression, with an average score difference of -0.30 logit between men and women. In addition, there are fluctuations in the level of relational aggression in the context of gender from year to year in some countries, such as the United States, China, Australia, and others. Recommendations for future research are to integrate a more in-depth social and cultural analysis in Indonesia.

Transfer pricing, earnings management and corporate governance among listed firms: Evidence from Ghana

PurposeThis study aims to examine the prevalence of transfer pricing and earnings management activities, and how they are impacted by corporate governance mechanisms.Design/methodology/approachUsing the political cost theory, the study provides insights into how opportunistic managerial behaviours which have a strong link to profit shifting and tax evasion are driven by corporate governance using data from 16 listed firms for the period 2008–2020.FindingsThe results reveal that the transaction-based transfer pricing model is better than the index-based model and the accrual-based earnings management model suits the political cost theory more than the real earnings management metric. Board size and female CEO increase transfer pricing aggressiveness but board independence, CEO tenure, CEO nationality and female Board Chairwomanship reduce transfer pricing aggressiveness. The findings also reveal the role of multinational enterprise status, private ownership, industry type, firm size, financial leverage, asset tangibility and firm age. For accrual-based earnings management, board independence, CEO tenure, and female Board Chairwomanship significantly decrease earnings management. Other factors include private ownership, firm size, and firm age.Practical implicationsThe findings of the study are relevant for shaping industry-level policies on earning management, transfer pricing and related-party transactions. Since these opportunistic managerial behaviours are the foremost drivers of tax avoidance and profit shifting, the findings of this study provide relevant insights for practitioners, tax and other regulatory authorities, policymakers and the academic community alike.Originality/valueThis is among the premier studies on the transfer pricing and earnings management nexus with corporate governance factors using the political cost theory, especially in the developing country context. It also reveals the significant impact of gender and suggests the need for gender diversity in corporate management.

Interspecific variability of the external female genital mutilation rate and its relationship with female aggression and sexual cannibalism in Cyclosa spiders

Interspecific variability of the external female genital mutilation rate and its relationship with female aggression and sexual cannibalism in Cyclosa spiders

Female perpetrators in intimate partner violence: perverse safe havens

This article considers the often-neglected role of women as intimate partner terror-ists within relationships and explores the ways that female aggression is manifested through psychological as well as physical means of intimidation. Using anonymised clinical material, the author discusses the development of toxic dynamics within an intimate partnership, the pathways through which early traumatic experience creates later destructive re-enactments and how forensic psychotherapy can be undertaken successfully, highlighting the pitfalls. The role of animal cruelty in abusive intimate partner relationships is discussed, with reference to the link between animal abuse and domestic abuse. The function of these violent destructive dynamics to serve as “perverse safe havens” within couples and the wider family systems is outlined. These entrenched dynamics maintain dysfunctional and abusive relation-ships but the harm they inflict is manifold and when breaking point is reached, foren-sic psychotherapy can enable essential changes to occur, as the clinical example demonstrates.

Some Specific Biological Risks of SARS-CoV-2 Infected Syrian Hamsters at Animal Biosafety Level - Lab 3

The emergence of novel severe acute respiratory syndrome 2 (SARS-CoV-2) has prompted extensive research to identify its pathogenesis, transmission, and reservoir entry in animals. Syrian hamsters (Mesocricetus auratus) are being identified as an ideal animal model for the study of SARS-CoV-2 infection due to their susceptibility and respiratory symptoms similar to that observed in humans. This study focused on the specific biological risks associated with the use of infected Syrian hamsters in animal biosafety level 3 (ABSL-3) laboratories. The professional and psychological training of professionals working with laboratory animals should be a priority. Biological safety requires the involvement of all parties from technical staff to top management. The COVID-19 pandemic has shown a limitation in experimental studies when obtaining the right strain of mice proved difficult. A rare experimental model of Syrian hamsters started to be used in the work, which Syrian hamsters have several distinctive characteristics associated with increased aggressiveness of females, leading to a requirement to keep them isolated and some technical difficulties during manipulations in the biological safety cabinet. Therefore, a risk-based approach must be introduced to reduce the additional risks to workers to an acceptable level. This includes enhanced accuracy in the use of personal protective equipment (PPE), rigorously following biosecurity protocols, and monitoring staff health to detect potential risk of zoonotic transmission. The implementation of international standards and regulations on biological safety and biosecurity is of paramount importance.

Sex differences in responses to aggressive encounters among California mice

Despite how widespread female aggression is across the animal kingdom, there remains much unknown about its neuroendocrine mechanisms, especially in females that engage in aggression outside the peripartum period. Although the impact of aggressive experience on steroid hormone responses have been described, little is known about the impact of these experiences on female behavior or the subsequent neuropeptide responses to performing aggression. In this study, we compared behavioral responses in both male and female adult California mice based on if they had 0, 1, or 3 aggressive encounters using a resident intruder paradigm. We measured how arginine vasopressin and oxytocin cells in the paraventricular nucleus responded to aggression using c-fos immunohistochemistry. We saw that both sexes disengaged from intruders with repeated aggressive encounters, but that on the final day of testing females were more likely to freeze when they encountered intruders compared to no aggression controls – which was not significant in males. Finally, we saw that percent of arginine vasopressin and c-fos co-localizations in the posterior region of the paraventricular nucleus increased in males who fought compared to no aggression controls. No difference was observed in females. Overall, there is evidence that engaging in aggression induces stress responses in both sexes, and that females may be more sensitive to the effects of fighting.

Influence of sex hormones on the aggressive behavior during peck order establishment and stabilization in meat and egg type chickens

In the poultry industry, broiler and layer strains are genetically selected for different purposes (e.g., high meat-yield and high egg-production). Genetic selection for productivity can have unintended consequences on the behavioral repertoire of the birds, including aggression. Alongside the increasing societal concern regarding the welfare of animal in agriculture, the number of countries that are advocating the prohibition of using battery cages for laying hens has resulted in the transition and adoption of cage-free or free-range systems. Thus, both broiler and layer chickens are housed in large flocks rather than housed individually in cages. Housing birds in groups increases the opportunity for birds to engage in social behaviors, including aggression, that are used to establish social status. Aggressive interactions are associated with the risk of injury and the potential for a subordinate animal to have unmet needs (e.g., access to feed). The aim of this study was to characterize the relationships among aggressive behavior, neurobiology, and hormones during peck order establishment and social hierarchy stabilization of 2 divergently selected strains (meat- and egg-type chicken). Meat-type strains performed more male on male (P < 0.001), male on female (P < 0.0001), and female on female (P < 0.0001) non-reciprocal aggression behavior (NRA) than egg-type strains. Greater serum testosterone and estradiol concentrations in the weeks after the peck order establishment were observed in meat-type birds compared those in egg-type birds for both males and females (all P < 0.05). Greater (P < 0.05) cellular densities of androgen receptors, but not estrogen receptors, were observed in the hypothalamus of meat-type birds compared to egg-type birds. These findings suggest that greater sex hormone concentrations in the meat-type birds may be a consequence of genetic selection for rapid growth resulting in more sex hormones-induced aggressive behavior.

Cross-context behavioural correlations and signals of aggression in females of a livebearing fish

Abstract Behaviours can be adaptively correlated with each other and with other aspects of phenotype. We investigated behaviour across foraging, mating, and risk contexts in females of the poeciliid fish, Girardinus metallicus. We quantified relationships between these behaviours and aggression signals, body size, and reproductive output. Behaviours describing aggression and boldness, some of which were repeatable, were correlated in females. Aggression was signalled by the darkening of a black spot on the extended dorsal fin or by fin flaring. Spot darkening occurred during intra- and intersexual interactions and was positively correlated with interfemale aggression and negatively correlated with the time females spent following males, suggesting that it is an honest indicator of motivational state. In contrast, fin flaring was directed only at females and occurred more frequently in the foraging context. Larger females had fewer offspring and received fewer courtship displays, possibly because they were more aggressive to males. In contrast to studies of males, we found a negative relationship between rank order of boldness and aggression, consistent with either a trade-off or with selection favouring the negative relationship. Our results highlight the importance of studying females in model systems to uncover novel patterns and potentially meaningful departures from what is typically seen in males.

Perbedaan Tingkat Perilaku Agresi Siswa SMA Sederajat di Kabupaten Labuhanbatu Ditinjau dari Jenis Kelamin dan Jenis Sekolah

This study was conducted with the aim of finding out the difference in the level of student aggression behavior reviewed from gender and type of school in Labuhan Batu Regency in 2019, this study is quantitative research with a sample of 346 students, sampling using Random Sampling. The instrument used is the aggression behavior scale. Data analysis with the Mann-Whitney Test. The results of the study showed that there was a difference in aggression behavior between men and women, where male aggression behavior was higher than female aggression behavior

A study to assess the level of aggression among government and private high school students

INTRODUCTION-Adolescent is a period of great stress and Strom as rapid physical and mental changes occur during this period and the individual comes under social pressure and faces new condition for which he received little training during childhood. At this stage emotion fluctuations occurs very frequently and quickly. OBJECTIVES OF THE STUDY- 1. To find out the mean difference for Aggression between government school and private school students (Adolescent) 2. To find out the mean difference for Aggression between males and females (Adolescent) MATERIALS AND METHOD- The present study was conducted on a sample of 60 students which consist of 30 government school students (15 male + 15 female) and 30 private school students (15 male +15 female), age range from 14 - 22 years. thus sample size was categorized into two categories based on gender and the types of school. random sampling, or probability sampling, is a sampling method that allows for the randomization of sample selection. Aggression scale test (A-Scale) was used for this study. RESULT- The mean difference for Aggression between government &amp; private and male &amp; female was 0.82 There was significant difference of Aggression of females and males. ( Value of t = 4.93 , significant at 0.01evel )

Shifting incubation rhythms in response to predation risk and the length of the response in mountain bluebirds

Abstract Parent birds may alter incubation rhythms in response to predation risk but few studies have examined the recovery time immediately after exposure to a predator. Here, we examined incubation rhythms in mountain bluebirds (Sialia currucoides) in response to a simulated nest predator, a taxidermy-mounted squirrel. We used data loggers (iButtons) to measure the recess (off-bout) length, recess rate, and constancy of incubation and found no relationship between incubation rhythms and female age, body size and aggressiveness. Incubating females reacted to the predator by reducing nest visitation rates and increasing recess length but did not change incubation constancy. Instead, constancy was negatively associated with ambient temperature. Changes in incubation behaviour lasted about 48 h before returning to pre-exposure patterns. Our results suggest that modifying incubation rhythms is costly for female birds and the demand to regulate egg temperature efficiently limits the length of behavioural responses to the threat of nest predation.

Male-specific vasotocin expression in the medaka tuberal hypothalamus: Androgen dependence and probable role in aggression

Terrestrial vertebrates have a population of androgen-dependent vasotocin (VT)-expressing neurons in the extended amygdala that are more abundant in males and mediate male-typical social behaviors, including aggression. Teleosts lack these neurons but instead have novel male-specific VT-expressing neurons in the tuberal hypothalamus. Here we found in medaka that vt expression in these neurons is dependent on post-pubertal gonadal androgens and that androgens can act on these neurons to directly stimulate vt transcription via the androgen receptor subtype Ara. Furthermore, administration of exogenous VT induced aggression in females and alterations in the androgen milieu led to correlated changes in the levels of tuberal hypothalamic vt expression and aggression in both sexes. However, genetic ablation of vt failed to prevent androgen-induced aggression in females. Collectively, our results demonstrate a marked androgen dependence of male-specific vt expression in the teleost tuberal hypothalamus, although its relevance to male-typical aggression needs to be further validated.

An appetite for aggressive behavior? Female rats, too, derive reward from winning aggressive interactions

While aggression is an adaptive behavior mostly triggered by competition for resources, it can also in and of itself be rewarding. Based on the common notion that female rats are not aggressive, much of aggression research has been centered around males, leading to a gap in the understanding of the female aggression neurobiology. Therefore, we asked whether intact virgin female rats experience reward from an aggressive interaction and assessed aggression seeking behavior in rats of both sexes. To validate the involvement of reward signaling, we measured mesolimbic dopamine turnover and determined the necessity of dopamine signaling for expression of aggression-seeking. Together our data indicate that female rats exhibit aggressive behavior outside of maternal context, experience winning aggressive behaviors as rewarding, and do so to a similar extent as male rats and in a dopamine-dependent manner.