共查询到20条相似文献,搜索用时 31 毫秒
1.
Differential interests between the sexes regarding the number of copulations can result in sexual harassment. Hence, females
may have less time available for foraging. Male sexual harassment often leads to fitness reduction in females. We used the
mating complex of the bisexual fish Poecilia mexicana and the co-occurring all-female Poecilia formosa to study sexual harassment and its incurred cost on female feeding efficiency. P. formosa is a sperm-dependent parthenogen that requires mating with host males to induce embryogenesis, but the male genes are not
used. We therefore predicted P. mexicana males to prefer conspecific females. Hence, costs of male sexual harassment should not occur in unisexuals. While P. formosa are at a disadvantage compared to P. mexicana females due to male mate choice (leading to sperm limitation), this could be traded-off by suffering less from sexual harassment.
In our experiment, we found males to direct significantly more pre-copulatory mating behaviour towards conspecific females,
whereas actual mating attempts did not differ between species. Contrary to our prediction, both types of females started feeding
later and spent less time feeding in the presence of a male partner compared to the time spent feeding with another female,
suggesting that females of both species suffer from male harassment. The focal females' feeding time declined with increasing
body size of the female competitor, and the same pattern was found when a male was present. We discuss that—besides sexual
harassment—other factors such as food competition and female mate choice may affect female feeding efficiency. 相似文献
2.
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
3.
Color polymorphisms have provided classical examples of how frequency-dependent selection maintains genetic variation in natural
populations. Here we tested for the first time, the hypothesized adaptive function of a female-specific color polymorphism
in odonates to lower male harassment towards females generally. Under conditions controlling for sex ratio, population density
and morph frequency, we also tested two major frequency-dependent selection hypotheses for the maintenance of the polymorphism.
Using groups of captive Enallagma hageni, whose females are either green or a male-like blue, we varied morph frequency at two sex ratios. We quantified sexual harassment
towards females by visual observations, and by the presence of dust on females that was transferred from dusted males. Per
capita harassment rate for the female-monomorphic treatments did not differ from that of the female-polymorphic treatments.
At a male-biased sex ratio, per capita harassment rate towards blue, but not green females increased with morph frequency,
providing partial support for frequency-dependent selection resulting from male learning of female morphs. Even at high frequency,
green females were not harassed more than blue, contrary to the prediction that males should always recognize green females
as mates. Moreover, frequency-dependent harassment towards blue females was not detectable using harassment measured with
dust evidence, which greatly underestimated the incidence of sexual harassment. Our findings identified problems with the
use of insectaries and the dusting technique to quantify male sexual harassment towards females, as well as with a past insectary
experiment on Ischnura elegans that failed to demonstrate frequency-dependent harassment. 相似文献
4.
Sexual coercion is a common behaviour for males trying to compensate for being inferior in male competition and/or female choice. We measured the cost of male sexual harassment for females as reduced feeding time in three populations of the Atlantic molly (Poecilia mexicana). Of these populations, one originated from a typical river habitat, another from a lightless cave chamber and the third one from a small, milky creek outside the cave. We gave hungry females an opportunity to feed in the presence of either another female or a male. We found the following: (1) male sexual harassment represents a cost in the river dwelling population and both small and large males significantly reduce female feeding time; and (2) sexual harassment was not detected in the other two populations (cave and cave entrance). In the cave molly, small males are at a disadvantage in female choice, but predation by an aquatic heteropteran selects against large male body size. 相似文献
5.
R. Terry Bowyer Janet L. Rachlow Kelley M. Stewart Victor Van Ballenberghe 《Behavioral ecology and sociobiology》2011,65(12):2251-2260
Evidence of female fomentation of male–male aggression as a mechanism of mate choice is rare, especially in mammals. Female
choice of mates in polygynous species may be masked by intense male competition or by males attempting to restrict female
choice. We studied protest moans of female Alaskan moose Alces alces gigas in interior Alaska, USA, from 1987 to 1990, to determine if moans incited male–male aggression. Alaskan moose exhibit a mating
system in which one dominant male (the harem master) herds, defends, courts, and attempts to mate with females in his harem.
Protest moans were given by females only in response to courtship. We hypothesized that if protest moans were related to females
reducing harassment and exercising mate choice, females should give protest moans more frequently when courted by small males
and less often when courted by large males, and that rates of male–male aggression would be elevated following protest moans.
Harems were composed of one large male, with a mean of 4.4 females (median = 3 females); 10% of 132 harems included ≥10 females.
The temporal pattern of protest moans from late August through November was associated with, but tended to lag behind, mating
behavior. The rate of protest moans given by females decreased with increasing size of males courting them. Male–male aggression
was significantly less during periods without protest moans than during periods in which protest moans occurred. These results
indicate that female moose gave protest moans to reduce harassment by smaller males, and assure a mating opportunity with
the most dominant male. Such a subtle mechanism of indirect mate choice by females may occur in other vertebrates in which
choice is limited by a mating system in which male–male combat and male dominance over females reduces opportunities for female
choice. The importance of female choice may be undervalued in studies of sexual selection in mammals. 相似文献
6.
Jay D. Evans 《Behavioral ecology and sociobiology》1998,44(1):35-42
Most social groups have the potential for reproductive conflict among group members. Within insect societies, reproduction
can be divided among multiple fertile individuals, leading to potential conflicts between these individuals over the parentage
of sexual offspring. Colonies of the facultatively polygynous ant Myrmicatahoensis contain from one to several mated queens. In this species, female sexuals were produced almost exclusively by one queen.
The parentage of male sexuals was more complex. In accordance with predictions based on worker sex-allocation preferences,
male-producing colonies tended to have low levels of genetic relatedness (i.e., high queen numbers). Correspondingly, males
were often reared from the eggs of two or more queens in the nest. Further, over half of the males produced appeared to be
the progeny of fertile workers, not of queens. Overall investment ratios were substantially more male biased than those predicted
by genetic relatedness, suggesting hidden costs associated with the production of female sexuals. These costs are likely to
include local resource competition among females, most notably when these individuals are adopted by their maternal nest.
Received: 3 March 1998 / Accepted after revision: 20 June 1998 相似文献
7.
Tim Ruploh Hans-Joachim Bischof Nikolaus von Engelhardt 《Behavioral ecology and sociobiology》2014,68(4):537-549
Group-living animals rely on social skills which ensure beneficial interaction and prevent harmful ones with conspecifics. In a previous experiment, we demonstrated that male zebra finches reared in groups during adolescence show consistently less courtship and aggressive behaviour as adults than pair-reared males. Here we tested whether such differences affect how they group with conspecifics, as an indicator of their social integration. Zebra finches were kept in pairs (male–female or male–male) or mixed-sex groups (three males and three females) during adolescence and were introduced to an established group of unknown conspecifics during adulthood. Male courtship and aggressive behaviour were quantified directly after introduction to the group and 48 h later. At the same time, male position in relation to other birds and the number of birds in proximity were recorded. Males that grew up in a small mixed-sex group during adolescence spent more time within groups, were observed in bigger groups and lost less weight than males raised in pairs, indicating that an enriched social environment during early development may facilitate social integration. However, we observed no differences in courtship and aggressive behaviour that could predict the differences in grouping behaviour of pair- and group-reared males. We discuss alternative explanations for the difference in grouping and how to test these in future research. 相似文献
8.
A fundamental question of sexual selection theory concerns the causes and consequences of reproductive skew among males. The
priority of access (PoA) model (Altmann, Ann NY Acad Sci 102:338–435, 1962) has been the most influential framework in primates living in permanent, mixed-sex groups, but to date it has only been
tested with the appropriate data on female synchrony in a handful of species. In this paper, we used mating data from one
large semi-free ranging group of Barbary macaques: (1) to provide the first test of the priority-of-access model in this species,
using mating data from 11 sexually active females (including six females that were implanted with a hormonal contraceptive
but who showed levels of sexual activity comparable to those of naturally cycling females) and (2) to determine the proximate
mechanism(s) underlying male mating skew. Our results show that the fit of the observed distribution of matings with sexually
attractive females to predictions of the PoA model was poor, with lower-ranking males mating more than expected. While our
work confirms that female mating synchrony sets an upper limit to monopolization by high-ranking individuals, other factors
are also important. Coalitionary activity was the main tactic used by males to lower mating skew in the study group. Coalitions
were expressed in a strongly age-related fashion and allowed subordinate, post-prime males to increase their mating success
by targeting more dominant, prime males. Conversely, females, while mating promiscuously with several males during a given
mating cycle, were more likely to initiate their consortships with prime males, thus reducing the overall effectiveness of
coalitions. We conclude that high-ranking Barbary macaque males have a limited ability to monopolize mating access, leading
to a modest mating skew among them. 相似文献
9.
ElizaBeth A. Fox 《Behavioral ecology and sociobiology》2002,52(2):93-101
Orangutan males demonstrate intrasexual dimorphism with corresponding alternative mating strategies. Sexual harassment is the predominant feature of the mating strategy that subadult males pursue. This study investigated the countertactics that females employ to reduce sexual harassment by subadult males. I observed 207 copulations during more than 9,000 h of focal follows of wild Sumatran orangutans at the Suaq Balimbing Research Station over a 23-month period. Rates of copulations initiated by subadult males increased during months of high fruit abundance, and most mating attempts were directed toward females with weaned infants. Simultaneous harassment by multiple subadult males increased significantly during months of high fruit abundance, and nearly all adult female-adult male consortships occurred during periods of high fruit abundance. Females who maintained spatial association with adult males, either via consortship or by nonmating temporary parties, received lower rates of harassment, as measured by the success rate of subadult male mating attempts. Adult female-adult male parties did not always result in mating between the associating dyad. Female initiation of protective services by adult males is one social tactic that female orangutans employ to reduce sexual harassment. Females therefore receive direct services from adult males, which may be one factor that influences female mate choice in Sumatran orangutans. 相似文献
10.
Michael J. Young Leigh W. Simmons Jonathan P. Evans 《Behavioral ecology and sociobiology》2010,64(6):915-925
Sexual selection can act through female choice and male–male competition. Although both processes can act simultaneously,
they are typically studied independently. Here, we adopt a more integrated approach to studying sexual selection by incorporating
measures of both processes using the western rainbowfish Melanotaenia australis, a freshwater fish endemic to northwestern Australia. We assessed male–male competition and female choice separately while
measuring the performance of individual males under both processes and used paternity analyses to estimate male reproductive
success. We then related the performance of males during each of these stages to their phenotype, which was described using
linear measures of size and color pattern traits, and spectrographic measures of the reflectance of color patches. We found
that female choice favored relatively large males and that these preferences were consistent within individual females and
repeatable between different females. Larger males were also more dominant in the competition trials and sired the majority
of offspring produced when females spawned. There was little evidence to suggest that sexual selection acted on male color
patterns either via female choice or male contest competition or during subsequent post-mating episodes of sexual selection.
We conclude, therefore, that male–male competition and female choice act concordantly to favor relatively large males and
that these patterns of mating success are reflected during post-mating episodes of sexual selection. 相似文献
11.
Nga Nguyen Russell C. Van Horn Susan C. Alberts Jeanne Altmann 《Behavioral ecology and sociobiology》2009,63(9):1331-1344
Close associations between adult males and lactating females and their dependent infants are not commonly described in non-monogamous
mammals. However, such associations [sometimes called “friendships” (Smuts 1985)] are regularly observed in several primate species in which females mate with multiple males during the fertile period.
The absence of mating exclusivity among “friends” suggests that males should invest little in infant care, raising questions
about the adaptive significance of friendship bonds. Using data from genetic paternity analyses, patterns of behavior, and
long-term demographic and reproductive records, we evaluated the extent to which friendships in four multi-male, multi-female
yellow baboon (Papio cynocephalus) groups in Amboseli, Kenya represent joint parental care of offspring or male mating effort. We found evidence that mothers
and infants benefited directly from friendships; friendships provided mother–infant dyads protection from harassment from
other adult and immature females. In addition, nearly half of all male friends were the genetic fathers of offspring and had
been observed mating with mothers during the days of most likely conception for those offspring. In contrast, nearly all friends
who were not fathers were also not observed to consort with the mother during the days of most likely conception, suggesting
that friendships between mothers and non-fathers did not result from paternity confusion. Finally, we found no evidence that
prior friendship increased a male’s chances of mating with a female in future reproductive cycles. Our results suggest that,
for many male–female pairs at Amboseli, friendships represented a form of biparental care of offspring. Males in the remaining
friendship dyads may be trading protection of infants in exchange for some resources or services not yet identified. Our study
is the first to find evidence that female primates gain social benefits from their early associations with adult males.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
12.
Among primates, group size is highly variable. The standard ecological model assumes that better predation avoidance as group
size increases favours living in larger groups, whereas increased travel costs and reduced net food intake due to within-group
competition for resources set the upper limit. Folivorous primates, however, tend to defy this generalisation in that some
live in small groups despite low costs of feeding competition. To resolve this ’folivore paradox’, it has been suggested that folivore group size is limited by social factors such as male
harassment or infanticide, or that females can disperse more easily and thus maintain group size near optimum levels. In this
paper, we examine the effects of group size on home range size, day-journey length, activity budget and diet in wild Thomas’s
langurs (Presbytis thomasi), which live in one-male multi-female groups with a limited life cycle. We examined only data from the stable middle tenure
phase when factors such as the strength of the breeding male or the way in which groups were formed did not influence ranging
and activities. During this phase, group size affected day-journey length and home range size, and had a minor effect on diet,
but did not influence time spent feeding or resting, allogrooming or birth rates. Hence the upper limit to group size during
the middle tenure phase in Thomas’s langurs is not set by feeding competition. The folivore paradox is not due to frequent
female dispersal in Thomas’s langurs. The timing of female dispersal is not as expected if it serves to keep group sizes near
the ecological optimum, and groups seem to be below this optimum. Instead, female reproductive success is presumably maximised
in small to mid-sized groups because larger groups show a clear trend to experience higher risk of take-over, often accompanied
by infanticide. Because females can redistribute themselves among nearby groups when groups reorganise each time a new male
starts up a new group, females can keep the group small. Thus, a social factor, risk of infanticide, seems to provide the
selective advantage to small group size in Thomas’s langurs.
Received: 29 July 1999 / Revised: 17 November 1999 / Accepted: 15 October 2000 相似文献
13.
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
14.
Antonia Köhler Philipp Hildenbrand Elke Schleucher Rüdiger Riesch Lenin Arias-Rodriguez Bruno Streit Martin Plath 《Behavioral ecology and sociobiology》2011,65(8):1513-1523
Sexual harassment by males has the potential to affect almost any aspect of female behavior and life history. Using Atlantic
mollies (Poecilia mexicana) as a model—a species in which males do not court but almost constantly try to forcefully mate with females—we asked whether
and how male harassment influences (a) females’ time budgets and (b) feeding rates (e.g., through frequent flight from male
approaches), and (c) whether metabolic rates are increased as a response to stress. Field observations in a natural P. mexicana population revealed that males (average feeding rate 15%) spent far less time feeding than females (60%), and clearly traded
off frequent pursuit of females with foraging. Most importantly, females’ feeding times were dramatically reduced when being
pursued by a harassing male. Also in standardized lab experiments, females spent significantly less time feeding when accompanied
by a male as compared to being in the presence of another female. This effect was also observed when partner fish (male or
female) were presented only visually, but could not interact physically with the focal female. It seems, therefore, that females
increase vigilance when a harassing male is around, which keeps them from feeding even before males actually approach them.
Based on the latter result, we asked whether a stress-induced increase in metabolic rates would be discernible. We measured
oxygen consumption and gill ventilation frequencies (opercular rates) of females in different social contexts (alone, with
another female, or a male). The predicted, strong body mass dependency of both physiological parameters was uncovered, but
no evidence for an effect of social context was detected. We argue that male harassment represents such a constant (but non-lethal)
stressor for poeciliid females that their metabolic stress responses have adapted to this through habituation. 相似文献
15.
Jennifer D. Cooper Peter M. Waser Eric C. Hellgren Timothy M. Gabor J. A. DeWoody 《Behavioral ecology and sociobiology》2011,65(4):775-785
Sexual dimorphism is common in polygynous species, and there is clear evidence that both intra-sexual competition and female
preferences can drive the evolution of large body size in males. In contrast, sexual monomorphism is often argued to reflect
a relaxation of male mate competition or an intensification of resource competition among females. Alternatively, it might
imply opportunities for females to circumvent or counteract male mate competition in a polygynandrous mating system. We test
the prediction that sexual monorphism is associated with polygynandry in the collared peccary (Pecari tajacu, Tayassuidae), a social ungulate closely related to the old-world suids. The genetic mating system in the Tayassuidae is
unknown, but its sexual monomorphism presents a striking contrast to the strong size dimorphism found in most Suidae, so that
a departure from the polygynous system common in Suidae would be noteworthy. We characterized genetic relationships among
adults within herds in three geographically distinct populations, assigned parents to 75 offspring, and tested for skew in
individual reproductive success. Parentage assignment data indicated that multiple males sire offspring within a herd, and
in the population for which genetic data were most complete, 19% of parentage assignments were potentially sired by extra-herd
males. Some litters have multiple sires, and neither males nor females monopolized reproduction, even in small herds. This
result supports our prediction and suggests that sexual monomorphism may either select for or be an evolutionary consequence
of a promiscuous mating system. 相似文献
16.
Mixed reproductive strategy and mate guarding in a semi-colonial passerine,the swallow Hirundo rustica 总被引:6,自引:0,他引:6
Anders Pape Møller 《Behavioral ecology and sociobiology》1985,17(4):401-408
Summary Both male and female swallows Hirundo rustica have a mixed reproductive strategy (parental care for offspring and extra-pair couplations). Mate guarding protects females from male harassment and male swallows from being cuckolded. Females hide their fertile period by copulating successfully with their mates for an extended period during first clutches. Males guard in the pre-fertile period, when many unpaired males are present. Early breeding swallows guard more than late breeders since more sexual chases of females by non-mate males take place in the early period. Solitarily breeding females experience few chases by strange males; copulation frequency, length of copulation period and mate guarding is adjusted to a lower level than among colonial birds. Male guarding activity is more intense in the fertile than in the pre-fertile period. Guarding reduces success of extra-pair copulation attempts.Three female swallows each paired and copulated with a single male and later changed to a new male before starting to breed. Extra-pair copulations most often take place between neighbouring swallows in the fertile period of the female. Many old, early breeding males and many young, late breeding females participate in extra-pair couplations. Successful extra-pair copulations peak in the fertile period contrary to success of pair copulations which does not change during the copulation period. 相似文献
17.
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
18.
The evolution of female social relationships in nonhuman primates 总被引:38,自引:14,他引:38
Elisabeth H. M. Sterck David P. Watts Carel P. van Schaik 《Behavioral ecology and sociobiology》1997,41(5):291-309
Considerable interspecific variation in female social relationships occurs in gregarious primates, particularly with regard
to agonism and cooperation between females and to the quality of female relationships with males. This variation exists alongside
variation in female philopatry and dispersal. Socioecological theories have tried to explain variation in female-female social
relationships from an evolutionary perspective focused on ecological factors, notably predation and food distribution. According
to the current “ecological model”, predation risk forces females of most diurnal primate species to live in groups; the strength
of the contest component of competition for resources within and between groups then largely determines social relationships
between females. Social relationships among gregarious females are here characterized as Dispersal-Egalitarian, Resident-Nepotistic,
Resident-Nepotistic-Tolerant, or Resident-Egalitarian. This ecological model has successfully explained differences in the
occurrence of formal submission signals, decided dominance relationships, coalitions and female philopatry. Group size and
female rank generally affect female reproduction success as the model predicts, and studies of closely related species in
different ecological circumstances underscore the importance of the model. Some cases, however, can only be explained when
we extend the model to incorporate the effects of infanticide risk and habitat saturation. We review evidence in support of
the ecological model and test the power of alternative models that invoke between-group competition, forced female philopatry,
demographic female recruitment, male interventions into female aggression, and male harassment. Not one of these models can
replace the ecological model, which already encompasses the between-group competition. Currently the best model, which explains
several phenomena that the ecological model does not, is a “socioecological model” based on the combined importance of ecological
factors, habitat saturation and infanticide avoidance. We note some points of similarity and divergence with other mammalian
taxa; these remain to be explored in detail.
Received: 30 September 1996 / Accepted after revision: 20 July 1997 相似文献
19.
David Bierbach Claudia Kronmarck Carmen Hennige-Schulz Stefan Stadler Martin Plath 《Behavioral ecology and sociobiology》2011,65(9):1699-1707
Mate choice copying was mostly described as a strategy employed by females to assess the quality of potential mates, but also
males can copy other males’ mate choice. An open question in this context is whether and how copying males evaluate sperm
competition risk, as mating with a female that has already copulated with another male obviously sets the stage for intense
sperm competition (i.e., in species with internal fertilization). Using the livebearing Atlantic molly (Poecilia mexicana) as a model, we asked (a) whether males of that species indeed copy other males’ choices, and if they do so, (b) whether
copying males strategically adjust their behavior to sperm competition risk. We used an approach where focal males could first
choose to associate with a large or a small stimulus female. Mate choice tests were then repeated after an “observation phase”
during which either no model male was present (treatment 1, control) or the previously non-preferred female could be seen
associating (treatment 2) or physically interacting (treatment 3) with a model male. We found that, after the observation
phase, males spent considerably more time with the previously non-preferred female in treatment (2), i.e., they copied the
model male’s choice. This effect was much weaker during treatment (3) where sexual interactions between the model male and
the formerly non-preferred female were allowed. Males, therefore, seem to adjust their copying behavior strategically to the
perceived risk of sperm competition. 相似文献
20.
Ellen J. Censky 《Behavioral ecology and sociobiology》1997,40(4):221-225
Mate choice by females has been documented in a variety of taxa. Female mate choice in species lacking male resource control
or paternal care might occur if preferred males provide protection from harassment. Female mate choice was investigated in
a natural population of the non-territorial lizard Ameiva plei (Teiidae). Consort pairs were allowed to form naturally. Consort males were significantly larger than non-consort males.
After removal of consort males, the “abandoned” female's reaction to the first male who approached her was recorded. Females
rejected all small males. Female preference for large males was significantly higher than preference for small males. Large
males may be better equipped to guard the females from harassment and behavior of large males is less harassing than behavior
of small males, thereby affording the female increased foraging time.
Received: 21 June 1996 / Accepted after revision: 28 December 1996 相似文献