Mate-guarding Behaviour Research Articles

Behavioral Interaction Between Males of Cephalonomia tarsalis (Ashmead) (Hymenoptera: Bethylidae) Competing for Females

Male Cephalonomia tarsalis (Ashmead) compete with one another for mates. The behavioral interactions between males for mates occur both on and off females. Males winning the first copulation do not exhibit apparent postcopulatory mate-guarding behaviors, and females accept subsequent copulations with losing males soon after separation. The duration of copulation when a second male is present is shorter than when only one male is present. However, females receive sufficient sperm for their life-time female progeny production in copulations disrupted artificially at 10 s (∼1/5 of the regular copulation duration) under normal noncompetition situations. This suggests that shorter copulations because of male–male competition could still result in adequate sperm transfer. Larger males were not more successful in competition than small males, but male competitive ability decreased with age.

Social monogamy in the cleaning goby Elacatinus evelynae: ecological constraints or net benefit?

We tested predictions from four hypotheses to explain the occurrence of long-term socially monogamous pairs in the Caribbean cleaning goby Elacatinus (=Gobiosoma) evelynae, namely (1) resource limitation, (2) low population and/or low mate density, (3) territorial defence and (4) net benefit of single-mate sequestration. We found no evidence that resources, in terms of available cleaning stations or clients to clean, were limited (1) or that after experimental goby removals, single individuals could not maintain cleaning stations alone (2). Population density was low but this did not prevent artificially widowed fish from remating quickly with individuals as large as their initial partners (3). Social monogamy in E.evelynae appears to result from the benefits associated with sequestering a large, high-quality mate (4). Both males and females showed intrasexual aggression towards experimental intruders consistent with mate guarding. Opportunities for polygynous matings by males, assessed by comparing the sizes, distances between and mating synchrony of neighbouring pairs, appeared both low and of limited value. Males therefore benefit most from guarding a larger, more fecund female. Females spent longer cleaning when paired with a large male, indicating that the benefits of guarding a high-quality mate may extend outside of the reproductive period for socially monogamous species. These results add to an increasing number of studies on coral reef fish showing mate-guarding behaviour and benefits to males and females from sequestering a single mate. Copyright 2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.

Milt quality, parasites, and immune function in dominant and subordinate Arctic charr

Within a species, different males may display different mating strategies. For example, some males may be selected to invest in attractiveness and mate guarding, whereas others are selected for increased sperm production and sneaky breeding. In systems with a hierarchical structure, dominant males are expected to adopt mate-guarding behaviour and subordinate males sneaky-breeding behaviour. In this study, we kept wild-caught and sexually ripe male Arctic charr (Salvelinus alpinus) in size-matched pairs and determined social rank from the number of aggressive encounters. After 4 days, subordinate males showed symptoms of stress, with higher blood glucose and erythrocyte levels than dominant males. There were no differences between dominant and subordinate males in parasite intensities or immune activity, measured as levels of granulocytes and lymphocytes in blood. Although subordinate males had smaller testes than dominant males, they still had a higher density of sperm cells and higher sperm numbers relative to the size of their testes. These results can be explained as indicating adaptation of subordinate males for reproduction in an unfavourable role, always exposed to sperm competition and out of synchrony with females' egg release. Our results suggest that rapid changes in social rank may affect ejaculate production.

Tests of the mate-guarding hypothesis for social monogamy: male snapping shrimp prefer to associate with high-value females

Social monogamy without biparental care has evolved in many taxa, and a number of hypotheses have been developed to explain this phenomenon. Several authors have suggested the importance of male mate-guarding behavior in the evolution of social monogamy, although empirical support for this hypothesis is lacking. In the caridean shrimp genus Alpheus, social monogamy may result from selection on males for long-term guarding of females because mating is temporally restricted to a short time after the female's molt. I used Alpheus angulatus to test two predictions of the extended mate-guarding hypothesis: Males should (1) be physiologically capable of predicting the timing of female sexual receptivity, and (2) prefer to associate with (guard) females that are closer to sexual receptivity. Data from a Y-maze experiment testing for distance chemical communication showed that males of A. angulatus were attracted to water treated by exposure to premolt females, repulsed by water treated by exposure to intermolt males and females, and did not appear to respond in either direction to water treated by exposure to premolt males. In mate choice experiments, significantly more males paired with premolt females than with postmolt females. These data suggest that males of A. angulatus engage in precopulatory mate-guarding behavior. Other factors (population density, sex ratio) may have played a role in the temporal extension of mate guarding to social monogamy. Copyright 2003.

Mate grasping in drosophila pegasa by

Abstract Among all species in the genus Drosophila whose sexual behavior has been studied, D. pegasa is unique in that males exhibit no courtship behaviour before they mount females. Instead, the male simply climbs on top of the female and rides on her abdomen ('grasping') for long intervals, often an entire 8-h observation period. In this study we conducted a series of observations and experiments to quantitatively describe grasping behaviour in D. pegasa and examine its relationship to social environment and the reproductive biology of the species. All observed courtship bouts involved grasping behavior, and males always initiated copulation during a grasping bout. The frequency of grasping and the average duration of a single grasping bout increased with the number of flies present. Males often copulated several times during a single grasping bout, and such multiple copulations during a single mounting also appear unique in the genus. Unexpectedly, the number of sperm that a male transferred to a female during a single grasping bout was negatively correlated with the number of copulations. This relationship was apparently due to repeated copulations by males who were unsuccessful at transferring sperm. Multiple copulations without sperm transfer may result from cryptic female choice. Male grasping behaviour in this species appears to have evolved as a substitute for display and courtship behaviours, but possibly also as a mate-guarding behaviour since males continue to grasp after they have successfully transferred sperm. The tarsal claws and pulvillar pads of D. pegasa are disproportionately larger than those of related Drosophila species, evolutionary changes that may facilitate grasping by males.

The mate-guarding behaviour of male kokanee oncorhynchus nerka

AbstractThe patterns of mate-guarding in kokanee (non-anadromous Oncorhynchus nerka) are analysed and discussed in relation to existing theory of precopulatory mate-guarding. Male salmon typically guard females prior to spawning events and aggressively exclude other males from their vicinity. Mate-guarding is thought to increase the likelihood of releasing gametes before other males (during a spawning event) and fertilising the greatest proportion of the clutch. The optimal duration of mate-guarding can be considered in a game context because the mate-guarding behaviour of other males influences the probability of finding an unguarded female if a male leaves a female in search of other opportunities. At the Meadow Creek spawning channel, males guarded females, searched for unguarded females, or joined groups of non-breeding males and females. In accordance with mate-guarding theory, males continued to guard the same females after presumed spawning events (but during her egg deposition period) more often than expected on the basis of random pairing. This prevented some males from ever pairing with females. Gaining familiarity with habitat features may confer a competitive advantage to mate-guarding males and may favour prolonged mate-guarding. Because of the importance of finding nesting females quickly, before other males, unpaired males may wait for pairing opportunities rather than occupy distant satellite positions to breeding pairs.

Extra-pair paternity and mate-guarding behaviour in the brown thornbill

We used multilocus DNA fingerprinting to assess parentage in the brown thornbill, Acanthiza pusilla, a socially monogamous Australian passerine. Extra-pair paternity was uncommon (6.2% of 178 offspring; 11.9% of 67 broods) and there was no evidence of intra-specific brood parasitism. Extra-pair paternity was limited because pairs spent more time together when females were fertile and males were able to evict intruding males before they could approach the female. Males were responsible for the close proximity of partners during the fertile period. Mate guarding therefore appears to be a male tactic aimed at preventing female infidelity rather than a cooperative behaviour of the pair aimed at preventing extra-pair copulations and/or female harassment. Females did not attempt to escape male guarding and were rarely observed to solicit copulations from intruding males. Nevertheless, females paired to smaller and younger males were more likely to cuckold their mates than females paired to larger and older males. This suggests that females may be more likely to seek or accept extra-pair matings when paired to small, young males or that old, large males are better at preventing their mates from engaging in extra-pair copulations. We found that male age but not male size influences mate-guarding behaviour. Older males tended to respond more aggressively to intruders. We therefore speculate that the relationship between male size/age and extra-pair paternity in brown thornbills may arise because female thornbills prefer large males as mates but are unable to express this preference as easily when paired to older males.

Mate guarding in the Seychelles warbler is energetically costly and adjusted to paternity risk.

Males may increase their fitness through extra-pair copulations (copulations outside the pair bond) that result in extra-pair fertilizations, but also risk lost paternity when they leave their own mate unguarded. The fitness costs of cuckoldry for Seychelles warblers (Acrocephalus sechellensis) are considerable because warblers have a single-egg clutch and, given the short breeding season, no time for a successful replacement clutch. Neighbouring males are the primary threat to a male's genetic paternity. Males minimize their loss of paternity by guarding their mates to prevent them from having extra-pair copulations during their fertile period. Here, I provide experimental evidence that mate-guarding behaviour is energetically costly and that the expression of this trade-off is adjusted to paternity risk (local male density). Free-living males that were induced to reduce mate guarding spent significantly more time foraging and gained significantly better body condition than control males. The larger the reduction in mate guarding, the more pronounced was the increase in foraging and body condition (accounting for food availability). An experimental increase in paternity risk resulted in an increase in mate-guarding intensity and a decrease in foraging and body condition, and vice versa. This is examined using both cross-sectional and longitudinal data. This study on the Seychelles warbler offers experimental evidence that mate guarding is energetically costly and adjusted to paternity risk.

MALE CHARACTERISTICS AND FERTILISATION SUCCESS IN BLUETHROATS

Abstract Extra-pair copulations (EPCs) can create or intensify sexual selection and, provided that fertilisation success is related to phenotypic traits, help explain sexual dimorphism in socially monogamous species. Previous experimental manipulations of the ornamental coloration in male bluethroats, Luscinia s. svecica, have shown effects on their social mating success, mate-guarding behaviour, and within-pair- and extra-pair paternity. This study investigates the relationship between male characteristics (reflectance of the blue throat feathers, width of the chestnut breast band, wing length, body condition and age) and fertilisation success under natural, non-experimental conditions. Combining three breeding seasons, 29% of 720 offspring were sired by extra-pair males and 54% of 136 nests contained one or more extra-pair offspring. The chroma (spectral purity) of the blue throat feathers and the width of the chestnut band were positively related to paternity in own nest, and for blue chroma this translated into a significantly positive relation with total fertilisation success. This suggests that differential within-pair paternity success exerts directional selection on the colour signal. None of the throat colour measures or morphological traits were significantly related to overall extra-pair fertilisation (EPF) success. However, restricting the analysis to males with one or more EPFs, there was a positive relation between amount of extra-pair paternity and blue chroma. Old males were more successful than young ones in achieving EPFs. Pairwise comparisons showed no plumage differences between cuckolded males and the males that cuckolded them. The absence of phenotypic correlates of male EPC-success agrees with our recent finding that females improve offspring quality through individual choice of EPC partners with 'compatible genes' rather than 'good genes' in an absolute sense. Our results indicate that experiments where traits are manipulated outside the natural range should be interpreted with caution, and illustrate the importance of a dual approach (experimental and correlative) in studies of sexual selection in the wild.

Costs of reproduction in male lizards, Sceloporus virgatus

Models of life history evolution typically assume a balance between the benefits of current reproductive activity and the costs to future reproductive success or survivorship, but empirical studies often find positive correlations between such components of fitness in undisturbed animal populations. I examined possible survivorship costs of reproduction in free‐ranging male lizards, Sceloporus virgatus, and found that males with low levels of mating success were less likely to survive to the following breeding season. I also investigated two possible indicators of reproductive effort, increase in ectoparasite load and decrease in body weight during the breeding season. Levels of parasitism with trombiculid mites at the end of the breeding season were not associated with any measure of fitness or body condition (mating success, survivorship to the following year, relative weight loss). Yearling males (which have low levels of mating success) usually gained weight during the breeding season, while older males generally lost weight during this period. This suggests that young males may have postponed reproduction in favor of body growth and that seasonal weight loss of older males might reflect reproductive effort. Within the group of older males, individuals with the highest levels of mating success did not have high levels of either weight loss or mortality. Mate guarding behavior, an alternative to the aggressive territorial behavior typical of many lizard species, may allow certain males to obtain mates without expending large amounts of energy or exposing themselves to great mortality risks.

BIOLOGY AND LARVAL MORPHOLOGY OFCEUTORHYNCHUS NEGLECTUS(COLEOPTERA: CURCULIONIDAE), A MINOR PEST OF CANOLA (BRASSICACEAE) IN WESTERN CANADA

AbstractA study was undertaken to determine aspects of the life history, behaviour, and host plant feeding preferences ofCeutorhynchus neglectusBlatchley, a minor pest of canola,Brassica napusL. andBrassica rapaL., in western Canada. The final-instar larva was described for the first time.Ceutorhynchus neglectuswas univoltine, with adults first occurring on host plants in early June. Mating occurred throughout June and July, and eggs were laid into the distal ends of developing siliques of flixweed,Descurainia sophia(L.) Webb (Brassicaceae). Mate guarding behaviour was observed for males ofC. neglectus, which remained attached to females long after copulation was completed and, if necessary, struggled with rival males to prevent them from fertilizing their mates. Larvae fed upon developing seeds and, when mature, bored through the pods, dropped to the soil, and constructed earthen cells approximately 2 cm beneath the soil surface where they pupated. Results from laboratory host preference studies were consistent with field observations which indicated that among selected species of Brassicaceae, leaves and siliques ofD. sophiawere preferred by adults ofC. neglectusas feeding sites. In contrast to flea beetles,Phyllotreta cruciferae(Goeze) (Coleoptera: Chrysomelidae), which fed indiscriminantly over the entire cotyledon surfaces of canola seedlings, adults ofC. neglectuscaused less cotyledon damage per individual and tended to feed on cotyledon edges. Because of its biology and host plant preferences,C. neglectusshould remain a minor pest of canola, and can only be expected to invade the crop when its preferred host (flixweed) is unavailable.

Coalitionary mate guarding by male chimpanzees at Ngogo, Kibale National Park, Uganda

Cooperative mate guarding by males is unusual in mammals and birds, largely because fertilizations are non-shareable. Chimpanzees live in fission-fusion communities that have cores of philopatric males who cooperate in inter-group aggression and in defending access to the females in their community. Male contest mating competition is restrained within communities, but single high-ranking males sometimes try to mate guard estrous females. Data from an unusually large chimpanzee commmunity at Ngogo, Kibale National Park, Uganda, that contains more males than any previously studied community show new variation in chimpanzee mate-guarding behavior. Contrary to expectation given the large number of males, mate guarding was as common as, or more common than, at other sites, and males other than the alpha male guarded more often. More strikingly, pairs or trios of top-ranking males sometimes engaged in cooperative aggression to prevent estrous females from mating with other males, but tolerated each other's mating activities. Both single males and coalitions mostly guarded periovulatory females. Mate-guarding coalitions were previously unknown in chimpanzees. Coalitions occurred in large mating parties, seemingly because these often contained too many males for single males to maintain exclusive access to estrous females. Coalition members gained higher shares of copulations than they could have expected from solo mate guarding, and suffered lower per capita costs of guarding (as inferred from aggression rates). Two males who most often participated in coalitions formed two-male coalitions at about the point where the number of males present made it unlikely that either could get 50% or more of total copulations on his own, and formed trios when this value dropped below 33%. Kin selection could be a factor in cooperation among male chimpanzees, but coalition members were not necessarily close relatives and the apparent structure of payoffs fit that of mutualism. Furthermore, reliance of male chimpanzees on support from allies to maintain high rank could have led to trading of mating exclusivity for support against mating competitors.

The nature and frequency of social interactions among free-living prairie voles ( Microtus ochrogaster )

Hypotheses relating the behavior of voles to their population cycles often assume that the rate of social interaction increases with population density. To test this assumption, we examined the frequency of social interactions in a population of prairie voles (Microtus ochrogaster) over a 7-year period. In addition, we characterized space use by resident animals, patterns of visitation by nonresidents to nests, and participants in social interactions. Social groups within the population typically displayed little overlap in their use of space, even at high population densities. Nevertheless, nonresidents, particularly wandering males, were captured as visitors at nests. The number of visits per social group did not increase in a simple linear manner with population density and was particularly variable when there were fewer than 100 animals/ha. At such times, more single females and fewer pairs received visits from males than expected based on the frequency of occurrence of these groups in the population; a similar pattern was noted during periods of high population density (≥100 animals/ha) but the comparisons failed to reach statistical significance. Furthermore, at high population density, more communal groups received visits from females than expected. Patterns of visitation to communal groups were influenced by the number of adult male residents (winter only), but not by the number of adult female residents or presence of philopatric female offspring. These data indicate that the frequency of social contact in prairie voles does not increase linearly with population density and is influenced by the spacing and possible mate-guarding behavior of resident animals.

Role of surface glycoproteins in mate-guarding of the marine harpacticoid Tigriopus japonicus

Surface glycoproteins serve as mate- and gamete-recognition molecules in some marine animals such as rotifers and sea urchins. We investigated the role of contact chemoreception of surface glycoproteins in mate recognition, mate-guarding, and spermatophore transfer in the marine harpacticoid Tigriopus japonicus Mori. Adult males accurately distinguished immature females from a pool of mixed-sex juveniles, and their behavior towards both live and dead females is described. A survey of the binding sites of twelve lectins to the surface of juvenile and adult females, and adult males demonstrated localized lectin-binding at sites considered important in mating behavior of each sex/age class. Treating adult males with the Triticum vulgaris lectin sharply inhibited normal mate recognition and guarding behavior, as did the monosaccharide glucosamine. Treatment of males with protease and detergents destroyed their mate-guarding behavior without affecting swimming behavior. These results suggest that protein receptors on the antennules of the males detect glycoprotein signals on the surface of females, recognizing carbohydrate moieties of glycoproteins to identify appropriate partners for guarding or mating. Surface glycoproteins may function as a common mechanism of sexual communication in many marine zooplankters.

EFFECT OF MALE / FEMALE SIZE RATIO ON MATING BEHAVIOR OF THE HERMIT CRAB PAGURUS FILHOLI (ANOMURA: PAGURIDAE) UNDER EXPERIMENTAL CONDITIONS

ABSTRACT We studied the mating behavior and clarified the mating sequences of the hermit crab Pagurus filholi under laboratory conditions. The mating sequences differed, depending on the male to female size ratio. Before copulation, larger males relative to potential female mates tended to perform precopulatory guarding behavior, i.e., grasping the rim of the shell of the female with their chelipeds, more frequently than smaller males. On the other hand, smaller males relative to the females appeared to insert their chelipeds and to attempt copulation by pulling the female out of the shell without performing precopulatory mate-guarding behavior. These different behaviors may be conditional strategies that depend on the male/female size ratio.

Copulation and mate-guarding patterns in polygynous European starlings

We recorded the timing and frequency of copulation and mate-guarding behaviour during the fertile period in relation to day of first ovulation and time of day in the facultatively polygynous European starling,Sturnus vulgarisAll within-pair copulations were female-solicited. Females solicited them at a high rate during both the pre-ovulatory and ovulatory period, but there were differences in solicitation rates between monogamous, primary and secondary females. Extra-pair copulation attempts were all male-initiated and females rarely engaged in them. Attempts by males were most frequent during the ovulatory period, when the probability of extra-pair fertilization was highest. Males intensively guarded their mate during both the pre-ovulatory and ovulatory period. In contrast to most other passerines, female starlings lay their eggs not at dawn but usually between 0900 and 1100 hours, implying that they may be most fertile in the late morning. During the ovulatory period, extra-pair copulation attempts were more frequent in the late morning than in the early morning, suggesting that males try to take advantage of this putative ‘insemination window’. Accordingly, there was some indication that mate guarding during the ovulatory period was more intense in the late than early morning. Females solicited within-pair copulations at a higher rate in the early morning than in the late morning, but copulation rate did not differ between early and late morning. The proportion of monogamous and polygynous males attempting extra-pair copulations did not differ significantly, but mate-guarding intensity differed significantly between female categories. Primary females were guarded less intensively than monogamous females suggesting that males trade mate guarding against mate attraction/courting additional females.

Coloured leg bands affect male mate-guarding behaviour in the bluethroat

Artificial traits such as coloured leg bands may affect an individual's mating success, as shown for some birds. One explanation is that colour-matching with a sexual ornament affects the individual’s sexual attractiveness. This study reports a colour-band experiment with free-living bluethroats,Luscinia s. svecicaa species where males have a distinct blue and chestnut throat and upper breast. There was no apparent difference in pairing success between males with ornament-matching colour bands (blue and orange) and males with non-ornamental colour bands. However, males with ornamental bands guarded their mates less intensely and spent more time singing, performing song flights and intruding into neighbours’ territories than males with non-ornamental bands. We conclude that colour bands affect the trade-off between mate guarding and advertisement behaviour in a way that is consistent with the hypothesis that bands with ornamental colours improve a male's attractiveness. The results are in concordance with a previous study of the same population, showing that males with experimentally reduced attractiveness guarded their mates more closely and advertised less for additional mates, than non-manipulated males.

Reproductive Behavior of Thyanta pallidovirens (Heteroptera: Pentatomidae)

Reproductive behavior of the stink bug Thyanta pallidovirens (Stal) was studied in the laboratory, including the determination of the sexual maturation period for both sexes, the effects of the number of copulations on fecundity, and the function of prolonged copulation. Mean premating periods for males and females were 3.6 ± 0.5 and 4.1 ± 0.6 d, respectively. Preoviposition period averaged 6.6 ± 0.9 d. Females preferred sheltered, roughtextured oviposition sites. Paired adults mated ≈13 times on average during their lifespan under laboratory conditions. The mean duration of copulations involving virgin females was >17 h, significantly longer than that of subsequent copulations, which lasted between 6.9 and 8.3 h. Multiple matings significantly increased female fecundity. Virgin males donated ≈17% of their body mass to a virgin female during mating. Duration of mating may be regulated by space available in the spermatheca for ejaculatory material. There was strong evidence of male mate choice, with males terminating copulation with small females before sperm was transferred. There was no indication of male mate-guarding behavior after copulation. Females almost always approached males from distances of >30 cm, suggesting that males attract females from a distance. Within 15 cm, males discern and approach females. Courtship behaviors of males included antennation of female antennae and abdomens, stroking the abdomens with the hind legs, and periodic male abdominal vibrations. Possible functions of these behaviors are discussed.

Dominance, Age, and Reproductive Success in a Complex Society: A Long-Term Study of the Mexican Jay

Observations of mate guarding by males and robbing of nest material by fe- males suggest the hypothesis that dominance should be related to reproductive success in the Mexican Jay (Aphelocoma ultramarina). We analyzed the probability of successful reproduction in this plural-breeding, group-territorial species with respect to variation in social rank, sex, age, flock territory, and year. We examined the correlates of dominance rank at two stages of nesting, early (before and during laying) and late (after laying). The correlates of rank differed between the sexes and nesting stages. In the early or prelaying stage, success in getting a mate and initiating laying was correlated with rank in males but not in females, and with age in both females and males. In the late stage, given that a bird had a nest with eggs, fledging success was not significantly related to rank overall. In females, however, a significant inter- action was found between rank and age such that top rank was associated with greater suc- cess in older but not younger females. These effects of dominance at two stages of the nesting cycle (i.e. before and after egg laying) are consistent with the mate-guarding behavior of males and the nest-robbing behavior of females during nesting. Received 30 January 1996, accepted 19 December 1996.

Mate-Guarding, Territorial Intrusions and Paternity Defence in the Polygynous Corn Bunting Miliaria calandra

Mate-guarding behaviour and territorial intrusions were examined in a population of polygynous Corn Buntings Miliaria calandra. All males showed only a weak tendency to mate-guard by close following of the female. Monogamous and polygynous males did not differ in their extent of mate-guarding, and there was no difference in the extent to which polygynous males guarded primary and secondary females. Territorial intrusions and attempted extra-pair copulations were infrequent and not timed to coincide with the fertile period of females. All intrusions were by territory-holding males, the majority of which were immediate neighbours. Unmated males did not intrude more than paired males and were not observed to attempt any extra-pair copulations. Polygynous males did not suffer significantly more intrusions than monogamous males. We suggest that either the high detectability of intrusions in an open habitat or female control over access to fertilizations made close mate-guarding unnecessary. Males may benefit more from maintaining their own territory in the hope of one or more females settling to breed, rather than seeking extra-pair copulations.