Female eviction, abortion, and infanticide in banded mongooses (Mungos mungo): implications for social control of reproduction and synchronized parturition

Most cooperatively breeding species exhibit high reproductiveskew, where reproduction within the social group is monopolizedby a dominant pair. In many of these species, social controlof reproduction is the mechanism driving reproductive skew:individuals within the social group actively reduce the reproductivesuccess of others. In species where females do not suppressconception in other females, alternative routes to skewing thesocial group's reproductive output include inducing abortionin rivals, evicting them, or killing their young. This studyexamines instances of female eviction, abortion, and infanticidein a cooperatively breeding species with low preparturitionreproductive skew, the banded mongoose (Mungos mungo). Althoughinstances of these behaviors are rare in this species, aspectsof their occurrence have implications for social control ofreproduction. Abortion can be induced by the stress of beingevicted. The readmittance of females that abort suggests thatreducing communal litter size is a possible selective pressurefor eviction. This is supported by the occurrence of evictionevents in groups with relatively high numbers of reproductivefemales and by the eviction of young reproductive females. Thetiming of abortion events suggests that synchronization of parturitionwith other females in the group is a major selective pressure.Infanticide could represent the selective pressure for synchronizedparturition. Alternatively, synchronization may minimize competitiveasymmetry between pups born to different females. This paperalso describes incidences where a female aborts or gives birthto her litter over different days in order to synchronize parturition:behavior previously unrecorded in mammals.     

Male-caused failure of female reproduction and its adaptive value in alpine marmots (Marmota marmota)

We studied reproductive performance of free-living alpine marmots (Marmotamarmota) for 14 years in the National Park of Berchtesgaden, Germany.Female reproduction was influenced by body condition and social factors.Reproduction depleted fat reserves, and only females emergingfrom hibernation with sufficient body mass were able to reproducesuccessfully. Marmots lived in social groups in territoriesdefended by a dominant male and female. Subordinate femalesnever reproduced, regardless of body mass. Territory takeoversby males impaired reproduction of dominant females, but onlyif the takeover occurred after the mating period. Reproductivefailures occurred despite clear signs of pregnancy such enlargednipples or late molt. Decreasing progesterone levels after themating period and the lack of evidence for direct infanticideby new territorial males suggest a block of pregnancy as a likelyexplanation for reproductive failures in groups with male takeoversduring gestation. Rendering female reproduction impossible increasedfuture reproductive success of new territory owners. Nonparous femalessaved the energetic cost of maternal investment and thus emergedwith higher body mass in the following spring. In line withthis, females failing to wean young had higher reproductivesuccess in the subsequent year.     

A novel postcopulatory block of reproduction in white-footed mice

Female white-footed mice (Peromyscus leucopus) fail to produce offspring when paired with a male from weaning until 150 days of age if an adult female or her odor is also present. The present study delineates more clearly which stage of the young female's reproductive cycle is inhibited by the chemosignal of the older female. Age at vaginal opening and first estrus are delayed by the presence of the older female, but only for about 10 days. The presence of a male counteracts this delay. Thus, the basis for the block is not a delay in puberty. The older female's presence does not influence the number of estrous cycles experienced during the 30 days following first estrus, nor does it influence the number of corpora lutea found at autopsy. The presence of sperm in the vaginae of young females indicates that they were copulating. Likewise, examination of embryos 2 and 3 days after copulation reveals normal developmental progress. However, implantation does not occur in young females that have been exposed to an adult female. Thus, the block occurs either during the final stages of embryo transport or in relation to the implantation process itself.     

Early arrival, initiation of nesting, and social status: an experimental study of breeding female red-winged blackbirds

Red-winged blackbirds (Agelaius phoeniceus) arrive at breedingsites several months before nests are constructed. Males inthis highly polygynous species presumably return early to defenddesirable territories. Females, however, also begin to arrivealmost two months before nesting is attempted. Early returnto breeding sites could enhance reproductive success by increasinga female's social status and thereby allowing earlier nesting.I measured the effect of experimentally delayed arrival on thetiming of nesting, reproductive success, and social status offemales. Birds were captured as they arrived in early springand detained in an aviary. These experimental females were laterreleased at their capture sites before control females beganconstruction of nests; controls had arrived during the sameperiod as experimentals but were not detained. Experimentalfemales nested, on average, more than a week later than controls,although I could detect no effect of timing on reproductivesuccess during this study. By manipulating arrival date, butnot covariates of arrival time such as age or experience, thisresult indicates that timing of arrival directly influencedlaying date. Delayed females were subordinate to control femaleswith the same mate. This decline in social status may have beenresponsible for the delay in nesting and could have fitnessconsequences for females in some years, because the offspringof earlier nesting, dominant birds are more likely to receivemale parental care in this population.     

Pheromone-induced reproductive inhibition in young female Peromyscus leucopus

Soiled bedding and urine from adult female white-footed mice (Peromyscus leucopus) were tested for their capacity to inhibit reproduction of young females. Test animals were given either physical or airborne contact with soiled bedding from adult females, adult female urine, clean bedding, or water from 21 to 150 days of age. Results indicate that reproductive inhibition is due to an airborne pheromone emitted by the adult females as a component of their urine. In the second experiment, young female mice were exposed to an adult female for 0, 1, 3, 6, 12, 18, or 24 h/day from 21 to 150 days of age. Results from this experiment show that exposure to adult females of as little as 3 h/day was sufficient to cause reproductive inhibition to occur. This phenomenon has important implications in terms of both female-female reproductive competition and socially mediated population regulation.     

Social environment and reproductive interference affect reproductive success in the frog Rana latastei

Variation in the social environment produces selection on morphologicaland behavioral traits. It is less clear how the social environmentgenerates variation in demography through behavioral mechanisms.Theory suggests that one aspect of social environment, relativeabundance of heterospecifics, influences the intensity of reproductiveinterference and its demographic effects. These effects arecountered by species recognition and female preferences. Westudied the effects of social environment on reproductive successin replicated, mixed breeding populations of two ranid frogs,Rana latastei and Rana dalmatina, the former being of internationalconservation concern. We manipulated the social environmentof female R. latastei experimentally by varying the relativeabundance of potential conspecific and heterospecific sexualpartners. We measured amplexus frequency and recorded the reproductivesuccess of R. latastei females. When conspecific males wererelatively uncommon, (1) the absolute and relative frequenciesof conspecific amplexus decreased, indicating a breakdown ofsexual isolation, (2) oviposition was less frequent, and (3)the percentage of viable embryos in deposited clutches decreased.R. latastei females in an environment of low relative conspecificabundance (1:5, R. Latastei:R. dalmatina) demonstrated 6.8%the reproductive success of females in an environment exclusivelywith conspecifics. We present a model for the dependence ofconspecific amplexus on the social environment. We discuss severalmechanisms that may influence reproduction by R. latastei, andwe support conservation of the species' preferred habitat toreduce opportunities for reproductive interference that occurat shared breeding sites.     

Effects of Aging and Mate Retention on Reproductive Success of Captive Female Peregrine Falcons

SYNOPSIS. Separating ecological (extrinsic) factors affectingreproduction from physiological and experiential (intrinsic)factors can be problematic in free-ranging animals. This studyexamined age-related changes in six measures of reproductivesuccess (clutch size, fertility, hatchability, brood size athatching, survivorship of nestlings, and brood size at fledging)for captive female peregrine falcons (Falco peregrinus) whereecological factors (i.e., access to mates, nesting sites, andfood) were not limiting and were similar across years and betweenindividuals. Mean nestling survivorship increased throughoutthe lifespan of the female while all other measures of reproductionpeaked at about seven years of age and decreased thereafter.Birds with prior breeding experience had higher productivitythan inexperienced birds of the same age. Productivity increasedwith increasing experience of the pair. Productivity droppedby an average of 53% when females experienced a change of mate,and then subsequently increased over a period of several years.Productivity was not affected when birds were moved to differentbreeding sites. There was no evidence that early improvementsin reproduction were related to chronological aging in the absenceof experiential differences. Birds that began breeding earlierproduced more fledglings during their lifetimes as a resultof higher annual productivity. Lifetime reproduction was notcorrelated with longevity because birds with higher maximalegg production had shorter breeding lifespans. Birds retainingmates produced more fledglings during their lifetime than birdsthat changed mates, but birds that changed mates more than oncedid not have lower lifetime reproduction than birds that hadonly one mate change. These results suggest that 1) age-relatedchanges in reproduction are not necessarily resource-mediated,2) in the absence of resource limitation, experience of thepair is a primary factor determining annual reproductive success,3) benefits of increasing experience may be offset by the onsetof senescence, 4) the cost of present egg production on futurereproductive potential supports a "pleiotropic" theory of aging,and 5) costs associated with mate changes may encourage selectionfor low "divorce" rates (i.e., lifetime monogamy) in this species.     

Reproductive success of solitarily and communally nesting white-footed mice and deer mice

To determine the fitness consequences of communal nesting inwhite-footed mice, Peromyscus leucopus, and deer mice, P. maniculalus,I compared the reproductive success of field populations offemales nesting solitarily, in communal groups of more thanone female, in extended families of successive litters, andin communal groups with extended families. Mean first littersize of weanlings and juveniles 6 weeks old did not differ significantlyfor pups raised under the four nesting situations. Similarly,for pups born into extended families, litter sizes of pups fromsecond litters did not differ significantly from those of firstlitters or from pups born to solitarily nesting females. Delayeddispersal of juvenile females did not result in resource competitionor inhibition of reproduction. Thus, reproductive success offemales was not significantly affected by additional membersin the nest. At least 26 of 28 communally nesting females wereclose relatives. Solitary nesting is the common breeding patternin Peromyscus, and extended families and communal nesting arealternative reproductive tactics in response to limited space,delayed dispersal, and local grouping among related females.     

Sexual selection for large male size in a polyandrous butterfly: the effect of body size on male versus female reproductive success in Pieris napi

Sexual selection theory predicts that the larger sex shouldbe that for which fitness increases at the faster rate withsize. In butterflies, as in most invertebrates, females areusually the larger sex, but previous comparative analysis hasshown that relative male size increases with female polyandryamong butterflies. In agreement with this pattern, males arelarger than females in the strongly polyandrous green-veinedwhite butterfly, Pieris napi L., and in this article we assessthe size dependence of reproductive success in both sexes. Inan experiment where virgin males and females were released inthe field, we found no strong association between size and malemating success. However, laboratory experiments showed thatthere was a strong correlation between size and the ejaculatethat the male delivered to the female at mating and that largeejaculates delayed female remating for a longer time comparedto small ejaculates. Moreover, female P. napi utilize male-derivednutrients received at mating to increase their fecundity. Hence,large males sire more offspring both by way of donating morenutrients to female egg production and by way of delaying femaleremating (given that the last male to mate with the female willfather most of the offspring). Laboratory experiments showedthat the association between size and fecundity was low, ornonexistent, among P. napi females allowed to mate only once.However, weak size dependence was found for polyandrous females.We hypothesize that size dependence of female fecundity maybe especially weak among polyandrous butterflies because a fundamentalsource of variation in fecundity relates to their ability tofind nutrient giving males, an ability which may be unrelatedto female size. According to this hypothesis there is a causalassociation between weak size dependence of female fecundityand polyandry, and a strong size dependence of male reproductivesuccess that may underlie the comparative pattern of positivecorrelation between relative male size and polyandry.     

Mate feeding, offspring investment, and sexual differences in katydids (Orthoptera: Tettigoniidae)

Food stress in the katydid Requena veriicalis (Orthoptera: Tettigoniidae)decreases the relative availability of males able to supplynutritious spermatophores to females and increases the valueof the male courtship meal (i.e., relative male parental investment).These changes cause female sexual competition in katydid populations.Here we examine the effect of food stress on male and femaleinvestment in single offspring and test the prediction thatmale-derived nutrients in eggs increase relative to nutrientsfrom the female's reserves. We varied the diet of female R.veriicalis and determined the fate of nutrients from male andfemale sources using I4C and 3H radiolabeled amino acids. Low-dietfemales retained more nutrients from male and female sourcesin somatic tissues and invested less in reproduction both becausethey produced fewer eggs and because they invested less peroffspring (egg) than females maintained on a high-quality diet.Moreover, opposite to our prediction, relative male investmentin individual eggs decreased in foodstressed females; femalesretained more nutrients in somatic tissues from the male sourcethan the female source. Food-stressed females may retain nutrientreserves, particularly those from the male, as an adaptive trategyfor immediate survival needs and future reproduction. Such afemale strategy is unlikely to compromise male reproductivesuccess; first-male sperm precedence means that males matingwith virgin females are likely to father most eggs laid, evenin future reproductive bouts. The decrease in male investmentin eggs of low-diet females does not conflict with the contentionthat relative parental investment controls male intrasexualcompetition because, in mate-feeding species, male investmentinfluencing this competition includes more than investment incurrent offspring; females should compete for males if courtshipgifts aid survival and later reproduction.     

Multiple mating in the traumatically inseminating Warehouse pirate bug, Xylocoris flavipes: effects on fecundity and longevity

Optimal mating frequencies differ between sexes as a consequence of the sexual differentiation of reproductive costs per mating, where mating is normally more costly to females than males. In mating systems where sexual reproduction is costly to females, sexual conflict may cause both direct (i.e. by reducing female fecundity or causing mortality) and indirect (i.e. increased risk of mortality, reduced offspring viability) reductions in lifetime reproductive success of females, which have individual and population consequences. We investigated the direct and indirect costs of multiple mating in a traumatically inseminating (TI) predatory Warehouse pirate bug, Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae), where the male penetrates the female's abdomen during copulation. This study aimed to quantify the effects of TI on female fecundity, egg viability, the lifetime fecundity schedule, longevity and prey consumption in this cosmopolitan biocontrol agent. We found no difference in the total reproductive output between mating treatments in terms of total eggs laid or offspring viability, but there were significant differences found in daily fecundity schedules and adult longevity. In terms of lifetime reproduction, female Warehouse pirate bugs appear to be adapted to compensate for the costs of TI mating to their longevity.     

Sexual selection and mating patterns in a mammal with female-biased sexual size dimorphism

In mammals, species with highly male-biased sexual size dimorphismtend to have high variance in male reproductive success. However,little information is available on patterns of sexual selection,variation in male and female reproductive success, and bodysize and mating success in species with female-biased size dimorphism.We used parentage data from microsatellite DNA loci to examinethese issues in the yellow-pine chipmunk (Tamias amoenus), asmall ground squirrel with female-biased sexual size dimorphism.Chipmunks were monitored over 3 years in the Kananaskis Valley,Alberta, Canada. We found evidence of high levels of multiplepaternity within litters. Variation in male and female reproductivesuccess was equal, and the opportunity for sexual selectionwas only marginally higher in males than females. Male and femalereproductive success both depended on mating success. We foundno evidence that the number of genetic mates a male had dependedon body size. Our results are consistent with a promiscuousmating system in which males and female mate with multiple partners.Low variation in male reproductive success may be a generalfeature of mammalian species in which females are larger thanmales.     

Territoriality and male reproductive success in arctic ground squirrels

Although territorial defense is a common form of reproductivecompetition among male vertebrates, the exact reproductiveconsequences of this behavior are often poorly understood.To explore relationships between territoriality and reproductivesuccess in a nongroup-living mammal, we quantified patterns of space use, mating success, and fertilization success formales in a free-living population of arctic ground squirrels(Spermophilus parryii plesius). Because litters of this speciesare sired almost exclusively by a female's first mate, we predictedthat territory ownership would be associated with first accessto estrous females. During the 2-week period when mating occurred,each male in the study population attempted to defend a distinctportion of the habitat, although the success of this defensevaried among individuals. Twenty-six of 28 females monitoredmated with the male on whose territory they resided. However,the majority of females observed throughout estrus (65%; n= 20) also mated with at least one other male, indicating thatterritory ownership was not associated with exclusive accessto females. In contrast, territory ownership was significantly associated with first access to estrous females; 20 (71.4%)of 28 females mated first with the male on whose territorythey resided. In this regard, the behavior of S. parryii plesiusparallels that of socially monogamous birds in which territorialdefense by males functions to deter extrapair copulations byfemales. Although territorial defense represents an important component of male reproductive success in arctic ground squirrels,other aspects of male behavior (e.g., the ability to dominateagonistic interactions on the day of a female's estrus) arealso critical. We suggest that future studies of vertebratemating systems will benefit by viewing such defense as onlyone of multiple axes along which conspecific males compete foraccess to females.     

The effects of size, age and a cost of early breeding on reproduction in female mountain hares

Both age and size may influence female reproductive performance in mammals, and successful early reproduction may lead to reduced success at later attempts. The effects of age, size and early reproduction on distribution of reproductive effort throughout a single breeding season was examined in female mountains hares Lepus timidus L. Hind foot length was used as an index of body size, because, unlike body weight, it did not fluctuate with reproductive status. Fifty-six female carcasses were collected from March to October 1984, and their litters were assigned to one of three chronologically equal'litter periods'(1–3) of equal length. Whereas number of ova shed was always independent of age, large females shed more ova than did smaller females in litter periods 1 and 2. Prenatal mortality of ova and embryos was highest during litter period 1, when it was independent of age and size. Although prenatal mortality remained high in first year females in litter period 2, there was an overall decline through to the final litter period when it was negligible. Total number of young produced through the season increased with skeletal size in old females (age > 1), but not significantly in first year females. It is concluded that large size, rather than age, favours early reproduction in mountain hares. Every additional offspring produced in litter periods 1 and 2 reduced that female's production in period 3. After correcting for this cost of early reproduction the number of young produced in the final litter period also increased with maternal size.     

Phenotypic selection and function of reproductive behavior in the subsocial bug Elasmucha putoni (Heteroptera: Acanthosomatidae)

To investigate the function of maternal care and determinantsof reproductive success in the subsocial bug Elasmucha putoni (Heteroptera: Acanthosomatidae), I used two different approaches,the measurement of phenotypic selection and female-removalexperiments under conditions differing in biotic-environmentalpressure. For two field populations, unattended eggs and youngernymphs consistently suffered severe predation pressure andattendance by parent females greatly enhanced their survival.In contrast, under enemy-excluded conditions, offspring performance was not reduced in broods without parent females, indicatingthat maternal care functions as a physical defense againstpredators. However, the determinant of female reproductivesuccess in E. putoni in the field was not the care behavioralone. Selection gradient analysis showed that early seasonoviposition and larger clutch size, as well as a longer durationof care by a female, was favored during the breeding episode.This study is the first to evaluate phenotypic selection onparental care and other reproductive traits in arthropods.     

Sociality and individual fitness in yellow-bellied marmots: insights from a long-term study (1962–2001)

Theoretical and empirical studies suggest that the age of first reproduction (the age at which reproduction begins) can have a substantial influence on population dynamics and individual fitness. Using complete survival and reproductive histories of 428 female yellow-bellied marmots (Marmota flaviventris) from a 40-year study (1962-2001), we investigated causes and fitness consequences of delayed maturity. Most females (86%) died without reproducing. The age of first reproduction of females that survived to reproduce at least once (n=60) ranged from 2 to 6 years. Females maturing later did not have a larger lifetime number of successful reproductive events or offspring production, nor did they experience improved survival. Females reproducing earlier had a higher fitness than those that delayed maturity. These results suggest that the net cost of early maturity was less than fitness benefits associated with early onset of reproduction, and that age of first reproduction in our study population is under substantial directional selection favoring early maturity. We conclude that female yellow-bellied marmots delay onset of reproduction not because of fitness benefits of foregoing reproduction at an earlier age, but due to the social suppression of reproduction by older, reproductive females, which enhances their own fitness to the detriment of the fitness of young females. Our results indicate that female yellow-bellied marmots that survive to reproduce may act to increase their own direct fitness, and that social suppression of reproduction of young females is a part of that strategy.     

Sex-specific consequences of life in the city

The vast majority of species are excluded from human-dominatedlandscapes, but some species persist and appear to thrive, despitefacing challenges they would not encounter in less disturbedhabitat. Corticosteroid (cort) secretion may play a significantrole in enabling an animal to cope with urban breeding habitatbecause it helps mediate physiological and behavioral responsesto environmental challenges. Here we present tests of 3 hypothesesrelating to cort secretion in urban animals: 1) environmentalchallenges vary between urban and rural habitat, as reflectedin differing levels of cort secretion in animals breeding inthese habitat types, 2) there are fitness correlates associatedwith variation in cort levels within populations, and 3) parasiteload is one of the mechanistic links between variation in cortlevels and reproductive success. Male white-crowned sparrows(Zonotrichia leucophrys) in urban habitat had significantlyhigher baseline corticosterone levels than males in rural habitat,whereas female Z. leucophrys' hormone levels did not differbetween the 2 habitat types. To assess the fitness correlatesof variation in hormone levels, we monitored seasonal reproductivesuccess in one urban population and found that baseline corticosteronelevels were predictive of female, but not male, reproductivesuccess: females with higher corticosterone fledged fewer offspring.Data do not suggest a direct relationship between corticosteronelevels and fitness and instead indicate an indirect relationshipbetween hormone secretion, territory quality, body condition,and reproductive success. Females with blood parasites had lowerheterophil:lymphocyte ratios, lower body condition scores, fewermates, and fledged fewer offspring than females without parasites.In contrast, parasites did not negatively affect reproductivesuccess in males but were associated with reduced body condition.Corticosterone levels did not differ between birds with andwithout parasites. In tests of all 3 of our hypotheses, we foundsex-specific effects, highlighting the importance of consideringsex in investigation of physiological responses to disturbance.     

Reproductive skew among males in a female-dominated mammalian society

The purpose of this study was to document patterns of reproductiveskew among male spotted hyenas (Crocuta crocuta), a speciesin which many normal mammalian sex roles are reversed. We usedpaternity determined from 12 microsatellite markers togetherwith demographic and behavioral data collected over 10 yearsfrom a free-living population to document relationships among reproductive success (RS), social rank, and dispersal statusof male hyenas. Our data suggest that dispersal status andlength of residence are the strongest determinants of RS. Natalmales comprise over 20% of the adult male population, yet theysire only 3% of cubs, whereas immigrants sire 97%. This reproductiveadvantage to immigrants accrues despite the fact that immigrants are socially subordinate to all adult natal males, and it providesa compelling ultimate explanation for primary dispersal inthis species. High-ranking immigrants do not monopolize reproduction,and tenure accounts for more of the variance in male reproductivesuccess than does social rank. Immigrant male hyenas rarelyfight among themselves, so combat between rivals may be a relativelyineffectual mode of sexual selection in this species. Instead,female choice of mates appears to play an important role in determining patterns of paternity in Crocuta. Our data supporta "limited control" model of reproductive skew in this species,in which female choice may play a more important role in limitingcontrol by dominant males than do power struggles among males.     

Female competition and its evolutionary consequences in mammals

Following Darwin's original insights regarding sexual selection, studies of intrasexual competition have mainly focused on male competition for mates; by contrast, female reproductive competition has received less attention. Here, we review evidence that female mammals compete for both resources and mates in order to secure reproductive benefits. We describe how females compete for resources such as food, nest sites, and protection by means of dominance relationships, territoriality and inter‐group aggression, and by inhibiting the reproduction of other females. We also describe evidence that female mammals compete for mates and consider the ultimate causes of such behaviour, including competition for access to resources provided by mates, sperm limitation and prevention of future resource competition. Our review reveals female competition to be a potentially widespread and significant evolutionary selection pressure among mammals, particularly competition for resources among social species for which most evidence is currently available. We report that female competition is associated with many diverse adaptations, from overtly aggressive behaviour, weaponry, and conspicuous sexual signals to subtle and often complex social behaviour involving olfactory signalling, alliance formation, altruism and spite, and even cases where individuals appear to inhibit their own reproduction. Overall, despite some obvious parallels with male phenotypic traits favoured under sexual selection, it appears that fundamental differences in the reproductive strategies of the sexes (ultimately related to parental investment) commonly lead to contrasting competitive goals and adaptations. Because female adaptations for intrasexual competition are often less conspicuous than those of males, they are generally more challenging to study. In particular, since females often employ competitive strategies that directly influence not only the number but also the quality (survival and reproductive success) of their own offspring, as well as the relative reproductive success of others, a multigenerational view ideally is required to quantify the full extent of variation in female fitness resulting from intrasexual competition. Nonetheless, current evidence indicates that the reproductive success of female mammals can also be highly variable over shorter time scales, with significant reproductive skew related to competitive ability. Whether we choose to describe the outcome of female reproductive competition (competition for mates, for mates controlling resources, or for resources per se) as sexual selection depends on how sexual selection is defined. Considering sexual selection strictly as resulting from differential mating or fertilisation success, the role of female competition for the sperm of preferred (or competitively successful) males appears particularly worthy of more detailed investigation. Broader definitions of sexual selection have recently been proposed to encompass the impact on reproduction of competition for resources other than mates. Although the merits of such definitions are a matter of ongoing debate, our review highlights that understanding the evolutionary causes and consequences of female reproductive competition indeed requires a broader perspective than has traditionally been assumed. We conclude that future research in this field offers much exciting potential to address new and fundamentally important questions relating to social and mating‐system evolution.     

Phenotypic plasticity in adult life-history strategies compensates for a poor start in life in Trinidadian guppies (Poecilia reticulata)

Low food availability during early growth and development can have long-term negative consequences for reproductive success. Phenotypic plasticity in adult life-history decisions may help to mitigate these potential costs, yet adult life-history responses to juvenile food conditions remain largely unexplored. I used a food-manipulation experiment with female Trinidadian guppies (Poecilia reticulata) to examine age-related changes in adult life-history responses to early food conditions, whether these responses varied across different adult food conditions, and how these responses affected overall reproductive success. Guppy females reared on low food as juveniles matured at a later age, at a smaller size, and with less energy reserves than females reared on high food as juveniles. In response to this setback, they changed their investment in growth, reproduction, and fat storage throughout the adult stage such that they were able to catch up in body size, increase their reproductive output, and restore their energy reserves to levels comparable to those of females reared on high food as juveniles. The net effect was that adult female guppies did not merely mitigate but surprisingly were able to fully compensate for the potential long-term negative effects of poor juvenile food conditions on reproductive success.