Cues In Mate Choice Research Articles

Sounds different: inbreeding depression in sexually selected traits in the cricket Teleogryllus commodus

If male sexual signalling is honest because it captures genetic variation in condition then traits that are important mate choice cues should be disproportionately affected by inbreeding relative to other traits. To test this, we investigated the effect of brother-sister mating on advertisement calling by male field crickets Teleogryllus commodus. We quantified the effect of one generation of inbreeding on nightly calling effort and five finer-scale aspects of call structure that have been shown to influence attractiveness. We also quantified inbreeding depression on six life history traits and one morphological trait. Inbreeding significantly reduced hatching success, nymph survival and adult lifespan but had no detectable effect on hatching rate, developmental rate or adult body mass. The effect of inbreeding on sexually selected traits was equivocal. There was no decline in calling effort (seconds of sound production/night) by inbred males, but there were highly significant changes in three of five finer-scale call parameters. Sexually selected traits clearly vary in their susceptibility to inbreeding depression.

Is Risk Taking Used as a Cue in Mate Choice?

More frequent risk taking among young men than women has been explained as a sexually selected trait, perhaps advertising male quality. We investigated this hypothesis in three studies. (1) Young men and women rated how attractive they would find it if a potential partner took various specific risks. A domain-specific risk inventory allowed us to distinguish whether risk taking is attractive generally or only in certain domains. Both sexes reported social and recreational risk taking as attractive (the latter not always significantly so), but other domains of risk taking as unattractive (ethics, gambling, and health) or neutral (investment). The sexes differed markedly little. Parallel studies in Germany and the United States yielded very similar results. (2) We asked subjects to predict how attractive the other sex would find it if the subject performed each risky behavior. Both sexes were rather accurate (which could be merely because they assume that the other sex feels as they do) and sex differences in attractive risk taking are not explicable by sex differences either in attraction or in beliefs about what others find attractive. However, our data could explain why unattractive risks are more often taken by men than women (men slightly underestimated the degree of unattractiveness of such risks, whereas U.S. women overestimated it, perhaps because they themselves found such risk taking more unattractive than did U.S. men). (3) Both members of 25 couples reported their likelihood of engaging in specific risky behaviors, their perception of these risks, and how attractive they would have found these behaviors in their partner. One hypothesis was that, for instance, a woman afraid of heights would be particularly impressed by a man oblivious to such risks. Instead we found positive assortment for risk taking, which might be explained by a greater likelihood of encountering people with similar risk attitudes (e.g. members of the same clubs) or a greater compatibility between such mates. Finally, contrary to the assumption that taking a low risk is likely to be less revealing of an individual's quality than taking a high risk, we found a strong negative relationship between the perceived riskiness of a behavior and how attractive it was judged.

Experimental evidence for female choice and energetic costs of male tail elongation in red-collared widowbirds

The black nuptial plumage of the highly polygynous male red-collared widowbird (Euplectes ardens) comprises a red carotenoid-based collar patch and a long graduated tail (c. 22 cm). Tail length was the strongest predictor of male mating success in a previous selection analysis, motivating this experimental test of the relative importance of tail plumes in male contest competition and female choice. Males were assigned to either a short (12.5 cm) or control (20 cm) tail manipulation prior to territory establishment. Male contest competition was unaffected by the tail treatments as the shortened- and control-tailed males were equally successful in acquiring territories of similar size and quality. In contrast, however, although the longer-tailed control males spent less time in flight and courtship displays, they attracted significantly more prospecting and nearly three times as many nesting females to their territories compared to the short-tailed males. In further support of tail length as the primary mate choice cue, none of the other measured and potential female cues (e.g. body size, collar colorimetrics, territorial behaviours or territory quality) influenced male reproductive success. In addition to potentially increasing detectability (‘signal efficacy’), the long tail is also a likely indicator of male quality (‘signal content’). Despite the higher activities of short-tailed males, control-tailed males showed a steeper decline in condition (relative body mass) during the breeding season. Furthermore, both short- and control-tailed residents lost more condition than did the short- and control-treated floaters (males not establishing territories), suggesting an interaction between tail length and the costs of territory acquisition, defence and courtship displays. These results confirm the role of mate choice and honest quality advertising as the main selection pressures behind elongated tails in widowbirds. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 86, 35–43.

Male competition is disruptive to courtship in the Pacific blue‐eye

The present study examined the effects of competition on male courtship in the Pacific blue‐eye Pseudomugil signifer, a species of fish where females have previously been shown to use courtship, but not male fighting prowess, as an important mate choice cue. Courtship bouts directed to a stimulus female were shortest when two males were allowed to freely interact (contact treatment) and longest when there was only one male (non‐interaction). Courtship length in trials where one of two males was confined to a clear cylinder (visual) was intermediate between the other two treatments. Courtship in visual and contact treatments was constantly disrupted. The percentage of interrupted courtships was higher for the contact compared to visual treatment where aggressive interactions were also longer in duration and took place more frequently. Within contact trials, dominant males courted longer than subordinates despite both males experiencing comparable rates of courtship disruption. These results suggest that male‐male competition can have important implications for adaptive female choice particularly in circumstances where the benefits being sought by females are unrelated to male fighting ability.

Have your cake and eat it too: male sand gobies show more parental care in the presence of female partners

Traditionally, male parental effort and mate attraction effort are expected to be in conflict as they compete for the same resource budget. However, the quality of care provided by the male may be of a direct benefit to females and may provide an important mate choice cue. In a laboratory experiment, we examined how males modified their parental behavior with respect to mating opportunity by allowing male sand gobies to mate with a single female either in a big or small nest (a constraint on future mating potential). We then exposed half of these males to the visual stimulus from additional females and recorded male egg fanning and nest building (two components of care), courtship behavior, and reproductive success through out the brood cycle. We found that males fanned longer and more frequently and did more nest construction in the presence of females and in big nests. Males guarding large nests courted females more than did males guarding small nests. All males consumed eggs during the brood cycle, but complete clutch cannibalism was most frequent when males were guarding small nests in the absence of females. The pattern of filial cannibalism that we observed suggests that males prematurely terminated care when their reproductive potential was low, that is, when there was little nest space for additional mating and no mates present. We found no support for a trade-off between mate attraction and parental care. Indeed, taken together our results suggest that males may use parental care as a courtship strategy and that males who invest in mate attraction also have higher parental effort.

Survival of male scarlet-tufted malachite sunbirds (Nectarinia johnstoni) on Mount Kenya and the influence of ornamentation

A prediction of handicap and signalling theories is that there should be a positive relationship between ornament size and viability. This prediction was tested in scarlet-tufted malachite sunbirds (Nectarinia johnstoni). These birds are endemic to the high-altitude zones of East African mountains. They are bright iridescent green with elongated central tail feathers and red pectoral tufts. The elongated tail is believed to be a mate choice cue, and the red tufts play a role in aggressive encounters between males: As adults, they feed almost exclusively on the nectar of Lobelia telekii flowers, which males defend from conspecifics. The long term survival of individually identifiable males colour-marked in 1989 and 1990 was investigated. Territorial adult males had an average annual survival rate of 72%, which is at the top of the range reported for tropical birds. The effects of morphology and territory characteristics on male survival were examined by adding covariates to the survival model. This analysis showed that male N. johnstoni with longer tails had a higher probability of survival than did short-tailed males. There was no apparent relation between tuft size or the number of L. telekii inflorescences on the territory and survival. The results presented here suggest that long-tailed males may be of intrinsically higher quality than are shorter tailed males. If this is true then females may benefit by using this trait as a mate choice cue through increased viability of their offspring.

Evaluation of Female Mate Choice Cues in a Group of Lake Malawi Mbuna (Cichlidae)

The mechanisms that underlie the diversity of cichlids in the East African Great Lakes are poorly understood. Sexual selection through female choice based on male body coloration has often been suggested as a driving force behind the speciation of these fishes. The objectives of this study were to investigate, through mate choice trials, the cues that guide species-isolating female choice. In a group of sympatric Lake Malawi mbuna (rock-dwelling fish), we investigated both visual and chemical cues that might guide female choice by giving gravid females a choice between a heterospecific and a conspecific male. Visual cues, in contrast to olfactory cues, were sufficient to stimulate courtship and thus guide female choice of males. Furthermore, in contrast to other studies on related species, we found that females courted only with conspecifics even if color was not a cue. Species-isolating female choice is likely based primarily on visual information.

Recent experience modulates forebrain gene-expression in response to mate-choice cues in European starlings.

Mate-choice decisions can be experience dependent, but we know little about how the brain processes stimuli that release such decisions. Female European starlings (Sturnus vulgaris) prefer males with long-bout songs over males with short-bout songs, and show higher expression of the immediate early gene (IEG) ZENK in the auditory forebrain when exposed to long-bout songs than when exposed to short-bout songs. We exposed female starlings to a short-day photoperiod for one of three durations and then, on an increased photophase, exposed them to one week of long-bout or short-bout song experience. We then examined their IEG response to novel long-bout versus novel short-bout songs by quantifying ZENK protein in two song-processing areas: the caudo-medial hyperstriatum ventrale and the caudo-medial neostriatum. ZENK expression in both areas increased with tenure on short-day photoperiods, suggesting that short days sensitize females to song. The ZENK response bias toward long-bout songs was greater in females with long-bout experience than in females with short-bout experience, indicating that the forebrain response bias toward a preferred trait depends on recent experience with that category of trait. This surprising level of neuroplasticity is immediately relevant to the natural history and fitness of the organism, and may underlie a mechanism for optimizing mate-choice criteria amidst locally variable distributions of secondary sexual characteristics.

Sexual selection and peripatric speciation: the Kaneshiro model revisited

Abstract The Kaneshiro model proposes a role for sexual selection in peripatric speciation. During population bottlenecks, derived males lose attractive traits and become discriminated against by ancestral females, whereas derived females are selected to be less choosy. This permits novel mate choice cues to evolve in derived populations. In a quantitative analysis of laboratory experiments, we show that bottlenecked males have indeed become less attractive, but females have not lost their ancestral preferences. Contrary to the model, mating asymmetries were not limited to bottlenecks, but regularly occurred between derived and ancestral populations. The simplest explanation for the observed mating asymmetries is loss of genetic variation and inbreeding in the derived populations. The Kaneshiro process is unlikely to isolate small daughter populations from their ancestor but with slight modifications it may become a strong candidate for speciation in allopatry manifested as isolation between daughter populations in secondary contact.

Reversible frequency-dependent switches in male mate choice.

Current sexual-selection theories predict that mating should occur preferentially with the highest-quality partner, and assume that for distinguishing among potential mates the choosy sex applies an internal representation of the characteristics of the desired mate, i.e. a template. Binary choice experiments were performed to test male mate choice between two different female colour morphs in the damselfly Ischnura elegans. Choice experiments were conducted before and after an habituation period, during which males were exposed to only one female colour morph. Given the choice between the two female morphs, males did exhibit a choice for the most recently experienced female morph. This is the first evidence for a reversible switch in mate choice in a frequency-dependent way. In contrast with previous studies on mate choice, template formation in male I. elegans seems not to be based on quality. Switching mate choice in a frequency-dependent manner, choosing the most common morph, probably allows males to minimize their search efforts and to maximize fitness.

Changes in expression and honesty of sexual signalling over the reproductive lifetime of sticklebacks.

Fitness costs of signalling are essential in order for reliable sexual signalling to prevail when the interests of the sexes conflict. This means that signalling can be subjected to a life history trade-off between present and future signalling effort. Here, I show that three-spined stickleback males (Gasterosteus aculeatus), who have a single breeding season during which they breed repeatedly, change their red nuptial coloration over the season depending on their body size at the start of breeding. Large males that completed several breeding cycles increased their red coloration over the season, whereas small males, who completed only a few cycles, did not. The increase in coloration was accompanied by an increase in parental success when males were energy constrained, but not when they had access to an unlimited food supply. Red coloration was thus an honest signal of male parental ability despite changes in signal expression when both signalling and parental care were costly and the investments in them changed simultaneously over the reproductive lifetime. However, the honesty of the signal varied over a lifetime. At the penultimate cycle, bright males cannibalized some of their eggs, probably to increase survival to the last cycle, whereas males cared for their offspring independent of coloration at the ultimate cycle.

POPULATION DIVERGENCE IN SEXUAL ORNAMENTS: THE WHITE FOREHEAD PATCH OF NORWEGIAN PIED FLYCATCHERS IS SMALL AND UNSEXY.

Models of sexual selection suggest that populations may easily diverge in male secondary sexual characters. Studies of a Spanish population of the pied flycatcher, Ficedula hypoleuca, and a Swedish population of the closely related collared flycatcher, F. albicollis, have indicated that the white forehead patch of males is a sexually selected trait. We studied the white forehead patch of male pied flycatchers (n = 487) in a Norwegian population over seven years. Males with large forehead patches were in general more brightly colored, but patch height was not correlated to body mass, body size, or parasite loads. Conditions during the nestling period did not seem to influence patch height as an adult. Patch height increased slightly from the first to the second year as adults, but then remained relatively constant at higher ages. Patch height was not related to survival. Year-to-year changes showed that males who increased in patch height also increased in body mass, suggesting that expression of the forehead patch may be partly condition dependent. However, changes in body mass explained only a small proportion of the variance in patch height between males. Thus, patch height would not be a good indicator of male quality. Furthermore, patch size was also not related to male ability to feed nestlings, indicating that females would not obtain direct benefits by choosing males with large patches. However, patch height could be a Fisher trait, but this requires heritability and there was no significant father-son resemblance in patch height. Comparisons of the males visited by each female during the mate sampling period indicated that chosen males did not have larger forehead patches than rejected males. Experimental manipulation of patch height did not affect male mating success. These results indicate that females do not use patch size as a mate choice cue. Finally, patch height did not predict the outcome of male contests for nestboxes, suggesting that the forehead patch is not an intrasexually selected cue of status. Norwegian pied flycatchers have smaller forehead patches than both Spanish pied flycatchers and Swedish collared flycatchers. We suggest that this pattern may be explained by the lack of sexual selection on the forehead patch in the Norwegian population as compared to the other populations, where the patch is apparently sexually selected. We discuss possible reasons for these population divergences, such as female choice on an alternative secondary sexual character (general plumage color) and speciation among Ficedula flycatchers.

The influence of habitat and male morphology on a mate-choice cue: the display nests of wrens

Wrens,Troglodytes troglodytesare highly polygynous passerines. Males build cock nests that are displayed to females and function as a mate-choice cue. Males with large numbers of nests are more likely to attract females than males with fewer nests. To be useful to females a cue used in mate choice must contain information. One way to evaluate the information content of such a cue may be to examine the factors that influence its size. The number of nests was predicted on territories with known building rates (immigration) and nest destruction rates (death) using an immigration–death function. This analysis suggested that if only building rate and destruction rates were considered then the number of nests on territories was consistently overestimated. In 1994 an experiment was conducted in which nest-site availability was manipulated. Males provided with additional nest sites built more nests and continued to build later in the year resulting in longer nest-building periods than controls. The converse was found when nest sites were experimentally removed. This suggested that the number of nests that could be constructed on a territory was limited by habitat structure. None of the morphological characters considered here significantly influenced the number of nests built by males. Therefore, the information content of this mate-choice cue will be primarily about characteristics of the habitat on the territory rather than characteristics of the male.

Carrier females and sender males: An evolutionary hypothesis linking female attractiveness, family resemblance, and paternity confidence

The article introduces and elaborates the hypothesis of carrier features, characteristics which in females are attractive to males as mate-choice cues. Female carrier features increase paternal resemblance and are ultimately attractive because they help pair-bonded males distinguish genetic offspring from those conceived by mates in extra-pair copulations. The proposed kin recognition mechanism, whether culturally evolved or innate, facilitates discriminatory paternal investment, and hence male fitness. Carrier features would be attractive to males in monogamous species where paternal investment is high, and cuckoldry represents a significant risk to male fitness. Logical space exists for male sender features, which tend to be expressed in offspring regardless of female characteristics. Conflict of genetic interests between the sexes should favor the evolution of carrier, rather than sender, features in both sexes. The argument centers on humans, for whom candidate carrier features are discussed with regard to physiognomy, behavior, recessive traits, and body odor. Criticisms are discussed, and testable predictions enumerated.

Female choice in a feral guppy population: are there multiple cues?

Mating behaviour in a feral guppy,Poecilia reticulata, population from Durban, South Africa was examined. Males bear carotenoid (orange) and melanin (black) spots and low levels of iridescent and yellow pigment. Areas of colour, body size and lengths of the dorsal fin and intromittent organ (gonopodium) were studied as female mate-choice cues. Attractiveness was positively related to the degree of orange coloration in all tests, and with the length of the gonopodium in some tests. Asymmetry of colour spots was investigated and it was concluded that either orange and black spots are not condition-dependent ornaments or the expected negative relationship between expression of condition-dependent ornaments and fluctuating asymmetry does not occur in these guppies. Several hypotheses regarding the maintenance of multiple secondary sexual characters are discussed.

Light Patterns as Cues for Mate Choice in the Lekking White-Throated Manakin (Corapipo gutturalis)

We explored in an exploded lek species the relationships between three alternatives hypotheses for typical skewed male mating success: (1) female preference for display-site characteristics; (2) female preference for male phenotypic traits; and (3) mate choice determined by the outcome of male dominance interactions. The possible role of these mechanisms of female choice was examined in the White-throated Manakin (Corapipo gutturalis), a species in which males display on the top of mossy fallen logs lying on the primary forest floor. Data on light intensity at the display site, lek attendance, male calling and display rates, visits by males and females, and mating success were collected on six males at a single lek. The two males with the brightest two arenas received high rates of female visitation and performed 71% of the mating attempts. However, only one of them successfully copulated because the other male was always disrupted by visiting males. The results suggest that light properties of the display site and attendance of the male determine the attractiveness of male display to females, whereas male interactions subsequently mediate copulatory success. Brightness of the display site appears as the primary cue for mate choice in C. gutturalis, but this is not used by females as an indicator of the males' relative dominance because the dominance status of males is not correlated with the brightness of their display sites.

5-α-androst-16en-3α-on: A male pheromone? A brief report

Olfactory cues play a prominent, yet underestimated role in shaping emotional attitudes towards conspecifics. Among humans olfactory cues can have effects on behavior. In a rating study (n = 290) females rated the smell of androstenone. The emotional reaction to androstenone changed during the menstrual cycle. Females rated the main component of male body odor unattractive. This changed to a neutral emotional response at the conceptive optimum around ovulation. The finding has direct consequences for hypotheses concerning the evolutionary loss of estrus. It is suggested that the cyclic-dependent emotional rating of androstenone may facilitate active female choice of sex partners and may be a proximate cue for female mate-choice.

Male Song as a Cue for Mate Choice in the European Starling

Abstract This study had two aims. First, we looked at individual differences in song characteristics between males of the European starling, and we related song behaviour to factors such as male age, pairing date, polygyny and male breeding success. Second, we experimentally tested whether song has an effect on female mating decisions. 1. During the breeding season, male starlings sing a very long and complex song consisting of a rapid succession of large number of different song types. We observed marked differences between males in average song bout length (a song bout was defined as a period of at least five seconds of song containing no pauses larger than 1.5 seconds) and in song repertoire size. Average song bout lengths ranged from 16 to 35 seconds. The individual repertoire size ranged from 23 to 67 song types. Repertoire size and average song bout length were positively correlated. 2. Both in the field and in captivity, yearling males sang shorter average song bout lengths and had smaller repertoire sizes than older males. 3. Males singing longer average song bouts and having larger repertoire sizes attracted females for pairing before their rivals with shorter average song bouts and smaller repertoire sizes.

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

AbstractPrevious 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.

Food and the deceptive acquisition of mates by polygynous male harriers

Female northern harriers Circus cyaneus are polygynous, marsh-nesting raptors, whose mate choices are enigmatic. I determined the mate choice cues employed by females by correlating the order in which males were chosen with characters that 1) significantly influenced reproductive success; 2) were assessable prior to settlement; and 3) varied between breeding situations. Only nest sites and male provisioning performance met all these conditions: wet nest sites significantly (P<0.05) increased nest survival and high provisioning rates significantly (P<0.01) enhanced brood survival. The order in which females settled was strongly correlated with provisioning performance in both years (r s -0.65, and r s -0.84), but not with nest site quality. Females thus apperared to choose males principally on provisioning performance. Despite using the same cue, however, females choosing mated males reared only 0.28 young for every nestling raised by concurrently settling monogamous females (the lowest ratio recorded for any avian species). Extrapolation of male courtship provisioning patterns from clutch sizes and laying date indicated that females received similar proportions prior to and during egg-laying, but that males later preferentially fed α females. Secondary females therefore chose mated males on the basis of a temporally changing and unreliable cue. The polyterritoriality, cooperative harems, skewed sex ratio, and sexy-son hypotheses were all inadequate in explaining polygyny in harriers. Female choice of mated males among harriers is best explained by the deceitful provisioning of food by males.