Dominant male red junglefowl (Gallus gallus) test the dominance status of other males

In sexual selection, honest signals are maintained by a variety of mechanisms. In red junglefowl (Gallus gallus), health, condition and social status affect comb size, a well-documented predictor of female choice. The comb size of subordinate male junglefowl appears to be suppressed when in the company of other males. One hypothesis for how social status could affect ornament expression in this way involves punishment of cheaters. Under this scenario, dominant males periodically challenge similar males signalling putative high status. For subordinate males, the risk of fighting a high-ranked male could make it prohibitively costly to develop ornamentation signalling dominance. We asked if dominance signals influenced the direction of aggression by dominant males. To address this issue, we conducted experiments in which 19 dominant-acting, large-combed male junglefowl were allowed to choose to fight one of two opponents. The two potential fight opponents differed in comb size, dominance behaviour, or in both traits. In 15 of 19 trials, dominant-acting males chose to fight large-combed, dominant-acting opponents rather than small-combed, subordinate-acting opponents. This is the first demonstration that aggression of dominant male birds is directed at other males based on the display of an ornament known to be attractive to females. However, males did not discriminate between fight opponents when potential opponents differed in only one of the two status indicators (large-combed males chosen in 11 of 19 trials, dominant-acting males chosen in 10 of 19 trials).     

Inter- and intra-sexual patterns of fluctuating asymmetry in the red-billed streamertail: should symmetry always increase with ornament size?

Recent work on fluctuating asymmetry has suggested that ornaments should have higher levels of fluctuating asymmetry than (1) non-ornaments and (2) homologous structures in the non-ornamented sex. In addition, as both ornament size and symmetry should increase with individual quality there should be a tendency for ornament symmetry to increase with ornament size. In non-ornaments, a U-shaped relationship between symmetry and size is expected, with the individuals at the extremes being more asymmetrical than individuals around the optimum. We tested these predictions in the red-billed streamertail (Trochilus polytmus), a sexually dimorphic endemic Jamaican hummingbird. The lengths of four bilaterally symmetrical traits (first and second outermost tail feathers, tarsi and wings) in 43 adult males and 42 females were measured. The second outermost tail feathers of adult males (which are elongated into streamers) were absolutely but not relatively more asymmetrical than non-ornaments (including the homologous feathers in females). When character size was controlled for, wings were shown to be relatively more symmetrical than other traits. Symmetry did not increase with increasing trait size in any of the morphological traits measured. There was a U-shaped relationship between asymmetry and trait size for four traits (adult male streamers, adult male wings and female outer tail feathers). These results do not support any of the predictions made by fluctuating asymmetry hypotheses and suggest that stabilising selection may act on ornaments as well as non-ornaments. These predictions have been supported in swallows and peafowl but not in sunbirds; this may be due to differences in female perception of tail ornaments. Perhaps male tails do not convey information about quality in some species, or there may be inter-specific differences in the relative costs of tail ornaments and the benefit of marginal increases in tail length and symmetry.     

Alternative reproductive tactics and male-dimorphism in the horned beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae)

Adult dung beetles (Onthophagus acuminatus) exhibit continuous variation in body size resulting from differential nutritional conditions experienced during larval development. Males of this species have a pair of horns that protrude from the base of the head, and the lengths of these horns are bimodally distributed in natural populations. Males growing larger than a threshold body size develop long horns, and males that do not achieve this size grow only rudimentary horns or no horns at all. Previous studies of other horned beetle species have shown that horned and hornless males often have different types of reproductive behavior. Here I describe the mating behaviors of the two male morphs of O. acuminatus during encounters with females. Females excavate tunnels beneath dung, where they feed, mate and provision eggs. Large, horned males were found to guard entrances to tunnels containing females. These males fought with all other males that attempted to enter these tunnels. In contrast, small, hornless males encountered females by sneaking into tunnels guarded by other males. In many instances, this was accomplished by digging new tunnels that intercepted the guarded tunnels below ground. Side-tunneling behavior allowed sneaking males to enter tunnels beneath the guarding male, and mate with females undetected. Both overall body size and relative horn length significantly affected the outcome of fights over tunnel ownership. These results suggest that alternative reproductive tactics may favor divergence in male horn morphology, with long horns favored in males large enough to guard tunnels, and hornlessness favored in smaller males that adopt the “sneaking” behavioral alternative. Received: 12 October 1996 / Accepted after revision: 8 August 1997     

Patterns of parental provisioning covary with male morphology in a horned beetle (Onthophagus taurus) (Coleoptera: Scarabaeidae)

Male dung beetles, Onthophagus taurus, are dimorphic for a secondary sexual trait, head horns. Horned males participate in the production of brood masses while hornless male do not. Here we examine the reproductive performance of females mated with males exhibiting alternative horn morphologies. We found that exposure to males may be costly for females in that it reduced the total number of brood masses produced. However, females paired with horned males produced significantly larger brood masses than females paired with hornless males or females producing broods alone. We discuss the possible selection pressures that may underly horn evolution in this genus. Received: 22 August 1997 / Accepted after revision: 19 January 1998     

Seasonal variation in the relationship between cellular immune response and badge size in male house sparrows (Passer domesticus)

The immunocompetence handicap hypothesis postulates that secondary sexual traits are honest signals of male quality because steroid hormones (such as corticosteroids and sex steroids), which are supposed to favor the development of secondary sexual traits, may also have immunosuppressive effects. Certain secondary sexual traits are not only used as mate choice signals but also play a role as badges of status. In the house sparrow (Passer domesticus), males have a bib of black feathers which is used both as a signal of social status in male-male interactions and by females when choosing a mate. We investigated the relationships between bib size and cellular immune response in male house sparrows during and outside the reproductive season. Males with large badges were found to have lower levels of immunocompetence, as assessed using a T-cell-mediated immunity assay, during the reproductive season, as predicted by the immunocompetence handicap hypothesis. Conversely, in November, the correlation between badge size and cellular immune response was positive, possibly reflecting the better access to trophic resources of large-badged dominant males in winter flocks. Received: 24 September 1998 / Received in revised form: 2 February 1999 / Accepted: 14 February 1999     

Female sensory bias may allow honest chemical signaling by male Iberian rock lizards

Some mate choice theories propose that only male signals that are honest and condition-dependent can be stable, while another hypothesis states that males evolve signals that exploit the sensory system of females. However, sensory traps might evolve into honest signals if they are differentially costly for males. We tested whether a pre-existing sensory bias for food chemicals explained chemosensory preferences of female Iberian rock lizards for male scents. We manipulated hunger levels of females and found that food-deprived females had increased chemosensory responses to chemical stimuli from both invertebrate prey and femoral secretions of males, but not to control water. Further tests suggested that cholesta-5,7-dien-3-ol (provitamin D₃), a lipid found in both prey and males’ scent, may be one of the chemicals eliciting these responses. Moreover, hungry females spent more time on scent marks of males that had experimentally increased cholesta-5,7-dien-3-ol than on scent marks of males alone, whereas for control females this effect was not significant. We suggest that preexisting sensory bias for essential nutrients (i.e., provitamin D) may be the origin of similar female responses to male chemicals. However, previous studies have suggested that the allocation of these chemicals to ornaments is costly and only high quality males can afford it. Therefore, preexisting sensory bias for essential nutrients may further allow the evolution and maintenance of honest sexual displays.     

Testis size variation in the greenfinch Carduelis chloris : relevance for some recent models of sexual selection

Interspecific evidence that testis size responds to selection caused by sperm competition has been obtained from many taxa. However, little is known about the sources of intraspecific variation in testis size, although such variation may have functional significance. Variation in testis size and asymmetry was studied within and between eight geographically separated (and genetically differentiated) populations of greenfinches Carduelis chloris. The relationships between testis size and plumage brightness (degree of yellowness) and the prevalence of haematozoan infections were also investigated in three of these populations, as they related to the predictions of the immunocompetence handicap hypothesis, and Møller's hypothesis relating directional testis asymmetry to phenotypic quality. There were large differences between populations in testis size, with males from northern populations having larger testes than those from southern populations. Within populations, large testes were associated with larger body size and greater age. When the influence of these factors was removed statistically, males with large testes were more likely to be infected with haematozoan parasites, and had brighter yellow plumage. No evidence was found that directional asymmetry in testis size was related to either of these measures of phenotypic quality. These results are consistent with the hypothesis that males with large testes, while signalling higher phenotypic quality as revealed by increased plumage brightness, also pay a cost in terms of reduced immunocompetence, revealed by the increased probability of infection in these males. That these patterns were similar in three different populations adds further strength to these conclusions. Our results suggest that studying the sources of variation in testis size among individuals can reveal interesting processes in sexual selection.     

No relationship between long-distance acoustic mate attraction signals and male fertility or female preference in spring field crickets

To father offspring, a male must succeed at two processes of sexual selection: (1) mate with a female and (2) fertilize her eggs. We investigated the relationships between pre- and post-copulatory male traits and female mating responses in wild-captured and laboratory-reared spring field crickets, Gryllus veletis. The phenotype-linked fertility hypothesis suggests that females may receive a direct benefit, enhanced fertilization efficiency, by mating with males that signal attractively. We measured fine-scale components of male acoustic mate attraction signals as well as how much time males spent signalling, measured female preference for males in mating trials and then quantified sperm number and viability. We found no relationship between male signalling traits and male fertility or female preference, providing no evidence for the phenotype-linked fertility hypothesis. We also found no difference in sperm metrics between wild-captured and laboratory-reared males. While female crickets may receive benefits by choosing males based on acoustic signal characteristics, whether the benefits are a result of genetic quality, seminal fluid contents or some other male trait remains unknown.     

Male asymmetry and postcopulatory sexual selection in the fly Dryomyza anilis

The significance of male asymmetry in postcopulatory sexual selection was studied in the fly Dryomyza anilis by examining whether male asymmetry is related to fertilization success. The traits measured were wing length, tibia length and the length of small and large claspers. The male claspers are situated at the tip of the abdomen, functional pair of claspers consists of a large and a small clasper on the same side of the body. These claspers are used to tap the female abdomen after sperm transfer, which has been shown to increase fertilization success for the mating male. Fertilization success was negatively related to the fluctuating asymmetry of wing length, suggesting either female preference for more symmetrical males or a relationship between male asymmetry and intrasexual selection which was reflected in mating performance. Fertilization success was also related to the length of small claspers, decreasing with increasing length of the claspers. In addition, males with asymmetrical small claspers enjoyed higher fertilization success than symmetrical ones. This study shows that fluctuating asymmetry in wing length is an important fitness trait in postcopulatory sexual selection. Since male tapping affects sperm distribution in the female's sperm storage organs, the higher fertilization success of males with asymmetrical small claspers could have a functional relationship with the asymmetrical position of female sperm storage organs. Received: 6 March 1997 / Accepted after revision: 8 November 1997     

Armaments and ornaments in the rock sparrow: a possible dual utility of a carotenoid-based feather signal

Females often base their mating preferences on male sexual secondary traits that are used to settle contests among males. Such traits are likely to be honest indicators of male quality if they are constantly used during costly male–male agonistic interactions. Carotenoid signals have been shown to work as a handicap because they are costly to produce. However, the role of carotenoids as “honest” signals during male contests is less clear, and it is not known whether a carotenoid-based trait can serve in both male–male competition and female choice. In this study, we studied the dual function of a carotenoid feather ornament in the rock sparrow (Petronia petronia), a bird species in which both sexes have a yellow throat patch whose size positively correlates with phenotypic measures. First, we investigated, in a field study, whether the size of a male’s yellow patch correlates with his ability to acquire a territory. Second, we tested the signal function of the yellow patch in two male–male interaction in captivity experiments. Finally, we measured female preference for males differing in throat patch size in a mate choice experiment. Our experiments revealed that the size of a male’s throat patch positively correlated with the number of nest boxes he was able to defend. Moreover, in controlled conditions, males with relatively large yellow patches had earlier access to food than those with small patches. Also, in an experiment in which a dummy rock sparrow with an experimentally manipulated yellow patch was positioned near a feeder, latency to feed by focal birds positively correlated with dummy patch size. Lastly, in a dichotomous mate choice experiment, females showed a proximity preference for males whose patch was experimentally enlarged. Taken together, these results suggest that the same carotenoid feather signal may be used in both male–male competition and female choice in this passerine bird.     

Sperm removal and ejaculate size correlate with chelae asymmetry in a freshwater crayfish species

Asymmetry in traits of sexual relevance may impair copulation behaviour and sexual performance of males, ultimately resulting in a fitness cost. Freshwater crayfish males use chelae, a sexually selected trait, to secure and position the female prior to and during mating. Thus, a relatively large chelae asymmetry, resulting from accidental loss and regeneration of one cheliped after autotomy, could have great consequences for male sexual behaviour. We studied copulatory behaviour and sperm expenditure of males paired to a mated female in Austropotamobius italicus, a freshwater crayfish species where both male and female mate multiply and where last-mating males are able to actively remove previously deposited sperm. We aimed at assessing whether male sperm removal and expenditure varied according to sperm allocated by first-mating males, and according to copulation behaviour and phenotypic traits (carapace length, chelae length and relative chelae asymmetry) of second-mating males. Second-mating males did not adjust their ejaculate size in relation to first-mating male ejaculate, nor to the first-mating male’s sperm removed. Moreover, the amount of sperm removed by second-mating males increased with increasing first-mating males ejaculate size, and first-mating male sperm remaining after removal did not correlate with the original first-mating male ejaculate size. Interestingly, the amount of sperm removed by second-mating males decreased with increasing relative chelae asymmetry, while increasing with male body size. However, second-mating (but not first-mating) asymmetric-clawed males produced larger ejaculates than symmetric-clawed ones. Importantly, the proportion of second-mating male sperm remaining after the two matings did not vary with relative chelae asymmetry nor with body size of second-mating males. Thus, small, asymmetric-clawed crayfish males appear to adopt sperm allocation tactics that allow them to fully compensate for their inferior sperm removal ability.     

Carotenoid-derived ornaments reflect parental quality in male and female yellow-eyed penguins (<Emphasis Type="Italic">Megadyptes antipodes</Emphasis>)

The handicap principle suggests that ornamental traits that function as honest signals in mate selection must be costly to be effective. We evaluated in the sexually monochromatic yellow-eyed penguin (Megadyptes antipodes) whether the carotenoid-derived plumage and eye coloration predicts parental quality and whether males and females within pairs mate assortatively in relation to these carotenoid-derived ornaments. In addition, we investigated whether age or body condition was related to the coloration of the ornamental traits. In yellow-eyed penguins, parental quality of males and females was predicted by eye and head plumage coloration. Even when we controlled for gender- and age-specific differences, eye and head plumage coloration reflected honestly parental quality. Males and females mated assortatively in relation to these ornamental traits. While age influenced coloration of both the eye and head plumage, body condition was related only to the saturation of plumage coloration. These results provide evidence that the carotenoid-derived ornaments in yellow-eyed penguins reflect the parental abilities of birds and, therefore, may be costly signals. Potentially, female and male yellow-eyed penguins could use eye and plumage coloration as an indirect cue in assessing age and quality of individual birds during mate choice. This is only the second study to examine plumage coloration in relation to sexual selection in penguins, while conspicuous ornamental traits in other species of penguin beg the question whether they also play a role in sexual selection.Electronic Supplementary Material Supplementary material is available in the online version of this article at Communicated by C.R. Brown     

Sexual selection favours small and symmetric males in the polygynous greater sac-winged bat Saccopteryx bilineata (Emballonuridae, Chiroptera)

We investigated how morphological traits of territorial males in the polygynous bat Saccopteryx bilineata were related to their reproductive success. Because of the frequency of aerial courtship displays and defence manoeuvres, and the high energetic costs of flight, we expected small and symmetric males to be better able to court females on the wing and to monopolize copulations with females in their harems. We predicted that small and symmetric males would sire more offspring within the colony and a larger portion of the young born within their harem than large or asymmetric males. We measured size and fluctuating asymmetry of 21 territorial males and analysed their reproductive success in 6 offspring cohorts (n=209 juveniles) using 11 microsatellite loci. As predicted, small and symmetric males had, on average, a higher reproductive success in the colony than large and asymmetric males. The percentage of young sired by males within their harem increased as males decreased in size, but was not influenced by fluctuating asymmetry. As fluctuating asymmetry of males correlated with their reproductive success within the colony but not within their harems, we infer that fluctuating asymmetry is probably related to female choice, whereas male size is probably important for harem defence on the wing.Communicated by G. Wilkinson     

Male mating competitiveness and age-dependent relationship between testosterone and social rank in bighorn sheep

In males, the acquisition and development of behavioral and morphological secondary sexual traits typically depends on testosterone and correlates with mating success. Testosterone level could affect competition for mates and thus be a target of sexual selection. We sought to relate testosterone levels to male mating competitiveness, by teasing apart the relationships between testosterone, behavior, and growth before the mating period. We monitored 24 adult bighorn rams (Ovis canadensis) at Ram Mountain, Alberta, from 2008 to 2011. Using linear mixed models, we tested the relationships between testosterone metabolites in feces, social rank, and both growth and size of two sexually selected traits: horns and body mass. The correlation between testosterone and social rank varied with age. Testosterone and rank were weakly and negatively correlated for young rams, positively correlated for prime-aged rams, and negatively correlated for older rams. Although testosterone had an increasingly positive effect on total horn length until 8 years of age, we could not detect any effects on annual growth rate of horns or body mass. Testosterone may be related to male’s ability to compete for mates through its relationship with behaviors determining social rank, rather than by influencing the development of morphological traits. Differences in testosterone levels among competitors may be a proximate cause of variance in fitness.     

Antioxidant status, flight performance and sexual signalling in wild-type parrots

During mate choice, individuals are predicted to assess traits that honestly signal the quality of potential partners. Locomotor capacity may be such a trait, potentially signalling condition and ability to resist oxidative damage. In this study, we experimentally manipulated nutritional status: Male wild-type budgerigars, imported from Australia, were provided with either an enhanced (EQ) or reduced quality (RQ) diet varying in vitamin (particularly retinol and α-tocopherol) and mineral levels. Then, we assessed whether this influenced locomotor capacity, i.e. escape flight performance, and sexual attractiveness in male budgerigars Melopsittacus undulatus. Males in the EQ group showed significantly greater total antioxidant capacity and higher blood plasma concentrations of the dietary antioxidants retinol and α-tocopherol, but not carotenoids, than the RQ group. Over 8 weeks of flight training, males on the EQ diet showed significantly greater improvement on the most strenuous flight test than RQ males. In mate choice trials, females preferred EQ over RQ males. EQ males that were relatively fast in escape flight trials were more strongly preferred in the mate preference arena than their RQ competitors. Interestingly, males with high plasma carotenoid levels flew slower and were less attractive than males with low carotenoid levels. This might indicate that carotenoids are not effective antioxidants in birds. Overall, our results show that dietary-derived antioxidants can influence sexual attractiveness and other fitness-related traits through multiple pathways. Locomotor capacity appears to be an honest signal of male condition in birds.     

Selective harvesting and habitat loss produce long-term life history changes in a mouflon population.

We examined the long-term effects (28 years) of habitat loss and phenotype-based selective harvest on body mass, horn size, and horn shape of mouflon (Ovis gmelini musimon) in southern France. This population has experienced habitat deterioration (loss of 50.8% of open area) since its introduction in 1956 and unrestricted selective hunting of the largest horned males since 1973. Both processes are predicted to lead to a decrease in phenotype quality by decreasing habitat quality and by reducing the reproductive contribution of individuals carrying traits that are targeted by hunters. Body mass and body size of both sexes and horn measurements of males markedly decreased (by 3.4-38.3%) in all age classes from the 1970s. Lamb body mass varied in relation to the spatiotemporal variation of habitat closure within the hunting-free reserve, suggesting that habitat closure explains part of these changes. However, the fact that there was no significant spatial variation in body mass in the early part of the study, when a decline in phenotypic quality already had occurred, provided support for the influence of selective harvesting. We also found that the allometric relationship between horn breadth and horn length changed over the study period. For a given horn length, horn breadth was lower during the second part of the study. This result, as well as changes in horn curve diameter, supports the interpretation that selective harvesting of males based on their horn configuration had evolutionary consequences for horn shape, since this phenotypic trait is less likely to be affected by changes in habitat characteristics. Moreover, males required more time (approximately four years) to develop a desirable trophy, suggesting that trophy hunting favors the reproductive contribution of animals with slow-growing horns. Managers should exploit hunters' desire for trophy males to finance management strategies which ensure a balance between the population and its environment. However, for long-term sustainable exploitation, harvest strategy should also ensure that selectively targeted males are allowed to contribute genetically to the next generations.     

Male lagoon gobies, <Emphasis Type="Italic">Knipowitschia panizzae</Emphasis>, prefer more ornamented to larger females

Female ornamentation may be directly sexually selected, by male choice or female competition, or occurs as the result of a genetic correlation, arising from sexual selection on males. However, increasing evidence supports the former hypothesis, suggesting that males actively choose their partner preferring traits indicative of female quality. In the lagoon goby, Knipowitschia panizzae, a polygynous species whose males perform parental care to eggs, body length and the size of a sex-specific yellow patch on the belly are known to be reliable indicators of female fecundity. In this paper, we tested, using dummies, the male’s mating preferences for female body and yellow belly patch sizes. The two experimental trials in which a single female trait was variable showed that males prefer a larger belly patch and a larger body size, indicating that both these characters are selected by male mate choice. However, when faced with dummies exhibiting an inverse combination of body and belly patch sizes (experiment 3), males significantly preferred the smaller ones with larger yellow belly patches. A calculation of dummy theoretical fecundity reveals that in the first two experiments, males would have received an immediate benefit from their choice in terms of egg number, whereas in the third one, males chose partners that would have provided them with fewer eggs. The male lagoon goby preference for females with larger belly patches, regardless of their size, suggests that this trait, in addition to indicating fecundity, conveys information about other aspects of female and/or egg quality.     

Courtship signalling with a labile bilateral signal: males show their best side

Asymmetries in courtship signals can result from both developmental instability during ontogeny and from temporary or permanent damage following mating, fighting, or interactions with predators. These two types of asymmetries, which can be divided into fluctuating asymmetry (FA) and damage asymmetry (DA), have both been suggested to play an important role in mate choice as potential honest indicators of phenotypic and/or genetic quality, while at the same time, DA may affect ornament asymmetry in a random manner. Interestingly, despite the massive research effort that has been devoted to the study of asymmetry during the past decades, very little is known about how an individual’s behaviour relates to asymmetry. Here, we measure and characterise asymmetry in morphological courtship signals in Corynopoma riisei, a fish where males carry elaborate paddle-like appendices on each side of the body that they display in front of females during courtship. Moreover, we investigate whether male courtship display, employing this bilateral morphological trait, reflects trait asymmetry. Finally, we assess whether males respond to phenotypic manipulations of DA with corresponding changes in courtship behaviour. We show that male display behaviour is asymmetric in a manner that reflects asymmetry of their morphological courtship trait and that male display behaviour responds to manipulations of asymmetry of these paddles. Our results thus suggest that males preferentially use their best side and, hence, that males respond adaptively to temporary changes in signal trait asymmetry.     

Do male barn swallows (<Emphasis Type="Italic">Hirundo rustica</Emphasis>) experience a trade-off between the expression of multiple sexual signals?

Some sexual selection models envisage exaggerated male secondary sexual characters to be costly and therefore reliable indicators of the quality of potential mates to choosy females. If male secondary sexual characters have a natural selection cost, they may be linked to each other by reciprocally constraining relationships that would prevent individual males from increasing their level of multiple signaling. Barn swallow (Hirundo rustica) males have at least two costly signals relevant to socio-sexual interactions: tail length and song. Under the hypothesis that a trade-off exists between male signals, we manipulated the maintenance cost of tail ornaments to test whether this reduced the quantity and quality of song, a condition-dependent, phenotypically plastic signal. Contrary to our expectation, tail elongation had no effect on singing activity and song complexity. However, tail-elongated males produced songs with longer terminal parts ('rattles'). Long rattles are associated with highly competitive social contexts and high circulating levels of testosterone, suggesting that tail-elongated males were more frequently involved in either male-male aggressive or inter-sexual interactions. Therefore, this study shows that males are not displaying multiple signals at the maximum possible level, implying that this system is open to unreliable communication. However, long-term trade-offs between signal expression and viability may prevent males from displaying both signals at higher rates.Communicated by: M. Webster     

Phenotypic correlates and survival consequences of male mating success in lek-mating greater prairie-chickens (<Emphasis Type="Italic">Tympanuchus cupido</Emphasis>)

Female choice and male–male aggression are two modes of sexual selection that can lead to elaboration of male morphological and behavioral traits. In lek-mating species, male mating success is often strongly skewed, and it is puzzling why variation in male traits is still observed given directional female choice. If male traits correlated with reproductive success are honest signals of male quality, there may be survival costs associated with the expression of those traits. In this study, we examined whether morphological, behavioral, and territorial traits are correlated with male mating success and survival in the lek-mating greater prairie-chicken (Tympanuchus cupido). We introduce a novel application of multinomial discrete choice models for analysis of female mate choice behavior. We found that behavioral and territorial attributes showed 6.5 times more variability among males than morphological traits. Both display and aggressive behaviors were strong predictors of male mating success, suggesting that both female choice and male–male aggression were important in determining mating success among male greater prairie-chickens. Moreover, annual survival of male prairie-chickens was independent of mating success and male traits. Females appear to be choosing males based on behavioral traits where large variation exists between males (coefficient of variation >30%). Behavioral traits were the most important factor in determining mating success of male prairie-chickens, but the mechanism underlying this relationship is unknown. In the future, experimental manipulations of male hormones or parasite loads could bridge the proximate mechanisms and ultimate consequences of factors mediating male mating success in lek-mating grouse.