Studies Of Mate Choice Research Articles

Female preference for blue in Japan blue guppies (Poecilia reticulata)

Guppies (Poecilia reticulata) are widely used as a model species in mate choice studies. Although native to South America, guppies have been introduced to natural water bodies in disparate regions of the globe. Here, for the first time, we examine guppies from one such introduced population in Japan where males have evolved a predominantly blue color pattern. Previous studies of wild-type guppies have shown blue to play a relatively minor role in the mate choice decisions of females compared to other traits, such as orange, and the importance of blue is not universally supported by all studies. The Japanese population therefore presents an ideal opportunity to re-examine the potential significance of blue as a mate choice cue in guppies. Mate choice experiments, in which female Japan blue guppies were given a choice between pairs of males that differed in their area of blue coloration but were matched for other traits, revealed that females prefer males with proportionately larger amounts of blue in their color patterns. We discuss possible factors, including sexual and ecological selection, which may have led to the evolution of unusually large areas of blue at the expense of other colors in Japan blue guppies. However, further studies are needed to distinguish between these scenarios.

Zebra finch females prefer males with redder bills independent of song rate—a meta-analysis

Male zebra finches display multiple secondary sexual traits such as song and red bill coloration. This color is dependent on carotenoids, which enhance immune function and are antioxidants. A red bill may thus function as an indicator signal. The zebra finch is extensively used in the study of carotenoid-dependent signaling. However, studies of female mate preferences for redder bills show mixed results. Here, we report a meta-analysis of mate-choice studies that reveals that female zebra finches do prefer males with redder bills (r = 0.61), except when there was reduced opportunity for imprinting or when bill color was experimentally manipulated, which both reduced preference for red bills to approximately zero. The latter may either be due to aspects of the experimental design or due to bill color being correlated with another trait such as song rate as was previously suggested. We show, however, in a separate meta-analysis on a different set of studies that the correlation between bill coloration and song rate (r = 0.14) was significantly lower than the r = 0.61 between bill color and attractiveness. We conclude, therefore, that the role of bill coloration in mate choice cannot be solely due to an association with song rate. Thus, we conclude that females do prefer males with redder bills when there was sufficient opportunity for sexual imprinting, but to what extent this is causally related to the bill color remains to be established.

Hybrid speciation in Heliconius butterflies? A review and critique of the evidence.

The evidence supporting the recent hypothesis of a homoploid hybrid origin for the butterfly species Heliconius heurippa is evaluated. Data from selective breeding experiments, mate-choice studies, and a wide variety of DNA markers are reviewed, and an alternative hypothesis for the origin of the species and its close relatives is proposed. A scenario of occasional red wing-pattern mutations in peripheral populations of Heliconius cydno with subsequent adaptive convergence towards sympatric mimicry rings involving H. melpomene and H. erato is offered as an alternative to the HHS hypothesis. Recent twists of this tale are addressed in a postscript.

Low-quality females prefer low-quality males when choosing a mate

Mate choice studies routinely assume female preferences for indicators of high quality in males but rarely consider developmental causes of within-population variation in mating preferences. By contrast, recent mate choice models assume that costs and benefits of searching or competing for high-quality males depend on females' phenotypic quality. A prediction following from these models is that manipulation of female quality should alter her choosiness or even the direction of her mating preferences. We here provide (to our knowledge) the first example where an experimental manipulation of female quality induced a mating preference for low-quality males. Zebra finches (Taeniopygia guttata) reared in small or large experimental broods became high- or low-quality adults, respectively. Only high-quality females preferred high-quality males' mate-advertising songs, while all low-quality females preferred low-quality males' song. Subsequent breeding trials confirmed this pattern: latency until egg laying was shortest in quality-matched pairs, indicating that quality-matched birds were accepted faster as partners. Females produced larger eggs when mated with high-quality males, regardless of their own quality, indicating consensus regarding male quality despite the expression of different choices. Our results demonstrate the importance of considering the development of mating preferences to understand their within-population variation and environmentally induced change.

Female túngara frogs vary in commitment to mate choice

Mate choice studies most often examine female preferences based on population responses, thus potentially overlooking individual differences in behavior. Moreover, such studies typically use invariant stimulus conditions to infer preferences. By using population responses and static stimulus presentations, it is difficult to thoroughly understand the complexity of the mate choice process, including variation present between individuals. Here, we investigated phonotactic mate choice behavior in female túngara frogs (Physalaemus pustulosus) in response to temporally dynamic presentations of male advertisement calls. We tested females on repeated trials to examine individual differences and found considerable variation in the extent to which females update their mate choice decisions. Females in our study were bimodally distributed and thus broadly classified as either committed or uncommitted to an initial mate approach. We compared body condition measures of females differing behaviorally and determined that females with larger residual body masses were more committed to initial mate choices than less massive individuals, despite the fact that all females were in reproductive condition and field collected in amplexus. Our results suggest that anuran phonotaxis, once considered to be a highly stereotyped behavior, is more complex and variable than previously thought.

Female choice for optimal combinations of multiple male display traits increases offspring survival

Females commonly incorporate information from more than 1 male trait when making mating decisions, which may increase their ability to choose high-quality males. Assessment of multiple male traits may also incur increasing costs of time and/or energy and should therefore provide an adaptive advantage over females that do not exhibit such complex mating decisions. Although this benefit has been assumed/concluded in previous mate choice studies, it has rarely been empirically verified with female fitness data. Here we show that female side-blotched lizards (Uta stansburiana) that assess males for optimal trait combinations of throat color (a polymorphic social signal) and dorsal patterning (a polymorphic antipredator trait) recruit more offspring to the next adult generation. Specifically, females preferred males with a barred dorsal pattern, but only when males were yellow throated (signaling a sneaker strategy in males). Females mated to sires with both these traits experienced high rates of progeny survival to adulthood, via inheritance of favorable genetic combinations from sires (indirect benefits). Previous results suggest that this is because barredness confers crypsis primarily in yellow-throated lizards and not in lizards with alternative throat colors. Together, these results support the hypothesis that female preference for multiple, interacting male traits is an adaptive response to complex patterns of natural selection on offspring, such as correlational selection on unlinked traits. Our results provide new evidence for an adaptive advantage to females that exhibit complex mating-decision rules and suggest that one advantage lies in reducing deleterious recombination of genes for traits that, only in specific combinations, enhance fitness. Key words: alternative strategies, color pattern polymorphism, correlational selection, crypsis, good genes sexual selection, indirect benefits, multivariate signaling (multicomponent display). [Behav Ecol]

Taxonomic and sensory biases in the mate-choice literature: there are far too few studies of chemical and multimodal communication

The sexual selection literature has grown rapidly in recent years. In an effort to elucidate biases in the focus of current mate-choice research here, I review 297 studies among 230 species. Among taxa, studies of birds were most common (40% of all studies), with insects, fishes, and anurans less well represented (20%, 18%, 14%, respectively). All other taxa were poorly represented in the literature (<3%). Across sensory modalities, studies of visual and acoustic signals were most common (46%, 30%, respectively), with relatively few studies investigating chemical, tactile, and electrical signals in mate choice (3%, 3%, <1%, respectively). Most mate-choice studies of birds and fishes investigated visual signals, while the majority of insect and anuran studies investigated acoustic signals. While these associations may reflect biological realities—birds and anurans tend not to emphasize chemical cues in mate choice; electric communication may indeed be quite uncommon—they may also be grossly misleading: chemical cues are likely critical for mate choice in millions of insect species. Moreover, I suggest that the particularly high vulnerability of chemical communication networks to anthropogenic fouling should provide immediate motivation for many more studies of chemical signals in mate choice. Finally, I find that despite widespread acceptance that male displays are often comprised of multiple elements produced across sensory modalities, studies simultaneously investigating the use of multiple cues in mate choice are rare. While not exhaustive, this review identifies biases in the focus of mate-choice studies, and should serve to identify fruitful directions for future mate-choice research.

Sexual Dimorphism and Parental Roles in the Thorn-Tailed Rayadito (Furnariidae)

AbstractSexual dimorphism, mating system, and parental care are known for only a few species of the large passerine family Furnariidae. We conducted a study of sexual dimorphism in morphology, coloration, and parental roles during incubation and chick-rearing in the Thorn-tailed Rayadito (Aphrastura spinicauda), a characteristic resident ovenbird of the southern temperate rainforests of Chile and Argentina. Through molecular sexing, morphological measurements, and spectrophotometric analysis of body plumage and rectrices of reproductive adults captured on Chiloé Island (southern Chile), we determined that males were between 2% and 10% larger than females in mass, tarsus length, and wing length, while no difference was found for the length of the bill or the two longest central rectrices and their characteristic spines, or in plumage coloration. Heavy males were paired with heavy females and light males with light females. Males and females participated equally in all reproductive activities during the incubation and nestling phases, except removal of nestling feces, in which females were twice as active as males. In a study of habitat use on Navarino Island (extreme southern Chile) we found that the extended graduated tail, with rectrices that end in spines, which gives the species its name, was not used as a support while foraging and could be related to another function such as sexual or social signaling. The absence of sexual dimorphism in plumage and parental roles in rayaditos may be related to the use of the long, graduated tail as a signal of quality by both sexes, although this hypothesis requires confirmation through future mate choice studies.

SEXUAL DIMORPHISM AND PARENTAL ROLES IN THE THORN-TAILED RAYADITO (FURNARIIDAE)

Sexual dimorphism, mating system, and parental care are known for only a few species of the large passerine family Furnariidae. We conducted a study of sexual dimorphism in morphology, coloration, and parental roles during incubation and chick-rearing in the Thorn-tailed Rayadito (Aphrastura spinicauda), a characteristic resident ovenbird of the southern temperate rainforests of Chile and Argentina. Through molecular sexing, morphological measurements, and spectrophotometric analysis of body plumage and rectrices of reproductive adults captured on Chiloé Island (southern Chile), we determined that males were between 2% and 10% larger than females in mass, tarsus length, and wing length, while no difference was found for the length of the bill or the two longest central rectrices and their characteristic spines, or in plumage coloration. Heavy males were paired with heavy females and light males with light females. Males and females participated equally in all reproductive activities during the incubation and nestling phases, except removal of nestling feces, in which females were twice as active as males. In a study of habitat use on Navarino Island (extreme southern Chile) we found that the extended graduated tail, with rectrices that end in spines, which gives the species its name, was not used as a support while foraging and could be related to another function such as sexual or social signaling. The absence of sexual dimorphism in plumage and parental roles in rayaditos may be related to the use of the long, graduated tail as a signal of quality by both sexes, although this hypothesis requires confirmation through future mate choice studies.

Female zebra finches prefer unfamiliar males but not when watching noninteractive video

There is great interest in investigating whether video can be used as an effective stimulus in avian behavioural research. Although there are clear predictions as to the efficacy and limitations of video, there are few empirical tests of whether video stimuli can elicit naturalistic behaviours in birds. Here we assess whether noninteractive digital video presented on flat thin-film transistor (TFT) monitors can be used in zebra finch mate choice studies. Specifically, we tested whether female finches prefer their pair-bonded male over an unfamiliar male when these males are presented as live birds or as noninteractive video images. Our data indicate that, when auditory cues are masked by white noise, female zebra finches strongly prefer to court unfamiliar live males. We hypothesize that the preference for unfamiliar males results from the masking of auditory cues that are crucial to pair-bond maintenance. In video stimulus trials, although females actively courted the video images of males more than they did live males in the live male trials, females did not prefer the unfamiliar males over their pair-bonded males. Therefore, noninteractive digital video presented on TFT screens solicits courtship behaviour from females but also fundamentally changes their mate preferences. We discuss these patterns in light of the possible visual and behavioural differences between the video and live male stimuli and conclude that video displayed on TFT monitors must be used with caution in mate preference studies.

Correlations between heterozygosity and measures of genetic similarity: implications for understanding mate choice

There is currently considerable interest in testing the effects of genetic compatibility and heterozygosity on animal mate preferences. Evidence for either effect is rapidly accumulating, although results are not always clear-cut. However, correlations between mating preferences and either genetic similarity or heterozygosity are usually tested independently, and the possibility that similarity and heterozygosity may be confounded has rarely been taken into account. Here we show that measures of genetic similarity (allele sharing, relatedness) may be correlated with heterozygosity, using data from 441 human individuals genotyped at major loci in the major histocompatibility complex, and 281 peafowl (Pavo cristatus) individuals genotyped at 13 microsatellite loci. We show that average levels of allele sharing and relatedness are each significantly associated with heterozygosity in both humans and peafowl, that these relationships are influenced by the level of polymorphism, and that these similarity measures may correlate with heterozygosity in qualitatively different ways. We discuss the implications of these inter-relationships for interpretation of mate choice studies. It has recently become apparent that mating preferences for 'good genes' and 'compatible genes' may introduce discordant choice amongst individuals, since the optimal mate for one trait may not be optimal for the other, and our results are consistent with this idea. The inter-relationship between these measures of genetic quality also carries implications for the way in which mate choice studies are designed and interpreted, and generates predictions that can be tested in future research.

Location, location, location: stripe position effects on female sword preference

The evolution of complex signals via sexual selection is becoming a primary focus in mate choice studies. Male swordtail fish, Xiphophorus helleri, have a secondary sexual trait, the sword, which is a composite trait consisting of four components favoured by sexual selection via female mate choice. The components include three coloured stripes and size. Although a complete sword is most attractive to female green swordtails, females prefer partial swords containing complete black stripes to incomplete swords lacking black coloration. Female swordtails also prefer longer swords. We addressed how subcomponents of the sword affect female mate choice. Digitally altered videos were used to investigate whether females respond differently to swords with proximal black stripes than to swords with distal black stripes. Although females preferred complete swords to both of the stimuli with partial stripes, they preferred males with distally striped swords to males with proximally striped swords. These results are discussed in light of hypotheses concerning the evolution of mating preferences for multicomponent traits. This study contributes to the growing body of information regarding the response of females to multicomponent visual traits.

Female mate attraction in ornate tree lizards, Urosaurus ornatus: a multivariate analysis

Recent reviews of mate choice have concluded that this phenomenon is rare or nonexistent in lizards. However, direct tests of lizard mate choice are few and generally limited in scope. We present results of a mate choice experiment with Urosaurus ornatus in which two male lizards differing in morphology, colour and behaviour were given the opportunity to attract a female lizard. Pairwise comparisons of selected and unselected males revealed that variation in individual traits failed to account for much of the variation in mate attraction success. However, a multivariate analysis revealed that mate attraction was related to multiple cues from a male's phenotype: body mass and head size as well as body and tail coloration all contributed to mate attraction. We argue that the additive and interactive effects of several traits combined may be more important than single traits in mate choice. We suggest that mate choice studies should account for multivariate effects of male traits, and also allow mate attraction to occur over variable spatial and temporal scales, paralleling mate choice under natural conditions.

Alternative reproductive strategies in the white-throated sparrow: behavioral and genetic evidence

Organisms exhibiting genetic polymorphism often also exhibit true alternative life-history strategies in which behavioral tactics are genetically fixed. Such systems are ideal for the study of the evolution of life histories because the consequences of selective episodes can be more easily identified. Here I report an interesting and classic example of a species exhibiting true alternative strategies. Due to a chromosomal inversion, male and female white-throated sparrows (Zonotrichia albicollis) occur as two distinct morphs, tan or white. Tan and white morphs mate disassortatively, and this mating pattern maintains the polymorphism in relatively equal proportions within the population. In comparison with tan males, white males are more aggressive, frequently intrude into neighboring territories, spend less time guarding their mates, occasionally attempt polygyny, and provide less parental care. White females are also more aggressive and solicit copulation from their mates twice as often as tan females. Multilocus DNA fingerprinting revealed that 31.8% of nestlings and 56.3% of broods from white male--tan female pairs were the result of extrapair fertilizations, whereas only 4.4% of nestlings and 6.3% of broods from tan male--white female pairs contained extrapair offspring. However, 4.4% of the nestlings (12.5% of broods) from tan male--white female pairs were attributable to conspecific brood parasitism, and brood parasitism was not a factor for white male--tan female pairs. For three excluded extrapair offspring, actual paternity was assigned to territorial white males, suggesting that, although white males are not preferred by females in previous mate choice studies, they do attempt to increase their reproductive success by securing additional matings via extrapair copulations. However, by doing so, white males also lose paternity at home. Behavioral and genetic evidence suggest that the two morphs use alternative strategies and that reproductive trade-offs may serve to maintain a competitive equilibrium between the morphs. Copyright 2003.

Behavioural patterns, preference, and motivation of female midwife toads during phonotaxis tests

During two-speaker phonotaxis tests performed with female midwife toads (Alytes obstetricans and A. cisternasii), the occurrence of behavioural patterns tentatively considered to be associated with entering amplexus and making a mate choice was noted. The individual repeatability of choice was assessed as a measurement of reliability of female preference, and the individual repeatability of response was assessed as a measurement of the degree of female motivation. The tests were grouped in two categories, spectral and temporal, according to the acoustic variable addressed in the test. Females selecting the alternative chosen less often by the population responded less often in phonotaxis tests and thus could be less motivated. Female repeatability was significant for temporal tests, but not for spectral tests. The observation of behavioural patterns during phonotaxis tests appears to be a useful complement to mate choice studies in anurans.

Modelling the evolution of female choice strategies under inbreeding conditions.

Recently, many mate choice studies have discussed the role of genetic compatibility and inbreeding for the evolution of mate choice. With population genetic simulations I compared the potential advantage of three different female choice strategies under inbreeding conditions. Females were assumed to benefit indirectly via a preference for (i) complementary males, (ii) males with few detrimental mutations, and (iii) non-inbred males. Probably related to the reduced inbreeding depression in offspring of choosy females, the choice-allele increased for all three strategies. However, the advantage of the strategies differed widely. Choice of males with fewer mutations provided a comparatively large advantage, choice of complementary males led to a reasonable advantage, and choice of non-inbred males only resulted in a minor advantage of female choice. My results show that complementary mate choice can be almost as beneficial as conventional good-genes choice of mates with lower genetic load. Compared to the two other mate choice strategies, choice of non-inbred males is less likely to contribute to the evolution of costly mate choice. The results of a recent study showing that female sticklebacks prefer males with a larger number of MHC-loci is thus unlikely to be related to an indirect benefit of choosing non-inbred males.

Male size and sequential mate preference in the cricket Gryllus bimaculatus

In crickets, females show preferences for male traits such as body size and either reject outright, take longer to mate with, or remove the spermatophores of nonfavoured males sooner, interrupting sperm transfer. In most mate choice studies, however, empirical tests so far have concentrated on choice between simultaneously presented males, which may not reflect the natural situation. We exposed sequentially to potential mates females that ranged from completely naıve (virgin) to twice mated. Naıve females did not remove the spermatophores of smaller males sooner, but tended (nonsignificant) to reject small males outright. With increasing experience, there was a general decline in spermatophore retention time, but large males were favoured: females either increased retention time when large males succeeded small males or maintained it for the same duration. There were more rejections when small males succeeded large or small males, but fewer when large males succeeded small males. Females appeared to ‘bet hedge’ at the first copulation, rather than be unable to judge male size/quality; but with increasing experience, their spermatophore retention and rejection behaviour clearly indicated a favouring of large males and an active discrimination against small males. There was a first-male advantage in terms of sperm transfer, but subsequent female behaviour compromised any advantage gained by a small first mate.

Hybrid Female Matings Are Directly Related to the Availability of Rana lessonae and Rana esculenta Males in Experimental Populations

In the hybridogenetic frog complex Rana lessonae and Rana esculenta, mate choice based on genetic benefit could be an important form of sexual selection. The hybrid R. esculenta, must coexist with the parental species R lessonae, which functions as a genetic host. The two types occur in varying ratios in natural populations depending on environmental conditions of the aquatic habitat. In highly disturbed habitats such as gravel pits, R. esculenta is most common, whereas R. lessonae is more frequent under less disturbed environmental conditions. To examine the influence of different proportions of males of the two types on mating success, we subjected hybrid females to different ratios of R. lessonae and R. esculenta males in artificial pools. Our results show that females mated according to the availability of the two types of males in the pools. However, combining data over all ratio treatments suggested a slightly higher mating frequency for R. lessonae males than for R. esculenta males, although the R. esculenta males behaved more aggressively, called more often, and tended to orient more frequently toward females than did R lessonae males. This, plus results from previous mate choice studies, suggests that R. esculenta females have a preference for mating with R. lessonae males because of genetic benefits; but which mate a female finally mates with is also influenced by other processes, such as the availability of the two male types at the time of mate choice as well as the strength of male-male competition.

Alternative reproductive tactics in atlantic salmon: factors affecting mature parr success

In Atlantic salmon, as in most salmonids, males can mature early in the life cycle, as small freshwater fish, termed parr, and/or undergo a sea migration before maturing as full–size adults. The alternative life histories are contingent on environmental and social circumstances, such as growth rate, territory quality or any other factor that affects the individual9s state. In order to model the choice of life history in this group of commercially valuable species, it is necessary to understand not only the relative contribution of the different male types to subsequent generations, but also to know the factors that affect reproductive success in each type. In this paper we present the results of a study designed to investigate the factors that affect the reproductive success of mature parr. We used highly polymorphic minisatellite DNA markers to analyse paternity in a series of mating experiments where the number and body size of parr were manipulated. The fraction of eggs fertilized by mature parr ranged from 26 to 40 per cent, with individual parr fertilizing up to 26 per cent of the eggs. A strong positive correlation was found between parr size and reproductive success. The relative success of parr decreased with increasing parr number. Data from this and other studies on variation in the timing and degree of parr reproductive success are discussed in relation to the evolution of male mating strategies and life history in salmonids.

Some Problems and Approaches in Avian Mate Choice

Some Problems and Approaches in Avian Mate Choice