Heterospecific Females Research Articles

Smaller rival males do not affect male mate choice or cortisol but do affect 11-ketotestosterone in a unisexual-bisexual mating complex of fish

Male mate discrimination may be affected by the social environment (presence or absence of rival males or mates), which can also affect stress and sex hormones (e.g., cortisol and 11-ketotestosterone (11-KT)). The Amazon molly, Poecilia formosa, is an all-female fish species dependent on sperm from mating with male P. latipinna. We investigated male mate choice in P. latipinna between conspecific females and P. formosa with a rival male present and no rival male present. We measured cortisol and 11-KT release rates from all fish. The presence of a rival male had no effect on male mate choice for conspecific females nor overall mating effort. Male 11-KT decreased on the second day after exposure to a rival male on the first day. Focal male 11-KT is positively correlated with the size of the rival male. Both conspecific and heterospecific females released more 11-KT when in the rival male treatment than when not. Neither male nor female cortisol was affected by the presence or absence of the rival male. We did not find an effect of rival males on male mate choice in contrast to our prediction. Instead, our findings may indicate a hormonal response to social competition.

Visual preference of males for conspecific mates in mutually ornamented fish: possible support for the species recognition hypothesis

Because sexual selection typically acts on males, the evolution of conspicuous ornamentation in females has been insufficiently studied. Genetic correlation between the sexes and sexual or social selection on females have been proposed to explain female ornamentation, but they cannot fully explain certain patterns observed in nature such as female ornamentation in non-territorial, promiscuous species. The species recognition hypothesis, which postulates that ornamentation is adaptive because it prevents maladaptive hybridization, might plausibly explain female ornamentation. We examined this in two sympatric, non-territorial, promiscuous fish species, Tribolodon hakonensis (TH) and Tribolodon sachalinensis (TS), in which both sexes display species-specific conspicuous coloration in the breeding season. We conducted experiments on visual mate choice of male TH for conspecific and heterospecific females, and compared their association times. TH spent more time near conspecifics, indicating that they used visual cues to recognize them. Because the females of the two species presented to the males did not differ in body size, shape or behavior, male preference for conspecifics was probably based on female nuptial coloration. These results suggest that female ornamentation may evolve or be maintained not only by sexual or social selection within a species but also by interspecific interactions (e.g., hybridization).

Kin Recognition in two Species of Cellar Spiders, (Pholcidae), and its Effects on Inter- and Intra-Specific Predation of Spiderlings

Intraguild predation and cannibalism are important behaviors that provide resources and influence interactions between different predators. Cannibalistic species should have a mechanism to identify offspring and suppress predation. We tested this hypothesis using two nonnative species of pholcid spiders in Ohio, Pholcus phalangioides and Pholcus manueli. In the laboratory we allowed females of both species to produce clutches. Once hatched the spiderlings were separated from their mother for 1 h and then reintroduced to the mother, a conspecific, or were introduced to an heterospecific adult female. The proportion of prey items consumed was recorded. Pholcus phalangioides predation patterns were consistent across species, but P. manueli feed on P. phalangioides young at twice the rate of young conspecifics, treating heterospecific young similar to control crickets. Further, mothers did not prey on their own young. These results highlight an important biological difference between the two species and indicate that intraguild predation may play an important role in interactions between the two species.

Effect of early experience on neuronal and behavioral responses to con- and heterospecific odors in closely related Mus taxa: epigenetic contribution in formation of precopulatory isolation

BackgroundThe most effective learning occurs during sensitive periods. Olfactory plasticity to main social olfactory cues is limited to a critical period to a large degree. The objective was to evaluate the influence of early olfactory experience on the behavioral and neuronal responses of males to con- and heterospecific odors of receptive females in two species, M. musculus (subspecies musculus, wagneri) and M. spicilegus, and thus to determine the potential role of epigenetic contribution in the formation of precopulatory isolation.ResultsMales were reciprocally cross-fostered shortly after the birth and were tested for response to con- and heterospecific urine odors of estrus females using two-choice tests at 70–85 days of age. Neuronal activity of non- and cross-fostered males was evaluated at 90–110 days of age in the MOB and AOB to con- and heterospecific female odor using fMRI (MEMRI). Non-cross-fostered males of three taxa demonstrated a strong preference for odor of conspecific females compared to odor of heterospecific ones. Spicilegus-nursed musculus preferred odor of heterospecific females. Wagneri-nursed spicilegus and spicilegus-nursed wagneri did not demonstrate significant choice of con - or heterospecific female odor. The level of MRI signal obtained from the evaluation of manganese accumulation in AOB neurons was significantly higher when the odor of conspecific estrus females was exposed, compared to urine exposure of heterospecific females. The response pattern changed to the opposite in males raised by heterospecific females. Response patterns of neuronal activity in the MOB to con- and heterospecific female odors were different in cross-fostered and control males.ConclusionThe maternal environment, including odor, had a greater effect on the level of MRI signal in the AOB than the genetic relationships of the recipient and the donor of the odor stimulus. Behavioral and neuronal responses to con- and heterospecific odors changed in closely related Mus taxa as a result of early experience. We demonstrated the importance of early learning in mate choice in adulthood in mice and the possibility of epigenetic contribution in the formation of precopulatory reproductive isolation.

Discrimination of Odors Associated With Conspecific and Heterospecific Frass by Sibling Species Dendroctonus frontalis (Coleoptera: Curculionidae: Scolytinae) and Dendroctonus mesoamericanus (Coleoptera: Curculionidae: Scolytinae).

In the Central American region, the aggressive, sibling bark beetles Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae) and Dendroctonus mesoamericanus Armendáriz-Toledano & Sullivan (Coleoptera: Curculionidae: Scolytinae) commonly colonize pines concurrently, and in nature they avoid heterospecific pairing, although it can be produced in the lab. We performed walking arrestment bioassays in the lab to examine the capacity of both sexes of both species to discriminate odors from frass expelled from gallery entrances of either solitary females or conspecific pairs of either species. Males of both species strongly preferred odors of frass from solitary, conspecific females over those of heterospecific females or pairs of either species. Female D. frontalis did not discriminate among these frass categories, whereas female D. mesoamericanus preferred frass of conspecific females. In gas chromatography-electroantennographic detection and gas chromatography-mass spectrometry analyses, we determined that males of both species could sense a nearly identical spectrum of approximately 16 host- and beetle-produced compounds present in frass of females of one or both species. Only two of these compounds, endo-brevicomin and ipsdienol, which were present in frass of female D. mesoamericanus and pairs of either species but absent in frass of solitary D. frontalis females, qualitatively distinguished these categories. Several known attractants and synergists for either species declined in concentration postpairing. Our results complement earlier research and indicate how semiochemical composition and concentration in frass might mediate male discrimination of attack sites of conspecific, unpaired females. Furthermore, our data indicate that semiochemical responses for walking females differ from those of males and between species.

Clonal fish are more aggressive to distant relatives in a low resource environment

Abstract Kin selection explains conditions under which closely related individuals should be less antagonistic towards one another. One benefit of kin selection is a reduction in aggression towards kin in various social contexts, such as foraging. In the gynogenetic Amazon molly, females have been shown to differentiate between clone types, preferring to associate with clonal sisters to non-sisters, regulating their aggressive behaviours accordingly. We ask if Amazon mollies in resource-limited environments retain the ability to regulate aggressive behaviours according to relatedness. We found that focal females regulated their aggressive behaviours depending on partner type. Females spent more time behaving aggressively towards the heterospecific females than either of the clonal lineages, and towards non-sister clones compared to clonal sisters. We are able to confirm that kin discrimination is maintained, resulting in females showing more aggression towards heterospecific females and non-sister clones in a food-limited environment, and that this aggression scales with relatedness.

The cost of living in mixed species populations: A fiddler crab example

Rising sea level is reducing the inter-tidal zone in many mangrove forests. This breaks down the normal species distribution patterns of fiddler crabs, with an increasing number of heterospecifics moving from adjacent zones into an area normally occupied by a single species. Here we examine the interspecific social and sexual interactions that have resulted. We show that male Austruca mjoebergi are just as likely to help their small conspecific neighbor fight off an intruder when the intruder is a conspecific or heterospecific male. It appears that keeping a known neighbor is preferable to having any new neighbor (even a heterospecific neighbor that would not compete for receptive females) since the costs of renegotiating territory boundaries would be the same whatever the species of the new neighbor. We also show that males court females of their own species just as vigorously as those of two heterospecific species. Courtship is costly, so the time and energy spent courting heterospecific females is wasted: a potentially high cost of living among heterospecifics.

Sexual conflict and the evolution of genitalia: male damselflies remove more sperm when mating with a heterospecific female

In Calopteryx damselflies, males remove rivals’ sperm stored by the female, thereby reducing sperm competition. This behaviour may create a sexual conflict, because females could lose the sperm stored in the spermatheca, used for long-term storage. Comparative evidence suggested antagonistic coevolution between sexes, which might prompt the evolution of narrow spermathecal ducts, or longer spermathecae, hindering sperm removal. Calopteryx haemorrhoidalis and C. splendens coexist and sometimes hybridize. Therefore, here I predicted that if females coevolve with conspecific males, heterospecific males should have an advantage when interspecific matings occur because females will show less resistance to them than to conspecific males. By hand-pairing females to males of both species, I found that in intraspecific and interspecific matings, sperm was almost completely removed from the bursa (97–100%), but only partially from the spermathecae, with more spermathecal removal in interspecific (63–71%) than intraspecific matings (14–33%). This suggests that heterospecific males are more efficient in sperm removal as predicted by a sexually-antagonistic coevolutionary scenario. Furthermore, in most cases, only the left spermatheca was emptied, suggesting that the evolution of more than one spermatheca might also be a female counter-adaptation to regain control over fertilization.

Male mate choice contributes to behavioural isolation in sexually dimorphic fish with traditional sex roles

Behavioural isolation between closely related species with exaggerated male mating traits is traditionally thought to be mediated by female preference for conspecific male ornaments. The role of male mate choice in maintaining boundaries between highly sexually dimorphic species is therefore comparatively neglected. However, mounting theoretical and empirical evidence supports the existence of male mate choice both within, and increasingly, between species with exaggerated male ornaments. We therefore tested the role of male mate choice in the maintenance of species boundaries for two sexually dimorphic species of darters (Percidae: Etheostoma). Using dichotomous choice assays, we measured male preferences of sympatric species Etheosotma barrenense and Etheosotma zonale for size-matched conspecific and heterospecific females, thus reducing the possibility that males would select for general indicators of fecundity. Our results show that males of both species strongly prefer conspecific females. A comparison with published data showed that the strength of preference for conspecific mates is just as strong for males as it is for females in E. barrenense. We also estimated the relative contribution of male mate choice, female mate choice and male–male competition to behavioural isolation. We found that male mate choice contributes as much as female mate choice to total behavioural isolation and thus likely plays an important role in behavioural isolation in these sexually dimorphic species. Our results suggest that the contribution of male choice to behavioural isolation should be studied in a larger variety of animal species to appreciate the relative roles of the sexes in the maintenance of species boundaries.

The chemical basis of mate recognition in two parasitoid wasp species of the genus Nasonia

AbstractTo recognize one's mate is essential for all sexually reproducing animals. In insects, mate recognition is often based on chemical cues such as hydrocarbons which are distributed over the insect's cuticle. In the parasitoid wasp genus Nasonia (Hymenoptera: Pteromalidae), interspecific mating possibly occurs in microsympatry between Nasonia vitripennis Walker and Nasonia giraulti Darling despite post‐zygotic isolation mechanisms preventing hybridization. Males of N. vitripennis are known to equally court con‐ and heterospecific females, which they recognize by means of cuticular hydrocarbons. A recent study surprisingly showed that this might not be the case in N. giraulti, leaving open how males of this species achieve the recognition of mating partners. In this study, we investigated chemical mate recognition in N. giraulti in more detail and compared observed behaviors with behaviors of N. vitripennis by conducting experiments with both species concurrently and under the same experimental conditions. We disentangled the role of female‐derived non‐polar cuticular lipids – i.e., cuticular hydrocarbons – and more polar cuticular lipids in the ability of males to recognize con‐ and heterospecific females. In addition, we tested whether females of the two species discriminate similarly between con‐ and heterospecific males. We demonstrate that, in contrast to N. vitripennis, males of N. giraulti prefer live conspecific females over heterospecific ones. Furthermore, in contrast to N. vitripennis, mate recognition in N. giraulti males is not based on cuticular hydrocarbons, but rather involves other chemical messengers, presumably more polar cuticular lipids. In both species, discrimination against heterospecific males decreases with female age.

The effects of conspecific and heterospecific interactions on foraging and oviposition behaviours of two parasitoids of Diaphorina citri

ABSTRACTDirect observation was used to construct activity budgets for Diaphorencyrtus aligarhensis (Shafee, Alam & Agarwal) (Hymenoptera: Encyrtidae) and Tamarixia radiata (Waterston) (Hymenoptera: Eulophidae), foraging for nymphs of Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae). Two populations of D. aligarhensis were used in experiments: a biparental population from Pakistan and a uniparental population from Taiwan. Parasitoids were provisioned with 20 D. citri nymphs, second through fifth instar; female parasitoids from all three populations foraged alone, in conspecific pairs, or in heterospecific pairs. Walking occupied approximately 40% of the activity budget of D. aligarhensis and ovipositor probing occupied 10–20%. In contrast, probing and walking each accounted for approximately 30% of the activity budget of T. radiata. The presence of conspecific females affected the activity budget of D. aligarhensis females, such that the focal female was observed walking less often and probing more frequently. Heterospecific females did not affect D. aligarhensis activity. These results suggest mutual interference may occur between D. aligarhensis females foraging on the same host patch. The behaviour of T. radiata was not significantly affected by the presence of conspecific or heterospecific competitors. These results are discussed with respect to the release of multiple species of natural enemies in the classical biological control programme targeting D. citri in California.

Behavioral and neuronal responses of two mouse species, Mus musculus and Mus spicilegus, to con- and heterospecific olfactory signals

The behavioral and neuronal responses of the males of two closely related species of mice (Mus musculus wagneri, M. spicilegus) to the urine odors of estrus con- and heterospecific females were studied. In two-choice odor tests males significantly longer investigated odor of conspecific females in comparison with heterospecific ones. To investigate neuronal activation in the main and accessory olfactory bulbs (MOB and AOB), one of the methods of functional tomography – manganese-enhanced MRI ( ME-MRI) – was used. There was a significant increase in Mn2+ accumulation in the dorsal section of the posterior part of the MOB in male M. m. wagneri and M. spicilegus exposed to odor of conspecific females compared with the control group males (odor not exposed). There was a local significant increase in manganese accumulation in the dorsal region of the anterior part of the MOB in the case of the exposure of odor of a heterospecific female. The exposure of heptanone-2 to mice resulted not only in an increase in Mn2+ accumulation in certain zones, but also in a significant decrease in the accumulation of Mn2+ in the rest of the olfactory bulbs. A significant increase in the accumulation of MRI contrast in AOB was observed in males only in the case of female urine-conspecific odor exposure. The results support the previously stated assumption of a significant difference in chemical communication systems in two species of mice. A comparison of these results and results obtained previously demonstrated the absence of any differences in behavioral and neuronal responses to con- and heterospecific odors of the house mouse subspecies allopatric (M. m. wagneri) and sympatric (M. m. musculus) to M. spicilegus. This fact does not allow us to assume the effect of the mechanism of “reinforcement” in the process of evolution in the formation of precopulatory reproductive isolation between the sympatric species M. spicilegus and M. musculus.

Potential costs of heterospecific sexual interactions in golden orbweb spiders (Nephila spp.).

Though not uncommon in other animals, heterospecific mating is rarely reported in arachnids. We investigated sexual interactions among four closely related and syntopical African golden orbweb spiders, Nephila inaurata, N. fenestrata, N. komaci, and N. senegalensis. In two South African localities, female webs were often inhabited by heterospecific males that sometimes outnumbered conspecifics. Species association of males with females was random in nature. In subsequent laboratory choice experiments, N. inaurata males chose heterospecific females in 30% of trials. We also observed natural mating interactions between N. inaurata males and N. komaci females, and between N. komaci males and N. inaurata females in laboratory experiments. While heterospecific mating in the laboratory never produced offspring, conspecific mating did. We discuss potential ecological and evolutionary consequences of heterospecific mating interactions in Nephila that may be particularly costly to the rarer species.

Herbivore Damage and Prior Egg Deposition on Host Plants Influence the Oviposition of the Generalist Moth Trichoplusia ni (Lepidoptera: Noctuidae).

Female insects have the difficult task of locating host plants that maximize the survival and success of their offspring. In this study, the oviposition preferences of the cabbage looper moth, Trichoplusia ni (Hübner), for soybean plants, Glycine max (L.), under various treatments-undamaged, mechanically damaged, damaged by T. ni or Spodoptera frugiperda (Smith) larvae or by Bemisia tabaci (Gennadius) adults, egg-free plants, and plants previously oviposited by conspecific or heterospecific females (S. frugiperda)-were investigated using two-choice tests. Additionally, the volatile compounds emitted by the plants under the different treatments were identified by gas chromatography-mass spectrometry. Our results showed that females showed no preferences for undamaged or mechanically damaged plants. However, they oviposited more often on undamaged plants than on those previously damaged by T. ni, S. frugiperda, or B. tabaci. In contrast, females preferred to oviposit on plants previously oviposited by conspecific and heterospecific females than on egg-free plants. Plants damaged by conspecific or heterospecific larvae emitted methyl salicylate, indole, and octyl butyrate, compounds not released by undamaged or mechanically damaged plants. Whitefly damage induced the release of higher quantities of Z(3)-hexenyl acetate, (R)-(+)-limonene, and (E)-β-ocimene compared to plants damaged by larvae and suppressed the emission of linalool. Egg deposition by conspecific and heterospecific moths induced the emission of (R)-(+)-limonene, octyl butyrate, and geranyl acetone but suppressed the release of linalool. This study showed that a generalist moth species can discriminate between plants of different quality, and suggests that females use volatile compounds as cues during this process.

Morphology and ultrastructure of the allomone and sex-pheromone producing mandibular gland of the parasitoid wasp Leptopilina heterotoma (Hymenoptera: Figitidae)

Chemical communication by the parasitoid wasp Leptopilina heterotoma is based largely on (−)-iridomyrmecin. The female wasps use (−)-iridomyrmecin as a defensive allomone, a chemical cue to avoid competition with con- and heterospecific females, and as a major component of their sex pheromone to attract males. Males of L. heterotoma produce (+)-isoiridomyrmecin, which is also used for chemical defense. In this study we show that females and males of L. heterotoma produce the iridomyrmecins in a pair of mandibular glands. Each gland consists of a secretory part composed of class 3 gland cells and their accompanying duct cells, as well as a reservoir bordered by a thin intima. The gland discharges between the mandible base and the clypeus. Males have considerably smaller glands than females, which corresponds to the lower amount of iridomyrmecins produced by males. Chemical analyses of the mandibular gland contents showed that the gland of females contained mainly (−)-iridomyrmecin, as well as low amounts of the other previously described iridoid pheromone compounds, while the glands of males contained only (+)-isoiridomyrmecin. The morphology and sizes of the mandibular glands of males and females of L. heterotoma have evolved to the multi-functional use of iridomyrmecin.

Intraspecific and interspecific competition for mates: Rana temporaria males are effective satyrs of Rana dalmatina females

Reproductive interference can seriously affect the reproductive success of involved individuals and may lead to local exclusion of the competitively inferior species. The components of male competitiveness in direct bodily fights for females have been studied rarely in a heterospecific context. In explosively breeding anuran amphibians, males are often coercive and indiscriminate, which frequently leads to interactions among heterospecific males. We experimentally assessed the competitiveness of male Rana dalmatina (RD) and R. temporaria (RT), two species with overlapping breeding both in time and space. The mating speed of the RD males decreased over the course of the breeding season, whereas RT males retained their swiftness. In addition, the RD males were rarely able to replace the RT males from amplexus with RD females, while takeovers frequently occurred among the RD males. Further, larger RD males were more successful in maintaining amplexus and in achieving takeovers when facing smaller conspecifics. Our results suggest that male body size is important for intraspecific competition among the RD males, but the RT males outcompete the RD males of all sizes, perhaps due to their larger body size. Hence, RT males are likely to be effective satyrs of RD females, because they may lower the reproductive success of the latter. Such interspecific differences in the competitiveness of males may represent an important mechanism that contributes to the arousal of asymmetric reproductive interference between species. Reproductive interference—interactions between species during mating with negative consequences on the fitness of involved individuals—is widespread in nature. Even though differences in the competitiveness of males of interfering species may have severe consequences, competitiveness of males has rarely been studied in an interspecific scenario in vertebrates. Males of anuran amphibians are often indiscriminate and coercive and engage in bodily fights for the possession of both conspecific and heterospecific females, which may often compromise the reproductive success of involved males and females. Here, we demonstrate that interspecific differences among ranid males can be large in the swiftness of pair formation, in the ability to defend the mating position and to perform takeovers. These differences are likely to lower the reproductive performance of the competitively inferior species, potentially leading to its local extinction.

Linking intra- and interspecific assortative mating: Consequences for asymmetric sexual isolation.

Assortative mating is of interest because of its role in speciation and the maintenance of species boundaries. However, we know little about how within-species assortment is related to interspecific sexual isolation. Most previous studies of assortative mating have focused on a single trait in males and females, rather than utilizing multivariate trait information. Here, we investigate how intraspecific assortative mating relates to sexual isolation in two sympatric and congeneric damselfly species (genus Calopteryx). We connect intraspecific assortment to interspecific sexual isolation by combining field observations, mate preference experiments, and enforced copulation experiments. Using canonical correlation analysis, we demonstrate multivariate intraspecific assortment for body size and body shape. Males of the smaller species mate more frequently with heterospecific females than males of the larger species, which showed less attraction to small heterospecific females. Field experiments suggest that sexual isolation asymmetry is caused by male preferences for large heterospecific females, rather than by mechanical isolation due to interspecific size differences or female preferences for large males. Male preferences for large females and male-male competition for high quality females can therefore counteract sexual isolation. This sexual isolation asymmetry indicates that sexual selection currently opposes a species boundary.

Mate choice and host discrimination behavior of the parasitoid Trichogramma chilonis.

Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) is an important natural enemy of many species of lepidopterous pests and a widely used biological control agent. Detailed knowledge about its mate choice and host discrimination behavior is lacking. In this study, we studied the mate choice and host discrimination behavior of T. chilonis in experimental arenas through video tracking. Males' mate recognition capacity was realized by perceiving the sex pheromone of females. When offered two females of different species, male could distinguish the conspecific female from Trichogrammatoidea bactrae Nagaraja (Hymenoptera: Trichogrammatidae), a species that has overlapping hosts with T. chilonis. When placed with two females of different mating status, male preferred mating with the virgin female to the mated female. T. chilonis females could distinguish unparasitized host eggs from parasitized ones (parasitized by conspecific females or heterospecific females). They preferred to stay on and lay eggs in unparasitized host eggs. When T. chilonis females were only provided with parasitized host eggs (parasitized by T. chilonis and T. bactrae females), conspecific superparasitism occurred more often than heterospecific superparasitism. Furthermore, the host egg discrimination ability of T. chilonis females was mainly achieved through antennal perception.

Chemical cues from females trigger male courtship behaviour in grasshoppers.

Gomphocerine grasshoppers use species-specific calling songs for sex recognition and mate attraction. In two closely related species, Chorthippus biguttulus and C. mollis, acoustic communication is the only experimentally characterized communication channel that elicits male courtship behaviour. However, courtship in these species involves extensive close-range interactions that are likely to be mediated by other signalling modalities, in particular chemical cues. We developed a bioassay to determine if female cuticular hydrocarbons (CHCs) act as chemical cues that induce courtship behaviour, and if males assess variation in CHCs to determine whether or not to court a female. The results of this approach provide evidence that grasshopper males use species- and sex-specific information from CHC signals and respond with a courtship song to the CHC profile of conspecific females but not to the CHC profile of heterospecific females and conspecific males. We conclude that males of C. biguttulus and C. mollis use multimodal channels for mating decisions, based on both acoustic and olfactory cues. We discuss various factors that might favour the evolution of male choosiness in grasshoppers.

Stable coexistence of ecologically identical species: conspecific aggregation via reproductive interference

Stable coexistence of ecologically identical species is not possible according to the established ecological theory. Many coexistence mechanisms have been proposed, but they all involve some form of ecological differentiation among the competing species. The aggregation model of coexistence would predict coexistence of identical species if there would be a mechanism that generates spatially aggregated distributions that are not completely correlated among the species. Our aim is to demonstrate that continued dispersal, triggered by reproductive interference between ecologically identical species, is such a mechanism. This study has been motivated by species using ephemeral patchy resources, such as decomposing fruits, fungal sporophores, carrion, and dung. We analyse an individual-based model with sexual reproduction, in which the progeny develops in ephemeral resource patches and the new generation disperses to a new set of patches. We assume spatially restricted dispersal, that patches differ in detectability, and that unmated females continue dispersal. In the model, reproductive interference (males spend some time searching for and/or attempting to mate with heterospecific females) reduces the mating rate of females, especially in the less common species, which leads to increased dispersal and reduces spatial correlation in species' distributions. For a wide range of parameter values, coexisting species show a systematic difference in their relative abundances due to two opposing forces: (1) uncommon species have reduced growth rate (Allee effect), which decreases abundance; (2) an abundance difference between the species reduces interspecific spatial correlation, which in turn reduces interspecific competition and allows the rarer species to persist at low density. Our results demonstrate a new mechanism for coexistence that is not based on ecological differentiation between species.