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1.
Recent studies have demonstrated that mating with multiple males can be beneficial for females and her offspring even if males contribute nothing but sperm. This was mainly established for species in which sperm from several males mix in the reproductive tract of the female, thus allowing sperm competition and/or female sperm choice. However, in species with last male sperm precedence, female re-mating decides against the previous male by strongly limiting his reproductive success. We tested the effect of female re-mating behaviour using the cellar spider Pholcus phalangioides, which shows strong last males sperm precedence and moderate levels of polyandry under natural situations. We predicted that females prevented from remating even though they are receptive would show reduced reproductive success compared to females that accept two copulations and females that reject a second male, since the latter two treatments were allowed to behave according to their decisions. However, if the number of matings per se had an effect on oviposition or on offspring performance, double-mated females should perform better compared to both treatments of once-mated females. We measured female fecundity and fertility over a period of 140 days, comparable to the species' natural reproductive peak season. Two thousand one hundred and fifty-two offspring from 67 first egg sacs were reared under two feeding levels. We registered development time and survival, and measured offspring adult size and mass. We found a positive effect of double mating, as in this treatment, oviposition probability was higher compared to the other treatments. Interestingly, adult female offspring of the DM treatment that were raised under low food level had a higher condition index compared to those from FS and RM, but development time, size and mass at adulthood were not affected by mating treatment. Female choice only seemed to affect hatching latency of the offspring. Overall, the main predictor of female reproductive output and success was female body size. 相似文献
2.
Parker's seminal work brought attention to the possibility of postmating sexual selection by non-random fertilization success.
Mechanisms for these processes are still only partly understood and there is clearly a need for more studies of intraspecific
variation in sperm precedence. Here, we report results from an experimental study of the variation in fertilization success
between males of the water strider Gerris lacustris. Genital morphology, male body size, and copulation duration were examined as possible correlates of paternity. The significance
of guarding duration was also analysed. Only male genital morphology was correlated to fertilization success. This is one
of the first studies showing a relationship between male genital traits and fertilization success, supporting the view that
sexual selection may be responsible for the rapid and divergent evolution of genital structures in animals with internal fertilization.
The fertilization success of last males varied considerably after double matings with a short mating interval (10 min). Last-male
priority ranged from 0 to 100% and usually one of the males involved fertilized almost all the eggs. After double matings
with a short mating interval, the proportion of eggs fertilized by the last male averaged 0.68 and was greater than 0.5. In
contrast, the average fertilization success was biased towards the first male when the matings were more spread out over time
(24 h). These results do not support earlier suggestions of a widespread last-male sperm priority in water striders.
Received: 28 July 1998 / Received in revised form: 15 March 1999 / Accepted: 28 March 1999 相似文献
3.
Costs and benefits associated with matings and the effects of mating frequency on fitness commonly differ between the sexes. As a result, outcrossing simultaneous hermaphrodites may prefer to copulate in the more rewarding sex role, generating conflicts over sperm donation and sperm receipt between mates. Because recent sex role preference models remain controversial, we contrast here some of their assumptions and predictions in the sea slug Chelidonura sandrana. For this hermaphrodite with sperm storage and internal fertilisation, risk-averse models assume that fitness pay-offs are constantly higher in the female than in the male function in any single mating. Moreover, excluding mutual partner assessment, these models predict male mating behaviour to be independent of receiver traits. The competing gender ratio hypothesis assumes that relative fitness pay-offs, and thus the preferred mating roles, vary and may reverse between matings and predicts that ejaculation strategies co-vary with receiver quality. We found that field mating rates of C. sandrana substantially exceeded what is required to maintain female fertility and fecundity, indicating large variation in direct female benefits between matings. We further demonstrate that male copulation duration adaptively increased with partner body size (i.e. fecundity) but decreased with recent partner promiscuity. These findings are compatible with the gender ratio hypothesis but contradict risk-averse models. 相似文献
4.
Kevin J. Delaney J. Andrew Roberts George W. Uetz 《Behavioral ecology and sociobiology》2007,62(1):67-75
Male signaling behaviors are often studied in a single context but may serve multiple functions (e.g., in male–male competition
and female mate choice). We examined the issue of dual function male signals in a wolf spider species Schizocosa ocreata (Hentz) that displays the same species-specific signaling behaviors in both male–male and male–female contexts. These signaling
behaviors have been described as either aggression or courtship according to the context observed. We tested the possibility
of dual functions by comparing the relationship between behaviors and outcome of male–male contests (winner/loser) and male–female
mating encounters (mating success). Frequency, rate, and mean duration of signaling behaviors did not vary with outcome of
male–male contests, which appears instead to be based upon relative size and body mass. Winners of contests had significantly
greater body mass than losers, and greater mass relative to opponents was significantly associated with probability of winning.
Overall, signaling rates were much higher in male–female interactions than in male–male contests and were higher for males
that successfully mated than for those that did not mate. Mean duration of some male displays was also greater for males that
successfully mated. However, male size was not associated with probability of mating. Taken together, results suggest an intersexual
selection context for the current function of male signals in these wolf spiders and that increased display vigor is associated
with male mating success. 相似文献
5.
Males of the brush-legged wolf spider, Schizocosa ocreata (Araneae: Lycosidae), possess a conspicuous male secondary sexual character: dark pigmentation and tufts of bristles on the
tibiae of their forelegs. We tested several hypotheses relating to the role of this conspicuous trait in sexual selection.
Triad mating experiments suggest that the tufts do not play an obvious role in the operation of sexual selection by either
male competition or female choice, as there were no significant differences in the mating success of intact and experimentally
shaved males. However, females mated more often with males that initiated courtship first, suggesting that capture of a female’s
attention by male signalling may play a critical role. In behavioral experiments that paired a single male with a female in
arenas that allowed both visual and vibratory signal transmission during courtship, female receptivity did not vary significantly
with the presence or absence of tufts. However, experiments that isolated the visual component of communication (by eliminating
vibratory communication) revealed a significant effect of the presence of tufts: females showed receptivity less often to
males with tufts removed. Female response to visual signals was much greater in S. ocreata than in its sibling congener, Schizocosa rovneri, which lacks male tufts. We hypothesize that the tufts serve to increase the efficacy of visual displays of S. ocreata, as vibratory communication is constrained by the complex leaf litter habitat of some populations. Such environmental constraints
may make visual signalling over distance a critical factor for effective courtship communication, which may in turn strongly
influence male fitness.
Received: 30 September 1994/Accepted after revision: 4 August 1995 相似文献
6.
Ben C. Sheldon Pete Davidson Gabriella Lindgren 《Behavioral ecology and sociobiology》1999,46(3):141-148
There is increasing evidence that sexual selection may be intense even in socially monogamous birds, resulting from both mate choice and sperm competition. We studied these two modes of sexual selection experimentally by removing paired male collared flycatchers, Ficedula albicollis, from their mates for 2 days and investigating the factors that influenced the likelihood of a replacement male appearing and how the removals influenced paternity. Replacement males (usually neighbouring males) appeared at 81% (n = 37) of nests where males were removed. The likelihood of this appearance was unaffected by the probable reproductive value of the female's clutch to the replacing male. A replacement was, however, less likely when the original male had a large forehead patch, a trait previously shown to be subject to sexual selection in this population. Experimental removal of males increased the level of sperm competition: 74% of experimental broods were multiply sired, compared to 29% of unmanipulated broods in a previous study. Only two factors predicted how paternity was shared between males: removed males fathered more young if removed closer to laying, and if they had larger forehead patches. The former result is consistent with last-male sperm precedence determining paternity, whereas the latter adds to other evidence that forehead patch size is the target of female preference in this species. Our results suggest that females exert some control over male replacement, and also that they may influence the fertilisation success of males by behavioural means. Received: 15 July 1998 / Received in revised form: 16 March 1999 / Accepted: 28 March 1999 相似文献
7.
Mate availability can vary widely in nature depending upon population density and sex ratio and can affect the ability of
individuals to be selective in mate choice. We tested the effects of prior encounters with the opposite sex (i.e., exposure
to the opposite sex either with or without mating) on subsequent mating behavior in two experiments that manipulated mate
availability for both males and females in the wolf spider, Hogna helluo. The probability of mating in the experimental trial depended upon whether the prior encounter involved mating or not, and
males and females responded in opposite directions. Exposure without mating resulted in a higher subsequent frequency of mating
for females and a lower subsequent frequency of mating for males, while prior mating experience resulted in a lower frequency
of female remating and a higher frequency of male remating. Prior exposure without mating did not affect female aggression.
However, mated females engaged in precopulatory cannibalism more frequently than virgins. Mated males escaped postcopulatory
cannibalism more frequently than virgins. Our results show that males respond to exposure without mating in the expected manner.
However, prior mating (1 week earlier) had unexpected effects on males, which may be due to mated males being of higher quality.
There were little or no effects of the size of the prior exposure individual or mate on subsequent mating behaviors. Further
research is needed to determine why different species use different degrees of prior information in mate choice. 相似文献
8.
We studied sexual selection in the red bishop, Euplectes orix, a colonial, polygynous weaverbird widely distributed over sub-Saharan Africa. Male reproductive success measured in terms
of the number of nests accepted by females and the number of eggs and nestlings in all the nests on a male's territory varied
considerably. The standardized variance (variance/mean2) in male reproductive success ranged from 0.505 to 1.737 in different years, indicating a high potential for sexual selection
in this species. An analysis of genetic parentage for 432 nestlings by non-radioactive, multilocus DNA fingerprinting confirmed
that male reproductive success (number of young sired on the territory) in this species can be reliably estimated by the measures
introduced above. In all 4 study years there was a strong positive correlation between male mating success and the total number
of nests that males built in their territories. The number of nests built can be partitioned into the number of weeks a male
held a territory and his nest-building performance. Both factors exert a significant positive effect on male mating success
and in combination explained between 53.3 and 86.3% of the variation in male reproductive success. Male morphological characters
were found to be of no importance. Males that established a territory in the following season built more nests and held their
territories for longer than males that did not establish a territory in the following season, suggesting that these measures
might be indicators of male condition and quality. Male nest-building performance (number of nests built per week) seems to
be unrelated to male condition or quality.
Received: 8 January 1999 / Received in revised form: 7 June 1999 / Accepted: 13 June 1999 相似文献
9.
Dominique Berteaux Joël Bêty Eddie Rengifo Jean-Marie Bergeron 《Behavioral ecology and sociobiology》1999,45(3-4):283-291
Multiple paternity in single litters conceived in the wild was recently demonstrated in meadow voles (Microtuspennsylvanicus). In this study, we used an experimental approach (males tethered and females allowed to mate freely with one or several males) to investigate the role of female meadow voles in multiple paternity. We found that among 29 (of 39) females that copulated during our experiment, 79.3% chose to mate with more than one male. Female behavior in meadow voles thus clearly promotes multiple paternity and their role is an active one. Some of the hypotheses explaining promiscuity in meadow voles should be reconsidered in light of this result. We do not know the primary determinant of female mate choice, but male body mass played a secondary role in driving female preferences. The partial dependence between male body mass and female choice, coupled with the active role played by females, indicates that intersexual selection has the potential for reinforcing the effects of intrasexual selection (male-male dominance relationships) in this species. Finally, we demonstrate that the time period over which tests are conducted is an important part of the design of experiments aimed at understanding the role of females in multiple paternity. Received: 14 April 1998 / Accepted after revision: 12 September 1998 相似文献
10.
Joris M. Koene Kora Montagne-Wajer Andries Ter Maat 《Behavioral ecology and sociobiology》2006,60(3):332-338
Simultaneous hermaphrodites have the opportunity to control the allocation of resources to the male and female function depending on the circumstances. Such flexibility also provides the possibility to influence sex allocation in the mating partner. To investigate this idea, we measured egg production (female investment) and sperm production as well as prostate gland size (both are part of male investment) under different mating regimes in the great pond snail Lymnaea stagnalis. We find no evidence for the prediction from sex allocation theory that sperm production increases with mating frequency. However, we do find that animals with more mating opporunities develop smaller prostate glands, in which seminal fluid is produced. Moreover, repeated mating increases egg production, thus shifting allocation towards the female function, and probably decreases growth. So, our data hint at a three-way trade-off between part of the male function (prostate gland), female function, and growth. Interestingly, sex allocation seems to be shifted in the opposite direction from the one predicted by theory. We discuss how this feminization is suggestive of a direct manipulation by the sperm donor, probably to stimulate immediate sperm use. 相似文献
11.
Merja Otronen 《Behavioral ecology and sociobiology》1994,35(1):33-38
Male fertilisation success in relation to male size and the mating situation (ordinary pair formation with a single, nonvirgin female vs. take overs) was examined in the fly Dryomyza anilis. In ordinary matings, large males achieved higher fertilisation success than small ones when they were the second to mate with the female. Take overs differ from ordinary pair formation in that the second male experiences intensified sperm competition. This is because in take overs the female is not able to discharge any of the sperm inseminated by the first male as she usually does before a new mating. Compared with ordinary matings, take overs reduced the fertilisation success of the second male by 8–10%, whereas that of the first male was 7–14% higher in take overs. Even though the intruder was always larger than the paired male his superior fertilisation success did not compensate for the effect of the sperm already present in the female. In D. anilis, males can increase their fertilisation success by tapping the female's external genitalia with their claspers or having several copulation bouts per mating. Thus, in a take over, the intruder could respond to the intensified sperm competition by performing more tapping sequences per copulation bout or more copulation bouts per mating. In matings observed in the wild, males performed more tapping sequences after a take over than after pair formation with a single female, although the difference was not significant. The results show that there are differences in fertilisation success between males of different size. In addition, different mating situations can result in considerable variation in the fertilisation success of an individual male. Higher fertilisation success for the first male after a take over may be significant, in particular, for the reproductive success of small males, which frequently lose their females to large males. 相似文献
12.
When females mate with more than one male, the ensuing sperm competition leads to the evolution of male mechanisms that skew
paternity. Males of the yellow mealworm beetle (Tenebrio molitor) transfer a spermatophore to females during copulation, but sperm release and storage occur later. We investigated how the
interval between two matings with different males affects sperm precedence by varying the interval between the copulations
so that the second mating was either: (1) before sperm release from the first spermatophore (<5 min); (2) after sperm release
but before spermatophore ejection (15–20 min); (3) after spermatophore ejection but before sperm storage (4 h), or (4) after
complete sperm storage (24 h). We collected offspring over a period of 2 weeks and determined paternity by protein electrophoresis.
There was second-male sperm precedence in all treatments, but when the interval was <5 min, the second male usually (86% of
cases) had complete sperm precedence (i.e., P
2=1). Investigations into the mechanism of second-male sperm precedence during <5-min mating intervals indicate that sperm
release from the first spermatophore is inhibited, a phenomenon which has not been previously documented.
Received: 31 January 2000 / Revised: 9 June 2000 / Accepted: 26 August 2000 相似文献
13.
Copulatory plug displacement and prolonged copulation in the Iberian rock lizard (Lacerta monticola)
Male Iberian rock lizards (Lacerta monticola) produce copulatory plugs that adhere firmly inside the female cloaca and occlude both oviducts. These plugs do not prevent rival male insemination, as they neither reduce female attractiveness or receptivity to rival males nor do they function as chastity belts. Prior to copulation, males bite various regions of the female body, including the cloacal region. A previous plug in the female cloaca is expelled only after rival male intromission. We hypothesized that: (1) such male pre-copulatory behaviours function to loosen plug adherence to the female cloaca, thereby facilitating intromission, and that (2) the hemipenis plays a role in displacing a previous plug prior to the delivery of a new plug. Neither of these hypotheses was supported. Instead, our results indicate that rival males can intromit the hemipenis past a previous plug in the female cloaca and deliver their own plug underneath it. Consequently, previous plugs are pushed away from the oviductal openings and even dislodged from the female cloaca. Copulation duration was determined both by the time used by males to deliver a plug and by the fact that males prolonged copulation beyond plug delivery. There seemed to be sexual conflict over prolonged copulation, which was resolved by the male/female head-length ratio. The adaptive value of Iberian rock lizard copulatory plugs and prolonged copulation in Iberian rock lizards is discussed in the context of sperm competition.Communicated by S. Downes 相似文献
14.
Leg ornamentation and the efficacy of courtship display in four species of wolf spider (Araneae: Lycosidae) 总被引:1,自引:1,他引:0
This study used both correlative and experimental video playback methods to test the hypothesis that the secondary sexual
traits of male wolf spiders act to increase the efficacy of visual courtship displays. Direct observations of courtship of
several lycosid genera and a review of the literature revealed a significant association between ornamentation and visual
courtship displays. This suggests that the ornamentation may be playing the role of amplifier for a visual display. To test
this hypothesis, male courtship behaviors of four Schizocosa species were experimentally manipulated using video-imaging techniques. Females of species with non-visually displaying,
non-ornamented males (Schizocosa duplex and S. uetzi) did not increase in frequency of receptivity when tufts were added to conspecific males. In a species with a visual display
and foreleg pigmentation (S. stridulans), the addition of foreleg tufts increased female receptivity. In a tufted species (S. crassipes), females tended to decrease their receptivity when male ornamentation was completely removed. In visually displaying species,
ornamentation acts to increase female receptivity, supporting its role as an amplifier of a visual display.
Received: 29 December 1997 / Received in revised form: 23 October 1999 / Accepted: 13 December 1999 相似文献
15.
Chad C. Smith 《Behavioral ecology and sociobiology》2007,61(9):1349-1358
Operational sex ratio (the ratio of sexually active males to fertilizable females) has a major influence on male competition
for mates and male–female interactions. The contributions of male and female density per se to mating system dynamics, however,
are rarely examined, and the fitness consequences are often inferred rather than quantified. Male mosquitofish (Gambusia affinis) compete aggressively and frequently harass females for copulations, a behavior thought to reduce female fitness. Female
fitness can also be reduced by increases in female density, which may affect food availability, cannibalism rates, and chemical
interactions between females. I manipulated male and female densities of G. affinis to measure their effects on male–male aggression, male harassment toward females, and female fitness. I found that males
chased rivals more often and attempted fewer copulations when female density decreased, but surprisingly male density had
no significant effect on the frequency of these male behaviors. In contrast, males’ agonistic displays toward other males
increased with male density, but display behavior was unaffected by female density. These results suggest that male and female
density do not always contribute equally or at all to the patterns of behavior we observe. Female fitness declined as female
density increased, the opposite pattern expected if male harassment is costly to females. This suggests that a strong, negative
effect of female density overwhelmed any potential costs of male harassment. Sources of female density dependence and the
consequences of changes in male and female density to patterns of male behavior are discussed. 相似文献
16.
Sperm competition can be a powerful selective force in the evolution of reproductive strategies and mating systems. In studies on sperm competition, patterns of sperm use are typically reported as the mean species value of P
2, determined as the proportion of offspring sired by the second male to copulate with a doubly mated female. However, the within-species variance in P
2 has mostly been ignored, although taking this variance into account may be crucial for understanding the underlying mechanisms of sperm competition. Paternity analysis among the offspring of doubly mated females of Panorpa germanica (Mecoptera, Panorpidae) revealed a relationship between relative copulation durations of both males and the proportion of offspring each male will sire. This correlation between proportional copulation durations and paternity suggests mixing of sperm from different males inside the female’s spermatheca. Yet, sperm mixing appears to be incomplete, as paternity was overall slightly shifted towards the second male on average fathering a higher proportion of the offspring than its relative copulation duration would predict in case of complete sperm mixing. For individual males, however, the outcome of sperm competition is rather unpredictable as the intraspecific variance in P
2 was found to be very high, irrespective of copulation durations. Possible causes of the observed variance in P
2 and the partial last male sperm precedence are discussed. 相似文献
17.
Xiaoguo Jiao Zhanqi Chen Jun Wu Hongyan Du Fengxiang Liu Jian Chen Daiqin Li 《Behavioral ecology and sociobiology》2011,65(2):325-332
Although the effects of male mating history on female reproductive output and longevity have been studied in insects, few
such studies have been carried out in spiders. In a mating system in which females are monandrous while males are polygynous,
females may incur the risk by mating with successful males that have experienced consecutive matings and suffer from the possible
depletion of sperm and/or associated ejaculates. Here, we examine the effects of male mating history on male courtship and
copulation duration, female reproductive fitness, and female adult longevity of the wolf spider, Pardosa astrigera. Results indicated that male mating frequency had little effect on their subsequent copulation success, and of 35 males tested,
about half of the males were able to copulate with five virgin females successively at an interval of 24 h. Male mating history
had little effect on their courtship duration. However, male mating history significantly affected male copulation duration,
female adult longevity, and reproductive output. Males that mated more frequently copulated longer and more likely failed
to cause their mates to produce a clutch, although there was no significant difference in the number of eggs laid and the
number of eggs hatched regardless of the first clutch or the second one. Multiple mating of male P. astrigera resulted in significant reduction in female adult longevity. Our results indicate that monandrous females mating with multiple-mated
males may incur substantial fitness costs. 相似文献
18.
Female seaweed flies, Coelopa frigida, have the potential to benefit from mating more than once. Single matings result in low fertility so females may benefit directly from multiple copulations by sperm replenishment. A chromosomal inversion associated with larval fitness, with heterokaryotypic larvae having higher viability than homokaryotypes, means that polyandrous homokaryotypic females have a higher probability of producing genetically fit offspring than monandrous homokaryotypic females. We allowed females to mate only once, repeatedly four times to the same male, or polyandrously four times to four different males. Multiply mated and polyandrous females laid more eggs and produced more offspring than singly mated and monandrous females, respectively. Polyandrous females laid more eggs, had higher egg-to-adult survival rates and produced more offspring than repeatedly mated females. Fertility rates did not differ between treatments. The observed fitness patterns therefore resulted from increased oviposition through multiple mating per se, and a further increase in oviposition coupled with higher egg-to-adult offspring survival benefits to polyandry. Daily monitoring of individual females over their entire life spans showed that multiple copulations induced early oviposition, with polyandrous females ovipositing earlier than repeatedly mated females. Singly mated and polyandrous females incurred a longevity cost independent of egg production, whereas repeatedly mated females did not. This suggests that repeatedly mating with the same male may counteract a general cost of mating. Longevity, however, was not correlated with overall female fitness. Our data are discussed in the overall context of the seaweed fly mating system.Communicated by G. Wilkinson 相似文献
19.
Sexual cohabitation as mate-guarding in the leaf-curling spider Phonognatha graeffei Keyserling (Araneoidea, Araneae) 总被引:1,自引:1,他引:1
The leaf-curling spider Phonognatha graeffei incorporates a twisted leaf into the central hub of its orb-web that is used as a retreat. This species is unusual among orb-weaving
spiders because males cohabit in the leaf retreat with both immature and mature females, mating with the former shortly after
the female molts. Cohabitation appears to be a form of mate-guarding because cohabiting males respond agonistically to rival
males that venture onto the web, and their behaviour depends upon the reproductive status of the female; males defending immature
females are more aggressive than those defending virgin, adult females. Males copulate with previously mated females for significantly
longer than with virgin females. Females may cannibalise cohabiting males, which occurs independently of whether the female
has been deprived of food. Females that cannibalise a single male do not have a higher fecundity than non-cannibalistic females.
Received: 2 February 1996 / Accepted after revision: 27 October 1996 相似文献
20.
Christopher Young Sabine Hähndel Bonaventura Majolo Oliver Schülke Julia Ostner 《Behavioral ecology and sociobiology》2013,67(10):1665-1677
Dominant mammalian males should gain a reproductive advantage due to their greater fighting abilities. However, the extent to which they can monopolise access to females varies across species. In primates and recently other mammalian species, the Priority of Access (PoA) model is commonly used to measure the degree to which male rank and female receptive synchrony affect mating skew. Few studies have examined the factors which lead to deviations from the expectations of the model. Here, we investigate male mating skew in wild Barbary macaques (Macaca sylvanus). We examined four of the main factors which affect male mating success: the roles of male rank, female receptive synchrony, coalitionary activity and female behaviour. We found that male mating was skewed up the hierarchy, but there was a large deviation from the PoA model's expectations with high-ranked males not gaining as big a share as expected. Females frequently initiated sexual encounters, predominantly with mid-ranked males, increasing their mating success. Male coalitionary activity independently increased mating success. Frequent associations with females were costly to males as they were the targets of bridging coalitions, decreasing future mating opportunities for the targets. High-ranking males did not increase their mating success directly through bridging coalitions but acted to dilute the effects of female behaviour. By examining different factors affecting mating skew, we are able to show that alternative male and female mating strategies are effective in reducing the monopolisation potential of the dominant male. 相似文献