Identification of acoustic stimuli that mediate sexual behavior inDrosophila busckii (Diptera: Drosophilidae)

We have shown that D. busckiimales and females, unlike other drosophilids that have been analyzed in this regard, court and copulate as well in relatively dim red light as they do in bright white light. We have also shown that males and females of this species flutter their wings during courtship and that wing fluttering in both sexes is associated with acoustic stimuli. Wingless males perform vigorous courtship but are incapable of mating, suggesting that females must perceive male song to be receptive to copulation. When they are tested with normal males, wingless females stimulate vigorous courtship, but their copulation frequencies are significantly lower than winged females. This observation suggests that perception of the female's song by either or both sexes facilitates mating.     

Mating behavior of male deer ticksIxodes dammini (Acari: Ixodidae)

To analyze the sexual behavior of male black-legged deer ticks Ixodes dammini,we collected ticks infesting 202 white-tailed deer. On average, 17.7 males and 8.8 females infested each deer. Field-collected males copulated with a mean of 2.25 females, and virgin males mated with 2.4 females. On experimental hosts, males established sexual contact with feeding females and repelled other males, and about half remained paired after their mate detached. Engorged females continue to be receptive, and males mate more readily with them than with nonfed females. We conclude that male I. damminiare endowed with a repertoire of behaviors which favor an opportunistic mating before seeking a host and a preference for mating with feeding females on the host accompanied by tenacious mate guarding.     

Dispersal Patterns Among Olive Colobus in Taï National Park

In Primates, females are more likely to be philopatric than males. However, in some species like Procolobus verus, females or individuals of both sexes disperse. In Taï National Park, Ivory Coast, olive colobus groups are small, with one or two adult males and 6 females. Dispersal is common for juveniles and adults of both sexes. Adult male dispersal is less common than adult female dispersal. Adult females immigrated especially into small, one-male groups indicating that food competition played a role. Furthermore, unknown sexually receptive females visited resident groups and mated with the resident males for a few days before disappearing again. Adult males dispersed when this improved their mating opportunities. All juveniles left their natal groups. The dispersal of juveniles may be a strategy to prevent inbreeding with their parents. Dispersal by juvenile males furthermore seemed to be the result of mate competition. The high dispersal rates, visits by receptive females, and dispersal of all individuals in the population suggest that moving between groups is a strategy that can be used ad hoc in several situations more easily in the olive colobus than in most other primates. The predation risks related to moving between groups were reduced by dispersing in conspecific or allospecific groups and by dispersing to neighboring groups.     

Male rank,reproductive behavior,and reproductive success in free-ranging rhesus macaques

Paternity assessment through DNA fingerprinting by synthetic oligonucleotide probes was applied to one birth cohort in a social group of free-ranging rhesus macaques (Macaca mulatta) on Cayo Santiago. The 11 group males and 9 males from other groups were observed mating with the females. Paternity was determined for 11 of the 15 infants. Male dominance rank was not associated with reproductive success. High-ranking resident males (N=5) sired 27% of the infants born during a one-year study. Four of the 11 infants of known paternity were sired by males of other social groups. The four infants of unknown paternity were sired either by males not observed mating with the females or the low-ranking male who was not fingerprinted. Male dominance rank was not associated with reproductive activity during conception cycles. These results suggest that the effect of rank on male reproductive success is not a predictable correlation, but a conditional probability.     

Social Relationships Among Male <Emphasis Type="Italic">Alouatta pigra</Emphasis>

We investigated male social relationships in 2 groups of black howlers (Alouatta pigra) in Palenque National Park, Mexico, over a 14-mo study characterized by frequent changes in male group membership. Both single males and pairs of males entered our focal groups. Single males tended to join groups, whereas pairs of males entering groups together successfully evicted resident males. The 19 male dyads across the 11 periods defined by changes in group membership were rarely in close proximity or interacting with one another. Nevertheless, 1 male formed significantly closer associations with resident females in 6 periods and achieved higher mating success during 4 of the periods when ≥1 female was sexually active. In the other 5 periods, no particular male maintained significantly closer associations with resident females, which may be a result of the rapid sequence of changes in male membership and corresponding social instability. Resident males participated frequently and consistently in mutual howling, but the resident male with the strongest female associations and highest mating success initiated howling bouts more frequently in all but 1 of the 6 socially stable periods. Though still preliminary, our findings suggest that variation in social relationships among male black howlers may be more related to their ability to establish strong relationships with females than to their relationships with one another.     

The Hilltopping Mating System of Leschenaultia adusta (Loew) (Diptera: Tachinidae)

Males of the tachinid fly Leschenaultia adusta perch on small trees and shrubs on the highest parts of Usery Peak in central Arizona. Individuals select twig perches on the downwind side of these plants and fly out spontaneously from time to time or in response to another passing insect. Conspecific males elicit chases that on occasion escalate into elaborate, high-speed pursuit flights that go back and forth near the plant for several minutes. Although several males sometimes perch together briefly in the same plant, typically only one individual remains at a site for more than an hour on any given day. These site-faithful males can be considered territorial residents; they constituted about one-quarter of the males marked during the study. More than half of these residents returned to the same perch plant for two or more days. Perch plants varied in their attractiveness to male flies; male preferences were largely consistent across two years of study. Given that females were occasionally observed mating at male-occupied plants, we place the mating system of L. adusta within the hilltopping territorial category in which males compete for landmark perching sites attractive to receptive females. As is true for other hilltopping insects, receptive females of L. adusta appear to be rare and widely distributed.     

Seasonal, sex, and interspecific differences in activity time budgets and diets of patas monkeys (Erythrocebus patas) and tantalus monkeys (Cercopithecus aethiops tantalus), living sympatrically in northern Cameroon

I examined seasonal, sex, and interspecific differences in activity time budgest and diets of patas (Erythrocebus patas) and sympatric tantalus monkeys (Cercopithecus aethiops tantalus) on the basis of 5-day data sets collected in three and two different seasons, respectively, by the method of focal animal sampling. The seasons included species-specific mating and birth seasons. As compared with not only the birth season but also conspecific females, both patas resident male and tantalus male spent less time feeding and more time resting, day and night, in their respective mating seasons. Given that day-resting time includes time for vigilance for non-resident males and receptive females, this may reflect that males should minimize time spent feeding to allow maximum participation in other fitness-increasing activities such as mating-relating activities asSchoener (1971) predicted. In both species, the males consumed fruits containing less protein but more calories and showed a high feeding rate to compensate for the shorter time spent feeding in the mating season. In contrast, females consumed protein-rich food types (i.e. animals, protein-rich seeds, leaves, and flowers) in the birth season to meet the high demand for protein due to pregnancy and lactation. Given that the season for males was considered to be not a calendar but a reproductive “season” (i.e. mating or birth season), both sexes of patas spent more time moving and less time day- and night-resting than did the tantalus counterparts irrespective of the “season”. Patas subsisted on fruits, gums, and supplementarily lipid-rich seeds as an energy source and animal matters and protein-rich seeds as a protein source. In contrast, tantalus subsisted on fruits and lipid-rich seeds as energy and flowers and leaves as protein.     

The influence of female age on male mating preference and reproductive success in cabbage beetle,Colaphellus bowringi

The influence of female age on male mating preference and reproductive success has been studied using a promiscuous cabbage beetle, Colaphellus bowringi Baly （Coleoptera： Chrysomelidae）. In a simultaneous choice test, middle-aged females had significantly greater mating success than young and old females. In single pair trials, when paired with middle-aged virgin males, middle-aged females mated faster, copulated longer, and had greater fecundity and fertility than young or old females, while the longevity of males was not significantly affected by female age. This study on C. bowringi suggests that middle-aged females are more receptive to mating, which can result in the highest male reproductive success.     

Protandry in the parasitoidCardiochiles nigriceps,as related to its mating system

A laboratory study was conducted of the emergence times and mating success ofCardiochiles nigriceps Viereck (Hymenoptera: Braconidae), a larval parasitoid of the tobacco budworm,Heliothis virescens (F.) (Lepidoptera: Noctuidae), and in view of this information, the parasitoid's mating system was explored. Observations on laboratory populations ofC. nigriceps confirmed the occurrence of two types of protandry, i.e. seasonal and diurnal; males emerged 2 days before females in a generation, and emerged about 1 hr before females on a given day. An experiment on mating success showed that newly emerged females are not receptive to males that emerged 1 hr earlier, but that these males and females often mate successfully after 1 more hr. The experiment also showed that 1- to 5-day-old males are more successful than 1-hr-old males in mating with 0- to 1-hr-old females. Thus, it is argued that males emerging on a given day have a disadvantage in competition for mates with males that emerged days earlier, and that this disadvantage may serve as a selection pressure toward diurnal protandry. A monogamous mating system for females ofC. nigriceps is suggested because sexual selection would be expected to be strong in species exhibiting both seasonal and diurnal protandry. A possibility of a sibling mating system inC. nigriceps is questioned partly because newly emerged females are unreceptive to males that emerged 1 hr earlier and partly because this parasitoid is solitary in what is considered highly dispersed hosts in the field.     

Male pioneering as a mating strategy: the case of the beetle Maladera matrida

1. The phenomenon of male pioneering, whereby males are active (daily) before females, is compared with protandry, a phenomenon whereby males are sexually matured before females. The effects of natural selection and sexual selection on both phenomena are discussed. 2. In Maladera matrida Argaman (Coleoptera: Scarabaeidae), males emerged from the soil a few minutes before females, every evening, to feed and mate. 3. Aggregations of males and females are formed at sites of plant damage where males initiated feeding. 4. All copulations were initiated at the beginning of the activity period so males that emerge earlier may increase their probability of finding a mate. 5. Females mate only once in an evening. 6. Males that emerge later may not find receptive females with which to mate. 7. The aggregation of beetles per se did not contribute to the individual mating success because it occurred during and after the copulating had begun. 8. Male pioneering may evolve through sexual selection by means of male–male competition in time to achieve receptive females.     

Causes and correlates of loss and recovery of sexual receptivity inLucilia cuprina females after their first mating

After an initial mating, females of the Australian sheep blowfly, Lucilia cuprina(Diptera: Calliphoridae), rejected mating attempts by males for several days. Almost all (>98%) females were unreceptive 24 h after mating. When tested 9 days after mating receptivity had returned in 24% of females denied the opportunity to oviposit and 45% of females given repeated opportunities to oviposit on liver. Those mated females that regained receptivity mated as readily as virgins. Gravid first-, second-, or third-cycle females that did not oviposit when presented with liver had a higher receptivity than those that laid. These non-layers laid after remating. Injection of 1 male equivalent of an extract of male accessory reproductive glands into virgin females switched off their receptivity within 5 h for at least 8 days. An extract of testis reduced receptivity 5 h after injection but had no detectable effect 3 days after injection. Both extracts increased the tendency of virgin females to oviposit. There was no difference in the sperm stores of females that refused to lay a second egg mass and comprised a high percentage of receptive females and those given no opportunity to lay this egg mass.     

Simultaneous polygyny of the gobiid fish Asterropteryx semipunctata in relation to mate availability

Nesting males of Asterropteryx semipunctata conducted spawning behavior with 2–6 females simultaneously. We carried out field observations on a rocky reef in Kagoshima, Japan, to examine the hypotheses that large males will show multi-female spawning behavior because of their mating advantage, and that simultaneous multi-female spawning will occur when the operational sex ratio (OSR; the ratio of receptive males to receptive females) becomes female-biased. Contrary to our prediction, neither the total number of multi-female spawnings during a spawning season nor mean number of spawning females at a time were correlated with nesting male sizes. This indicates that larger males often did not conduct multi-female spawnings. As predicted, the incidence of multi-female spawning followed the change in the OSR over time—as the OSR in the study area became biased toward females, the incidence of multi-female spawnings gradually increased. Our results suggest that mate availability affects mating patterns in A. semipunctata.     

Sperm Competition and Optimal Timing of Matings in Microcebus murinus

Female promiscuity is common in mammals and leads to sperm competition: the sperm of ≥2 males compete for ova. Scientists understand the possible role of optimal insemination periods for male reproductive success in many species as well as the impact of monopolization of receptive females. Information from experiments combined with detailed observations from the field that allow determining the relative impacts of the elements in the same species are rare. We studied sperm competition and the role of optimal insemination periods in gray mouse lemurs (Microcebus murinus), a small solitary nocturnal primate from Madagascar. We used controlled matings to identify the relative impact of both contest and scramble competition, which characterize their mating system, on paternity. Fifteen females mated with 3–6 males in quick succession. Our experiments revealed that the optimal insemination period is during early receptivity. Early but not first mating males are more likely to sire offspring. Comparison with our field data indicate that the timing of male monopolization efforts correspond with the optimal insemination period.     

Spatial organization of the fat dormouse (Glis glis) in an oak-hornbeam forest during the mating and post-mating season

Home range (HR) size and overlap, movements, and nest site use of fat dormice Glis glis (Linnaeus, 1766) were studied by live-trapping and radiotracking in the Bialowieza Forest in north-eastern Poland. The study was conducted during a mast year of oak Quercus robur (2001) and hornbeam Carpinus betulus (2002). Average HR size measured by 100% minimum convex polygons varied from 3.6 to 7.0 ha in males and from 0.55 to 0.76 ha in females. HR size in males was significantly larger in the hornbeam mast year than in the oak mast year, which was probably due to the lower energy value of hornbeam mast. Males had significantly larger HRs and used more nest sites than females. In contrast to females, HRs of males overlapped extensively. In the mating season, core areas of males overlapped significantly more and they shared their core areas with more males than in the post-mating season. During the mating season, males were found to share nest sites with other males or with a single female. Additionally, groups of 2–3 males were observed aggregating around a female during the mating season. Our data suggest that fat dormice have a promiscuous mating system where the females are territorial, and the non-territorial males directly compete for access to receptive females during the mating season.     

Mating strategies in two species of dart-poison frogs: a comparative study

Comparative field studies of species of dart-poison frogs in the genus Dendrobates were carried out to test predictions from two hypotheses that attempt to explain female-female competition for mates in species of Dendrobates with male parental care. The sex role reversal hypothesis proposes that males invest so much time and energy in parental care that receptive males are rare relative to receptive females, and females compete to find and mate with receptive males. The parental quality hypothesis proposes that females compete to monopolize the parental effort of particular males, because they potentially suffer a cost when their mates care for the offspring of other females. Comparisons between species with male parental care (Dendrobates leucomelas) and female parental care (Dendrobates histrionicus) contradicted prediction of the sex role reversal hypothesis, but were consistent with predictions of the parental quality hypothesis. Male D. histrionicus did not compete for mates more aggressively than male D. leucomelas, and male D. leucomelas were not more selective about mating than male D. histrionicus. Female D. leucomelas and D. histrionicus were both selective about mating; female D. leucomelas associated with and competed for particular males, whereas female D. histrionicus did not.     

The function of male aggressive displays towards females in mountain gorillas

In groups ofGorilla g. beringei, male aggression towards females regularly takes the form of male display. This paper examines male display towards females in two Karisoke study groups (Group 5 and Group BM) in 1989, a period when none of the females were new immigrants. Results are based on 259 hr of focal observations and 121 hr ofad libitum observations on male behaviors towards females. The goal is to see if the data are compatible with four non-mutually exclusive hypotheses to explain male displays towards females: (1) demonstration of male fighting abilities to influence female long term residence decision; (2) decrease potential competitive inequities between females; (3) provision to females of an occasion to confirm their subordinance to a male; and (4) short term influence on mating. First, male-female proximity was tested against proportion of male displays, to rule out the possibility that males display towards females simply because they happen to be close by. There was no association between proximity and male display. Dominant males were responsible for a higher proportion of displays than subordinate males. This is consistent with the idea that males display to demonstrate their fighting abilities, or their qualities as protector, since dominant males are the ones offering long term protection against infanticide and predators. Females that were in a position to transfer did not receive a higher proportion of male display, however. Long term resident dominant females received a higher proportion of displays from the dominant males, which is consistent with the idea that males attempt to decrease potential competitive inequities between females. There was an association between female appeasement reactions and male displays, which suggests that males display to create occasions for the females to confirm their subordinance to them. Estrous females did not receive a higher proportion of male displays, and there was no association between male display and copulation, suggesting that male displays are not a form of courtship aggression aimed at influencing mating in the short term.     

Mating system of an exceptional primate, the olive colobus (Procolobus verus)

In the olive colobus (Procolobus verus), many groups have multiple males and the males have large testes. This indicates that even though this species lives in small groups, single males do not monopolize the groups. We investigated the strategies employed by males to secure their mating success, and sought to determine whether the lack of male monopolization was a result of female mating strategies, as indicated by the exaggerated sexual swellings of the females. Four study groups were monitored for demographic changes, and group composition was determined in six additional groups in Taï National Park, Ivory Coast, between 1994 and 1999. Social behavior was recorded by scan and focal sampling in the study groups. The almost permanent association of olive colobus with Diana monkeys (Cercopithecus diana) in effect provided males a resource at which they could expect females to visit and sometimes even permanently join them, as well as protection from predators. As alternative strategies for obtaining females, one male took over the group of another male and one male immigrated into a bisexual group. Within bi‐male groups, dominant males mated most frequently and males defended their groups during intergroup interactions. Lone females that visited groups or solitary males had a swelling more often than expected, and generally mated with the males they visited. Females had long receptive periods, several consecutive receptive cycles, and some overlap in receptive periods within groups. Females mated with extragroup males, and during infertile periods. We concluded that the males used the Diana monkeys for safety reasons and to obtain mating partners, and that female reproductive biology and behavior prevented the monopolization of groups of females by single males. Our data were inconclusive as regards the benefits to females of avoiding monopolization by males. Am. J. Primatol. 62:261–273, 2004. © 2004 Wiley‐Liss, Inc.     

Reproductive behavior and the maintenance of all-female Poecilia

Synopsis There are four members involved in the breeding complexes of poeciliid fishes found in the freshwaters of northeastern Mexico: males and females of a bisexual species, and diploid and triploid unisexuals. Both unisexuals reproduce by gynogenesis, i.e., an asexual type of reproduction where the sperm triggers egg development but the male genome is excluded to produce clonal offspring. The three types of females are closely related, which suggests that they are potential competitors since all three require the service of the same males. The potential for competition is compounded by a highly skewed sex ratio in favor of females. On the average the unisexuals comprise about 30% of the Poecilia females. This high frequency coupled with a close genetic relatedness to their bisexual hosts, raises the question of how the unisexuals are maintained in nature.Other investigators who work with bisexual/unisexual complexes in the related genus, Poeciliopsis, have postulated that male dominance hierarchies are responsible for restricting the access of subordinate males to their conspecific females. Consequently, these subordinate males mate with unisexual females. The current report tests whether or not this hypothesis applies to bisexual/unisexual complexes of Poecilia.We have found that linear dominance hierarchies appear to function in the defense of home ranges and do not restrict access of males to females. Dominant males exhibit less mating activity than subordinate males towards females. Previous reports showed that males are reproductively competent throughout the year, whereas females show striking asynchrony in their reproductive readiness. Such asynchrony limits the proportion of receptive females at any one time. Consequently, there are more males ready to mate than there are females receptive to their mating attempts. This may lead to mating frenzies. We postulate that these indiscriminate matings maintain the fertility of both unisexuals. When the relative reproductive outputs of adult females are compared, both unisexuals appear as fit as their bisexual congeners.     

Copulation Is Not a Prerequisite to Male Reception of Eggs in the Golden Egg Bug Phyllomorpha laciniata (Coreidae; Heteroptera)

Females of the golden egg bug, Phyllomorpha laciniata, lay eggs on the backs of conspecifics. Male response to female oviposition attempts is either passive or resistant. Passive males remain still during oviposition, while resistant males move repeatedly and thereby delay or avoid being encumbered. We investigated how previous mating experience affected male acceptance of eggs. Males from two Spanish populations, from Andalusia and Catalonia, were allowed to mate with single females repeatedly. These experimental pairs were then presented with either a single, nonmating male or a pair in copula. We expected mating partners to resist oviposition attempts less strongly than nonmating males but no differences were detected. However, there was a significant difference in behavior exhibited by males from the two populations; males from Catalonia were relatively passive but males from Andalusia routinely resisted encumbrance. Predation pressure and the availability of receptive females may explain the observed differences between the populations.     

Predation risk and alternative mating tactics in male Trinidadian guppies (Poecilia reticulata)

In the guppy (Poecilia reticulata), males have two alternative mating tactics. Individual males may either display to a receptive female prior to attempting to copulate with her or attempt to quickly sneakcopulate with a female without first displaying to her or without a prior receptive response from her. In this study, I experimentally investigated the effects of simulated local increases in the risk of predation (in the form of a cichlid fish predator model in situ) on the mating tactics used by free-ranging male guppies in two typical macrohabitats (riffle and pool) of a Trinidadian river. Focal male guppies displayed to females significantly less often on average, and conversely attempted sneak copulations more often, in the presence of the predator model than in its absence; this pattern was similar for both habitats. These fish therefore performed a lower proportion of sigmoid displays and increased their sneaky mating attempts when the apparent risk of predation had increased locally. This predator-mediated response is consistent with a trade-off between mating success and risk of mortality due to predation. The results are the first to confirm risk-sensitive mating behaviour in free-ranging male guppies within a population, and demonstrate the potential importance of predators in influencing the relative use of alternative mating tactics in this species on a microgeographical scale in the wild.