The Influence of Physical and Acoustic Experience on Sequential Mate Preference in the Cricket Gryllus bimaculatus. Is Song Important?

Female Gryllus bimaculatus alter their mate choice based on size depending on previous experience with males. Male crickets sing to attract mates and several studies have identified call parameters important in female choice. We tested the hypotheses that exposure to acoustic stimuli before and/or after mating, from males of different sizes, in isolation and together with physical exposure influences female choice (willingness to mate and spermatophore retention time [SRT]). Females exposed to ad lib. song of multiple males post-mating had a shorter SRT than females in acoustic isolation. Exposure to ad lib. song of multiple males prior to mating had no effect on SRT. Females did not alter SRT depending on exposure to acoustic stimuli from males of different sizes either post or ante mating. Females exposed to acoustic and physical stimuli (though gauze) from large males had a shorter SRT than those exposed to small males but only when the exposure was post-mating. We were unable to identify any correlation between call parameters and body size in G. bimaculatus. Females use male song to locate potential mates but physical exposure to males is needed to allow females to judge male size and this exposure only influences SRT if it takes place post-mating.     

Alternative Female Choice Tactics in the Scorpionfly Hylobittacus apicalis(Mecoptera) and Their Implications

Females of the scorpionfly Hylobittacus apicalis choose mateson the basis of material benefits (nuptial arthropod prey size)and probably on the basis of genetic benefits males deliverat mating. Females feed on the male's prey throughout copulation.They prefer males with large prey as mates and often refusemales who present small prey. That females may value male geneticquality is suggested by differences in ability of males to obtainlarge prey, which if inherited would influence offspring fitness,and by females often terminating mating with males with smallprey before they transfer any sperm or a complete ejaculate.Females hunt only when males with prey are not available becausehunting exposes individuals to predators. Female Hylobittacusapicalis exhibit alternative mate choice tactics, which arecondition-dependent in expression and probably comprise a conditionalstrategy. Body size, recent feeding history, and male availabilitydetermine how discriminating an individual female actually is,and these conditions may determine the value of material andgenetic benefits in mate choice decisions. The results suggestthat female choice controls male behavior. When females becomechoosy, males are forced to obtain rare large prey despite theincreased risks to males associated with this behavior. The implications of the findings on H. apicalis are discussedin relation to condition dependent female choice patterns inother species and the evolutionary maintenance of female choice.     

Sex-role reversal revisited: choosy females and ornamented, competitive males in a pipefish

In the pipefish Syngnathus typhle sex roles are reversed, thatis, females compete more intensely than males over mates. However,competition over mates among individuals of one sex does notnecessarily prevent members of that same sex from being choosy,and choosiness in the other sex does not prevent competitionwithin it. In an experiment we allowed a female pipefish tochoose freely between two males, after which we released themales and let the three interact. Comparisons with earlier resultsshow that both sexes courted partners and competed with consexuals.However, females courted more often than did males, and courtshipwas more frequent in treatments involving large individualsthan in treatments with small individuals. Males competed amongthemselves for access to mates but for a shorter duration thanfemales in the same situation. Males displayed an ornament towardsfemales but not to males during mating competition. Females,however, used their ornament in both contexts. Females did notalways mate with the male of their previously made choice, whichwe interpret as females being constrained by male-male competition,male motivation to mate, or both. Thus, in this sex-role reversedspecies, mate choice in the more competitive sex may be circumventedand even overruled by mate competition and mating willingnessin the least competitive sex. Hence, sex roles should not beconsidered as sexes being either choosy or competitive but ratherthat males and females may exhibit different combinations ofchoice and competition.     

Male body length influences mate-choice copying in the sailfin molly Poecilia latipinna

Females can choose a male independently of other females' matepreferences, or they can copy the mate choice of other females.Alternatively, mate-choice copying and independent mate choicecan interact if females assess male traits when deciding whetheror not to copy. We investigated how mate-choice copying interactswith a preference for large males in the sailfin molly (Potecilialatipinna). Sailfin molly females exhibited a preference forlarger males. They also copied the mate choice of other femaleswhen males were of similar body length. Females did not copy,however, when males differed substantially in body length. Ourresults show that conspecific mate copying occurs in the sailfinmolly but does not override a preference for larger males.     

配偶选择中“听众效应”及鸣唱对雌性灰文鸟行为的影响

配偶选择是性选择研究核心问题之一。雌性通过选择高质量的雄性配偶获得直接利益,如资源、营养和保护等,也可以通过获得高质量雄性提高后代的适合度。配偶选择研究对于研究性选择机制和进化均具有重要意义。目前,对配偶选择的研究主要集中在影响配偶选择的因素及雌性"听众效应"中雄性-雄性竞争方面。鸣唱对配偶选择的影响和雄性"听众效应"中雌性-雌性竞争的研究对于探索鸟类配偶选择中信号交流、调整的方式及选择策略均具有重要意义。以灰文鸟为对象,研究了雄性鸣唱对雌性配偶选择的影响及雄性"听众效应"对雌性灰文鸟同性竞争行为的影响进行了探讨。实验一利用双向选择装置,以配偶鸣唱(求偶鸣唱或非求偶鸣唱)和非配偶鸣唱(求偶鸣唱或非求偶鸣唱)对雌鸟进行刺激,观察雌鸟对两端鸣唱的偏爱状况。实验二主要观察雌鸟之间在无听众、听众为熟悉的雄性和听众为配偶条件下的竞争行为。结果表明,雌性灰文鸟大多偏爱配偶鸣唱,相对于配偶的非求偶鸣唱更偏爱非配偶的求偶鸣唱。求偶鸣唱比非求偶鸣唱更具有吸引力,求偶鸣唱更能刺激雌性灰文鸟配偶选择的积极性,这种积极要付出更多的时间和资源,但雌鸟可以通过选择更高质量的雄性配偶获益。在配偶雄性作为听众条件下雌鸟攻击行为最高,显著高于熟悉雄性为听众的条件下,并且两者都显著高于无听众条件下雌鸟的攻击行为。雌性灰文鸟会基于不同"听众"而对雌-雌竞争行为做出适当调整。上述研究结果对于深入理解鸟类的性选择行为机制具有重要帮助作用。     

Female-female aggression and female mate choice on black grouse leks

We studied female-female aggression in relation to female mate choice in black grouse, Tetrao tetrix, in central Finland, in 1994-1998. Aggression occurred on average every other minute when there was more than one female on a territory, and aggressive behaviour was most prominent when several females attended the lek. Interactions tended to be proportionally most frequent on the territories of the highest-ranking males, although not significantly so. Females that were chased by other females did not mate with lower-ranking males than their aggressors did. Furthermore, chased females were only rarely (6% of cases) forced to move off the territory by agonistic interactions and copulations were disrupted by other females even less often (3% of cases). The choice of a mating territory did not depend on the outcome of aggression even though the aggressors were more likely to mate on the territory where aggression occurred than elsewhere. There was a marginally significant tendency for aggressors to mate earlier in the season. Females placed themselves further away from other females on the territory when soliciting a copulation than just before aggression. Our results suggest that aggression between females does not effectively constrain female choice in black grouse. Its function may be to aid females to secure undisturbed mating opportunities for themselves rather than to prevent others from mating with a particular male. Copyright 2000 The Association for the Study of Animal Behaviour.     

Why do pied flycatcher females mate with already-mated males?

The contribution of the pied flycatcher Ficedula hypoleuca male in parental care was studied to examine why some females mate with already-mated males. No difference in feeding rate was found between older and yearling monogamous males, when comparing nests at the same time. Monogamous and primary females were helped significantly more in parental care by the male than were secondary females of polygynous males. Females could only partly compensate for the absence of a male and of nestlings were reduced in nests with low male assistance. Differences in mate and territory quality were far too slight to make it advantageous for females to choose already-mated males instead of mating with monogamous males. We suggest that males, by being polyterritorial, deceive females into accepting polygyny; and females can be deceived since they do not have time to find out the marital status of males.     

Mate sampling by female barking treefrogs (Hyla gratiosa)

Despite intense interest in mate choice, relatively little isknown about how individuals sample prospective mates. Indeed,a key issue is whether females sample males or simply matewith the first male encountered. We investigated mate samplingby female barking treefrogs (Hyla gratiosa). Females choosingmates in natural choruses did not move between males but insteadmated with the first male they approached closely. Most femalesmated with the male closest to them at the start of their mate-choiceprocess, and females were more likely to mate with the closest male when the distance to other males was large. These observationsare consistent with the hypothesis that females do not samplepotential mates but instead mate with the first male they distinguishfrom the rest of the chorus. To test this initial detectionhypothesis, we conducted a playback experiment in which weoffered females a choice between two calls, one of which was detectable above the background chorus sound at the female'srelease point, and one of which became detectable only as femalesmoved toward the initially detectable call. Females did notprefer the initially detectable call, thus ruling out the initialdetection hypothesis and implicating sampling of potentialmates by females. Based on the behavior of females in natural choruses, we hypothesize that females approach the chorus, moveto locations where they are able to detect the calls of severalmales simultaneously, and choose a mate from among these malesat some distance from the males. Such simultaneous samplingmay be common in lekking and chorusing species, which havebeen the subjects of many studies of sexual selection.     

Preexisting behavior facilitated the loss of a sexual signal in the field cricket Teleogryllus oceanicus

Behavioral preadaptations can provide an accommodating environmentin which novel morphological characters may be selected. A veryrecent morphological mutation, flatwing, has caused the lossof male song in field crickets (Teleogryllus oceanicus) fromthe Hawaiian island of Kauai. Previous studies in this and relatedspecies have shown that females require male courtship songto mount males, but flatwing T. oceanicus males still achievematings. Females from Kauai may have a relaxed requirement formale courtship song, or flatwing males may compensate for theirinability to sing by altering other courtship behaviors. Wetested whether male courtship and female responses to male courtshipwere preadapted in a way that facilitated the spread of themale wing mutation or if parallel changes in male courtshipand female responses accompanied the mutation. We performedmating trials in 2 captive-bred populations to assess how matingbehavior varied depending on the presence or absence of courtshipsong playback. The first was an ancestral population from Kauaiestablished prior to the emergence of the flatwing mutation,and the second was derived from Kauai after the mutation becameprevalent. Mating behaviors did not differ qualitatively orquantitatively between the ancestral and current populations,and females from both accepted males for mating in the absenceof courtship song. Our results provide direct evidence thata mechanism allowing flatwing males to mate with females wasin place before the mutation actually arose on Kauai and demonstratehow preexisting behavior facilitated the rapid spread of a novelmorphological mutation.     

Repeatability of mate choice in female red jungle fowl

We staged female mate choice trials between pairs of males andrepeated the process for each female to determine the repeatabilityof female preference for males in red jungle fowl (Gallus gallus)in the first and second half of the breeding season. We measuredmale morphological traits (the size and color of the comb andthe brightness of the hackle feathers) that females are knownto use in choosing a mate. In the first half of the breedingseason, females showed repeatability in their choices of matewith respect to the male's comb characters. Females did notshow a repeatable preference with respect to male hackle feathers,and we found no repeatability of mate choice in the second halfof the season. Females seem to primarily look at the male'scomb when choosing a mate, and other ornaments seem only ofsecondary importance.[Behav Ecol 7: 243-246 (1996)]     

Female sailfin mollies, Poecilia latipinna, remember males and copy the choice of others after 1 day

Theoretical and experimental evidence indicates that females copy the mate choice of other females under certain conditions. In all mate choice copying experiments with fish to date, females were allowed to copy the choice of a model female immediately after the focal female had observed a model female interacting with a male. It is not known whether females continue to copy the choice of the model female after a longer interval. We investigated whether sailfin molly females also copy the choice of other females when they are prevented from copying immediately after observing a model female next to a previously nonpreferred male. We performed three copying experiments in which females could copy the choice of the model female immediately after, 1 h after or 1 day after observing the model female next to the previously nonpreferred male. In control experiments, we tested whether females chose consistently when they had no opportunity to copy, and whether females showed shoaling behaviour under these conditions. Females copied the choice of the model female immediately after, 1 h after and even 1 day after the observation of the model female interacting with the previously nonpreferred male. Females chose consistently between males when they had no opportunity to copy, and females did not shoal under these conditions. We conclude that females remember individual males with whom a model female had interacted, even after 1 day. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.      

Why is Female Choice not Unanimous? Insights from Costly Mate Sampling in Marine Iguanas

Females do not unanimously choose the single 'best' male, even when female choice is strong, such as in leks, or in polygynous mating situations. A possible explanation is that females base their choices on limited information, perhaps because gathering information is costly. We tested this hypothesis by continuously observing individual female marine iguanas throughout the mating period in order to document the information they gathered about each potential mate. Females actively visited approximately five additional males during the 3 d prior to copulation, compared to the males seen on their normal foraging routes. Females were more likely to visit large-bodied males, but preferentially copulated with the male that had the highest display rate of all males they visited. Females that mated on a dense territory cluster mated with more active males than did those that mated on dispersed territories. However, females on a dense cluster also lost more body mass, potentially as a consequence of high rates of interaction with males. This mass loss may represent an important cost and result from postural changes in response to male attention. Such costs may explain why females only gather a certain amount of information and why females on dispersed territories choose less active mates. Lack of complete information introduces subjectivity into female choice: what is perceived as best by one female may not be perceived as best by another. Thus, lack of complete information may prevent unanimity of female choice.     

Female remating and the intensity of female choice in black-horned tree crickets, Oecanthus nigricornis

Repeated mating by females of many species occurs at frequenciesin excess of those needed to acquire additional sperm for fertilizingova. I tested three alternative hypotheses for the rate of rematingby females of the courtship-feeding tree cricket, Oecanthusnigricornis Walker, by manipulating diet quality and courtshipfeeding and measuring the time to remating by the female inrelation to four aspects of male phenotype (age, condition,fluctuating asymmetry, and size). First, in courtship-feedingspecies, remating may be due to selection to increase the amountof nutritional resources provided by males, with nutrient-deprivedfemales remating more quickly. Second, remating may functionas a mechanism of postcopulatory mate choice, with females rematingquickly when the quality of a previous mate is low. Third, quicknessof remating may be the consequence of precopulatory mate choiceprior to future matings, with females remating more quicklywith high-quality males, regardless of the quality of priormates. Females on a low-quality diet remated quickly, did notvary remating speed with the phenotype of their first mate,and did not differentially reject prospective second mates withdifferent phenotypes. In contrast, both the degree of coyness(measured as the frequency of mate rejection) and the intensityof female choice (measured as the size differential betweenaccepted and rejected mates) increased with diet quality. Theseresults support both the material-benefits and the precopulatorymate-choice hypotheses for remating speed of female tree crickets.There was mixed support for the postcopulatory choice hypothesis:females on the high-quality diet remated more slowly after firstmating with relatively large males, in support of the postcopulatorychoice hypothesis; however, the remating interval of femaleson the high-quality diet decreased with the condition of thefirst mate, opposite to the prediction of the postcopulatorychoice hypothesis     

Function of pair duets in the eastern whipbird: cooperative defense or sexual conflict?

Paired male and female eastern whipbirds, Psophodes olivaceus,sing precisely coordinated, male-led duets. Four broad explanationshave been proposed for the function of duets: 1) cooperativeresource defense, 2) prevention of partner usurpation, 3) defenseof an individual's own position within the partnership, or 4)mate identification and localization. These 4 hypotheses makedifferent predictions about how male and female residents shouldrespond to simulated intrusion by other pairs or individuals.We compared the behavioral and vocal responses of 20 pairs ofeastern whipbirds to simulated territorial intrusions by: 1)a solitary singing male, 2) a solitary singing female, and 3)a duetting pair. Males and females did not coordinate theirapproach to the playback speaker and showed sex-specific responsesto playback. Males did not respond differently to duetting versussolo singing intruders. By contrast, females approached moreclosely during solo female song than during solo male song orduet playback. Females also produced specific vocalizationsonly in response to duet and solo female playback. Both sexesapproached the speaker more closely and quickly during playbackof same-sex solo songs than opposite-sex solo songs. Finally,females answered more of their mate's songs during simulatedintrusion by a lone female than during simulated intrusion bya lone male. Our results suggest that duets in this speciesprimarily function to allow females to defend their exclusiveposition in a partnership. Mate defense by females is unusualin birds but may be promoted in eastern whipbirds by a female-biasedsex ratio and the need for exclusive access to male care. Thus,duets result from independent and conflicting strategies ofmate and territory defense in males and females.     

Is female preference for male repertoires due to sensory bias?

There are several possible explanations for the female preference for male repertoires in birds. These males are older, and have better territories; thus there are functional reasons for females to prefer these males. However, there is an alternative explanation; females may habituate less quickly to song repertoires than single songs. I tested whether females have a non-functional, sensory bias for male song repertoires, by testing female preference for a repertoire in zebra finches (Taenopygia guttata), a species in which males possess a single stereotyped song. Females chose between a male repertoire of four different phrases created from the song phrase of one individual and that of one of those phrases repeated four times (natural zebra finch song). Females were also given a choice between the above repertoire and a song made from the phrases of four related males (''family'' stimulus). I tested female preference by training females to press a button for presentation of a song stimulus, and counting the number of button presses. Females preferred the song repertoire to a single phrase song, and did not differentiate between the repertoire and song phrases from four males. Evidence from the Estrildidae indicates that having a single song is the ancestral state for zebra finches, so the preference is not ancestral.     

Mating strategies based on foraging ability: an experiment with grasshoppers

Female mate choice and the benefits of this behavior are criticalaspects of Darwinian sexual selection, but they are seldom documentedbecause it is difficult to identify the male trait(s) that femalesmay be seeking. We conducted experiments with grasshoppers (Melanoplussangutnipes: Orthoptera, Acrididae) to examine this behavior.Males that feed more intensively and select a diet mix thatpermits greater food intake (food intake per body mass per time)in laboratory trials were preferentially selected by females.These better foraging males on average provide greater paternalinvestment (greater spermatophore mass) to the female, whichincreases her reproductive rate (eggs produced per body massper time). However, paternal investment may not entirely explainfemale choice of better foraging males, because these maleswere still selected even if they had their food intake restrictedor had been allowed to recently mate, which reduces spermatophoreproduction. Furthermore, males change their mating strategyin response to female choice and the foraging abilities of surroundingmales. Poorer foraging males attempt forcible copulation ratherthan displaying and allowing female choice. A male will facultativelyswitch between these strategies depending on the foraging abilitiesof the surrounding males. While females attempt to reject forciblecopulation, forcible copulation reduces the frequency with whichfemales successfully copulate with better foraging males. Therefore,males that are less "attractive" to females adopt alternativemating strategies to counter female choice which would excludethem from mating.[Behav Ecol 7: 438–444 (1996)]     

Mate choice in the monogamous and polychromatic Midas cichlid, Cichlasoma citrinellum

Choice of mate in the Midas cichlid, Cichlasoma citrinellum (Günther, 1864), has been examined from a number of perspectives, proceeding from general species attributes to individual differences.
The Midas cichlid discriminates against closely-related, highly-similar Cichlasoma , and recognizes sex, probably chemically in both cases. It is polychromatic and changes from the normal (N) pattern to gold (G) or even white at almost any age. Gold colouration inhibited attack and made it difficult to mate an N female with a G male; the inhibiting effect was cancelled by using a larger N female.
Because the Midas cichlid is also biparentally monogamous, early experience could easily influence later choice of mate. G females of G × G parents preferentially spawned adjacent to G males; N females of N × N spawned mainly before N males. N females of G × G pairs, however, showed no preference.
Groups of females were reared by all four combinations of two colours and two sexes, or by no parents. Females reared by identically pure-coloured parents responded most to males of those colours, whereas females raised by mixed-colour parents did not discriminate. Females reared without parents preferred N males. Regardless of their own or their parents' colour, juveniles spent more time with N juveniles and behaved less aggressively towards them, compared to G juveniles.
Fish were offered a choice among potential mates that differed in aggressiveness, size or breeding experience. Males did not choose on the basis of those traits. Females preferred large, aggressive, experienced males. Pairs with large aggressive males more readily kept a breeding territory, and aggressive experienced males guarded young more effectively. All females were equally aggressive in protecting their young.     

Should I stay or should I go? Female brood desertion and male counterstrategy in rock sparrows

Brood desertion involves a series of interactions between themembers of a pair. This process is likely to be based on eithermember's perception of the other's propensity to desert. Wemanipulated this perception in males by experimentally increasingfemale body mass in the rock sparrow (Petronia petronia), aspecies in which females can desert their first brood beforethe nestlings from the first brood leave the nest. We predictedthat the male would either desert the brood first or stay evenif this implied the risk of caring for the brood alone. We foundthat males mated to loaded females did not leave but stayedand significantly increased their courtship rate and mate guarding.Unexpectedly, they also increased their food provisioning tothe nestlings, even though loaded females did not reduce theirnestling-feeding rate. The increase in male feeding rate maybe explained as a way for the male to reduce the female's propensityto switch mate and desert or to increase her propensity to copulatewith the male to obtain paternity in her next brood. Altogether,our results demonstrate that the perception of the risk of beingdeserted by the female does not necessarily induce males todesert first, contrary to what is generally assumed by theoreticalmodels.     

Female zebra finches prefer the songs of males who quickly solve a novel foraging task to the songs of males unable to solve the task

Correlative evidence suggests that high problem‐solving and foraging abilities in a mate are associated with direct fitness advantages, so it would benefit females to prefer problem‐solving males. Recent work has also shown that females of several bird species who directly observe males prefer those that can solve a novel foraging task over those that cannot. In addition to or instead of direct observation of cognitive skills, many species utilize assessment signals when choosing a mate. Here, we test whether females can select a problem‐solving male over a non‐solving male when presented only with a signal known to be used in mate assessment: song. Using an operant conditioning assay, we compared female zebra finch (Taeniopygia guttata) preference for the songs of males that could quickly solve a novel foraging task to the songs of males that could not solve the task. Females were never housed with the test subject males whose song they heard, and the only information provided about the males was their song. We found that females elicited more songs of problem‐solving males than of non‐solvers, indicating that song may contain information about a male’s ability to solve a novel foraging task and that naïve females prefer the songs of problem‐solving males.     

Copulation Song in Drosophila: Do Females Sing to Change Male Ejaculate Allocation and Incite Postcopulatory Mate Choice?

Drosophila males sing a courtship song to achieve copulations with females. Females were recently found to sing a distinct song during copulation, which depends on male seminal fluid transfer and delays female remating. Here, it is hypothesized that female copulation song is a signal directed at the copulating male and changes ejaculate allocation. This may alter female remating and sperm usage, and thereby affect postcopulatory mate choice. Mechanisms of how female copulation song is elicited, how males respond to copulation song, and how remating is modulated, are considered. The potential adaptive value of female signaling during copulation is discussed with reference to vertebrate copulation calls and their proposed function in eliciting mate guarding. Female copulation song may be widespread within the Drosophila genus. This newly discovered behavior opens many interesting avenues for future research, including investigation of how sexually dimorphic neuronal circuits mediate communication between nervous system and reproductive organs.