共查询到20条相似文献,搜索用时 46 毫秒
1.
George W. Uetz David L. Clark J. Andrew Roberts Meghan Rector 《Behavioral ecology and sociobiology》2011,65(4):753-761
For visual signaling to be effective, animal signals must be detected and discriminated by receivers, often against complex
visual backgrounds with varying light levels. Accordingly, in many species, conspicuous visual displays and ornaments have
evolved as a means to enhance background contrast and thereby increase the detection and discrimination of male courtship
signals by females. Using video playbacks, we tested the hypothesis that visual courtship displays and leg decorations of
male Schizocosa ocreata wolf spiders are more conspicuous against complex leaf-litter backgrounds. Video exemplars of courting males with manipulated
leg tufts were superimposed on different backgrounds (complex leaf litter in sun or shade, featureless gray background) and
presented to female spiders. Females were more likely to orient to males presented against lighter backgrounds (litter in
sun, gray) than the darker ones (litter—shade). Males with larger tufts were also more likely to be detected, as latency to
orient was shortest for enlarged and longest for removed tufts. Latency of females to approach was shorter against lighter
backgrounds, and approach latency was longest for males without tufts. Female receptivity scores were significantly greater
for males against lighter backgrounds, and males with larger tufts had higher scores. These results suggest that both complexity
and light level of display backgrounds affect the detection of male visual courtship signals by females and that aspects of
the male phenotype may increase chances of detection (and receptivity) against visually complex backgrounds. 相似文献
2.
Fluctuating asymmetry (FA) can indicate developmental instability in bilaterally symmetric organisms, and studies have shown
that the degree of asymmetry in male secondary sexual characters influences female mate choice in a number of taxa. In male
Schizocosa ocreata wolf spiders, conspicuous tufts of bristles on the forelegs are a critical component of visual courtship signals, which appear
to play a role in female mate choice. Previous studies have shown that females exhibit reduced receptivity to males with regenerative
asymmetry, a consequence of leg loss and regeneration that causes males to be grossly asymmetric with respect to this important
signaling character. We provide data on the occurrence of FA in the tufts of S. ocreata, and examine further the influence of asymmetry on female mate choice. The distribution of tuft area asymmetry values from
a sample of field-collected males was normal, with a mean value of zero, indicating true FA. For a subset of males measured
directly after field collection and prior to feeding, tuft asymmetry was significantly negatively correlated with measures
of body size (body length) and condition (abdomen volume/cephalothorax width). Receptivity responses of females to visual
signals from live males of similar size varied with the degree of asymmetry in male tufts. Since FA covaries with male body
size and condition, which may also influence behavioral vigor, we used video image manipulation to alter the degree of asymmetry
in tufts of a courting male while holding size and condition constant. Asymmetry treatments represented values within the
range of natural FA variation as well as more extreme values characteristic of regenerative asymmetry. With the confounding
effects of male size, condition, and behavior held constant, female spiders exhibited reduced receptivity responses to all
experimental asymmetric video images relative to a control video stimulus. There were no differences in the frequency of female
receptivity among the various asymmetry treatments, suggesting that discrimination against asymmetry in conspecific male signal
characters is not simply a rejection of extreme phenotypes. Results suggest that asymmetry in a key male secondary character
used in visual signaling, independent of any concomitant behavioral or size factor, is an important criterion in mate choice.
Received: 26 February 1998 / Accepted after revision: 12 September 1998 相似文献
3.
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
4.
G. W. Uetz William J. McClintock Douglas Miller Elizabeth I. Smith Kristina K. Cook 《Behavioral ecology and sociobiology》1996,38(4):253-257
Males of the brush-legged wolf spider Schizocosa ocreata (Hentz) have conspicuously decorated forelegs used in courtship and agonistic displays. Approximately one in five juvenile
males has a missing or regenerating foreleg, and regeneration of a leg lost during development usually results in the absence
of a decorative tuft on that leg. The subsequent asymmetry in this male secondary character significantly decreases success
in both courtship of females and male-male agonistic interactions. Experimental removal of tufts from one leg of previously
successful symmetric males produces similar results. As a test for concomitant behavioral effects, female spiders were shown
video images of a courting male with symmetric tufts and the same video image altered to have asymmetric tufts. Female receptivity
to the asymmetric video image was lower. In contrast to fluctuating asymmetry resulting from developmental instability, leg
tuft asymmetry in S. ocreata most likely arises from a single event during ontogeny – possibly leg loss from an aggressive or predator encounter – and
may serve as a quality indicator in female mate choice.
Received: 27 July 1995/ Accepted after revision: 19 November 1995 相似文献
5.
Male fitness is often determined by the ability of the male to gain access to multiple mates, although in species that exhibit
sexual cannibalism, males might increase their likelihood of being cannibalized with each encounter. This risk should create
selection for males who are able to perceive potential risks associated with mating encounters. We studied male Schizocosa ocreata wolf spiders to determine whether they use female chemotactile cues (silk, excreta) as indicators of potential risks and
how these cues affected subsequent male courtship behaviors. Female treatments included satiated females vs. starved females,
as well as a treatment where females had recently cannibalized a male S. ocreata. We performed experiments to assess (1) if males use female chemotactile cues to determine potential risks associated with
differing female feeding treatments and alter courtship investment, and 2) how male experience with female chemotactile cues
affected courtship investment in subsequent female encounters. At first encounter, males do not vary courtship investment
(number of bouts, duration, and vigor) with different female feeding treatments. However, male behaviors during subsequent
encounters with female chemotactile cues varied in complex ways, depending on female feeding treatment and male first encounter
experience. These data suggest that male experience impacts perception of female chemical cues and offers the male opportunity
to avoid sexual cannibalism in high-risk situations. 相似文献
6.
David L. Clark J. Andrew Roberts Meghan Rector George W. Uetz 《Behavioral ecology and sociobiology》2011,65(6):1237-1247
Animal color patterns often reflect a compromise between natural selection for crypsis or inconspicuousness to predators and
sexual selection for conspicuousness to potential mates. In leaf litter-dwelling wolf spider species like Schizocosa ocreata, body coloration often closely matches the background coloration of a generally brown environment. However, body parts used
in communication should exhibit high contrast against background coloration. We used spectral analysis to examine male and
female S. ocreata for matching and contrasting coloration against leaf litter. Values were plotted in multivariate color space, based on reflectivity
in different frequency ranges. When viewed from above, colors of both males and females overlap with values for dead brown
leaf litter and soil, suggesting cryptic coloration when viewed by potential predators. However, when viewed from a lateral
perspective, both males and females show color values that are polar opposites of litter backgrounds, suggesting higher contrast
when viewed by other spiders. Moreover, male secondary characters used in visual signaling by S. ocreata (tibia brushes) show the highest level of background contrast. These findings suggest that S. ocreata wolf spiders have color patterns that provide both crypsis and background contrast at the same time, depending on receiver
viewing perspective. 相似文献
7.
Individual variation in female preference for male traits may influence mate choice, especially if benefits and costs of choosiness
vary with the range of available males or reproductive timing. We examined variation in female preference for male leg tuft
size in Schizocosa ocreata (Hentz) wolf spiders with video playback. Dichotomous (simultaneous) choice test experiments included all possible combinations
of four stimuli (i.e., modified versions of the same video male stimulus): average tuft size (control), reduced (−25%), enlarged
(+25%), and no tufts (removed). Females exhibited a directional preference for larger tuft size independent of the nature
of the choice (except for reduced tufts vs no tufts where no difference was seen). Female preference in the short term (over
a period of 4 days) was also highly repeatable for control vs reduced tufts, but not for control vs enlarged tufts. Responses
of females in ‘no-choice’ presentations of a single (control) male stimulus varied with age post-maturity; females were less
receptive in weeks 1 and 2, highly receptive at week 3, and less thereafter. Mated females were least receptive and most aggressive
towards a male stimulus. Females offered choices repeatedly at different ages post-maturity consistently preferred the control
male vs reduced tufts over all 3 weeks but varied in their preference for enlarged tufts vs control male. In the first 2 weeks,
females preferred the enlarged tuft male stimulus, but showed no preference by the third week. Females tested in week 4 showed
no preference in either choice. Results suggest that the potential interaction between female preference for male traits and
female reproductive timing may be a critical consideration in mate choice. 相似文献
8.
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
9.
Tagide N. deCarvalho Daniel J. Fergus Rayna C. Bell Kerry L. Shaw 《Behavioral ecology and sociobiology》2012,66(9):1333-1340
In many organisms, mating behavior occurs at a particular time of day, which may be important for avoiding mate competition or interspecific mating. Crickets of the Hawaiian genus Laupala exhibit an unusually protracted courtship in which males produce a series of nuptial gifts prior to the species-typical time of mating. Mating time is one of several rhythmic behaviors that have diverged among closely related Laupala species, which exhibit an extremely high speciation rate. Mating rhythm may reflect direct selection on male and/or female sexual receptivity or the pleiotropic consequence of selection on other rhythmic behaviors. To examine the role of sexual rhythmicity in Laupala cerasina, we characterized the time boundaries or “circadian gate” of courtship and mating, as well as female phonotactic response to male song. We also examined which sex is responsible for mating rhythmicity by phase-shifting males relative to the female photophase. Our results demonstrate that mating behavior is gated by the end of the light phase. Time limits to female mating receptivity were not observed and thus male rhythm alone appears to be responsible for the timing of mating. Furthermore, when courtship is initiated later in the day, males produce fewer nuptial gifts and increase nuptial gift production rate while delaying mating, suggesting that the number of gifts a female receives is important to male reproductive success. 相似文献
10.
Palestina Guevara-Fiore Jessica Stapley Penelope J. Watt 《Behavioral ecology and sociobiology》2010,64(10):1665-1672
Males vary in the degree to which they invest in mating. Several factors can explain this variation, including differences
in males’ individual condition and the fact that males allocate their energy depending on the context they face in each mating
attempt. Particularly, female quality affects male reproductive success. Here, we studied whether male guppies (Poecilia reticulata) strategically allocated more mating effort, in terms of mating behaviour and male–male competition, when they were matched
with a receptive (R) female than a non-receptive one. In accordance with our prediction, we found that males increased their
mating behaviour when they were with a receptive female. Even though male guppies can inseminate non-receptive females, we
only found high levels of courtship between males that were with a receptive female rather than a non-receptive one. Although
there was little affect of female receptivity on male–male competition, we found that males chased and interrupted courtships
more with receptive females than with non-receptive females regardless of odour. Finally, we also studied whether the sexual
pheromone produced by receptive female guppies is a cue that males use in order to increase their mating effort. We found
that males were more attracted to a female when they perceived the sexual pheromone, but only increased their mating and aggressive
behaviours when females showed receptive behaviour. This strategic increase in mating effort could result in higher male reproductive
success because mating attempts towards receptive females are likely to be less costly and males could have a greater probability
of fertilisation. 相似文献
11.
Female choice of multiple male criteria in guppies: interacting effects of dominance,coloration and courtship 总被引:9,自引:0,他引:9
Astrid Kodrie-Brown 《Behavioral ecology and sociobiology》1993,32(6):415-420
Summary I experimentally examined the relative importance of social dominance, color patterns, and courtship behavior in male mating and reproductive success in the guppy Poecilia reticulata. Female choice of males is based on a complex set of behavioral and morphological traits. The results of 59 paired-male one-female visual choice and mating trials showed that male mating success was positively correlated with dominance, courtship intensity, and male coloration. Only dominant males engaged in full copoulations, and they sired two-thirds of the broods. An analysis of the paternity of broods and results of mating trials showed that a female's visual response when the sexes are separated by a glass partition is a good predictor of a male's reproductive success when the partition is removed and they are allowed to mate. A canonical correlation analysis of male behavioral and morphological traits indicated that female visual response and male mating success were positively correlated with male courtship and with agonistic behavior. However, the relative importance of color varied. Carotenoid and iridescent spots were important both in attracting the female's attention and in enhancing male mating success. Melanins were not correlated with either mating success or female response. There was a relatively low correlation (48%) between male behavioral and morphological variables and female response variables (full copulation and female visual response). These results suggest that female choice is subtle, and is based on a complex suite of male behavioral and morphological traits as well as on competitive interactions among males. 相似文献
12.
Love bites: male fang use during coercive mating in wolf spiders 总被引:1,自引:1,他引:0
Julianna L. Johns J. Andrew Roberts David L. Clark George W. Uetz 《Behavioral ecology and sociobiology》2009,64(1):13-18
Evolutionary conflicts of interest between the sexes are common, as mating tactics and strategies that increase fitness benefits
for one sex may incur costs for the other. As a consequence, antagonistic coevolution between the sexes often results in a
complex arms race between male persistence and female resistance. Coercive mating (e.g., forced copulation) likely benefits
males by increasing the probability of mating; however, costs to females may be high, including injury or even death. Here,
we report on a study of the use of fangs by males of the wolf spider Schizocosa ocreata (Hentz) during forcible mating with resistant females, which results in hemolymph loss and scar tissue formation in females.
Microscopic inspection revealed that fang wounds (evidenced by scar tissue) were absent on unmated (virgin) females but were
found on mated females and were significantly more frequent in coercively mated females. Experimental fang immobilization
studies found no difference in copulation success between experimental (fangs immobilized) and control (sham manipulation)
males. However, males that had use of their fangs had significantly longer copulation duration. These findings represent a
previously unknown male mating tactic in spiders and an unrecognized potential cost of mating for female spiders. 相似文献
13.
Sexual conflict in the snake den 总被引:3,自引:0,他引:3
Red-sided garter snakes (Thamnophis sirtalis parietalis) court and mate in spring, soon after they emerge from large communal overwintering dens in south-central Manitoba. Because
of a massive bias in the operational sex ratio, every female attracts intense courtship from dozens to hundreds of males.
We suggest that this courtship constitutes significant ”harassment,” because it delays the females’ dispersal from the den
and hence increases their vulnerability to predation. Small females may face the greatest costs, because they are less able
to escape from amorous males (who court all females, even juvenile animals). Our measurements show that males are stronger
and faster than females. Experimental trials confirm that the locomotor ability of females (especially small females) is greatly
reduced by the weight of a courting male. Arena trials show that intense courtship stimulates females to attempt to escape.
Remarkably, some females that are too small to produce offspring may nonetheless copulate. This precocious sexual receptivity
may benefit juvenile females because copulation renders them unattractive to males, and thus allows them to escape more easily
from the den. Female ”tactics” to escape male harassment may explain other puzzling aspects of garter snake biology including
size-assortative mating, temporal patterns in dispersal from the den, avoidance of communal dens by young-of-the-year snakes,
and female mimicry. Hence, sexual conflict may have influenced important features of the mating system and behavioral ecology
of these animals.
Received: 8 May 2000 / Revised: 28 July 2000 / Accepted: 30 July 2000 相似文献
14.
Summary Luyten and Liley (1985) obtained evidence that in populations of Trinidad guppies from two clear headwater streams, where Rivulus harth is the major aquatic predator, selection has favored visual aspects of male mating behavior — display activity and conspicuous coloration. Males in two lowland turbid stream populations, with numerous aquatic predators, were found to rely more heavily upon non-display components of courtship. In this study males of the four populations were placed in competition in clear water for mating with females of the same populations. Males of two populations were allowed to compete in turbid water. Mating success was determined on the basis of the frequency of insemination and the proportion of sperm attributable to males of the competing populations. The sperm of competing males were identified by radioisotope labelling and autoradiographic techniques. Males from headwater populations were more successful than lowland males in mating with headwater females in clear water. There was no difference in mating success of headwater and lowland males in competition for lowland females in clear water, but in turbid water lowland males were more successful in inseminating lowland females. Males were more successful in mating with females of their own population when the two headwater population were in competition. The results are consistent with the hypothesis that conspicuous coloration and high frequency and duration of display are adaptations to clear water conditions, and that non-display tactics are adapted to turbid water. Evidence of intrapopulation preferences suggest that male traits and female sexual responses in the guppy have evolved in parallel as predicted by sexual selection theory. 相似文献
15.
George W. Uetz J. Andrew Roberts David L. Clark Jeremy S. Gibson Shira D. Gordon 《Behavioral ecology and sociobiology》2013,67(9):1471-1482
Multimodal signals may compensate for environmental constraints on communication, as signals in different modalities vary in efficacy. We examined the influence of complex microhabitats on transmission of vibratory and visual signals of courting male Schizocosa ocreata wolf spiders (Araneae: Lycosidae) with laser Doppler vibrometry (LDV) and behavioral observations in lab and field. We measured maximum potential detection distance of visual and vibratory signals by females in laboratory mesocosms, recorded vibration signal attenuation on different substrates, and estimated transmission distances for male vibration signals in the field. We also determined effective line-of-sight visual detection distances in the field with laser distance measures. Together, these data were used to estimate the potential and effective active space of multimodal signals. LDV measures show leaves are highly conductive substrates for wolf spider vibratory signals compared to others (soil, wood, rock). For both visual and vibratory modes, lab estimates of maximum potential distance for signal transmission and detection (behavior studies) exceeded estimates of effective active space (signal attenuation, “vanishing point,” and “line-of-sight” measures). Field estimates of transmission distance for signal modes overlap, such that in close range (<20 cm), vibratory signals are more likely to be detected, while farther away, visual signals are more likely to be seen. These findings thus support current hypotheses regarding how multimodal communication might extend the range of overall signal active space or compensate for environmental constraints. 相似文献
16.
Effect of female molt stage and sex ratio on courtship behavior of the blue crab Callinectes sapidus
In many species, males and females actively participate in courtship, and the outcome of pre-mating interactions influences
the mating success of both sexes. Female blue crabs, Callinectes sapidus, mate soon after their final molt to maturity; thus female molt stage dictates the timing of mating. In a field experiment,
we manipulated female molt stage and sex ratio to test their effects on the courtship behavior of both sexes, if female behavior
influences the behavior and pairing success of males, and if male courtship influences male pairing-success. Early-molt-stage
females avoided males during courtship, whereas late-molt-stage females sought out males. As a result, males had to pursue
and capture early-molt-stage females whereas males displayed to late-molt-stage females and more easily physically controlled
them. Males sometimes abandoned late-molt-stage females, but this occurred more often when females were abundant. The rate
at which females avoided males was positively correlated with that of males abandoning females, and males that were unsuccessful
at pairing met with higher rates of female resistance than successful males, suggesting that female behavior influences male
pairing-success. Unlike unsuccessful males, successful males more often made the transition between display and maintaining
physical control of the female. At high male sex ratios, males initiated courtship more readily; thus both sexual competition
and female behavior influence male courtship in this species.
Received: 7 July 1996 / Accepted: 10 January 1998 相似文献
17.
Males often use elaborate courtship displays to attract females for mating. Much attention, in this regard, has been focused
on trying to understand the causes and consequences of signal variation among males. Far less, by contrast, is known about
within-individual variation in signal expression and, in particular, the extent to which males may be able to strategically
adjust their signalling output to try to maximise their reproductive returns. Here, we experimentally investigated male courtship
effort in a fish, the Australian desert goby, Chlamydogobius eremius. When offered a simultaneous choice between a large and a small female, male gobies spent significantly more time associating
with, and courting, the former, probably because larger females are also more fecund. Male signalling patterns were also investigated
under a sequential choice scenario, with females presented one at a time. When first offered a female, male courtship was
not affected by female size. However, males adjusted their courtship effort towards a second female depending on the size
of the female encountered previously. In particular, males that were first offered a large female significantly reduced their
courtship effort when presented with a subsequent, smaller, female. Our findings suggest that males may be able to respond
adaptively to differences in female quality, and strategically adjust their signalling effort accordingly. 相似文献
18.
P. Andreas Svensson Topi K. Lehtonen Bob B. M. Wong 《Behavioral ecology and sociobiology》2010,64(12):1967-1970
Courtship displays are often important in determining male mating success but can also be costly. Thus, instead of courting
females indiscriminately, males might be expected to adjust their signalling effort strategically. Theory, however, predicts
that such adjustments should depend on the rate with which males encounter females, a prediction that has been subject to
very little empirical testing. Here, we investigate the effects of female encounter rate on male courtship intensity by manipulating
the time interval between sequential presentations of large (high quality) and small (low quality) females in a fish, the
Australian desert goby Chlamydogobius eremius. Males that were presented with a small female immediately after a large female reduced their courtship intensity significantly.
However, males courted large and small females with equal intensity if the interval between the sequential presentations was
longer. Our results suggest that mate encounter rate is an important factor shaping male reproductive decisions and, consequently,
the evolutionary potential of sexual selection. 相似文献
19.
Summary One of the roles ascribed to spider courtship is that of mate recognition and reproductive isolation. We describe behavioral mechanisms underlying these functions in three species of wandering spiders of the genus Cupiennius (Ctenidae). C. salei and the two sympatric species C. getazi and C. coccineus discriminate conspecifics and heterospecifics in a multistage process which covers three principal phases of courtship: (1) Chemical phase: male spiders initiate vibratory courtship communication less often upon contact with heterospecific than with conspecific female silk. (2) Vibratory phase: females respond with their own vibration less often and with increased delay to the vibratory courtship signals of heterospecific males than to those of conspecific males. (3) Tactile phase: in heterospecific pairings males and females interrupt the contact phase if their courtship has progressed thus far. The product of the probabilities of passing through each of the different stages of courtship is between 0.44 and 0.88 for conspecific pairings, but zero for most heterospecific pairings. This is to a greater extent due to the behavioral barriers of the vibratory and the tactile phase than to that of the chemical phase. Male taxis on tracks of female silk does not depend on the species-specificity of the silk. Female vibrations are not essential for species recognition: males increase their signal rates, orient toward and approach responding females in both con- and heterospecific pairings. Female attacks on males are similar to attacks on prey; males defend themselves with outstretched front legs and are caught and killed by the female in only 5% of the cases. In all phases of courtship, female C. salei are least and female C. getazi most selective. When female C. coccineus and C. getazi are involved in heterospecific pairings no copulation is attempted. In contrast, 13 copulations of C. salei with males of the other two species were observed; egg sacs never resulted from these copulations. Among males, those of C. getazi were least selective. The likelihood of heterospecific pairs passing through all phases of courtship is higher in case of the allopatric than in that of the sympatric species. This finding applies to the courtship as a whole, but not necessarily to each of its phases.Offprint requests to: F.G. Barth 相似文献
20.
In most mating systems, males and females are commonly within signalling and receiving distance of conspecifics during courtship and mating activities. Although it is well known that females who observe sexual interactions between conspecifics will use public information obtained from these interactions when making their own mating decisions, much less is known about whether males use this type of information in making mating decisions. We used the Trinidadian guppy (Poecilia reticulata) to test whether males use public information to (i) copy the apparent mate choice of another male and (ii) modify their mating preference for a given female in the presence of one or two sexual rivals (potential copiers). We show that males use public information to copy the mate choice of other males and that males alter their mating preferences in response to the presence of an audience of sexual rivals, but find no evidence of a stronger audience effect when the number of sexual rivals increases. Collectively, these results indicate that males pay attention to their immediate social environment in making mating decisions and suggest that they avoid having another male copy their mate choice by weakening or even reversing their initial mating preference in the presence of eavesdropping male sexual competitors. Our findings highlight the importance of social context and public information in male mate-choice decisions and have implications for the evolution of male mating preferences and of social information use in populations. 相似文献