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1.
The males of butterflies transfer a spermatophore to the female during mating that can contain nutrients enhancing the reproductive potential of their partners. The nutrients transferred by males can be derived from both larval and adult feeding. These nutrients may be depleted by multiple matings. An apparent difference in adult feeding behaviour between the sexes is puddling on mud, dung and carrion, which in most butterfly species is exclusively a male behaviour. A possible explanation for this division in feeding behaviour is that nutrients derived from puddling by males are transferred to the female during mating. Here, we test this hypothesis in the African fruit-feeding butterfly Bicyclus anynana. We varied the male nuptial gift by (1) feeding males either a diet with or without sodium, and (2) varying the number of previous successful copulations by remating males up to five times on consecutive days. The results show both a strong effect of order of mating on the mating duration, and an individual effect with some males typically copulating for a shorter time than others. The effects on female reproduction were, however, minimal. The total number of eggs per female and the sodium content of the eggs did not differ significantly between diets, nor were they affected by the mating histories of the males. Eggs showed a non-significant lower hatching for females partnered by a male who had already mated several times. There was an indication of an interaction with male diet: the sodium treatment showing a decline in egg hatchability with order number of male mating, whilst the control treatment showed a constant hatchability. The results are discussed in relation to determinants of male gift-giving strategy and to other potential explanations for a restriction of puddling to males in butterflies.Communicated by M.A. Elgar 相似文献
2.
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
3.
C. Cordero 《Behavioral ecology and sociobiology》2000,48(6):458-462
The differential costs of mating paid by males and females influence the nature and strength of sexual selection. In butterflies,
males invest a relatively large amount of time and resources in each mating, but male survival costs of mating have not been
demonstrated. I present the results of experiments designed to measure the effect of different aspects of mating on male longevity
in the polygynous butterfly Callophrys xami. In experiment 1, I compared the longevity of pairs of males that produced similar amounts of spermatophore, but that mated
at different rates, a different numbers of times, and that produced spermatophores at different rates, and found that the
longevity of ”low-mating-rate” males was not different from that of ”high-mating-rate” males. In experiment 2, the longevity
of virgin males was not significantly different from that of multiply mated males. In experiment 3, I used resource-limited
males resulting from experimental food limitation of last-instar larvae; resource-limited virgin males lived significantly
more days than resource-limited multiply mated males. Since ecological costs of mating (e.g., disease transmission, predation
risk) were excluded in the experiment, diminished male longevity was a product of physiological costs of sexual interactions.
These results suggest that the cost of ejaculate production is an important cause of longevity reduction when there are resource
limitations; however, the role of other possible physiological costs of mating in longevity reduction is still unknown.
Received: 21 March 2000 / Accepted: 26 August 2000 相似文献
4.
Experimental evidence of a testosterone-induced shift from paternal to mating behaviour in a facultatively polygynous songbird 总被引:5,自引:2,他引:3
Previous studies have suggested that testosterone (T) profiles of male birds reflect a trade-off between mate attraction behaviours
(requiring high T levels) and parental care activities (requiring low T levels). In this study, we experimentally elevated
T levels of monogamous males in the facultatively polygynous European starling (Sturnus vulgaris), and compared mate attraction and paternal behaviour of T-treated males with those of controls (C-males). T-males significantly
reduced their participation in incubation and fed nestlings significantly less often than C-males. Females paired to T-treated
males did not compensate for their mate’s lower paternal effort. The observed reduction in a male’s investment in incubating
the eggs was accompanied by an increased investment in typical female-attracting behaviours: T-males spent a significantly
higher proportion of their time singing to attract additional females. They also occupied more additional nestboxes than C-males,
although the differences just failed to be significant, and carried significantly more green nesting materials into an additional
nestbox (a behaviour previously shown to serve a courtship function). T-males also behaved significantly more aggressively
than C-males. During the nestling period, the frequency of mate-attracting behaviours by T-treated and control males no longer
differed significantly. Despite the reduced paternal effort by T-males and the lack of compensation behaviour by females,
hatching and breeding success did not differ significantly between T- and C-pairs.
Received: 7 February 2000 / Revised: 10 August 2000 / Accepted: 3 September 2000 相似文献
5.
Male-male competition ensures honest signaling of male parental ability in the three-spined stickleback (Gasterosteus aculeatus) 总被引:1,自引:0,他引:1
U. Candolin 《Behavioral ecology and sociobiology》2000,49(1):57-61
The importance of socially imposed costs for the evolution and maintenance of honest sexual signals has received less attention
than other costs. Here I show that male-male competition can increase the honesty of sexual signaling in relation to male
parental ability in a species with flexible signaling. When four three-spined stickleback (Gasterosteus aculeatus) males were allowed to court a female first separately and then in competition, red nuptial coloration under competition
reflected male parental ability more accurately than red coloration when separated. Parental ability was determined as the
ability of the male to raise a clutch of eggs to the hatching stage under interaction with other breeding and non-breeding
males. The increased honesty under competition was probably due to subordinate males of poor parental ability decreasing their
color expression under interaction to reduce the risk of fights with superior males. However, socially imposed costs of signaling
were probably not the main factors maintaining honest signaling, as red coloration reflected male parental ability also in
the absence of competition, although less accurately. Nevertheless, the small-scale differences that male-male competition
induced can significantly facilitate adaptive female choice and have large impacts on sexual selection.
Received: 7 July 2000 / Revised: 31 August 2000 / Accepted: 4 September 2000 相似文献
6.
Sperm characteristics associated with different male reproductive tactics in bluegills (Lepomis macrochirus) 总被引:3,自引:0,他引:3
We examined the availability and motility of sperm from parental and sneaker male bluegills (Lepomis macrochirus), a colonially nesting sunfish (Family Centrarchidae) with male parental care and a high incidence of cuckoldry by both sneaker
and satellite males. We found no differences between sneakers and parentals in length and swimming speed of sperm, or percent
and duration of sperm activity. In sneaker milt, however, sperm was almost 50% more concentrated than in parental milt (16.5×106 vs 11.5×106 sperm/μl of milt, respectively). Despite this difference in sperm concentration, stripped ejaculates from sneakers contained
almost 400 million fewer sperm (only 32% as many sperm) than those from parentals due to their much smaller stripped ejaculate
volumes (only about 19% that of parentals). Thus unless sneakers can compensate by releasing more sperm or gaining closer
proximity to eggs at the time of spawning, they may be at a disadvantage with respect to sperm competition. We discuss these
results in relation to models for the evolution of alternative reproductive behaviours in this species and suggest that the
cuckolders may be making the best of a bad situation.
Received: 18 February 2000 / Revised: 23 March 2000 / Accepted: 14 September 2000 相似文献
7.
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
8.
In species where males use alternative reproductive tactics and male phenotypes are confronted with different risks of sperm
competition, theory predicts that between-male-type differences in sperm expenditure may evolve. In the frog Crinia georgiana big males can monopolize females, whereas small males often engage in polyandrous matings. Consequently, big males may experience
a lower risk of sperm competition than do small males. We tested if the predictions from theoretical models can be applied
to the mating system of C. georgiana. Our results showed that small males do not have larger testes relative to their body size compared to their larger counterparts
and that the efficiency with which sperm number, size, motility, and longevity are produced by the testes does not differ
between small and large males in the predicted way. These results are not in alignment with predictions from a loaded raffle
model of sperm competition on sperm expenditure in males with alternative phenotypes. The plasticity in mating tactics used
by C. georgiana males and a high intraseasonal variation in male densities may have prevented the evolution of enhanced sperm performance
in smaller males. A fair raffle in the sperm competition game played by C. georgiana males could also explain the observed patterns in sperm traits. Future investigations determining the parameters responsible
for the deviation from theoretical predictions in this system will test the degree to which current theoretical models can
indeed be applied to species with plastic reproductive tactics. 相似文献
9.
Testosterone and the allocation of reproductive effort in male house finches (Carpodacus mexicanus) 总被引:9,自引:1,他引:8
Testosterone has been proposed to serve as the mediator that controls the relative effort that an individual male bird will
devote to mating effort versus parental effort. Here, we demonstrate a testosterone-influenced trade-off between parental
and mating efforts in male house finches. Male house finches with experimentally elevated testosterone fed nestlings at a
significantly lower rate, but sang at a higher rate than males without manipulated testosterone levels. Females mated to testosterone-implanted
males fed nestlings at a significantly higher rate than females mated to males without testosterone implants, resulting in
similar feeding rates for both treated and untreated pairs. The effects of testosterone on male house finches, however, were
not as dramatic as the effects of testosterone observed in some other socially monogamous species of birds. Because extra-pair
copulations are uncommon in house finches and males provide substantial amounts of parental care, these more modest effects
may be due to differences in how the allocation of reproductive effort affects the costs and benefits of different reproductive
behaviors.
Received: 6 June 2000 / Accepted: 17 July 2000 相似文献
10.
Many fishes are characterized by intense sperm competition between males that use alternative mating tactics. In externally
fertilizing fishes, males’ proximity to females during spawning can be an important determinant of fertilization success.
Here, we assess how mating tactic, body length, speed during streak spawns, and periphery cover affect males’ proximity to
females during sperm competition in the externally fertilizing bluegill (Lepomis macrochirus). Bluegill are characterized by three mating tactics referred to as parental, sneaker, and satellite. Parentals are territorial
and construct nests, while sneakers use a streaking behavior, and satellites use female mimicry to steal fertilizations from
parentals. We show that a small body length is important for sneakers but not for satellites to obtain a close position to
the female during spawning. Specifically, smaller sneakers obtain a closer position to females than larger sneakers in part
by positioning themselves closer on the periphery of a parental’s nest before streaking but show no difference in the speed
at which they streak. The amount of peripheral vegetation around a parental’s nest did not appear to affect proximity of sneakers
to females, and there was no relationship between the amount of peripheral vegetation and the frequency of intrusions by either
sneakers or satellites. Finally, parentals were farther from the female when a sneaker or satellite intruded than when they
spawned alone with the female. 相似文献
11.
Social and mating system of cooperatively breeding laughing kookaburras (Dacelo novaeguineae) 总被引:4,自引:0,他引:4
DNA fingerprinting was combined with field observations over four breeding seasons to investigate the social structure and
mating system of the laughing kookaburra (Dacelo novaeguineae). Groups comprised a socially dominant pair and up to six helpers of either sex. Helpers were always recruited from young
hatched in the group. Territorial inheritance, which is a feature of other cooperative breeders and an oft-cited benefit of
philopatry, did not occur. Helpers only attained dominant status in an established group by dispersing into a vacant dominant
position in that group. However, helpers could also form new groups by excising a new territory, often through a ”budding”
process. The mating system was overwhelmingly monogamous. There were no cases of extra-group parentage in a sample of 140
nestlings; within groups of three or more birds, dominance predicted parentage almost perfectly (99.2% of 129 nestlings),
irrespective of whether helpers in the group were related to one or both dominant birds. This is contrary to predictions from
models of reproductive skew, possibly because they currently fail to incorporate the willingness of females to share reproduction
among males.
Received: 15 May 1999 / Received in revised form: 2 November 1999 / Accepted: 6 November 1999 相似文献
12.
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
13.
P. J. Cordero S. C. Griffith J. M. Aparicio D. T. Parkin 《Behavioral ecology and sociobiology》2000,48(5):353-357
Recent evidence has revealed an apparently high degree of control by female birds over the physiological aspects of their
reproduction and offspring sex allocation, consistent with adaptive hypotheses of sex allocation and differential investment
in their offspring. In the house sparrow, we investigated possible mechanisms that may be used by females to enhance the fitness
returns from a reproductive effort. Using molecular techniques, we demonstrate that house sparrow eggs containing male embryos
are significantly larger than those containing female embryos. We also found that male embryos were laid randomly with respect
to laying order. We speculate that this sexual dimorphism of eggs is adaptive, because male house sparrows show greater variance
in condition-dependent reproductive success than females. More important, the result provides further evidence of the ability
of females to detect or control ovulation of either male or female ova and to differentially invest in one sex over the other.
Received: 19 January 2000 / Revised: 29 June 2000 / Accepted 20 July 2000 相似文献
14.
Summary. In the moth Utetheisa ornatrix the female is promiscuous and receives a nuptial gift of pyrrolizidine alkaloid (PA) by seminal infusion from each mate.
The alkaloidal gifts are transmitted by the female to the eggs, which are protected as a result. We here show that individual
eggs may receive PAs from more than one male source and that individual males have no assurance that the PA they themselves
contribute to the female will find its way exclusively to eggs of their siring.
Received 28 June 2002; accepted 28 August 2002. 相似文献
15.
We used data from a long-term study (15 years) of fallow deer to report for the first time the lifetime mating success, overall
variance in lifetime mating success, and age-specific mortality levels of males. Fallow bucks that gain matings have higher
social dominance rank, higher rates of fighting, and invest more in vocal display during the breeding season than unsuccessful
males. Therefore, we examined if mating was associated with trade-offs in terms of survival, lifespan, and mating potential.
We found that the variance in lifetime mating success was very high: 34 (10.7%) males mated, and of those, the 10 most successful
males gained 73% of all matings (n=934). Mortality rates were generally high and only 22.3% (71/318) of males reached social maturity, i.e., 4 years. The oldest
male was 13 years old. We found that fallow bucks that mated were not more likely to die during the following year, did not
suffer from a reduction in lifespan, and did not incur lower mating success later in life as a result of mating during the
early years of social maturity. Our results show that mating males at age 5 years (and possibly 9 years) may be more likely
to survive than non-mating males. Additionally, the number of matings gained by males during the first years of social maturity
was positively correlated with lifespan. We suggest that mating males are of higher quality than non-mating males because
they are not more likely to incur trade-offs as a result of their increased reproductive efforts.
Received: 9 November 1999 / Revised: 30 April 2000 / Accepted: 27 May 2000 相似文献
16.
L. Hughes B. Siew-Woon Chang D. Wagner N. E. Pierce 《Behavioral ecology and sociobiology》2000,47(3):119-128
The mating system of the Australian lycaenid butterfly, Jalmenus evagoras, is highly unusual compared to most other Lepidoptera. Characteristics of this system, which has been termed an ’explosive
mating strategy,’ include the formation of an intensely competitive mating aggregation of males, a highly male biased operational
sex ratio, a lack of discrimination and mate choice by both sexes, a high variance in male mating success, and female monogamy.
In this study, we tested the hypothesis that multiple mating by males imposes physiological costs resulting in smaller spermatophores,
and that this results in a fitness cost to females. We found that male J. evagoras transferred only 2.2% of their eclosion weight during their first mating, consistent with the hypothesis that males of monandrous
species produce a relatively small investment. The wet weight of the ejaculate declined by an average of 27% at the second
mating and the dry weight by 29%, and an intermating interval of 5–9 days was needed for the ejaculate to return to the size
at the first mating, regardless of male size or age. Wet ejaculate mass increased proportionally with male size, though dry
mass was proportionally larger in smaller males. Ejaculate mass tended to increase with male age at both first and second
matings. Female characteristics, in general, did not affect ejaculate mass, although the wet weight of the ejaculate was positively
associated with female weight at the second mating. Copulation duration increased from 2.4 h to approximately 3 h at the second
mating, and to over 4 h at the third and fourth matings. Fecundity was positively correlated with female size but not with
mating history, copulation duration, or any other characteristics measured for either males or females. Female longevity declined
significantly as the number of times the male partner had previously mated increased. We conclude that despite the small male
investment in ejaculate, the costs of multiple mating may nonetheless be significant, as indicated by the reduction in ejaculate
mass, an increase in copulation duration, and reduction in female lifespan with increasing mating number.
Received: 22 January 1999 / Received in revised form: 28 July 1999 / Accepted: 18 September 1999 相似文献
17.
M. Pyron 《Behavioral ecology and sociobiology》2000,48(2):132-136
Most comparative analyses of relative testes mass find that testes are larger in species in which more sperm competition is
predicted (multiple males mate with individual females). I tested for differences in adjusted testes mass (for body mass)
by spawning mode and by sexual size dimorphism in a comparative analysis of 37 minnow species. No significant differences
were found for testes mass by spawning mode or sexual size dimorphism. These results imply a lack of response to selection
on testes size from sperm competition in minnow species. Possible explanations for the lack of the expected relationship between
testes mass and mating systems in minnows are presented.
Received: 8 November 1999 / Received in revised form: 27 January 2000 / Accepted: 13 February 2000 相似文献
18.
Geir Rudolfsen Rudolf Müller Davnah Urbach Claus Wedekind 《Behavioral ecology and sociobiology》2008,62(4):561-567
The mating behavior and reproductive strategies of Alpine whitefish like Coregonus zugensis (Nüsslin) are poorly understood, probably because they spawn in deep water where direct observations are difficult. In this
study, we interpret life-history and sperm quality traits of fish that we caught from their spawning place. We found that
males invest heavily into gonadal tissue (up to 5.6% of their body weight), which is, in comparison to other fish, consistent
with external fertilization, distinct pairing and moderate to high communal spawning, or no pairing and low to moderate communal
spawning. Sperm competition theory and recent experimental studies on other salmonids predict that males optimize ejaculate
characteristics in relation to the costs of sperm and the level of competition they have to expect: dominant males are predicted
to invest less into ejaculate quality and to have slower spermatozoa than subdominant males. We found that spermatozoa of
older males are slower than those of younger males. Moreover, older males have larger breeding tubercles, a secondary sexual
trait that has, in some previous studies, been found to be linked to good condition and to good genetic quality. Our results
suggest that C. zugensis has age-linked reproductive strategies, that multimale spawning is common, i.e., that sperm competition plays a significant
role, and that older males are on average dominant over younger males at the spawning place. 相似文献
19.
Spermatophore characteristics in bushcrickets vary with parasitism and remating interval 总被引:4,自引:0,他引:4
Male bushcrickets provide females with a nuptial gift, a spermatophore, which is transferred to females at mating. The spermatophore
consists of a gelatinous mass, the spermatophylax, and the sperm-containing ampulla. Male spermatophore size is positively
correlated with insemination rate and female refractory period and therefore with male reproductive success. In this study,
we examined spermatophylax weight, ampulla weight and sperm number in males of Poecilimon mariannae parasitized by the acoustically orienting fly Therobia leonidei. We show that in parasitized males, spermatophylax weight decreases with the level of parasitism. In line with the hypothesis
that parasitism is a cost to reproduction, we found that spermatophylax weight was reduced at remating. In contrast, the replenishment
of the spermatophylax in unparasitized males was complete after 2 days and was increased no further after 3 days. Both sperm
number and ampulla weight showed an increase over time since last mating and sperm production was estimated at a constant
rate of 500,000 per day in all individuals, regardless of parasitism. The allocation of investment in components of the spermatophore
varies greatly with parasitism and remating. Both factors had rather independent effects on spermatophore constitution, revealing
functional constraints acting on spermatophore characteristics in bushcrickets, which are important for understanding the
selection pressures working on its components.
Received: 13 September 1999 / Received in revised form: 4 February 2000 / Accepted: 13 March 2000 相似文献
20.
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