Reproductive behavior of females and its relation to the mating success of two male forms inMnais pruinosa (Zygoptera: Calopterygidae)

The behavior of females of the damselflyMnais pruinosa was observed in the breeding season. Males consisted of both territorial (esakii) and non-territorial (strigata) types in the study area. Females sometimes arrived at a stream for mating and oviposition. The staying time of females in the stream was 1–3 hours, while that of males was 5–8 hours. The proportion of the males that copulated with the females did not differ between the two male forms present in the stream. In the Calopterygidae, of which the females usually perform multiple copulation, oviposition without subsequent recopulation is considered to be advantageous for a mated male in order to avoid the risk of sperm displacement. From such a viewpoint, the time spent for oviposition was measured for females that arrived at the stream after copulation with different male forms. The ratio was 69.1: 11.5–30.9 betweenesakii andstrigata males. Assuming that the oviposition time is proportional to the number of fertilized eggs laid, this ratio would represent the relative reproductive success of the two male forms. In fact, the relative abundance of the two male forms was also biased in favor ofesakii males (61.7:38.3) in this population. The mechanism of coexistence of the two male forms is discussed in relation to their reproductive success.     

Correlates of reproductive success within alternative mating tactics of the common shrew

Male common shrews (Sorex araneus) adopt two discrete matingtactics. The most successful males, in terms of number of offspringfathered, are those that establish large overlapping home rangesin areas of high female density early in the breeding season.An alternative, less successful mating tactic is to travel longdistances in search of mating opportunities. This study is aninvestigation of correlates of reproductive success for malesadopting these different mating tactics. Reproductive successunder natural conditions was assessed using DNA fingerprinting,and survival of offspring was monitored in the field. The numberof offspring fathered by males with overlapping home rangeswas positively correlated with the number of female ranges overlappedduring the breeding season and with testes mass. The numberof offspring fathered by males that made long-distance movementswas positively correlated with their epididymal sperm counts.It is argued that competitively superior (overlapping) malesachieve high reproductive success by competing to maximize thenumber of females inseminated, whereas those adopting an alternativemating tactic instead compete largely via sperm competition,aiming to maximize insemination success with any particularfemale. There was no significant difference in the fluctuatingasymmetry (FA) of males adopting different mating tactics (FAwas measured as the difference in length of the paired lateralscent glands). Fluctuating asymmetry was not related to thenumber of offspring fathered by males adopting either matingtactic, but was significantly correlated with the proportionof male offspring fathered that survived to sexual maturity.Although apparently not correlated with mating success in thisspecies, FA may reflect some aspect of genetic quality thataffects offspring survival. [Behav Ecol 7: 334–340 (1996)]     

Effects of site fidelity and breeding performance on mate retention in a short‐lived passerine,the tree swallow Thachycineta bicolor

We studied the relationship among re‐mating, site fidelity and breeding performance in the tree swallow Tachycineta bicolor using 16 y of data on reproductive biology in a population breeding in nest boxes near Ithaca, New York. Of 217 pairs for which both members survived the non‐breeding season, 76% mated with a new partner and 24% reunited with their previous mate. Pairs did not increase their breeding success by breeding together for more than one breeding season. Males produced fewer fledglings after breeding with a new partner, but females neither increased nor decreased their success when breeding with a new mate. Females who bred with a new partner were younger than females that reunited with their previous mates, and they were more likely to move to a different nest box. Males that bred with a new mate were of similar age to males that reunited, and they did not move more often. The probability of breeding with a new partner was better predicted by female age than by previous breeding success, suggesting that re‐mating was not strongly affected by past breeding performance. Because younger females change breeding sites more frequently than do older females and females that mated with a new partner were younger than females that reunited with their previous mates, we suggest that the tendency of tree swallows to change partners between years is a by‐product of lower site fidelity of younger females rather than a strategy for increasing breeding success.     

A life-history perspective on strategic mating effort in male scorpionflies

In species with high male mating effort, there is a trade-offbetween mating effort spent in a current mating and resourcesleft for future matings. Consequently, to maximize their reproductivesuccess, males have to invest strategically, saving resourcesin matings with low reproductive gain for future, more valuablematings. However, as males age, the expected future reproductivesuccess constantly declines. Thus, the importance of resource rationing may drastically change during a lifetime. Males ofthe scorpionfly Panorpa cognata offer females a costly nuptialgift before copulation, which functions as male mating effort.Resources for the production of these salivary masses are severelylimited for males in poor condition. We found that males investedmore in copulations with high-quality females than in copulationswith low-quality females. However, males ceased to discriminateas they became older. Old males, with a relative small numberof expected future matings, did not invest differentially incopulations with high- versus low-quality females. In copulationswith low-quality females, males invested more in late thanin initial matings, whereas in matings with high-quality females,time of mating had no influence on mating effort. These resultsimply that males adaptively change their resource allocationstrategy during the course of the season. Initial matings seemto be characterized by male prudence; in later matings, malesseem to adopt a more opportunistic mating strategy.     

Mating system, sexual dimorphism, and the opportunity for sexual selection in a territorial ungulate

In mammals, species with high sexual size dimorphism tend tohave highly polygynous mating systems associated with high variancein male lifetime reproductive success (LRS), leading to a highopportunity for sexual selection. However, little informationis available for species with weak sexual size dimorphism. Ina long-term study population, we used parentage analysis basedon 21 microsatellite markers to describe, for the first time,variance in male lifetime breeding success (LBS) of roe deer,a territorial ungulate where males weigh less than 10% morethan females. LBS ranged from 0 to 14 (mean = 4.54, variance= 15.5), and its distribution was highly skewed, with only afew males obtaining high LBS and many males failing to breedor siring only one fawn. As predicted for polygynous specieswith low sexual size dimorphism, the standardized variance inmale LBS was low (I_m = 0.75) and was only slightly higher thanthe standardized variance in female LRS (I_f = 0.53), suggestinga low opportunity for sexual selection. The I_m value reportedhere for roe deer is much lower than values reported for highlydimorphic ungulates such as red deer (I_m > 3). We suggestthat, along a continuum of opportunity for sexual selection,roe deer occupy a position closer to monogamous and monomorphicterritorial ungulates than to highly polygynous, sexually dimorphicungulates with dominance rank–based mating systems suchas harems or roving mating systems.     

Mating behaviour and mating success in woodfrogs Rana sylvatica

Mating behaviour of woodfrogs was investigated in a woodland pond in southeastern Michigan. Males became sexually mature one year before females and outnumbered females by 5.6 to 1 at the breeding site. Males employed searching behaviour to obtain mates. Yearly male mating success varied from 0 to 2 matings, and larger males had a greater probability of mating than smaller males. The mating season lasted less than 10 days. Most egg masses were deposited in 1 m² of a 256-m² pond. Experimental introduction of egg masses to the breeding site indicated that presence of eggs was sufficient to stimulate egg deposition. The influence of selection for synchronous sexual receptivity in females, communal egg deposition, and delayed female sexual maturation on male mating behaviour and variation in male mating success is discussed.     

Male ornamentation, timing of breeding, and cost of polygyny in the collared flycatcher

Highly ornamented males are often thought to be better ableto provide females with resources, parental assistance, or goodgenes. Individual variation in such male abilities may overridethe costs of polygyny and therefore largely explain within-populationvariation in mating patterns. We investigated the influenceof variation in male ornamentation and the environment on thecosts of polygyny for female collared flycatchers (Ficedulaalbicollis), using data from a long-term study involving 2733breeding attempts over 19 years. We show that females sufferreduced reproductive success when mated polygynously but thatthe costs of polygyny depend on an interaction between maleornamentation and timing of breeding. Among early breeders,polygynously mated females experience higher reproductive successwhen mated to less ornamented males, but among late breeders,females mated polygynously to highly ornamented males were moresuccessful. We suggest that a high effort spent on obtainingextrapair matings early in the season renders highly ornamentedmales less able to assist two females in caring for the young.Thus, a male's ability to simultaneously gain from extrapairmatings and polygyny may be limited through direct effects onfemale reproductive success. Given such limitation, extrapairmatings may be expected to be less frequent in species withbiparental care and a high level of social polygyny.     

Male territorial aggression and androgen modulation in high latitude populations of the Sooty, Passerella iliaca sinuosa, and Red Fox Sparrow, Passerella iliaca zaboria

The Fox Sparrows, Passerella iliaca, include multiple groups and subspecies distributed at several latitudes from the Alaskan arctic to the southwestern United States. As such, this species represents a potential model for investigating latitudinal variation in androgen secretion and aggressive territoriality in male passerines. Breeding male Fox Sparrows from two subspecies within two groups, the Sooty Fox Sparrow, P. i. sinuosa, and the Red Fox Sparrow, P. i. zaboria, were assessed for aggressive territoriality and androgen responsiveness at multiple latitudes in arctic and subarctic Alaska. Subarctic Sooty Fox Sparrows had higher circulating androgen levels in the early (8.54 ng/ml) versus mid–late breeding season (2.44 ng/ml). Males in the mid–late breeding season did not up-regulate androgen secretion in response to social challenge, but were aggressive and spent more time within 5 m of a decoy during a simulated territorial intrusion (STI) than early breeding males. Male subarctic Red Fox Sparrows had slightly higher circulating androgen levels (2.29 ng/ml) than arctic males (1.10 ng/ml) in the mid–late breeding season. However, androgen levels were not correlated with blood collection time after a social challenge in either group, suggesting that neither arctic nor subarctic males up-regulate androgen secretion during the mid–late breeding period. Arctic males spent more time within 5 m of a decoy and sang less than subarctic males during an STI in the mid–late breeding season. These findings demonstrate that the Fox Sparrow is a tractable model for investigating the latitudinal regulation of aggressive territoriality and androgen responsiveness in passerines.     

Female choice, male interference, and sperm precedence in the red-spotted newt

Darwin first identified female choice and male—male competitionas forms of sexual selection resulting in the evolution of conspicuoussexual dimorphism, but it has proven challenging to separatetheir effects. Their effects on sexual selection become evenmore complicated when sperm competition occurs because spermprecedence may be either a form of cryptic female choice ora form of male—male competition. We examined the effectsof tail height on male—male competition and female choiceusing the sexually dimorphic red-spotted newt (Notophthalmusviridescens viridescens). Experiment 1 examined whether maletail height influenced male mating success. Males with deeptails were more successful at mating with females than thosewith shallow tails. Successful, deep-tailed males also were bigger(snout-vent length; SVL) than unsuccessful, shallow-tailed males,but they did not vary in tail length or body condition. Of these,only tail height and tail length are sexually dimorphic traits.Experiment 2 tested the hypothesis that the differential successof males with deeper tails was due to female choice by examiningboth simultaneous female preference for association and sequentialfemale choice. We found no evidence of female choice. When maleswere not competing to mate with females, tail height did notinfluence male mating success. Successful males did not havedifferent SVL and tail lengths than unsuccessful males. Thus,tail height in male red-spotted newts appears to be an intrasexuallyselected secondary sexual characteristic. Experiment 3 usedpaternity exclusion analyses based on molecular genetic markersto examine the effect of sperm precedence on sperm competitionin doubly-mated females. Sperm precedence likely does not havea pervasive and consistent effect on fertilization success becausewe found evidence of first, last, and mixed sperm usage.     

Age-related decrease in male reproductive success and song quality in Drosophila montana

In the present paper, we have studied the effects of aging onmale reproductive success and song quality in Drosophila montana.We analyzed the reproductive success of wild-caught males attheir normal breeding age during the mating season and aftermaintaining the males in laboratory from 1 to 5 months. In linewith the mutation accumulation theory of aging, none of thefactors affecting the reproductive success of wild-caught malesduring the mating season were related to male longevity. However,mating activity and progeny production of the males decreasedwith male age. Interestingly, there was no significant variationin progeny production between males at their normal breedingage, whereas at older age, the variation between males becomessignificant. The quality of sexually selected song traits deterioratedwith male age in concert with the decrease in male reproductivesuccess. The size of the males did not have an effect on malereproductive success at the normal breeding age, but at olderage, larger males were able to maintain the sexually selectedcarrier frequency of the song at higher level than the smallermales. We conclude that by experimentally extending the reproductiveage of the males beyond that which they normally experiencein nature, it is possible to expose relationships between reproductivesuccess, sexually selected characters, and body size that arenot apparent when analyzed for the males at their normal breedingage.     

Mating behaviors,courtship rank and mating success of male feral cat (Felis catus)

The mating behavior of the male feral cat (Felis catus) living on a small island was investigated. The cats in the study area (6.0 ha) formed the “feeding groups” at the garbage sites (Yamane et al. 1994; Izawa et al. 1982). We examined the factors influencing fighting ability, rank during courtship, and mating success of the male cat. Males with heavier body weight mostly won over lighter males in the agonistic encounters during the estrous season. Heavier males occupied the more advantageous positions to copulate with the estrous females and had higher mating success. These results suggest that body weight was one of the important factors affecting the courtship rank and the mating success of the male cat. When males visited and courted the females of feeding groups other than their own, they were sometimes defeated by the lighter males in that particular group, which lowered their courtship rank and success in copulations. These results indicate that the location of the courting male (inside or outside of its own group) and the kind of females they courted (member of the same group or not) were also important factors.     

Coping with the cold: temperature and mating activity of male sagebrush crickets Cyphoderris strepitans (Orthoptera: Haglidae)

Abstract. The effect of temperature on male sexual displays is well documented but its role in mediating the differential mating success of males is less well established. Male sagebrush crickets Cyphoderris strepitans Morris and Gwynne occur in high‐elevation sagebrush meadows in mountainous areas of the western U.S.A., and often are observed singing at temperatures as low ?8 to ?4 °C to attract sexually receptive females. Males exhibit differential mating success based on their previous mating experience: virgin males have a higher probability of obtaining a mating than do non‐virgin males of securing an additional mating. This differential mating success is mediated in part by an unusual form of nuptial feeding behaviour. Females feed on males’ hind wings at mating and the costs imposed on males as a consequence of this behaviour constrain male mating success. In the present study, to determine whether sagebrush crickets are capable of some degree of thermoregulation, and also to investigate whether this ability is influenced by male mating experience, thoracic temperatures of males of varying mating status were measured in relation to ambient temperature throughout the breeding season. A full factorial model examining the effect of site of capture, mating status, body mass and ambient temperature reveals that only ambient temperature has a significant effect on thoracic temperature after controlling for all other factors. It is concluded that differences in the calling times of virgin and non‐virgin males and their ability to secure mates does not result from differences in their ability to cope physiologically with low temperatures.     

Lek fidelity and movement among leks by male Greater Sage‐grouse Centrocercus urophasianus: a capture‐mark‐recapture approach

Males in lek mating systems tend to exhibit high fidelity to breeding leks despite substantial evidence of skewed mating success among males. Although movements between leks are often reported to be rare, such movements provide a mechanism for an individual to improve lifetime fitness in response to heterogeneity in reproductive conditions. Additionally, estimates of apparent movements among leks are potentially biased due to unaccounted variation in detection probability across time and space. We monitored breeding male Greater Sage‐grouse Centrocercus urophasianus on 13 leks in eastern Nevada over a 10‐year period, and estimated movement rates among leks using capture‐mark‐recapture methods. We expected that male movement rates among leks would be low, despite predictions of low breeding success for most males, and that detection rates would be highly variable among leks and years. We used a robust design multistate analysis in Program mark to estimate probability of movements among leks, while accounting for imperfect detection of males. Male Sage‐grouse were extremely faithful to their leks; the annual probability of a male moving away from its original lek of capture was approximately 3% (se = 0.01). Detection probabilities varied substantially among leks (range = 0.21–0.95), and among years (range = 0.30–0.76), but remained relatively constant within years at each lek. These results suggest that male Sage‐grouse dispersal is either rare, or consists primarily of dispersal of sub‐adults from their natal areas prior to the breeding season. The study highlights the benefits of robust design multistate models over standard ‘live‐encounter’ analyses, as they not only permit estimation of additional parameters, such as movement rates, but also allow for more precise parameter estimates that are less sensitive to heterogeneity in detection rates. Additionally, as these data were collected using capture‐mark‐recapture methods, our approach to estimating movement rates would be beneficial in systems where radiotagging is detrimental to the study organism.     

Breeding site fidelity in penduline tit Remiz pendulinus in Southern Hungary

Birds move between breeding locations to gain a better territory, avoid competition or reduce the deleterious effect of inbreeding. We investigated breeding site fidelity in a small European passerine, the penduline tit (Remiz pendulinus). This species has an exceptionally diverse breeding system, in which both males and females may have up to 5–7 mates in a single breeding season, and the eggs are incubated by a single parent: either the male or the female. We investigated the movements of males and females within three breeding seasons in Southern Hungary (2002–2004). Males moved for shorter distances between breeding sites (116 m, 63–333 m; median, lower quartile–upper quartile) than females (942 m, 415–2,382 m). Movements of males and females were consistent between years, and they were repeatable between subsequent nests of males, but not of females. Taken together, our results suggest that adult male penduline tits are more site-faithful than adult females. We suggest that this difference has an implication on their breeding ecology since male parental behaviour (desert/care) is expected to be influenced by local mating opportunities, whilst female parental behaviour is likely to depend on the mating opportunities in a large area around their breeding site.     

Male Mating Tactics in Captive Rhesus Macaques (Macaca mulatta): The Influence of Dominance, Markets, and Relationship Quality

Male mating success in a multimale–multifemale group can depend on several variables: body condition, dominance, coalitions, “friendship,” or an exchange of services for mating access. Exchange patterns may also be determined by market effects or social relationships. We studied the mating tactics of males in a captive, multimale–multifemale group of rhesus macaques and the resulting patterns of mating and paternity to determine the influence of dominance rank, mating markets, and relationship quality on their mating tactics. Male rank was positively related to the total number of copulations and the number of mating partners, but did not explain male mating distribution completely. Moreover, male fertilization success was not related to male rank. Males did not exchange grooming for mating access on the same day and neither the supply nor the rank (as a proxy for quality) of receptive females affected the amount of male grooming, suggesting that market effects did not explain male mating access. However, there was a positive correlation between long-term grooming patterns of both males and females and mating access, indicating that social relationships were important for male mating access. Paternity data revealed that these social relationships were also important for male reproductive success. We conclude that both male rank and male–female “friendship” determined male mating access in these rhesus macaques, but that “friendship” was more important in determining paternity, emphasizing the importance of intersex social bonds in male mating success in multimale primate societies.     

Male perch selection and the mating system of the robber fly,Promachus albifacies (Diptera: Asilidae)

We studied the activity and spatial distribution of the robber fly,Promachus albifacies, in a desert grassland habitat in central New Mexico. Late in the season males spent most of the daytime on or near cholla and yucca plants that had dead stems or dead flower stalks at least 1 m high. Of the three hypotheses (thermoregulation, foraging, mate encounter site) considered as explanations for this distribution, the mate-encounter-site hypothesis was best supported. Plants used by females as oviposition sites were the focus of male activity. Males perched within or near these plants and attempted copulations with females detected nearby. Most matings were initiated at these locations. Seasonal changes in male and female activity also supported the mate-encounter-site hypothesis. Early in the season, females spent little time ovipositing, and predictably, males spent little time on or near these plants. Such a mating system may be described as resource defense polygyny, since males acted aggressively toward one another at oviposition sites even when females were not present. However, the short tenure of males at these sites is suggestive of scramble competition polygyny. We discuss possible reasons why this particular mating system has evolved.     

Effects of size and sex on the courting success and foraging behaviour of Embiotoca jacksoni

To test life-history theory that body size and sex should influence how animals allocate time to foraging versus reproductive activities, we measured the effects of size and sex on courting success and foraging behaviour of black surfperch Embiotoca jacksoni off Santa Catalina Island, southern California. Observations of focal fish were made while snorkelling, during which the length of each fish (estimated to the nearest cm), total duration of courting encounters and foraging rates were recorded. We made observations during and outside the mating season. Courtship occurred only between pairs and its duration increased with the size of both the male and female. Although males would court females that were smaller or larger than themselves, pairs that were closely matched in size had long courting sessions, whereas those that differed considerably in size courted only briefly. Small fish foraged more than larger fish, both during and outside the mating season. Males and females foraged at similar rates outside of the mating season, but during the mating season males reduced their foraging rates to less than half that seen outside of the mating season, whereas females continued to forage at the same rate. This decrease in foraging rate of males during the mating season was seen in all sizes of males but was proportionally greatest in the largest males. These observations indicate that males trade off time spent on foraging for time spent courting during the mating season, whereas females do not.     

Sexual selection in sticklebacks in the field: correlates of reproductive, mating, and paternal success

Male sticklebacks display multiple ornaments, and these ornamentshave been shown to be preferred by females in laboratory experiments.However, few field data exist, and it is not known whether thesepreferences are simultaneously or sequentially operative ina single population. We report correlates of reproductive successin two stickleback populations that differ in their ecology,over several periods within their breeding season. In both populationslarger males had higher reproductive success, but not in all periodsof the breeding season. Reproductive success increased withredness of the throat only in the Wohlensee population, andonly in one period that was characterized by low average success.In the Wohlensee population, the parasitic worm Pomphorhynchuslaevis is abundant, and reproductive success decreased withthe presence of the parasite. In the Roche population, maleswith nests concealed in a plant had higher mating success. Thesenests were less likely to fail, suggesting that females preferredto spawn in concealed nests because of higher offspring survivorship.The different sexual traits appear to reveal different aspectsof male quality (multiple message hypothesis): females probablyfind large males attractive because of their higher paternalquality, but it seems more likely that red males are preferred forbetter genetic qualities. Females also discriminate on territoryquality, and male traits may be important in competition forthese territories. The correlates of reproductive success werenot consistent during the season, probably due to changes inthe availability of ripe females. Such fluctuating selectionpressures will contribute to the maintenance of genetic variationin sexual traits.     

Non-random mating by size in American toads, Bufo americanus

Male American toads, Bufo americanus, captured in amplexus at least once during the season were significantly longer than males captured only singly in the same breeding population in all three cases studied. Absence of any correlation between the body lengths of the members of amplexing pairs argues against selection for optimal relative size. Males successful at breeding were those that (1) were larger, (2) were at the pond more nights, and (3) spent more time calling than unsuccessful males. Residency, per se, did not enhance breeding success, however, as on any given day successful males were equally likely to come from recaptured males previously present at the pond and unmarked males presumed new to the pond. Amount of movement about the pond did not vary with breeding success; all males tended to remain in one area on any given night and to change areas between nights. A very low displacement rate (about 7%) of males in amplexus argues against primacy of this form of male-male competition in producing differential mating by size. Rather it appears that some combination of other forms of intrasexual competition and female choice caused the mating pattern seen.     

The dynamics of male harem dominance in southern elephant seals (Mirounga leonina) at the South Shetland Islands

Breeding chronology, harem structure and changes in male harem dominance were studied at Stranger Point, Isla 25 de Mayo/King George Island, principally by extensive field census work during the 2003 breeding season. Males were individually identified and their size estimated by using a photogrammetric method. Peak female haul out for the population occurred on 31 October, when a total of 276 females were observed along 7 km of coastline, distributed in ten harems with a median size of 16 females. Overall sex ratio and harem sex ratio for the breeding population were 1:6.7 and 1:10.6, respectively. A total of 33 males were identified associated with harems. Male size conferred an advantage in terms of dominance hierarchy, since dominant males (4.91±0.15 m) were significantly longer than subordinate males (4.63±0.19 m). Harems were dominated by an average of 4.5 (range 2–7) different males during the breeding season. Elephant seals at Stranger Point breed in very low density aggregations. The main breeding events in this population occurred later than at other breeding sites, which agrees with previous observations in the area. Male movement among harems suggests that differences in mating success among males could be achieved through their different behaviours.