The Role of Mate-Choice Copying and Disruption Effects in Mate Preference Determination of Limia perugiae (Cyprinodontiformes, Poeciliidae)

Recent experimental and theoretical evidence suggests that social factors may play an important role in female choice and sexual selection. This is in contrast to the assumption made by most classical sexual selection models that female preferences are entirely determined by genetic factors. This study examined whether female preferences in the poeciliid fish Perugia's Limia (Limia perugiae) are reversible through (i) mate‐choice copying (imitative) behavior, or (ii) a disruption effect (reduced consistency of female preference in response to disruption). Females in binary choice trials were given a mate‐choice copying opportunity by exposing them to a second, model female displaying a preference for a male that was not initially preferred. Females were found to reverse their initial preference significantly more often when presented with an opportunity to observe the model female then in the absence of such an opportunity. In separate trials, females were presented with the opportunity to observe a model female displaying a preference for a male that was initially preferred. No significant difference was observed in the number of reversals between treatments in which females were presented with a copying opportunity that contradicted their initial preference and one that reinforced it. Our results suggest that mate‐choice copying does not contribute significantly to female preferences in L. perugiae and that disruption may reduce the ability of females to choose consistently.     

Mate Choice Copying in Humans

There is substantial evidence that in human mate choice, females directly select males based on male display of both physical and behavioral traits. In non-humans, there is additionally a growing literature on indirect mate choice, such as choice through observing and subsequently copying the mating preferences of conspecifics (mate choice copying). Given that humans are a social species with a high degree of sharing information, long-term pair bonds, and high parental care, it is likely that human females could avoid substantial costs associated with directly searching for information about potential males by mate choice copying. The present study was a test of whether women perceived men to be more attractive when men were presented with a female date or consort than when they were presented alone, and whether the physical attractiveness of the female consort affected women’s copying decisions. The results suggested that women’s mate choice decision rule is to copy only if a man’s female consort is physically attractive. Further analyses implied that copying may be a conditional female mating tactic aimed at solving the problem of informational constraints on assessing male suitability for long-term sexual relationships, and that lack of mate choice experience, measured as reported lifetime number of sex partners, is also an important determinant of copying.     

Mate Choice in Female Red-necked Pademelons,Thylogale thetis (Marsupialia: Macropodoidea)

Changes in the behaviour of captive female red-necked pademelons, Thylogale thetis, before, during and after oestrus were observed relative to the location of potential male mates. A penned female was presented with four adjacent, individually caged males representing the size classes large, medium, small and subadult. The female's behaviour was videotaped for 8–9 d spanning oestrous (3 d), post-oestrous (3 d) and normal (3 d) sessions of time. Changes in the activity, orientation and location of six penned females, relative to the caged males, were transcribed from videotape. A model of female pademelon behaviour pattern was developed. Results suggest that the females spent a significantly greater amount of time directly in front of the largest available male, relative to the other three smaller males during the oestrous period only, and that a significant proportion of this time was spent involved in active behaviours (grooming and locomotion, compared with inactive behaviours of sitting and scan/sniffing). Although there was a significant preference for females to orientate their bodies away from the location of the males, they faced the males significantly more during oestrus than any other session. Furthermore, the females faced the large male significantly more frequently than any other male. This study provides evidence for mate choice by female red-necked pademelons.     

Male Mate Choice in Mixed Bisexual/Unisexual Breeding Complexes of Poecilia (Teleostei: Poeciliidae)

The livebearing all-female fish Poecilia formosa reproduces by gynogenesis, a modified form of parthenogenesis. P. formosa forms at least two breeding complexes: in its northern range it exists sympatrically with Poecilia latipinna and in its southern range with Poecilia mexicana. Differences between these complexes and their possible origin are discussed. Embryogenesis is triggered by sperm of males of these closely related sympatric species. Because inheritance is strictly maternal, from the male point of view energy and time invested are totally lost. In this study we wanted to elucidate whether males are able to distinguish between conspecific and parasitic females. It could be shown that males are able to distinguish females optically, but that this ability was obscured as soon as chemical and/or tactile contact was possible. Furthermore, we found that females in an attractive phase of their sexual cycle are always preferred, regardless of species. This is possibly the mechanism by which parasitic females obtain the matings they need to reproduce.     

Consort Intrusion and Female Mate Choice in Japanese Macaques (Macaca fuscata)

Consort intrusion behavior has been proposed to largely function as a means of preventing or suppressing the reproductive activity of subordinate males. In the Japanese macaques of Arashiyama B troop this behavior was found to be ineffective in influencing female mate choice and affecting differential reproduction. Mainly directed towards the female of the pair intrusion resembled sexual solicitation and appeared to be an extension of consort behavior. Although the intruder male was almost always dominant over the other male, intrusion failed to provide priority of access to the estrous female as she most frequently chose to remain with her current partner. Copulations which were intruded upon were as likely to end in ejaculation as those which were undisturbed. Only a small proportion of intruder male-female pairs mated. Pairs that did mate were likely to have been in consort before or during the period in which intrusion occurred. No significant correlation was found between male rank order and number of possible females impregnated. Individual young, middle to lower ranking males were estimated to have been reproductively the most successful.     

Male Mating History Influences Female Mate Choice in the Trinidadian Guppy (Poecilia reticulata)

Based on the phenotype‐linked fertility hypothesis, sexual selection should favour females that can accurately assess the recent mating history of available sexual partners and preferentially avoid mating with recently‐mated males [who may be sperm depleted (SD)] so as to minimize the risk of their eggs not being fertilized. This hypothesis has received to date only limited attention and empirical support. Therefore, in the current study, we investigated experimentally whether females of a vertebrate species, the Trinidadian guppy (Poecilia reticulata), are able to assess the recent mating history of males, and thus potentially their functional fertility, and choose to avoid mating with males that appear to have recently mated and who may be sperm limited. Individual virgin females were first given a dichotomous choice between a male that had not been recently observed to interact sexually with another female (i.e. not sperm‐depleted) and another male that had been observed to interact sexually with a female (i.e. potentially sperm‐depleted) as sexual partners. Paired males were matched for body length and coloration. Immediately following this test, the focal females were subjected to a free‐swimming mate‐choice test using the same paired stimulus males. As predicted, on average, female guppies avoided the apparently recently‐mated (and potentially sperm‐depleted) male and exhibited a significant preference for the other male not recently observed mating (and thus not likely sperm limited) during both tests. We do not yet fully understand the underlying mechanisms of this preference. Therefore, further research on the particular cues that females use to assess the recent mating history and fertility status of males is required.     

Phylogeny of Limia (Teleostei: Poeciliidae) based on NADH dehydrogenase subunit 2 sequences

Complete sequences for the mitochondrial gene NADH Dehydrogenase 2 (ND2) and partial sequences for the tRNA-Met and tRNA-Trp genes were obtained for 11 populations of the poeciliid fish genus (or subgenus) Limia, including species from Hispaniola, Cuba, Jamaica, and Grand Cayman Islands. Additional sequences for Limia (2 species), Pamphorichthys (3), Poecilia (16), and Xiphophorus (1), all from the tribe Poeciliini, were extracted from GenBank, as was a sequence for Heterandria formosa, from the tribe Heterandriini. Phylogenetic analyses included parsimony, distance methods, and maximum-likelihood. Several Limia species groups that had been proposed based on morphological data were evaluated. The versicolor species group was strongly supported, as was the close relationship between the Cuban Limia vittata and the Grand Cayman Limia caymanensis. However, the proposed vittata species group was not upheld by the ND2 data. The phylogenetic position of Limia melanogaster, from Jamaica, was either sister to the versicolor species group or basal to all other included Limia species. Limia was found to be monophyletic; however, Limia species from the island of Hispaniola were not monophyletic. There was little support for any proposed sister group to Limia. The phylogeny was used to reconsider a previous comparative study of poeciliid courtship behavior and sexual dimorphism. The data indicated that there may have been two independent appearances of courtship display behavior in Limia; considering the tribe Poeciliini as a whole, there is evidence for as many as five appearances of display (including two within Limia), or a complex pattern of gains and losses of such behavior. The application of phylogenetic information to the comparative study did not refute the previously hypothesized correlation between the presence of a courtship display and the presence of sexual dimorphism in poeciliid fish.     

Female Reproductive Status and Mate Choice in the Hide Beetle, Dermestes maculatus

Models of mutual mate choice predict that when the costs of mating indiscriminately increase, so may the choosiness of the conventionally non-choosy sex. In a series of behavioral trials, we tested both male and female chemo-reception and mate choice in the hide beetle, Dermestes maculatus. Using olfactometer bioassays we found that males detected and responded more rapidly to individual mated females but had a limited ability to detect virgin females or discriminate between virgin and mated females when presented simultaneously. Both mated and virgin females were unable to detect the presence of virgin males. Copulation behaviors were comparable when males were presented with a virgin or mated female either individually or simultaneously. However, when presented simultaneously, virgin females had a higher probability of receiving a copulation than their mated counterparts. Our data show that males respond to variation in female reproductive status, but that female propensity to mate does not change. We suggest that mutual mate choice may be an important force, even in systems in which there is apparently strong selection for female mate discrimination.     

Orange Spots as a Visual Cue for Female Mate Choice in the Guppy (Poecilia reticulata)

Previous studies have suggested that orange pigment in the color patterns of male guppies is a cue for female choice. This paper describes a manipulative experiment designed to test this hypothesis. The color patterns perceived by females were manipulated by varying the color of light used to illuminate the experimental aquaria. Orange light dramatically reduces the conspicuousness of orange spots to human observers, and probably also to female guppies. As in previous experiments, female guppies discriminated among males based on differences in the extent of orange pigment, under white, blue, and green light conditions. Under orange light, however, females no longer appeared to discriminate on the basis of orange spots. These results support the hypothesis that orange spots, rather than other correlated characteristics, are a basis for female choice under normal lighting conditions.     

Mate Choice in Male Mandrills (Mandrillus sphinx)

Male primates that attempt to monopolize access to receptive females by mate‐guarding expend time and energy and risk injury, making reproduction costly. Males should therefore show mate choice and preferentially allocate mating effort to females that are likely to be fertile and those that will produce high‐quality offspring. Specifically, males should preferentially mate‐guard high‐ranking females rather than low‐ranking females, as such females are more likely to be fertile and are able to invest more in offspring. Males should also prefer parous females to nullipares, for similar reasons. Finally, males should avoid mating with close relatives, to avoid the deleterious effects of inbreeding. We investigated 13 group‐years of mate‐guarding observations for two semi‐free‐ranging groups of mandrills to examine the influence of these factors on male investment in mate‐guarding. We found that males mate‐guarded higher‐ranking females more than lower‐ranking females, and parous females more than nullipares. Female age, true relatedness and maternal kinship did not influence male mate‐guarding. Our results suggest that male mandrills do exercise mate choice for higher‐quality females, in the form of higher‐ranking and parous females. As alpha males are responsible for the great majority of mate‐guarding, this can lead to assortative mating, where high‐ranking males reproduce with high‐ranking females, and has important implications for social relationships and kin selection.     

Diet Quality Affects Mate Choice in Domestic Female Canary Serinus canaria

Mate choice is the result of intra‐ and intersexual selection. Even though a consensus between females is often observed in favour of some males, different constraints can affect their choice. Context (early learning, mate‐choice copying, prior experience, etc) and/or condition (genetics, body condition, age, etc) can deflect the choice of a female from its ‘standard of beauty’. In domestic canaries Serinus canaria, females display their acceptance of a male by producing a particular sexual behaviour called ‘copulation solicitation display’ (CSD). Previous studies have shown that the number and intensity of these CSDs are more important when females listen to sexy ‘A’ phrases with a rapid tempo (A16) in comparison with A phrases with a slow tempo (A8). In this study, we assess the relationship between food quality (highly or poorly diversified food during a short period) and female choosiness towards these two types of phrases. We confirm that females discriminate between A16 and A8. Nevertheless, the difference between the number of sexual responses towards A16 and A8 is weaker among females with a poorly diversified food diet in comparison with females with a highly diversified food diet. This suggests that even a short‐term modification of condition could decrease females’ selectivity towards high‐value stimuli and increase their response rates towards low‐value signals.     

Size-Dependent Female Mate Copying in the Guppy (Poecilia reticulata): Large Females are Role Models but Small Ones are not

Previous work on guppies has shown that small females copy the mate‐choice decisions of larger females, but not vice versa. We extended this work to ask, when put in a situation where they have little information available to distinguish between males, whether large females will also copy large females, and small females will copy small ones. Using Dugatkin's criteria, our study suggests that large females copy the mate‐choice decisions of large females, that small females might copy the decisions of large females, but that neither small nor large females copy small females. Our results provide support for the notion that females are more likely to copy when they perceive that there is an imbalance between their ability to assess a male's quality and the ability of another female to assess that male. However, we did not find evidence of mate copying using criteria used by other researchers.     

Female Mate Choice, Calling Song and Genetic Variance in the Cricket, Gryllodes sigillatus

Female preferences for song patterns of males of Gryllodes sigillatus and genetic variance of morphological traits correlated with them were analyzed. Females preferred short pulses associated with large males. The males’ thorax width, wing length and femur III length showed stronger relationship with the song pulse duration, whereas the relationship between pulse duration and wing width was not significant. Interestingly, this last trait was the only one that showed significant levels of genetic variance. Perhaps these results could be explained by the evolutionary response to sexual selection. Sexual selection could deplete the genetic variance in the male traits related to male‐mating success.     

Premating Behavior in the Subgenus Limia (Pisces: Poeciliidae): Sexual Selection and the Evolution of Courtship

A three-year field-study of Richardson's ground squirrels was conducted to assess whether alarm calling functions to warn close relatives (“kin selection” hypothesis) or manipulate conspecifics (a “selfish” hypothesis). S. richardsonii had distinct calls for terrestrial and aerial predators, and the responses of squirrels varied appropriately according to the context of calls, implying that calling conveyed correct information concerning the nature of the danger. Alarm calling elicited by naturally occurring encounters with potential predators during 454 h of observation, and by a thrown frisbee in 70 experimental trials, was not equally probable for all age/sex classes. Squirrels were most likely to call when they had offspring or siblings nearby, which is supportive of the hypothesis that alarm calling is maintained by kin selection. Adult males, residing in the vicinity of either their probable progeny or their nonlittermate half-siblings, were the most likely age/sex class to call during the lactation period when young were below ground and were most vulnerable. I conclude that alarm calling by Richardson's ground squirrels is nepotistic rather than manipulative.     

工作记忆对雌性锯腿原指树蛙配偶选择的影响

大多数无尾两栖类的配偶选择依赖声音通讯。为吸引雌性,雄性可通过增加音节数量或鸣声复杂性的方式提升鸣声吸引力。工作记忆是指在进行复杂认知活动时对过去短时间内接收到的信息进行处理和储存的一种记忆程序。目前,大多数无尾两栖类鸣声通讯研究侧重于揭示鸣声信号的功能,但关于工作记忆对雌性配偶选择的影响及其在复杂求偶信号进化过程中的作用的研究十分匮乏。本研究以锯腿原指树蛙(Kurixalus odontotarsus)为实验对象,利用趋声性实验测试雌性对不同复杂程度鸣声信号的工作记忆。雄性锯腿原指树蛙的鸣声主要包含A音节("呱"音)和B音节("啾"音),两类音节可以组成不同复杂程度的鸣声,如简单的广告鸣叫5A、复杂的组合鸣叫5A2B和5A5B。实验过程中为雌蛙播放不同复杂程度的鸣声刺激对(5A vs. 5A2B及5A vs. 5A5B),然后进行不同时长安静处理(0 s、5 s、10 s、15 s和30 s)。若安静处理后大部分雌蛙仍选择之前播放复杂鸣声的音箱,则认为此次安静处理时长在雌性对复杂鸣声的工作记忆范围内。实验数据通过广义估计方程(GEE)和精确二项分布检验进行统计分析。研究结果表明,相较于5A,雌性对组合鸣叫5A2B的工作记忆大约有15 s,对5A5B的工作记忆大约有10 s;而组间比较结果表明,雌性对于5A2B和5A5B的工作记忆没有显著性差异。因此,本研究认为复杂鸣声信号会通过工作记忆影响雌性的行为决策,且工作记忆对复杂鸣声信号进化的影响可能具有物种特异性。     

Influence of Inbreeding on Female Mate Choice in Two Species of Drosophila

Many organisms have been reported to choose their mates in order to increase the heterozygosity of their offspring by avoiding mating with relatives or homozygous individuals. Most previous studies using Drosophila melanogaster have used artificial chromosomes or extreme inbreeding treatments, situations unlikely to be matched in nature. Additionally, few studies have examined the interaction between female inbreeding status and her choice of mate. Using females and males from populations that had experienced either random mating or one generation of sib-sib inbreeding, we measured the preferences of females for males. Our results indicate that outbred males were chosen more often than inbred males and that this preference may be more pronounced in outbred females than in inbred ones.     

Spatio-Temporal Dynamics of Field Cricket Calling Behaviour: Implications for Female Mate Search and Mate Choice

Amount of calling activity (calling effort) is a strong determinant of male mating success in species such as orthopterans and anurans that use acoustic communication in the context of mating behaviour. While many studies in crickets have investigated the determinants of calling effort, patterns of variability in male calling effort in natural choruses remain largely unexplored. Within-individual variability in calling activity across multiple nights of calling can influence female mate search and mate choice strategies. Moreover, calling site fidelity across multiple nights of calling can also affect the female mate sampling strategy. We therefore investigated the spatio-temporal dynamics of acoustic signaling behaviour in a wild population of the field cricket species Plebeiogryllus guttiventris. We first studied the consistency of calling activity by quantifying variation in male calling effort across multiple nights of calling using repeatability analysis. Callers were inconsistent in their calling effort across nights and did not optimize nightly calling effort to increase their total number of nights spent calling. We also estimated calling site fidelity of males across multiple nights by quantifying movement of callers. Callers frequently changed their calling sites across calling nights with substantial displacement but without any significant directionality. Finally, we investigated trade-offs between within-night calling effort and energetically expensive calling song features such as call intensity and chirp rate. Calling effort was not correlated with any of the calling song features, suggesting that energetically expensive song features do not constrain male calling effort. The two key features of signaling behaviour, calling effort and call intensity, which determine the duration and spatial coverage of the sexual signal, are therefore uncorrelated and function independently.     

Female Choice, Female Reluctance to Mate and Sexual Selection on Body Size in the Dung Fly Sepsis cynipsea

We investigated the mechanisms of sexual selection in the common dung fly Sepsis cynipsea and how these affect selection on body size at the population level. Because of the presumed costs associated with mating, we predicted that there would be a decrease in the general reluctance of females to mate with any particular male at higher male densities at the mating site, a fresh cow pat, resulting in indirect female choice and a decrease in the strength of sexual selection. In contrast, classical direct female choice and male‐male competition should result in increased selection intensities because more opportunities for choice and competition exist at higher densities. Female reluctance to mate and female assessment of males are expressed in prominent female behaviour to repel mates in several insect species, including S. cynipsea. Laboratory pair‐wise choice experiments showed that large males were more likely to obtain copulations, which also ensued more promptly, suggesting female assessment of male quality (direct female choice). There was a basic influence of male activity but little further effect of male scramble competition on the outcome of mating. Another laboratory experiment showed a decrease in female shaking duration per male, associated with an asymptote in the shaking duration per female, as male density and harassment increased, but did not show the increase in mating frequency predicted by the female reluctance hypothesis. A study estimating sexual selection differentials in the field showed that directional selection for larger males was present overall and was negatively related to seasonally mediated variation in male density. Our study suggests that direct female choice in combination with indirect female choice (due to an interaction of female reluctance to mate and male persistence) is most consistent with the behavioural and selection patterns observed in S. cynipsea, but male effects cannot be definitively excluded.