共查询到20条相似文献,搜索用时 635 毫秒
1.
Summary Many lizards autotomize their tails to escape when grasped by a predator. It is hypothesized that tail loss causes a reduction in social status, thereby potentially lowering their reproductive success. We experimentally induced tail loss in Lacerta monticola in a semi-natural enclosure, and show that tail loss reduced social status and mating access in males. Tailless males increased body mass more rapidly than tailed dominant males, probably due to lower aggression costs. Also, tailless females were courted less and copulated less than tailed females, supporting the hypothesis that tail loss decreases reproduction potential.Correspondence to: J. Martin 相似文献
2.
We examined how reproductive state affected shifts in behavior of adult female Podarcis sicula toward chemical cues from a natural snake predator (Coronella austriaca). The oviparous P. sicula lizards do not experience a major physical burden during reproduction, but gravid females substantially increase duration of basking. Therefore, gravid lizards are likely to experience a greater risk of mortality because they are exposed to predators for longer periods. Both gravid and non-gravid females shifted patterns of locomotion when confronted with snake chemical cues, but the change was notably larger when females were non-gravid. When non-gravid, lizards responded to predator scent by increasing the number of stand-ups and starts, while such a response was not observed when females were gravid. By contrast, gravid lizards clearly reduced the time spent basking in the presence of predator scent, whereas no change in basking behavior was observed when females were non-gravid. Thus, females exhibit differential behavioral responses to predator scents that is dependent on reproductive state. 相似文献
3.
We performed male attraction experiments and staged courtship sequences to test for non-random mating with respect to social
behavioral phenotype in the comb-footed spider, Anelosimus studiosus. While asocial behavior is the dominant phenotype in all A. studiosus populations examined to date, a social phenotype approaches a frequency of 15% in colder environments. We collected test
subjects from higher latitude polymorphic populations and scored all individuals as to their behavioral phenotype prior to
their use in these trials. Males of both phenotypes differentially approached and courted social females over asocial females
and no-spider controls. By offering males different numbers of females of one type vs. the other in subsequent trials, we
determined that the difference in attractiveness between the two phenotypes social/asocial is 1.5/1. Both the web produced
by a female and a female that has been removed from its web attract males. We suggest that the male attracting pheromone is
present on females and is also attached to silk threads. Staged encounters completed between males and females of the respective
phenotypes demonstrated that courting males suffer significantly less pre-copulatory sexual cannibalism with social females
than with asocial ones, and thus, female social tendency is phenotypically linked to sexual aggression. We propose that the
male preference for social females is adaptive because of the observed asymmetry in courtship success. 相似文献
4.
Summary Vigilance behavior, predator detection abilities, and responses to real and model predators were studied in two species of capuchin monkeys (Cebus albifrons and C. apella) in a Peruvian lowland rain forest. Adult males were more vigilant than adult females in both species, mainly because the males spent less time feeding and foraging and partly because they were at the periphery more often than the females. The increased vigilance of adult males is reflected in their superior performance in the detection of (model) predators. Adult and subadult males were also far more likely to approach and mob real and model predators. Adults that were outside the center of the group increased foraging activities but cut back an feeding, much of which was done in exposed tree crowns. Current theory suggests that primate groups are multi-male when a single male is unable to defend sexual access to the group of females. In these small capuchin groups, which are multimale, the enhanced safety of females and young provided by extra adult males furnishes a more plausible explanation. A comparison of the two capuchins with the ecologically similar Southeast Asian Macaca fascicularis suggests that the high predation risk outside the group may also have caused the unusual male career profile in capuchins, which have a long tenure of dominants and a very long potential lifespan. Further predictions of this hypothesis are developed. 相似文献
5.
Tess Driessens Beatrijs Vanhooydonck Raoul Van Damme 《Behavioral ecology and sociobiology》2014,68(2):173-184
Although the visual display behavior in Anolis lizards has received ample attention, the function of dewlap extensions (DE), push-ups (PU), and head-nods (HN) in general, and in Anolis sagrei in particular, remains highly equivocal. Therefore, our primary goal was to quantify the display rates of these visual signal types (DE, PU, and HN) in a variety of contexts, using A. sagrei as study species. To our knowledge, this is the first study to test individuals of both sexes in a repeated-measures design across multiple contexts, including predator, non-predator and social interactions (mirror, male–male, male–female, female–male). We found that males have an overall higher signaling rate than females across all contexts. In addition, we found that lizards of both sexes exhibited higher display rates in the presence of conspecifics than when confronted with a predator or non-predator, suggesting that DE, PU, and HN function in intraspecific communication, not in predator deterrence. Whereas females did not significantly raise display rates in a consexual and heterosexual context with respect to subject-alone context, males did. The PU signal type only appears to play a major role for A. sagrei males during aggressive encounters. During heterosexual interactions, increased frequencies of all signal types suggest that DE, PU, and HN are essential for male courtship. Finally, we suggest that intersexual selection is probably a driving force for frequency-related dewlap use in both sexes. In contrast, pronounced intersexual differences were detected for PU and HN rates within a social context. 相似文献
6.
Antipredator behavior of a social desert rodent: footdrumming and alarm calling in the great gerbil, Rhombomys opiums 总被引:2,自引:0,他引:2
J. A. Randall Konstantin A. Rogovin Debra M. Shier 《Behavioral ecology and sociobiology》2000,48(2):110-118
We sought to understand why a social, desert rodent, the great gerbil, Rhombomys opimus, expends energy and possible risk of predation by footdrumming and vocalizing in the presence of a diversity of terrestrial
predators: snakes, monitor lizards, polecats, foxes, and humans. Behavioral observations, human approaches, and experiments
with tethered predators revealed that both male and female gerbils called and footdrummed in the presence of offspring, close
relatives, and potential mates. Because adults called more often when pups were present, and solitary gerbils seldom gave
an alarm, the alarm behavior probably warns conspecifics, especially vulnerable offspring, of potential danger. We also found
that gerbils altered alarm behavior with the type of predator. They drummed more in the burrow when a dog that could not enter
the burrow was present, and they drummed more out of the burrow in response to a snake that could enter the burrow. Gerbils
vocalized and stood in an alert posture in response to all stimuli. The different footdrumming responses of gerbils to terrestrial
predators seems related to the hunting style and type of risk posed by the predator, especially its ability to enter the burrow
system.
Received: 23 August 1999 / Received in revised form: 6 December 1999 / Accepted: 25 February 2000 相似文献
7.
Predation risk affects courtship and attractiveness of competing threespine stickleback males 总被引:6,自引:3,他引:6
Ulrika Candolin 《Behavioral ecology and sociobiology》1997,41(2):81-87
The effect of predation risk and male-male competition on male courtship behaviour and attractiveness to females was studied
in the threespine stickleback (Gasterosteus aculeatus) by presenting dummy or live females to solitary and competing males under different predation risks. In the presence of
a predator, males decreased courtship activity. Different courtship components were, however, adjusted to different extents
and in opposing directions to predation risk, probably because the single components may have varied in riskiness. The presence
of a competing male decreased overall courtship activity, but increased the frequency of zigzags, suggesting zigzagging to
be a competitive strategy against other males. In the presence of a predator male courtship activity was not affected by a
competitor. Female mate choice correlated with the males' previous frequency of zigzags towards a dummy female. However, when
a live female paid attention to a male, the male decreased zigzagging and instead increased leading and fanning behaviours,
probably trying to attract the female to the nest to mate. Predation risk affected the attractiveness of males as females
reduced their attention to a male when he faced a predator and reduced his courtship activity. As females instead increased
their attention to a competing male that had increased his courtship activity, due to decreased competition, males clearly
are balancing mating opportunities against predator avoidance. When males vary in their susceptibility to predators, predation
risk may thus affect mating success of competing males.
Received: 31 January 1997 / Accepted after revision: 15 April 1997 相似文献
8.
Summary Increased basking and reduced agility in gravid female southern water skinks (Eulamprus tympanum) suggest that they will be more vulnerable to predators. However, gravid females shift their anti-predator tactics towards crypsis, by allowing potential predators (such as a human observer) to approach more closely than do males and non-gravid females. Gravid females were taken no more frequently than were non-gravid females or males when exposed to two types of natural predators, birds (kookaburra, Dacelo gigas) or snakes (common blacksnakes, Pseudechis porphyriacus) in field enclosures. Both these results suggest that the vulnerability of potential prey in this system is determined by the predator's probability of detecting a potential prey item, not its probability of capturing the prey item after detection. Hence, laboratory-based measures of performance demonstrating reduced escape speed may sometimes have little relevance to actual fitness under field conditions, if the probability that an animal will be taken by a predator depends primarily on whether or not it is seen, rather than on how quickly it can escape.
Correspondence to: L. Schwarzkopf 相似文献
9.
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
10.
Intensive study of arboreal forest-dwelling primates and their predators in Africa is increasingly revealing that crowned
eagles (Stephanoaetus coronatus) are major predators of primates. Gray-cheeked mangabeys (Lophocebus albigena) are overrepresented in the diets of crowned eagles in Kibale National Park, Uganda, and adult male mangabeys are represented
more than females. We focused on the behavior of adult male gray-cheeked mangabeys living in social groups in Kibale National
Park (1) to clarify the interactions between mangabeys and eagles that might put adult males at greater risk and (2) to better
understand individual variation in behavioral responses to predators. Adult male mangabeys in five groups responded to observer-confirmed
presence of crowned eagles 88 times over a 13-month period. While all males gave alarm calls, only the highest-ranking male
in each of four groups chased eagles. These males had elevated levels of fecal cortisol metabolites in the days immediately
after they engaged in active defense, suggesting that they perceived such behavior as risky. In the one group where male ranks
were unstable and there were no infants, no male was observed to chase eagles. We suggest that males pursue the dangerous
tactic of chasing eagles only when they are likely to have offspring in the group. Males in larger groups also spent less
time alarm calling to crowned eagles (from first to last call in a group), and our observations confirmed that the duration
of their alarm calls was related to eagle presence. Thus, eagles spent less time around larger mangabey groups. Alarm calling
by adult male mangabeys may signal to this ambush predator that it has been detected and should move on. 相似文献
11.
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
12.
Earlier studies on reproductive behavior of the tautog Tautoga onitis under laboratory conditions indicated that differences in courtship and spawning behavior were apparently related to the number of males attempting to spawn with a female. It had also been conjectured that certain ecological factors such as availability and distribution of food and shelter would play a role in the establishment of territoriality and defense of a female, indirectly influencing courtship activities and the resultant spawning mode. In the present work we have examined this question more closely by varying the number of males, females and amount of shelter available. Regardless of the social situation, in every instance single males, through aggression, attempted to limit access to a female and pair spawn. The degree to which this succeeded depended on the male's place in the dominance hierarchy, the number of males in proximity which were actively attempting to spawn and the availability of shelter. Courtship activity of the female was influenced by the amount of male attention. When attention was high, the nuptial shading of the female never developed maximally. On the other hand, when male attention was low, the female showed progressive and maximal shading development to attract males. The significance of the findings is discussed. 相似文献
13.
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
14.
Mats Olsson 《Behavioral ecology and sociobiology》1993,32(5):337-341
Summary Male sand lizards (Lacerta agilis) are polygynous and guard individual females for several hours to days after copulation. Even though the copulation itself only lasts 2–4 min, the total time that a male invests per female is considerably more and may constitute a substantial investment during a mating season. In such situations, when male copulation frequency is constrained, or when variation in female fecundity is high, mate choice by males may be adaptive. Large body size in female sand lizards is correlated with higher fecundity. In choice experiments performed in the laboratory, male sand lizards preferred to court large females rather than small females. In addition, when there was little difference in size between the females in the experiment, the males visited the two females more often before they started to court the preferred female. The results from a field study during 1984 and 1987–1990 showed that females are non-aggressive, have small neighboring home ranges (c. 100 m2) and may share burrows and sites for thermoregulation. This means that females can be found close together and thus gives males the opportunity to choose a mate. Assortative mating with respect to size was observed in a natural population, as well as a limited number of direct choices of females by males. These results support the results of the choice experiment. 相似文献
15.
Summary A laboratory study on the ontogeny of social behavior in pikas (Ochotona princeps), an alpine lagomorph, was conducted to determine the role of early relationships between adult females and young and among siblings in the development of territorial and dispersal behaviors. Sex differences during development were examined because field studies have reported greater dispersal distances in young females than young males. At birth, females were significantly heavier than males. There were no sex differences in nursing frequency until after the 2nd week of age, when males initiated more nursing attempts than females. By the end of the weaning period (weeks 5 and 6), adult females became non-interactive with young, but aggression of young toward littermates and the mother increased until the eighth week. At this time, young males outweighed their sibling females. Young were dominant over their mothers by the age of 5 weeks, and young males were dominant over their sibling females.Sex differences were observed in aggression, scent-marking, exploratory activity, and submissive vocalizations, with higher rates in young males, except for submissive vocalizations, which were higher in females (Table 2). Vocalizations and scent-marking behavior increased over time, and were positively correlated with interaction rates.These data support the hypothesis that female young disperse farther than male young largely as the result of unsuccessful competition with male siblings for available territories close to the birthplance. A dispersal strategy for pkkas is proposed. 相似文献
16.
José Martín Emilio Civantos Luisa Amo Pilar López 《Behavioral ecology and sociobiology》2007,62(2):173-179
Evidence for parasite-mediated sexual selection has been found in many species that use visual ornaments to attract females.
However, in many animals, variation in female responses to scents of parasitized males suggests that parasitic infections
might also affect information conveyed by pheromones (i.e., chemical ornaments). Thus, pheromones might also function in parasite-mediated
sexual selection. We show here that female lizards Psammodromus algirus responded differently to femoral gland secretions of males according to the parasite load and health of these males. Scents
of healthier males elicited more tongue flicks (a chemosensory behavior) by females, suggesting that these scents were more
attractive. Chemical analyses showed that parasite load and the T-cell-mediated immune response were related to the variability
in the proportions of some lipids in secretions of males. Further trials testing the chemosensory responses of females to
chemical standards indicated that females actually discriminated the chemicals related to males’ health from other chemicals
found in secretions. We suggest that these chemical ornaments may provide reliable information on the health and degree of
parasitic infection of a male. 相似文献
17.
Jonathan P. Evans Jennifer L. Kelley Indar W. Ramnarine Andrea Pilastro 《Behavioral ecology and sociobiology》2002,52(6):496-502
Previous work has shown that under elevated predation risk, male guppies (Poecilia reticulata) switch from courtship to less conspicuous coercive mating attempts. This behavioural transition is traditionally interpreted as a 'risk-sensitive' response that makes males less conspicuous to predators. However, predation risk leads to behavioural changes (such as schooling and predator inspection) in females that may result in coercive mating attempts being more profitable in high-risk situations. Here, we tested the hypothesis that the switch to coercive mating by male guppies in high-risk situations is mediated by adjustments in female behaviour, rather than directly by the predator. We used replicate models resembling a known guppy predator to simulate predation risk in wild-caught guppies from a high-predation population in Trinidad. Our results revealed that males performed proportionately more coercive mating attempts when presented with a female that had been exposed previously to a model predator compared to when males were paired with non-exposed females. Total mating activity (combined rates of courtship and forced mating attempts) did not differ significantly among the two treatment groups, indicating that overall mating activity is unaffected by predation risk. Importantly, when we subsequently presented both sexes concurrently with a predator model, total mating activity and the proportion of forced mating attempts remained unchanged in the high-risk treatment. Taken together, these results indicate that the transition from courtship to forced mating attempts under elevated predation risk is mediated by changes in female behaviour, which we suggest may favour the use of coercive mating under high predation risk. 相似文献
18.
Katalin Bajer Orsolya Molnár János Török Gábor Herczeg 《Behavioral ecology and sociobiology》2010,64(12):2007-2014
The role of ultraviolet (UV) signals in intraspecific communication has been identified in a number of vertebrate taxa. In
lizards, the signalling role of UV has only been shown in male–male competition and male mate choice. Here, we investigated
whether male UV colour can be a basis of female association preference in European green lizards (Lacerta viridis), a species where males develop blue nuptial throat colouration with high UV reflectance. We experimentally manipulated the
UV colour of male pairs, where the members of the pair did not differ significantly in body length, body weight, head size,
throat UV chroma and brightness or throat blue chroma and brightness measured prior to colour manipulation. By providing these
pairs of males to females (only visual stimuli could be perceived by the females), we assessed the role of UV in female association
preference irrespective of other potentially important visual traits. We found that unmated but receptive females preferred
males of higher UV reflectance. Our results show for the first time that UV colour can be an important male signal in female
preference in reptiles. 相似文献
19.
Martin N. Muller Melissa Emery Thompson Sonya M. Kahlenberg Richard W. Wrangham 《Behavioral ecology and sociobiology》2011,65(5):921-933
The extent to which active female mating preferences influence male reproductive success in mammals is unclear, particularly
for promiscuously breeding species like chimpanzees (Pan troglodytes). Previous studies from multiple long-term study sites have shown that female chimpanzees mate more restrictively around
ovulation, and this has been taken as evidence for female choice. However, none of these studies rigorously evaluated the
alternative hypothesis that restrictive mating results not from unconstrained choice, but in response to coercive mate guarding,
in which males use punishment and intimidation to reduce female promiscuity and promote their own mating interests. Nor did
they consider evidence for the potential genetic or phenotypic benefits that females might be choosing. Using 11 years of
data from the Kanyawara community in Kibale National Park, Uganda, we previously demonstrated that males achieve elevated
mating success with those females toward whom they direct high levels of aggression. Here we extend those findings to show
that even female copulatory approaches, which have previously been attributed to female choice, are correlated with male aggression.
Specifically, individual females at our site initiated periovulatory copulations most frequently with the males who were most
aggressive toward them throughout their cycles. Those males showed high rates of aggression toward females throughout estrus,
despite achieving high copulation rates, demonstrating a continuing conflict of interest over the exclusivity of mating access.
Because sexual coercion is potentially widespread in primates and other mammals, our results stress the importance of considering
the influence of male aggression in studies of female choice. 相似文献
20.
Dominance relationships between females and males are characteristic traits of species and are usually associated with sexual dimorphism. Exploring the social and contextual circumstances in which females win conflicts against males allows one to study the conditions triggering shifting power asymmetries between the sexes. This study investigates dominance relationships in bonobos (Pan paniscus), a species in which females are thought to display social dominance despite male-biased sexual dimorphism. To identify dominance relationships among females and males, we first explored how intrasexual dominance status affects the outcome of intersexual conflicts. Second, by incorporating social and behavioral information about the context of intersexual conflicts, we tested to which extent different components of power are relevant to the observed asymmetries in the relationships. Post-hoc analyses indicate a sex-independent dominance hierarchy with several females occupying the top ranks. Our results also reveal that two factors—female leverage and motivation to help offspring—had a significant influence on the outcome of intersexual conflicts. The results of our study do not indicate an overall reduction in male aggression against females but do show lower levels of male aggression in the mating context, and an absence of male aggression toward those females displaying visual signs of elevated fecundity. This indicates that both female sexuality and male mating strategies are involved in the shifting dominance relationships between the sexes. 相似文献