Confidence of paternity and paternal care: covariation revealed through the experimental manipulation of the mating system in the beetle Onthophagus taurus

Theoretical models of paternal care predict that facultative reductions in male care may occur under certain conditions. One important parameter that has been shown to influence the outcome of these models is a male's confidence of paternity. In this study, we tested whether the amount of care provided by horned males in the dimorphic beetle, Onthophagus taurus, varied with his confidence of paternity. Male care results in an increased weight of dung provided in the brood masses produced by the pair. Using the sterile male technique we showed that a horned male's paternity declined with the number of sneak males in the population. The relationship was nonlinear, with paternity declining most rapidly between a frequency of one and three sneaks, and stabilizing thereafter at about 50%. A horned male's paternity was directly related to the number of copulations with the female, relative to the number of copulations achieved by sneaks. Horned males were shown to reduce their care in relation to their declining paternity. Video analysis demonstrated that reductions in male care occurred through a combination of male desertion and a trade‐off between caring and paternity assurance behaviours. The number of fights with sneak males was negatively related to the amount of care provided by a horned male. These results suggest that by gauging his expected paternity through the number of fights with sneaks, a horned male is able to assess his paternity and reduce his investment accordingly. Our data thus provide strong empirical support for the proposed link between paternity and paternal care.     

Male reed buntings do not adjust parental effort in relation to extrapair paternity

Parental effort is considered to be costly; therefore, malesare expected to provide less care to unrelated offspring. Theoreticalmodels suggest that males should either reduce their care tothe entire brood or alternatively distinguish between relatedand unrelated nestlings and direct provisioning to kin whenpaternity is in doubt. Reed buntings (Emberiza schoeniclus)have been found to have high levels of extrapair paternity (EPP,i.e., offspring of a male other than the male attending thenest; 55% of offspring), and males are therefore under strongselection pressure to adjust their parental effort accordingto the proportion of EPP in their brood. In this study, we investigatedwhether male reed buntings exhibit a reduction in paternal care(incubation and provisioning nestlings) in relation to decreasedpaternity. We also assess whether males bias their provisioningtoward kin. We measured incubation time, provisioning rates,and food allocation to individual nestlings using video recordingsat the nests. Microsatellite DNA analysis was used to analyzethe paternity of offspring. In direct contrast to a previousstudy on the same species, our results provided no indicationthat males lowered their effort with decreased paternity. Furthermore,in nests of mixed paternity, males did not bias their provisioningbehavior to kin. It remains to be investigated whether the absenceof a relationship between paternity and paternal care can beascribed to absence of reliable paternity cues or whether thebenefits of reducing paternal care did not outweigh the costsin our study population. We found no evidence that the levelof paternal care affected male survival or offspring mass, suggestingthat both the benefits and costs of any reduction in paternalcare would have been low.     

Certainty of paternity and paternal effort in the collared flycatcher

Models of optimal parental investment predict that variationin certainty of paternity can affect the optimal level of paternalinvestment when a male's expected paternity in different nestingattempts is not fixed throughout his lifetime. Several attemptsto test this prediction experimentally in monogamous birds havefailed to induce a reduction in care by males. This may be becausethe method used, detaining males, is a poor model for what happenswhen a male's certainly of paternity is naturally reduced. Wecaught and detained female collared flycatchers Ficedula albicollisfor 1 h immediately after laying on one or two occasions inan attempt to induce variation in certainty of paternity forthe males they were mated to. By capturing females immediatelyafter laying we hoped to exploit the existence of an "inseminationwindow" since males should be very sensitive to female absenceduring this period. The general effect of the experimental manipulationwas consistent with reduced certainty of paternity: males respondedby reducing their level of paternal care to nestlings, and malesmated to females that had been caught on one morning fed nestlingssignificantly less often and made a smaller share of feedingvisits than males mated to control females. The effects of theexperiment were generally weak, however, and we argue that certaintyof paternity may be fixed well before egg laying, in which caseexperimental manipulations are unlikely to have large effects.It is difficult to predict die effects of natural variationin certainty of paternity on levels of male paternal care becausedifferential allocation by females mated to attractive malesmay act in the opposite direction     

Paternity and paternal effort in the pumpkinseed sunfish

Theoretical models suggest that males should adjust their parentaleffort according to paternity when parental effort is costly,paternity varies among clutches, and males have a cue to assesspaternity. To date, nearly all tests of this theory have beenconducted using birds as model organisms. In this study we examinedthese three factors and the relationship between paternity andmale parental care in a fish system. In the pumpkinseed sunfish(Lepomis gibbosus), parental care is provided exclusively bymales (parentals), but some males (sneakers) parasitize othersby sneaking fertilizations. Parental males significantly lostweight during the parental care period. Clutch size and amountof parental effort did not affect a male's probability of obtainingmore eggs. Paternity was variable among broods. The proportionof young sired by a parental male was not associated with frequencyof fanning eggs or defense of hatched young, but was positivelycorrelated with levels of nest defense during the egg stage.Egg survivorship might restrict an adjustment of fanning behavior,and a general decline in parental behavior (with brood age)might explain the lack of adjustment once the eggs hatch. Parentalmales did not adjust their care when we experimentally manipulatedone possible cue of paternity. Together, these results indicatethat male pumpkinseeds do adjust their care in relation to paternity,but the cues used to assess paternity are not clear.     

Faithful females receive more help: the extent of male parental care during incubation in relation to extra‐pair paternity in songbirds

Parental care provided by males occurs in a diverse array of animals and there are large differences among species in its extent compared with female care. However, social and ecological factors responsible for interspecific differences in male's share of parental duties remain unclear. Genetic fidelity of females has been long considered important. Theory predicts that females should receive more help from their mates in raising the offspring in species with high genetic fidelity. Using avian incubation behaviour as a model system, we confirmed this prediction. The extent of male's help during incubation increased with decreasing rate of extra‐pair paternity across species (22 species of socially monogamous songbirds from 13 families; male's share of incubation ranged from 6% to 58%), even after accounting for covariates, biases in species selection and intraspecific variability. Moreover, this result was not sensitive to two different phylogenies and branch length estimates. We suggest that our findings support the notion, backed by theory, that genetic fidelity is an important factor in the evolution of male parental care. We offer several behavioural scenarios for the coevolution between male's share of parental duties and the genetic mating system.     

Diverse parentage relationships in paternal mouthbrooding fishes

While mouthbrooding is not an uncommon parental care strategy in fishes, paternal mouthbrooding only occurs in eight fish families and is little studied. The high cost of paternal mouthbrooding to the male implies a low risk of investment in another male''s offspring but genetic parentage patterns are poorly known for paternal mouthbrooders. Here, we used single-nucleotide polymorphism genetic data to investigate parentage relationships of broods of two mouthbrooders of northern Australian rivers, mouth almighty Glossamia aprion and blue catfish Neoarius graeffei. For N. graeffei, we found that the parentage pattern was largely monogamous with the brooder male as the sire. For G. aprion, the parentage pattern was more heterogeneous including observations of monogamous broods with the brooder male as the sire (73%), polygyny (13%), cuckoldry (6%) and a brood genetically unrelated to the brooder male (6%). Findings demonstrate the potential for complex interrelationships of male care, paternity confidence and mating behaviour in mouthbrooding fishes.     

Experimentally increased badge size increases male competition and reduces male parental care in the collared flycatcher

Experimental enlargement of sexually selected traits that are energetically cheap to produce is expected to reveal costs resulting from increased risk of predation or social competition. Given a trade-off between sexually selected traits and life history traits such costs may be expected to affect not only the males themselves but also their offspring. In this study I manipulated the size of the forehead patch, a sexually selected trait that functions as a badge of status in male collared flycatchersFicedula albicollis). First, I found that a male''s likelihood to establish a breeding territory with respect to his original badge size was affected by the treatment such that old males (older than or equal to two years) with relatively small original badges enjoyed an increased likelihood of establishing a breeding territory while young males (yearlings) suffered a reduced likelihood of establishment when their badges were enlarged as compared to unchanged. Second, young males with enlarged badges that were able to establish a territory fed their nestlings less in relation to their females compared to the control males. However, the females adjusted their parental effort to such an extent that no significant differences were observed in total feeding rate nor in reproductive success between the two groups of males. These results suggest that experimentally enlarged badge size in the collared flycatcher may result in increased male competition and that males have to trade their effort spent in male contest against their parental effort.     

Why Do Cuckolded Males Provide Paternal Care?

In most species, males do not abandon offspring or reduce paternal care when they are cuckolded by other males. This apparent lack of adjustment of paternal investment with the likelihood of paternity presents a potential challenge to our understanding of what drives selection for paternal care. In a comparative analysis across birds, fish, mammals, and insects we identify key factors that explain why cuckolded males in many species do not reduce paternal care. Specifically, we show that cuckolded males only reduce paternal investment if both the costs of caring are relatively high and there is a high risk of cuckoldry. Under these circumstances, selection is expected to favour males that reduce paternal effort in response to cuckoldry. In many species, however, these conditions are not satisfied and tolerant males have outcompeted males that abandon young.     

Feathers,suspicions, and infidelities: an experimental study on parental care and certainty of paternity in the blue tit

Theoretical models on parental care predict that males should decrease their parental effort when paternity is in doubt. Males may use some cues to assess their certainty of paternity, and try to avoid rearing offspring sired by extra‐pair males. We have previously reported in a socially monogamous passerine, the blue tit (Cyanistes caeruleus), that males decorate their nests with feathers, and that when this ornament is manipulated, males appear to have suspicions about the presence of an intruder male. Here, we decrease the male's certainty of paternity through experimental feather supplementation to analyse whether the outcome of our experiment supports the assumptions of the parental care theory. Male C. caeruleus responded to the feather supplementation experiment by reducing their parental investment (feeding frequency and nest defence) in comparison with control males. The occurrence of extra‐pair offspring in experimental nests was double than that in controls. This suggests that the manipulation was successful not only in altering males' perceived paternity, but also, indirectly, the actual paternity. Furthermore, males that gained extra‐pair young also had a higher than average probability to lose paternity in their nest, which may imply that male C. caeruleus faced a trade‐off between obtaining extra‐pair fertilizations and maintaining paternity in their own nest. Overall, this study supports the idea that males are prone to decrease their parental effort when they perceive that the risk of losing paternity is high. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 552–561.     

Devoted fathers or selfish lovers? Conflict between mating effort and parental care in a harem‐defending arachnid

When there is a temporal trade‐off between mating effort and parental care, theoretical models predict that intense sexual selection on males leads to reduced paternal care. Thus, high‐quality males should invest more in mating effort because they have higher chances of acquiring mates, whereas low‐quality males should bias their investment towards parental care. Once paternal care has evolved, offspring value should also influence males’ decisions to invest in offspring attendance. Here, we performed a manipulation under field conditions to investigate the factors that influence male allocation in either mating effort or parental care. We predicted that facultative paternal care in the harem‐holding harvestman Serracutisoma proximum would be negatively influenced by male attractiveness and positively influenced by offspring value. We found that attractive males were less likely to engage in egg attendance and that the higher the perceived paternity, the higher the caring frequency. Finally, egg mortality was not related to caring frequency by males, but predation pressure was much lower than that recorded in previous studies with the same population. Thus, the benefits of facultative male care may be conditional to temporal variation in the intensity of egg predation. In conclusion, males adjust their investment in either territory defence or egg attendance according to their recent mating history and perceived paternity. Our findings suggest that exclusive paternal care can evolve from facultative paternal care only if the trade‐off between mating effort and parental care is circumvented.     

Do Female Red-winged Blackbirds Engage in a Mixed Mating Strategy?

Parentage analyses of broods of nestling red-winged blackbirds (Agelaius phoeniceus) revealed that extra-pair fertilizations (EPFs) accounted for 24% of the offspring. 8% of attempted copulations and 13% of male courtship displays during observations of focal females were by extra-pair males. In addition, mates and non-mates often chased and occasionally made physical contact with females; 34% of those chases in which contact was made were extra-pair chases. Females behaved variably during both within-pair and extra-pair events; females crouched less and resisted more frequently during extra-pair courtship than during within-pair courtship. All extra-pair events, whether natural or induced by male removal, were either resisted or accepted by the female. In 318 focal female-hours of observation during the fertilizable period, no female was ever seen in another male's territory soliciting a copulation. In addition, removal of females' mates resulted in frequent extra-pair courtship and copulation; all of these occurred on the removed male's territory. Some females left their mates' territories on occasion — these forays were nearly always off the study area, no female was ever seen copulating with an extra-pair male while on these forays, and neither the frequency nor the duration of female forays correlated with the frequency of extra-pair fertilizations within broods. There were no associations between extra-pair fertilizations and female age, settlement order, nest order, or clutch size. The number of fledglings produced from a nest was significantly positively associated with the number of sires of the brood. Fewer offspring apparently starved in broods that were multiply sired, yet males did not provide courtship feedings during either within-pair or extra-pair copulations, nor was any paternal care provided to young sired through extra-pair matings. The frequency of infertile eggs was low (< 1%); in those instances of infertile eggs the territory owner sired some young in the same nest or another nest on his territory. Fewer broods were a mixture of within-pair and extra-pair paternity than expected by chance. Clear evidence implicating a mixed strategy on the part of females could not be gathered. Because females behaved variably and because not all costs and benefits to females of extra-pair copulations could be measured, it remains possible that female behavior patterns are either (1) part of a mixed strategy, or (2) part of a strategy minimizing the costs of copulation.     

High rates of extra‐pair paternity in a socially monogamous beetle with biparental care

1. Nest construction and paternity assurance are predicted to favour biparental care in insects. The horned passalus (Odontotaenius disjunctus) is a socially monogamous beetle with biparental care that breeds in decaying logs. The genetic mating system of the horned passalus was investigated to determine if paternity assurance is likely to drive the evolution or maintenance of paternal care in this system. Parental time budgets were also examined to better understand the types and frequencies of behaviours performed by parents. 2. Genotyping‐by‐sequencing revealed high levels of extra‐pair paternity, with 54.8% of offspring sired by extra‐pair males and 70% of nests containing extra‐pair young. 3. More heterozygous social males were cuckolded less than more homozygous social males. Extra‐pair mating, however, seems unlikely to increase offspring genetic diversity as extra‐pair offspring were not more heterozygous than within‐pair offspring, and average brood heterozygosity did not increase with higher rates of extra‐pair paternity. 4. Behavioural observations demonstrated that parents spent on average 46.5% of their time processing the decaying wood resource for larval offspring. Because resource processing is a by‐product of feeding and provides shareable benefits for all larvae in the brood, this form of paternal care could be favoured despite low paternity.     

Coevolution of female fidelity and male help in populations with alternative reproductive tactics

In socially monogamous species, pair-bonded males often continue to provide care to all offspring in their nests despite some degree of paternity loss due to female extra-pair copulation. Previous theoretical models suggested that females can use their within-pair offspring as ‘hostages'' to blackmail their social mates, so that they continue to provide care to the brood at low levels of cuckoldry. These models, however, rely on the assumption of sufficiently accurate male detection of cuckoldry and the reduction of parental effort in case of suspicion. Therefore, they cannot explain the abundant cases where cuckolded males continue to provide extensive care to the brood. Here we use an analytical population genetics model and an individual-based simulation model to explore the coevolution of female fidelity and male help in populations with two genetically determined alternative reproductive tactics (ARTs): sneakers that achieve paternity solely via extra-pair copulations and bourgeois that form a mating pair and spend some efforts in brood care. We show that when the efficiency of mate guarding is intermediate, the bourgeois males can evolve to ‘specialize'' in providing care by spending more than 90% of time in helping their females while guarding them as much as possible, despite frequent cuckoldry by the sneakers. We also show that when sneakers have tactic-specific adaptations and thus are more competitive than the bourgeois in gaining extra-pair fertilizations, the frequency of sneakers and the degrees of female fidelity and male help can fluctuate in evolutionary cycles. Our theoretical predictions highlight the need for further empirical tests in species with ARTs.     

Different reproductive tactics in male collared flycatchers signalled by size of secondary sexual character

Most studies of variation in male reproductive tactics have focused on conspicuous categorical differences in mating behaviour (i.e. variation in mating strategies). However, in the presence of trade-offs between investment in competition over matings, parental care and survival, a male''s optimal allocation rule might vary according to his physiological condition and social or ecological environment. Thus, there may also be more subtle variation in male reproductive tactics. Here, I show that the reproductive effort (estimated as residual change in condition) of male collared flycatchers was affected by the size of their forehead patch (a secondary sexual character), age and date of arrival at the breeding grounds. Among early males (i.e. males with a high likelihood of both attracting more than one female and obtaining extra-pair copulations), large-patched males made a relatively large reproductive effort and as a result were in worse condition at the time of feeding offspring as compared to small-patched males. Furthermore, among early breeders, young males and males with experimentally increased forehead patch size made a relatively high effort. By contrast, regardless of age and badge size, there were no such patterns observed among late breeders. These results suggest that collared flycatchers use different reproductive tactics depending on both internal and external factors, and that the size of a secondary sexual trait may not only indicate variation in individual condition but also predict how resources will be allocated between pre- and post-mating reproductive activities.     

Sperm competition mechanisms,confidence of paternity,and the evolution of paternal care in the golden egg bug (Phyllomorpha laciniata)

Theoretical models predict how paternal effort should vary depending on confidence of paternity and on the trade-offs between present and future reproduction. In this study we examine patterns of sperm precedence in Phyllomorpha laciniata and how confidence of paternity influences the willingness of males to carry eggs. Female golden egg bugs show a flexible pattern of oviposition behavior, which results in some eggs being carried by adults (mainly males) and some being laid on plants, where mortality rates are very high. Adults are more vulnerable to predators when carrying eggs; thus, it has been suggested that males should only accept eggs if there are chances that at least some of the eggs will be their true genetic offspring. We determined the confidence of paternity for naturally occurring individuals and its variation with the time. Paternity of eggs fertilized by the last males to mate with females previously mated in the field has been determined using amplified fragment length polymorphisms (AFLPs). The exclusion probability was 98%, showing that AFLP markers are suitable for paternity assignment. Sperm mixing seems the most likely mechanism of sperm competition, because the last male to copulate with field females sires an average of 43% of the eggs laid during the next five days. More importantly, the proportion of eggs sired does not change significantly during that period. We argue that intermediate levels of paternity can select for paternal care in this system because: (1) benefits of care in terms of offspring survival are very high; (2) males have nothing to gain from decreasing their parental effort in a given reproductive event because sperm mixing makes it difficult for males to reach high paternity levels and males are left with no cues to assess paternity; (3) males cannot chose to care for their offspring exclusively because they can neither discriminate their own eggs, nor can they predict when their own eggs will be produced; and (4) males suffer no loss of further matings with other females when they carry eggs. Thus, our findings do not support the traditional view that paternal investment is expected to arise only in species where confidence of paternity is high. The results suggest that females maximize the chances that several males will accept eggs at different times by promoting a mechanism of sperm mixing that ensures that all males that have copulated with a female have some chance of fathering offspring, that this probability remains constant with time, and that males have no cues as to when their own offspring will be produced.     

Male burying beetles extend,not reduce,parental care duration when reproductive competition is high

Male parents spend less time caring than females in many species with biparental care. The traditional explanation for this pattern is that males have lower confidence of parentage, so they desert earlier in favour of pursuing other mating opportunities. However, one recent alternative hypothesis is that prolonged male parental care might also evolve if staying to care actively improves paternity. If this is the case, an increase in reproductive competition should be associated with increased paternal care. To test this prediction, we manipulated the level of reproductive competition experienced by burying beetles, Nicrophorus vespilloides (Herbst, 1783). We found that caregiving males stayed for longer and mated more frequently with their partner when reproductive competition was greater. Reproductive productivity did not increase when males extended care. Our findings provide support for the increased paternity hypothesis. Extended duration of parental care may be a male tactic both protecting investment (in the current brood) and maximizing paternity (in subsequent brood(s) via female stored sperm) even if this fails to maximize current reproductive productivity and creates conflict of interest with their mate via costs associated with increased mating frequency.     

Male-male competition and parental care in collared flycatchers (Ficedula albicollis): an experiment controlling for differences in territory quality

Females are known to benefit from mate choice in several different ways but the relationship between these benefits has received little attention. The quality of resources provided by males, such as nest sites, and paternal care are often assumed to covary positively However, because the location of the nest affects the cost of parental care, these two benefits from mate choice can easily be confounded. To investigate the provisioning ability of successful competitors while controlling for differences in territory quality we removed early-settled pairs of collared flycatchers (Ficedula albicollis) and allowed replacement by later-arriving males or floaters (i.e.'poor competitors'). A control group of early-settled males (i.e. 'good competitors') had their females removed. Females paired to good competitors enjoyed a significantly higher reproductive success and tended to receive more parental assistance from their mates compared with females mated to poor competitors. Thus, some males seem able not only to compete successfully over resources but also to feed their offspring at a relatively higher rate. An alternative explanation, that poor competitors invested less in offspring quality in response to a lower share of paternity, could be rejected. The rate of extra-pair paternity did not differ between the two treatment groups. Our results suggest that male- male competition can sometimes facilitate female choice of superior care-givers. Thus, a female's benefit from choosing a competitive male may not be restricted to the quality of the resource he defends but can also include superior paternal care.     

The ‘Widow Effect’ and its Consequences for Reproduction in Burying Beetles,Nicrophorus vespilloides (Coleoptera: Silphidae)

Burying beetles tend their young on small vertebrate carcasses, which serve as the sole source of food for the developing larvae. Single females are as proficient at rearing offspring as male-female pairs, yet males opt to remain with their broods throughout most of the larval development. One potential benefit of a male's extended residency is that it affords him the opportunity of additional copulations with the female, which could ensure his paternity in a replacement brood should the female's first egg clutch fail to hatch. We tested this hypothesis by manipulating males' access to their mates during the production of replacement clutches, using genetic colour markers to determine the paternity of offspring. Females were induced to produce a replacement brood by removing their first clutch of eggs. In one experimental treatment, we removed the female's mate upon the removal of her first egg clutch (‘widowed’ females); in a second treatment, the female was permitted to retain her mate up until she produced a replacement clutch. There was no significant difference in paternity between males removed from females before the initiation of replacement clutches and those permitted to remain with their mates. However, widowed females produced fewer offspring in replacement broods than did females permitted to retain their mates. This difference occurred primarily because a significantly greater proportion of widowed females opted not to produce a replacement clutch, a result we refer to as the ‘widow effect’. This widow effect was further shown in those replicates in which females of both treatments produced replacement clutches: widowed females took significantly longer to produce a replacement clutch than did females permitted to retain their mates. The loss of her mate could be a signal to a female that a take-over of the carcass is imminent. Her reluctance to produce a replacement clutch under these circumstances might constitute a strategy by which she conserves carrion for a subsequent reproductive attempt with an intruding male successful at ousting her previous mate. Regardless of its functional significance, the widow effect favours the extended residency of males and therefore contributes to the selective maintenance of male parental care.     

Confidence of paternity and paternal care by eastern bluebirds

Male birds are often faced with low confidence of paternityin their mates' offspring, raising the question of how paternalcare covaries with confidence of paternity. We tested the hypothesisthat male eastern bluebirds (Sialia sialis) reduce care of nestlingsin response to experimentally decreased confidence of paternity.Actual paternity, as assessed by DNA fingerprinting, had noeffect on male feeding rates, nor did males reduce care whenconfidence of paternity was experimentally decreased. Malesthat had been removed for 2 days while their mate was fertile(experimental group) fed nestlings at absolute rates similarto those of control males. The proportion of feeding trips providedby males was also similar for control and experimental nests.We found no difference in fledging success and nestling growthbetween experimental and control broods. Seven original residentmales were displaced by previously unbanded males. Althoughthese replacement males appeared to feed nestlings at normalrates, the nests attended by replacement males suffered reducedfledging success compared to control and experimental nests.Overall, we found no evidence that males reduce feeding effortwhen confidence of paternity is experimentally decreased. Malesmay tolerate some reduction in confidence of paternity withoutreducing care if paternal care is crucial to nestling survival.Alternatively, males may assess paternity within a brood usingcues other than their ability to guard their fertile mates.     

Experience Matters: Females Use Smell to Select Experienced Males for Paternal Care

Mate choice and mating preferences often rely on the information content of signals exchanged between potential partners. In species where a female''s reproduction is the terminal event in life it is to be expected that females choose high quality males and assess males using some honest indicator of male quality. The Nereidid polychaete, Neanthes acuminata, exhibits monogamous pairing and the release of eggs by females terminates her life and larval success relies entirely on a male''s ability to provide paternal care. As such females should have developed reliable, condition-dependent criteria to choose mates to guarantee survival and care for offspring. We show that females actively chose males experienced in fatherhood over others. In the absence of experienced males dominance, as evident from male-male fights, is utilized for mate selection. The preference for experienced males is not affected by previous social interactions between the individuals. We show that the choice of the partner is based on chemical signals demonstrating a ‘scent of experience’ to females providing evidence for the role of chemical signals in sexual selection for paternal care adding to our understanding of the mechanisms regulating condition-dependent mate choice.