Potential Mates Research Articles

The indirect influence of potential mates on survival and reproduction of Tyrophagus curvipenis (Acari: Acaridae).

The social-sexual environment is well known for its influence on the survival of organisms by modulating their reproductive output. However, whether it affects survival indirectly through a variety of cues without physical contact and its influence relative to direct interaction remain largely unknown. In this study, we investigated both the indirect and direct influences of the social-sexual environment on the survival and reproduction of the mite Tyrophagus curvipenis (Acari: Acaridae). The results demonstrated no apparent influence of conspecific cues on the survival of mites, but the survival and reproduction of mated female mites significantly changed, with the females mated with males having a significantly shortened lifespan and increased lifetime fecundity. For males, no significant difference was observed across treatments in their survival and lifespan. These findings indicate that direct interaction with the opposite sex has a much more profound influence on mites than indirect interaction and highlight the urgent need to expand research on how conspecific cues modulate the performance of organisms with more species to clarify their impacts across taxa.

Female Mate Choice in Wild Kenyan Blue Monkeys (Cercopithecus mitis).

Female mate choice may drive sexual selection, but discerning whether female behaviors reflect free expression of choice or responses to constraints can be difficult. We investigated the efficacy of female choice in wild blue monkeys using 10 years of behavior and paternity data (N = 178 male-female dyads). Although blue monkeys live modally in one-male polygynous groups, where male-biased intersexual power is expected, females can access multiple potential mates during seasonal male influxes and occasional intergroup encounters. Additionally, extra-group males sire offspring. We examined female resistance rates to male-initiated sexual interactions, and unsolicited proceptive behavior that females directed to males (corrected for male availability). Females seldom resisted male solicitation, but initiated sexual interactions more than males. Females generally preferred residents. Those who preferred non-residents tended to have residents with longer tenures, but neither female parity nor rank influenced the tendency to prefer non-residents vs. residents. The male most solicited by a particular female fathered that female's infant 82% of the time; odds of siring were 26 times higher for most vs. nonpreferred males. Female preference predicted paternity even more strongly among non-resident males, with odds of siring 33 times higher for most vs. nonpreferred non-residents. Neither female rank nor parity influenced her likelihood of having her preferred partner as sire. Paternity by preferred males did not affect infant survival. While we cannot fully discount the effect of male-male competition on paternity, these results suggest that blue monkey females can exercise choice successfully, even in a polygynous mating system.

Herbicide changes the role of body condition in mating interactions of a wolf spider but courtship is primarily affected by female immunity

AbstractAnimals that live in human‐impacted landscapes experience an onslaught of novel stimuli that may interfere with natural communication pathways. During mating, this interference may alter the criteria deployed to assess potential mates as males and females find they must shift their focus and emphasize alternative sensory modalities. The wolf spider, Tigrosa helluo (Araneae, Lycosidae) is common in agricultural fields where commercial formulations of herbicides with glyphosate as the active ingredient are regularly applied. With the development of genetically resistant crops, glyphosate‐based herbicides have become among the most widely used and heavily applied agricultural chemicals in the world. In a laboratory experiment, we explored the effects of this herbicide on male—female interactions during courtship, mating, and sexual cannibalism. We expected that it might impact assessment such that there was a shift in the features that were important to the outcome of mating interactions. When herbicide was present, female body condition, an indication of recent feeding success, became important to mating success. This result was, in part, due to higher rates of sexual cannibalism in parings of males and females with low body condition values. The leg raises and pedipalp waves that males perform in courtship were not affected by herbicide nor were they related to mating success but, across all treatments, they were negatively correlated with lytic activity of females as measured just prior to pairing. This result indicates that males detected this aspect of the female's physiology and that a strong immune response made the female less attractive, possibly because it indicated a current or recent infection. Taken together, these results verify that a common herbicide shifts mating criteria used by an agribiont spider and, separate from the herbicide, the immune status of females affects the reactions of courting males.

Signaled Similarity of Personality Dimensions in Mate Choice

Signaling theory offers an interpretation of how one’s impression of a potential mate’s personality affects mating strategies. It remains unclear how people perceive the (dis)similarity of a potential mate to one’s own personality and use this information in mating contexts. We focus on this distance in personality similarity between a potential mate and oneself, particularly in deciding whether to interact. We present a novel framework for investigating this issue via an online chatting tool. The actual personality of 24 participants was measured according to the Big Five Inventory. Then, participants were paired to have a conversation. Their face, occupations, and income were hidden, and their voice transformed to be neutral in pitch. They talked about their own experiences as related to the Big Five dimensions. Analysis of their communications showed their willingness to consider their partners as a friend, lover, and spouse was most explained by the distance between self-recognition of the impression of one’s own personality presumably held by the partner and the impression of the partner’s personality. Our results suggest people rely on the meta-perception of their personality rather than their actual personality, at least when considering potential mates when they first meet.

Does losing reduce the tendency to engage with rivals to reach mates? An experimental test.

Male-male contests for access to females or breeding resources are critical in determining male reproductive success. Larger males and those with more effective weaponry are more likely to win fights. However, even after controlling for such predictors of fighting ability, studies have reported a winner-loser effect: previous winners are more likely to win subsequent contests, while losers often suffer repeated defeats. While the effect of winning-losing is well-documented for the outcome of future fights, its effect on other behaviors (e.g. mating) remains poorly investigated. Here, we test whether a winning versus losing experience influenced subsequent behaviors of male mosquitofish (Gambusia holbrooki) toward rivals and potential mates. We housed focal males with either a smaller or larger opponent for 24 h to manipulate their fighting experience to become winners or losers, respectively. The focal males then underwent tests that required them to enter and swim through a narrow corridor to reach females, bypassing a cylinder that contained either a larger rival male (competitive scenario), a juvenile or was empty (non-competitive scenarios). The tests were repeated after 1 wk. Winners were more likely to leave the start area and to reach the females, but only when a larger rival was presented, indicating higher levels of risk-taking behavior in aggressive interactions. This winner-loser effect persisted for at least 1 wk. We suggest that male mosquitofish adjust their assessment of their own and/or their rival's fighting ability following contests in ways whose detection by researchers depends on the social context.

Novel behavioral observations and body scarring for the bluntnose sixgill shark (Hexanchus griseus) offer clues to reproductive patterns and potential mating events

Novel behavioral observations and body scarring for the bluntnose sixgill shark (Hexanchus griseus) offer clues to reproductive patterns and potential mating events

Is promiscuity the key? Multiple paternity in the garden dormouse (Eliomys quercinus)

Many mammals have a promiscuous mating system with multiple sired litters. Promiscuity can increase the genetic variability, reduce the risk of inbreeding, and increase the effective population size, and is therefore crucial for preventing genetic loss and maintaining adaptability. This is particularly true for small and threatened populations. The garden dormouse (Eliomys quercinus) is a threatened species, which exhibited a drastic decline over the last 20–30 years. The aim of this study was therefore to investigate the mating system of the garden dormouse in mountain forest habitat by parentage analyses using 5 polymorphic microsatellite markers combined with morphometric data and information about the nesting behavior. Genetic parentage analyses revealed that 64% (9 of 14) of the litters were sired by at least two males, suggesting that garden dormice have a promiscuous mating system. The genetic findings were further supported by indirect indicators of promiscuity, such as testes, that were nearly four times larger than predicted for a rodent of its body mass and only slight male biased sexual size dimorphism. The finding of a promiscuous mating system in garden dormice should be taken into account in future conservation efforts. Due to its habitat preferences and limited dispersal potential garden dormice are vulnerable to forest fragmentation. The connection of suitable habitats facilitates dispersal and promotes access to potential mating partners, which could be especially important for populations colonizing new habitats. Access to potential mates may also reduce inbreeding, loss of genetic variability which is crucial for populations viability and survival.

Impact of Natural and Mechanical Mating on Fecundity and Egg Retention in Muga Silkworm, Antheraea assamensis (Lepidoptera: Saturniidae)

Lepidopteran muga silkworm Antheraea assamensis belonging to Saturnidae is an economically important insect geographically endemic to Assam and the northeastern region of India. Like any other insect species, oviposition is one of the most vital aspects of A. assamensis as it allocates the majority of its energy during its lifecycle. Muga silkworm seed production technology has still not been studied much in detail. The demand for silkworm seeds rises during the commercial rearing season in the region, Central Silk Board has established seed production centres to cater for the demand of the sericulture industry. The number of seed cocoons processed for commercial seed production is 1.5-2.5 lakhs per annum. Muga silkworm emergence pattern is asynchronous, no. of male and female moths is not equal during operations. A. assamensis is nocturnal in habit, and emergence and coupling take place at night. Due to the asynchronous pattern of emergence, it is quite often that female moths run out of mates in the seed production centres. Due to the depleting number of potential male mates, the mating will be done mechanically by putting male female moths in a bamboo box to save the time and energy of silk moths. So, an experiment was conducted to study the difference in fecundity between naturally mated and mechanically mated muga silkworms and its impact on mating duration at Silkworm Seed Production Centre, Kaliabari, Boko, Assam during commercial crop (April-May & Oct-Nov) of 2023. The results of the study showed that maximum fecundity was observed in silkworms which are naturally mated with 214±12.08 eggs per female. Whereas, the mechanically mated muga silkworm females showed slightly less fecundity compared to naturally mated females with 203.2±12.77 eggs per female. The results on egg retention showed a clear difference with 18.6±4.77 and 16.6±8.64 eggs per female in natural and mechanical mating, respectively. The slightest reduction in fecundity and increased egg retention in female moths might be due to the impact of mechanical mating on mating duration which reported only 5.5±1.29 hrs, whereas natural mating facilitated a higher mating duration with 8.2±1.30hrs, respectively. This study showed the significance of mating type (natural and mechanical) and its impact on fecundity and egg retention of muga silkworm.

Urbanization alters the song propagation of two human-commensal songbird species.

Urban expansion has increased pollution, including both physical (e.g., exhaust, litter) and sensory (e.g., anthropogenic noise) components. Urban avian species tend to increase the frequency and/or amplitude of songs to reduce masking by low-frequency noise. Nevertheless, song propagation to the receiver can also be constrained by the environment. We know relatively little about how this propagation may be altered across species that (1) vary in song complexity and (2) inhabit areas along an urbanization gradient. We investigated differences in song amplitude, attenuation, and active space, or the maximum distance a receiver can detect a signal, in two human-commensal species: the house sparrow (Passer domesticus) and house finch (Haemorhous mexicanus). We described urbanization both discretely and quantitatively to investigate the habitat characteristics most responsible for propagation changes. We found mixed support for our hypothesis of urban-specific degradation of songs. Urban songs propagated with higher amplitude; however, urban song fidelity was species-specific and showed lowered active space for urban house finch songs. Taken together, our results suggest that urban environments may constrain the propagation of vocal signals in species-specific manners. Ultimately, this has implications for the ability of urban birds to communicate with potential mates or kin.

To house or oust: Honey bee (Apis mellifera) colonies can evaluate and evict drones of low quality

Across the animal kingdom, males advertise their quality to potential mates. Males of low reproductive quality, such as those that are sick, may be excluded from mating. In eusocial species, there is some evidence that reproductive females gauge the quality of their mates. However, males often spend much more time with non-reproductive females when being raised or when returning from unsuccessful mating flights. Do non-reproductive workers evaluate the quality of male reproductives? Here we address this question using male honey bees (Apis mellifera), called drones, as a model. We generated immune-challenged drones by injecting them with lipopolysaccharide and tested: 1) do workers evict immune-challenged drones from their colony, 2) do cuticular hydrocarbon (CHC) profiles, body size, or mass change when drones are immune-challenged, and 3) are these changes used by workers to exclude low quality males from the colony? We found that an immune challenge causes changes in CHC profiles of drones and reduces their body mass. Workers selectively evict small and immune-challenged drones who, themselves, do not self-evict. This work demonstrates that some eusocial males undergo an additional layer of scrutiny prior to mating mediated by the non-reproductive worker caste.Significance statementMales of some species must advertise their quality to mates but, in the case of eusocial species, must they also advertise their quality to nestmates? By manipulating honey bee male quality, we found that small and immune-challenged drones are evicted from colonies overnight. Workers may not use a drone’s cuticular hydrocarbon profile to make this assessment. This is a new example of social immunity expressed against adult males and an example of worker involvement in reproductive decisions.

Localized Expression of Olfactory Receptor Genes in the Olfactory Organ of Common Minke Whales.

Baleen whales (Mysticeti) possess the necessary anatomical structures and genetic elements for olfaction. Nevertheless, the olfactory receptor gene (OR) repertoire has undergone substantial degeneration in the cetacean lineage following the divergence of the Artiodactyla and Cetacea. The functionality of highly degenerated mysticete ORs within their olfactory epithelium remains unknown. In this study, we extracted total RNA from the nasal mucosae of common minke whales (Balaenoptera acutorostrata) to investigate ORs' localized expression. All three sections of the mucosae examined in the nasal chamber displayed comparable histological structure. However, the posterior portion of the frontoturbinal region exhibited notably high OR expression. Neither the olfactory bulb nor the external skin exhibited the expression of these genes. Although this species possesses four intact non-class-2 ORs, all the ORs expressed in the nasal mucosae belong to class-2, implying the loss of aversion to specific odorants. These anatomical and genomic analyses suggest that ORs are still responsible for olfaction within the nasal region of baleen whales, enabling them to detect desirable scents such as prey and potential mating partners.

Behavioural Endocrinology in the Social Sciences

Hormones are the endocrine system’s messengers and an important coordinating mechanism of the body’s growth, development, and functioning, with often simultaneous effects throughout the body and brain. Echoing calls for more interdisciplinary research bridging the gap between endocrinology and social sciences, we review evidence for hormones influencing human psychology (behaviour, cognition, and sociality), with a focus on health, sexuality, and further outcomes. We focus on four steroid hormones: testosterone (T), cortisol (C), estrogen (E), and progesterone (P). Embedded into life history theory as a prominent evolutionary framework, effects of T are conceptualised as modulating trade-offs between mating and parenting effort, especially when exposed to potential mates, interacting with offspring, and during competition. The challenge hypothesis suggests acute increases in T when facing challenges, with high T being linked to more competitive behaviour. The dual-hormone hypothesis postulates that C, as a measure of stress, inhibits the effects of T on status-seeking behaviour. The allostatic load framework suggests that chronic stress as indicated by high C levels could have detrimental health consequences. Various measurements of C are negatively related to socioeconomic status. The female steroid hormones E and P coordinate female reproduction by regulating the development and function of the uterus. They affect women’s sexual desire as well as self-perceived attractiveness and are influenced by endogenous (e.g. pregnancy) as well as exogenous (e.g. hormonal contraceptives) factors. We address misinterpretations of biological determinism, highlight potential challenges in measuring hormones, and discuss ways in which social scientists can continue to incorporate hormones into their research.

Hybrids of two destructive subterranean termites established in the field, revealing a potential for gene flow between species.

Hybridization between invasive pest species may lead to significant genetic and economic impacts that require close monitoring. The two most invasive and destructive termite species worldwide, Coptotermes formosanus Shiraki and Coptotermes gestroi (Wasmann), have the potential for hybridization in the field. A three-year field survey conducted during the dispersal flight season of Coptotermes in Taiwan identified alates with atypical morphology, which were confirmed as hybrids of the two Coptotermes species using microsatellite and mitochondrial analyses. Out of 27,601 alates collected over three years, 4.4% were confirmed as hybrid alates, and some advanced hybrids (>F1 generations) were identified. The hybrid alates had a dispersal flight season that overlapped with the two parental species 13 out of 15 times. Most of the hybrid alates were females, implying that mating opportunities beyond F1 may primarily be possible through female hybrids. However, the incipient colony growth results from all potential mating combinations suggest that only backcross colonies with hybrid males could sometimes lead to brood development. The observed asymmetrical viability and fertility of hybrid alates may critically reduce the probability of advanced-hybrid colonies being established in the field.

Cip1, a CDK regulator, determines heterothallic mating or homothallic selfing in a protist

Mating type (sex) plays a crucial role in regulating sexual reproduction in most extant eukaryotes. One of the functions of mating types is ensuring self-incompatibility to some extent, thereby promoting genetic diversity. However, heterothallic mating is not always the best mating strategy. For example, in low-density populations or specific environments, such as parasitic ones, species may need to increase the ratio of potential mating partners. Consequently, many species allow homothallic selfing (i.e., self-fertility or intraclonal mating). Throughout the extensive evolutionary history of species, changes in environmental conditions have influenced mating strategies back and forth. However, the mechanisms through which mating-type recognition regulates sexual reproduction and the dynamics of mating strategy throughout evolution remain poorly understood. In this study, we show that the Cip1 protein is responsible for coupling sexual reproduction initiation to mating-type recognition in the protozoal eukaryote Tetrahymena thermophila. Deletion of the Cip1 protein leads to the loss of the selfing-avoidance function of mating-type recognition, resulting in selfing without mating-type recognition. Further experiments revealed that Cip1 is a regulatory subunit of the Cdk19-Cyc9 complex, which controls the initiation of sexual reproduction. These results reveal a mechanism that regulates the choice between mating and selfing. This mechanism also contributes to the debate about the ancestral state of sexual reproduction.

Sexual selection: competition for resources provided by mating partners

Abstract Ever since Darwin’s pioneering work, the definition of sexual selection has been subject to recurrent controversies. The main focus of a more recent debate centers on whether or not sexual selection encompasses intra-sexual competition for resources other than gametes. Specifically, it has been proposed to define sexual selection as competition for access to gametes and to consider competition for any other resources provided by mates as forms of natural selection. In this review, I elaborate on several drawbacks of this gamete-centered approach arguing that it (1) implies an artificial split of pre-copulatory competition for mates into two indistinguishable processes, (2) hinders the identification and quantification of sexual selection and, therefore, its distinction from other forms of natural selection, (3) gives rise to an overly male-biased perception on sexual selection, and (4) does not conform to Darwin’s original conception. In an attempt to provide a definition, which is explicit regarding the ultimate target of intra-sexual competition, I propose to define sexual selection as competition for access to reproductive resources provided by potential mating partners. I specify the main characteristics of this alternative definition in the context of previous ones and discuss potential limitations.

The Mating Psychology of Incels (Involuntary Celibates): Misfortunes, Misperceptions, and Misrepresentations

ABSTRACT Mating represents a suite of fundamental adaptive problems for humans. Yet a community of men, called incels (involuntary celibates), forge their identity around their perceived inability to solve these problems. Many incels engage in misogynistic online hostility, and there are concerns about violence stemming from the community. Despite significant media speculation about the potential mating psychology of incels, this has yet to be formally investigated in the scientific literature. In the first formal investigation of incel mating psychology, we compared a sample (n = 151) of self-identified male incels with non-incel single males (n = 149). Findings revealed that incels have a lower sense of self-perceived mate-value and a greater external locus of control regarding their singlehood. Contrary to mainstream media narratives, incels also reported lower minimum standards for mate preferences than non-incels. Incels (and non-incel single men) significantly overestimated the importance of physical attractiveness and financial prospects to women, and underestimated the importance of intelligence, kindness, and humor. Furthermore, incels underestimated women’s overall minimum mate preference standards. Our findings suggest that incels should be targeted for interventions to challenge cognitive distortions around female mate preferences. Implications for incels’ mental health and misogynistic attitudes are discussed, as well as directions for future research.

Learning from fights: Males' social dominance status impact reproductive success in Drosophila melanogaster.

In animals, the access to vital resources often relies on individuals' behavioural personality, strength, motivation, past experiences and dominance status. Dominant individuals would be more territorial, providing them with a better access to food resources and mate. The so-called winner and loser effects induce individuals' behavioural changes after experiencing a victory or a defeat, and lead to an individual persistent state influencing the outcome of subsequent fights. However, whether and how development of winner and loser effects affect individuals' fitness is controversial. The aim of this study is to evaluate how individuals' fitness can be influenced by previous fighting experience in Drosophila melanogaster. In this study, we assess various behavioural performances as indicators for dominant and subordinate fitness. Our results show that subordinates are less territorial than dominants although their locomotor abilities are not affected. We also demonstrate that in a non-competitive context, experiencing a defeat reduces males' motivation to court females but not the reproductive success while in a competitive context, it negatively affects males' reproductive success. However, we found no impact upon either males' ability to distinguish potential mates nor on females' choice of a specific mating partner. Overall, these results indicate that previous defeats reduce reproductive success, a commonly used estimate of individual fitness.

C. elegans males optimize mate-preference decisions via sex-specific responses to multimodal sensory cues

For sexually reproducing animals, selecting optimal mates is important for maximizing reproductive fitness. In the nematode C.elegans, populations reproduce largely by hermaphrodite self-fertilization, but the cross-fertilization of hermaphrodites by males also occurs. Males' ability to recognize hermaphrodites involves several sensory cues, but an integrated view of the ways males use these cues in their native context to assess characteristics of potential mates has been elusive. Here, we examine the mate-preference behavior of C.elegans males evoked by natively produced cues. We find that males use a combination of volatile sex pheromones (VSPs), ascaroside sex pheromones, surface-associated cues, and other signals to assess multiple features of potential mates. Specific aspects of mate preference are communicated by distinct signals: developmental stage and sex are signaled by ascaroside pheromones and surface cues, whereas the presence of a self-sperm-depleted hermaphrodite is likely signaled by VSPs. Furthermore, males prefer to interact with virgin over mated, and well-fed over food-deprived, hermaphrodites; these preferences are likely adaptive and are also mediated by ascarosides and other cues. Sex-typical mate-preference behavior depends on the sexual state of the nervous system, such that pan-neuronal genetic masculinization in hermaphrodites generates male-typical social behavior. We also identify an unexpected role for the sex-shared ASH sensory neurons in male attraction to ascaroside sex pheromones. Our findings lead to an integrated view in which the distinct physical properties of various mate-preference cues guide a flexible, stepwise behavioral program by which males assess multiple features of potential mates to optimize mate preference.

Fish responses to underwater sounds depend on auditory adaptations: An experimental test of the effect of motorboat sounds on the fish community of a large fluvial lake.

Freshwater fishes exhibit a wide range of auditory adaptations and capabilities, which are assumed to help them navigate their environment, avoid predators, and find potential mates. Yet, we know very little about how freshwater environments sound to fish, or how fish with different auditory adaptations respond to different soundscapes. We first compiled data on fish hearing acuity and adaptations and provided a portrait of how anthropogenic sounds compare to natural sounds in different freshwater soundscapes. We then conducted a sound-enrichment field experiment at Lake Saint Pierre, a large fluvial lake in Canada, to evaluate the effect of motorboat sound exposure on the fish community by looking at the extent to which changes in species abundances were linked to auditory adaptations. Data compilation showed that the hearing acuity of most species overlaps with a wide range of ambient and anthropogenic underwater sounds while the field experiment showed that species with more specialized auditory structures were captured less often in sound-enriched traps, indicating avoidance behavior. Our findings highlight the importance of considering species' sensorial adaptations when evaluating the community-scale effects of anthropogenic sounds on the fish community, especially at low levels of anthropogenic activity.

Infection‐related sexual conflict in mating behaviors of wolf spiders

AbstractResistance to mating by females has been hypothesized as a tactic to assess potential mates and avoid undesirable ones. Previous studies show infection with the pathogenic bacteria, Pseudomonas aeruginosa, triggers a costly immune response and negatively impacts fitness in the wolf spider Schizocosa ocreata (Hentz 1844). Studies also show that infection can be transmitted during copulation, suggesting that there are potential fitness costs associated with mating with an infected individual. We examined impacts of infection on mating interactions of male and female S. ocreata. As studies show infection can be detected through chemical cues, we tested whether males or females avoid mating with infected individuals when given the opportunity. We paired infected and uninfected (control) males and females and recorded their behavior. We found that mating outcome was independent of infection for males and females. While higher male courtship rates and more frequent female receptivity displays were associated with successful mating, we saw no direct effect of infection status on mating outcome. However, among spider pairs that did not mate, females were found to be significantly more resistant and aggressive toward infected males than control males. Male aggression, on the other hand, was greater in pairs that did result in mating. These results suggest that sexual conflict in mating can be related to infection status, and that females can recognize infected males and alter their behavior in response.