Intersexual spatial relationships in a lekking species: blue-crowned manakins and female hot spots

Leks offer an intriguing evolutionary problem: why do malesaggregate when this apparently leads to fitness costs? Aggregationcosts can be balanced if males settle on patches where theyare more likely to encounter females (hot-spot hypothesis).We evaluated whether female hot spots can account for patternsof lek structure in the blue-crowned manakin (Lepidothrix coronata)by modeling female distribution patterns relative to lek locationsin two 100-ha plots. Individual females were mapped based onnest locations and capture points and had their home ranges(HRs) modeled based on radiotelemetry data. The number of femalesthat lekking males can be expected to encounter was estimatedas the number of individual female HRs overlapping each maleterritory; hot spots were defined as patches where more femalesare found than average. We investigated how changes in femaleHR size and devaluation effects (decrease in female availabilitydue to the presence of neighboring males) influence male accessto females. Both factors strongly influenced the expected ratesof female encounter, but the hot-spot hypothesis was not supported:most male territories consistently overlapped fewer or justas many female HRs as expected by chance. Leks were not closerto hot spots than similar-sized nonlek sites. A proportion ofmales were, indeed, settled at hot spots, but, contrary to predictionsof the hot-spot hypothesis, they belonged to smaller leks thanmales located outside hot spots. Our results indicate that thislack of spatial correlation between males and females resultspartly from differences in sex-specific habitat preferences.     

Non-defendable resources affect peafowl lek organization: a male removal experiment

A lekking mating system is typically thought to be non-resource based with male providing nothing to females but genes. However, males are thought to clump their display sites on areas where they are more likely to encounter females, which may depend on non-defendable resource location. We tested this hypothesis on a feral population of peacocks. In agreement, we found that, within the lek, display site proximity to food resources had an effect on female visitation rate and male mating success. The attractiveness of display sites to male intruders was explained by the distance to the feeding place and by the female visitation rate. We randomly removed 29 territorial males from their display sites. Display sites that were more attractive to male intruders before removal remained highly attractive after removal and display sites closer to the feeding area attracted the attention of intruders significantly more after removal. Similarly, display sites that were more visited by females before removal remained more visited after removal, suggesting again that the likelihood of encountering females is determined by the display site location. Overall, these results are in agreement with non-defendable resources affecting lek spatial organization in the peafowl.     

Assessing lek attendance of male greater sage-grouse using fine-resolution GPS data: Implications for population monitoring of lek mating grouse

Counts of males displaying on breeding grounds are the primary management tool used to assess population trends in lekking grouse species. Despite the importance of male lek attendance (i.e., proportion of males on leks available for detection) influencing lek counts, patterns of within season and between season variability in attendance rates are not well understood. We used high-frequency global positioning system (GPS) telemetry data from male greater sage-grouse (Centrocercus urophasianus; n = 67) over five lekking seasons (2013–2017) at eight study sites in Nevada to estimate lek attendance rates. Specifically, we recorded daily locations of sage-grouse in relation to mapped lek boundaries and used generalized additive models to assess temporal variation in attendance rates by age class (subadult vs. adult). Average timing of peak attendance occurred on 16 April but varied from March 16, 2014 to April 21 , 2016. Overall, adult males attended leks at higher rates (0.683 at peak) and earlier in the season (19 March) than subadults (0.421 at peak on April 19). Peak attendance probability was positively related to cumulative winter precipitation. Daily probabilities of lek switching differed between adults (0.019 at peak on March 3) and subadults (0.046 at peak on March 22), and lek switching was negatively related to distance to nearest lek. Our results indicate variable patterns in lek attendance through time, and that lek switching may occur at higher rates than previously thought. We demonstrate the use of generalizable daily attendance curves to date-correct lek counts and derive estimates of male abundance, although such an approach will likely require the incorporation of information on age structure to produce robust results that are useful for population monitoring.     

Relationships between Blood Parasites, Mating Success and Phenotypic Cues in Male Sage Grouse Centrocercus urophasianus

In lek breeding Sage Grouse Centrocercus urophasianus in easternCalifornia, male mating success is strongly correlated withindividual differences in lek attendance, and in the rate andacoustic quality of courtship display, suggesting that theseprovide cues by which females choose mates. Increased lek attendanceand high display rates are also associated with elevated metabolicexpenditure. This paper examines the hypothesis that the abilityto commit energy to display is related to the incidence of bloodparasites. A single hematozoan genus, Haemoproteus, was foundin 37.5% of 184 Sage Grouse sampled over a five year period.Parasitism varied across years and increased through the breedingseason. However, no measure of display performance or matingsuccess was significantly correlated with decreased parasiteload among adult males. Several additional lines of evidence,including numerically low infection intensities, the absenceof detectable effects of parasites on hematocrit and erythrocyteproduction, and the seasonal distribution of parasite incidenceallsuggested that infections were unlikely to impact male courtshipdisplay. Alternative factors maintaining individual variationin male display performance in this population are also evaluated.     

The Social Implications of traditional use of lek sites in the ruff Philomachus pugnax

In almost every letting vertebrate, adult males use traditionallek sites. This paper attempts to explain this phenomenon byinvestigating the social implications of traditional use oflek sites. A population of ruffs Philomachus pugnax was observedduring six breeding seasons, and lek stability, site fidelity,male copulatory success, and male dominance relationships werestudied. Ninety percent of the territorial males were site-faithfulwithin and between years, and male dominance, copulatory success,and order of territory establishment were all inter-correlated.Males that were relatively dominant and successful as first-yearterritorials were more likely to return to the area, establishedthemselves even earlier in their second year, and rose in successrank. The frequency of disrupted copulations was very low, despitethe tightly clustered territories on leks. This suggests thatwell-developed dominance relationships exist between males.Site-faithful males are more likely to acquire accurate informationabout the competitive abilities of other males, and such informationis probably necessary for stable dominance relationships todevelop. Such relationships reduce the intensity of male aggression,thereby reducing the risk of male injury. High levels of maleaggression also deter females. Furthermore, stable dominancerelationships enables low-and medium-ranked males to remainon the leks while waiting for the top males to drop out. Thehigh site-fidelity of lekking males, thus, is suggested to haveevolved to facilitate the establishment of stable dominancerelationships, which are beneficial to all territorial males,irrespective of rank     

Queuing in space and time reduces the lek paradox on an antelope lek

Lek systems, where females often use centrality to assess male quality, highlight a general paradox in evolutionary biology: how can female preferences for males providing good genes persist when consequential strong directional selection is predicted to deplete additive genetic variance in male quality and thereby obliterate benefits of choosiness? An explanation contributing to the resolution of this lek paradox may be that genetic variance is retained when an indirect mate choice cue, such as centrality on a lek, is an imperfect indicator of male genetic quality. Here I investigate whether the presence of alternative male mating tactics limits the reliability of centrality as a quality indicator in lek-breeding topi antelopes. Whereas males establishing territories directly on the central lek were relatively large, smaller peripheral males regularly shifted their territories centripetally and in this way also occasionally obtained central territories. By such opportunistic queuing, small males could increase their mating success drastically; however, their territorial tenure in the lek centre was relatively short, consistent with moderate competitive ability. These results suggest that male topi antelopes can obtain central lek territories through alternative mating tactics, providing scope for variance in male quality on the central lek. In a separate finding, the mating success of central males was found to increase during territorial tenure, independent of estimated age. The demonstration of queuing in both space and time on a mammalian lek highlights the importance of considering male tactical dynamics over time in order to avoid an inflated appearance of the lek paradox.     

The lek mating system of the worm pipefish (Nerophis lumbriciformis): a molecular maternity analysis and test of the phenotype‐linked fertility hypothesis

The origin and maintenance of mating preferences continues to be an important and controversial topic in sexual selection research. Leks and lek‐like mating systems, where individuals gather in particular spots for the sole purpose of mate choice, are particularly puzzling, because the strong directional selection imposed by mate choice should erode genetic variation among competing individuals and negate any benefit for the choosing sex. Here, we take advantage of the lek‐like mating system of the worm pipefish (Nerophis lumbriciformis) to test the phenotype‐linked fertility hypothesis for the maintenance of mating preferences. We use microsatellite markers to perform a parentage analysis, along with a mark–recapture study, to confirm that the worm pipefish has an unusual mating system that strongly resembles a female lek, where females display and males visit the lek to choose mates. Our results show that the most highly ornamented females occupy positions near the centre of the breeding area, and males mating with these females receive fuller broods with larger eggs compared to males mating with less‐ornamented females. We also conduct a laboratory experiment to show that female ornaments are condition‐dependent and honestly signal reproductive potential. Overall, these results are consistent with the predictions of a sex‐independent version of the phenotype‐linked fertility hypothesis, as male preference for female ornaments correlates with fertility benefits.     

Female mate choice across spatial scales: influence of lek and male attributes on mating success of blue-crowned manakins

Lekking males compete for females within and among leks, yet female choice is expected to work differently at each of these spatial scales. We used paternity analyses to examine how lek versus male attributes influence mate choice in the blue-crowned manakin Lepidothrix coronata. We tested the hypotheses that females prefer (i) to mate at larger leks where a larger number of potential mates can be assessed, (ii) to mate with unrelated or highly heterozygous males expected to produce high-quality offspring, (iii) to mate with males that display at higher rates, and that (iv) display honestly reflects male genetic quality. Our results show that (i) males at larger leks are not more likely to sire young, although females nesting close to small leks travel further to reach larger leks, (ii) siring males are not less related to females or more heterozygous than expected, (iii) within a lek, high-display males are more likely to sire young, and (iv) both male heterozygosity and display rate increased with lek size, and as a result display does not reliably reflect male genetic quality across leks. We suggest that female mate choice in this species is probably driven by a Fisherian process rather than adaptive genetic benefits.     

Lek size variation and its consequences in the ochre-bellied flycatcher, Mionectes oleagineus

Several hypotheses suggest that the costs and benefits of displayin aggregations of different sizes play a major role in boththe evolution of leks and in the distribution of males acrossleks of different sizes. We examined the consequences of variationin lek size for both males and females in a study of the ochre-belliedflycatcher, Mionectes oleagineus. We observed 41 solitary displaysites and leks, ranging in size from 1 to 5 mates, over 3 breedingseasons. Although mean visitation rate by females was positivelycorrelated with lek size, female visitation rate per male remainedconstant across lek sizes. The rate at which females visitedthe male who had the highest female visitation rate at eachlek was positively correlated with lek size as predicted bythe hotshot hypothesis. Neither mean nor per capita intrusionrates were correlated with lek size. For the top-ranked male,however, there was a significant correlation between intrusionrates and the size of the lek at which he displayed. Intrusionat leks may be costly, as 28% of female visits were interruptedby intruders. Solitary mates suffered no such interference.Females show no preferences for larger leks, visiting and matingat solitary sites as well as at leks. However, females preferentiallyvisit males with high singing rates, and this male trait maydetermine visitation patterns. Our data argue that preferencesfor larger leks are not important in the evolution of lekkingin this species, nor do they affect lek size. Instead, the dataare in accordance with the predictions of both the hotshot andhot-spot models. These processes may be operating simultaneouslyin this species     

Modelling environmental and survey influences on lek attendance using long‐term lek survey data

Targeted lek surveys, in which historically active lekking areas are surveyed over multiple years, are commonly used to monitor lek‐mating birds. Lek surveys are usually used in habitats and species in which individuals are not easily detected when they are not lekking. Unfortunately, lek surveys suffer from a number of shortcomings, most notably the failure to observe lekking individuals when they are near but not actively attending a lek. Like other sources of imperfect detection, inconsistency in lek attendance may bias estimates of annual population sizes or the proportion of lekking arenas active in a given year. In turn, this may result in unreliable estimates of trends, distributions or other parameters of interest. An improved understanding of the factors affecting lek attendance is crucial to improving the efficacy of many lek monitoring programmes and the utility of lek surveys in estimating population and distributional dynamics. We assess variation in lek attendance in the Lesser Prairie Chicken Tympanuchus pallidicinctus using a subset of data from a long‐term monitoring programme in eastern New Mexico, USA. Focusing on lek‐years in which at least one male was observed, we used generalized linear models to assess the influence of lek size and survey and environmental characteristics on the probability that at least one male was observed in attendance. Our best‐supported model provided evidence for influences of each of these sources of variation. Models suggested that surveyors may improve the likelihood of detecting lek attendance by making small changes to survey duration, targeted survey dates and by considering environmental factors such as weather, habitat and human disturbance. In addition to improving detection, consideration of lek attendance patterns and associated behaviours may improve estimation for more effective conservation in a variety of lekking bird species.     

Sharp-tailed grouse lek attendance and fidelity in upper Michigan

To assess and improve existing monitoring protocols for sharp-tailed grouse (Tympanuchus phasianellus) in the eastern Upper Peninsula of Michigan, we used data from 58 radio-collared grouse (46 M, 12 F) monitored within 3 openland landscape types: a xeric, conifer-dominated site, a wetland-dominated site, and a site dominated by low-intensity agriculture. We used lek counts and radio telemetry to determine lek attendance rates, factors affecting lek attendance rates, lek fidelity, and inter-sexual variation in these parameters. Our analysis indicated lek attendance varied with respect to sex of bird, day of year, time after sunrise, and wind speed. Peak male lek attendance rates exceeded those of females by up to 40%, and peak lekking activity for both males and females occurred during the second and third weeks of April. Male lekking activity occurred earlier and was sustained longer than that of females. Lekking activity was negatively related to time of day and wind speed. We observed strong lek fidelity as radio-collared birds attended a primary lek 94% of the time, indicating a low probability of multiple counting of individual birds. We also proposed a method to adjust lek count data for the probability that birds are on a lek during lek counts. Our proposed method can be used by researchers and managers to improve estimates of the number of birds attending a lek by reducing the negative bias associated with observed counts. © 2011 The Wildlife Society.     

Manipulating lek size and composition using decoys: an experimental investigation of lek evolution models

Four theoretical models have been proposed to account for the origin and maintenance of leks: hotspot, female preference, hotshot, and black hole models. Each has been validated in particular cases, and most are not mutually exclusive; therefore, it has been difficult to contrast and separate them, empirically and experimentally. By using decoys to mimic natural leks in the little bustard, artificial leks attracted wild birds. Then, by manipulating artificial lek size and structure (sex ratio, male phenotype), the study of responses of wild males and females allowed us to test specific predictions derived from the four classical models of lek evolution. The hotspot model was not supported because female decoys did not attract wild males. Conversely, hotshot males do exist in this species (attracting both wild females and males), as does a female preference for a particular lek size (four males). Finally, males aggressive toward decoys attracted fewer females, consistent with one of the mechanisms by which the black hole model may work. Therefore, three models of lek evolution were partly or fully supported by our experimental results: hotshot, female preference, and black hole models. We suggest that these models actually fit within each other, ensuring the evolution, functioning, and long-term maintenance of leks.     

To lek or not to lek: mating strategies of male fallow deer

We studied the mating system of fallow deer (Dama dama) for6 years in central Italy. Males in this population could defendterritories that were either single, clumped in leks, or satelliteto leks. The most highly successful males in our study werein leks. When we considered all males, there were no significantdifferences in average copulatory success according to territorytype because many lek males did not achieve any copulations,which were seen in only a few lek territories. The variancein copulatory success, however, was much greater for leks thanelsewhere. Single territories were occupied for shorter timesduring the rut than lek territories. Fighting among males wasmore frequent in the lek, even when we excluded highly successfullek males from the analysis. Chases of nonterritorial malesand harem size were correlated with the number of copulationsachieved by individual males, but did not vary according toterritory type. Copulatory success of some individuals increasedwith age, but there were no age differences among males holdingdifferent types of territories. Satellite males switched tolek territoriality in the course of one rut, but switches fromsingle territory to lek territory were rare. We suggest thatmales in single territories are inferior competitors that selecta low-risk, lowbenefit strategy, whereas those in lek territorieswhere no copulations were seen may be attempting to establishthemselves on the lek to increase their copulatory success infuture years.     

Red deer females collect on male clumps at mating areas

Mating strategies in mammalian herbivores are adapted to thedispersion of females, and female dispersion is mainly determinedby resource dispersion, although it is frequently unclear whetherfemales may also be influenced by the location of males. Inthe red deer (Cervus elaphus) the distribution of females beforethe rut predicts the places were males should establish territoriesand even their relative success. However, the number of femalesusing the mating areas in Doñana increases during therut. We observed 20 areas of meadows, used by grazing femalesbefore the rut. At the onset of the rut, the number of females increasedin some of these areas and decreased in others, and the opposite patternwas found after the rutting period. Changes in the vegetationat mating and nonmating areas could not account for the changesin female distribution; even some of the highest quality meadowswere vacated by females during rut. In selecting the matingareas, females avoided isolated small meadows within the scrubarea and preferred larger meadows where a number of neighboringrutting males could be found. Females also avoided those areas heavilyused by fallow deer (Dama dama), a competing sympatric species.We found that females suffered less sexual harassment when inlarger harems and when their harem was surrounded by other harems.Our results, together with those in the literature about thispopulation, indicate that red deer females collect during theearly rut in mating areas containing several rutting males,although once there they may select particular sites based on availabilityof food rather than based on the presence of a particular male. Byjoining harems in large meadows they are less harassed, andat the same time they probably increase their chances of matingwith highly competitive males. The results from Doñanasupport the idea that harassment avoidance may lead to femalemovements to areas with male territories without lek breedingor female comparison of male phenotypes and may bring an insightinto those factors leading to clumps of male territories andleks.     

Are males with more attractive resources more selective in their mate preferences? A test in a polygynous species

In many polygynous species, males typically direct more intensecourtship toward more fecund females. Here we examined thisbehavior in relation to the attractiveness of a male's resource.We used the territorial polygynous beaugregory damselfish (Stegastesleucostictus) and manipulated the quality of male breeding territorieswith two types of artificial sites. We also investigated variablenatural breeding territories. Previous studies have shown thatthese different breeding sites were of different qualities,as judged by the number of eggs accrued by the defending male.Males on all three types of breeding sites did court females,and males using the highest quality sites exhibited significantlyhigher courtship intensity. However, only the group of maleson the highest quality site-type modulated their courtship intensityto female quality (i.e., female size). This indicates that males requiredsome minimal level of resource attractiveness (i.e., a threshold) beforethey exhibited mate preferences based on female quality. Further differencesin the resource attractiveness for males defending the high-qualityartificial sites were not related to differences in courtship behavior.     

The Red Queen Visits Sage Grouse Leks

Coevolution between parasites and host is a sufficient althoughnot necessary condition for the evolution of secondary sexualcharacteristics. I review evidence supporting the role of parasitesin the maintenance of lek behavior in Sage Grouse (Centrocercusurophasianus). Males bearing avianmalaria (Plasmodium pediocetii)or lice (Lagopoecus gibsoni or Goniodes centrocerci) have significantlylower reproductive success than noninfected males. Malaria-infectedmales attend leks significantly less frequently and lek attendanceis highly correlated with male reproductive success. Inaddition,males with malaria secured copulations later in the breedingseason with hens that wereyounger, in poorer condition, andless successful than mates of malaria-free males. Lice createhematomas on the air sacs of males which females can detectto avoid lousy males. Results of our field studies are reinforcedby experiments; captive males given antibiotics to reduce parasiteloads are chosen more often by females in arena trials. Ourresults lend empirical support for Hamilton and Zuk's (1982)interpretation of the RedQueen's hypothesis, although many unknownsremain in our understanding of the interaction between parasitesand Sage Grouse.     

Male signalling and lek attractiveness in the Mediterranean fruit fly

I tested the null hypothesis that females of the Mediterranean fruit fly, Ceratitis capitata, were equally likely to visit leks composed of males with high versus low mating success. In laboratory trials, the observed distribution of matings among males differed significantly from that expected by chance, owing primarily to the higher than expected numbers of individuals with low (mated 0-1 days over 6 consecutive observation days) or high (mated 4 or more days) mating scores. I termed these two groups as 'low' and 'high' maters, respectively. In the field, greater numbers of female sightings were made at artificial leks of high maters than low maters. This result apparently reflected a greater calling propensity among high maters. Slopes of female sightings versus calling level did not differ significantly between leks of low and high maters, suggesting that the observed relationship between calling activity and female sightings was independent of male mating status. Following the same protocol, I conducted a second experiment to examine whether males used the signals of conspecific males to locate lek sites and, if so, whether signal attractiveness varied with male mating ability. Attraction of males to calling conspecifics was far weaker than that observed for females, and over five different trials a total of only seven male sightings were made at any of the established leks. Copyright 2000 The Association for the Study of Animal Behaviour.     

Uganda kob prefer high-visibility leks and territories

In lekking species, where males provide estrous females withlittle more than sperm, it has been widely supposed that theonly possible benefits to females of mate choice are genetic.We studied female choice of leks and territories in a reduncineantelope, the Uganda kob (Kobus kob thomasi), and found thatfemales consistently preferred high-visibility mating sites.Leks were elevated and had shorter grass and fewer thicketsthan the surrounding areas. Changes in the number of male andfemale kob on 10 leks were correlated with changes in surroundinggrass height, and both females and males preferred leks withexperimentally reduced grass height over neighboring controls.Within a lek, territory popularity was the primary determinantof male daily mating success, and females preferred territoriesrelatively far from thickets, but removal of thickets did notaffect female territory preferences. Because lion hunting successon kob increases with grass height and thicket density, femalesmay benefit directly from these preferences by reducing therisk of predation.     

Mate choice or harassment avoidance? A question of female control at the lek

Recent studies on the reproductive behavior of fallow deer,Dama dama, propose that harassment from nonterritorial maleshas a major influence on female movements and mate selection,leading ultimately to the evolution of lek mating in this species.In order to support this statement, one must demonstrate thatfemale movements between lek and isolated territories, and amonglek males, lead to a reduction in levels of harassment. We arguethat current evidence in favor of this view is inconclusive.A quantification of the total harassment costs experienced byfemales in lek and isolated territories has never been made.In addition, female movements within the lek may actually leadto higher levels of disruption and harassment: The rate at whichfemales join male territories increases with harem size (thenumber of females present in the territory), even though haremsare disrupted increasingly with size due to a higher frequencyof intrusions by nonterritorial males. Females also join maleterritories at a higher rate while these males are engaged incopulatory sequences, but copulatory sequences are again associatedwith high levels of disruption and harem instability. In theabove studies it is argued that females are nonselective intheir mating preferences. This assessment is based on the findingthat males that adopt different reproductive strategies do notdiffer in their mating rates. Here mating rate is measured asthe number of copulations received per female-hour. There area number of reasons, however, why females exhibiting matingpreferences might remain longer with preferred males, and sothe above preference measure cannot be used to exclude the possibilitythat females are selective. More research is required to identifythe major factors influencing patterns of mate selection andthe evolution of leks in this species. We suggest a number offield tests that may help to identify these factors.     

Mate retention, harassment, and the evolution of ungulate leks

Current models of lek breeding mostly suggest that males defendclustered mating territories because females show a preferencefor mating on leks. Here we argue that, in lek-breeding ungulates,males may also gain benefits from holding clustered mating territoriesbecause clusters retain does in estrus. We show that in fallowdeer (Dama dama) harems are commonly disrupted by young males.Bucks that hold territories on the lek that lose their haremsquickly regain does as other harems are disrupted, whereas bucksdefending isolated, single territories rarely regain does thesame day. The risk of harassment may also help to explain whydoes in estrus leave the large, unstable herds that they usuallylive in. Does in estrus are frequently chased by young maleswhen outside male mating territories. Benefits of moving tothe lek (versus moving to single territories) include reducedrisks of long chases. Though intrusions by young bucks are thecommonest cause of does leaving male territories in our studypopulation, other factors that cause does to move between neighboringharems (including disturbance by predators and persistent courtshipby males) may generate benefits to males holding clustered matingterritories. Once clustered mating territories have developed,the additional costs of mate choice are likely to be low, andfemale preferences for particular male characteristics may belikely to develop.