神农架川金丝猴投食群的攻击行为及等级序列

为探讨人工补食条件下川金丝猴的攻击行为在维持社会等级中的作用,2007 年1 ～ 6 月,采用行为取样法
和全事件记录法对神农架自然保护区投食群的攻击行为及等级序列进行研究。我们共记录到8 种攻击行为,按
频次多少依次为:咕叫、抓打、追赶、瞪眼、瞪咕、驱赶、抢食、打架。攻击行为的发起者在性别间和年龄间
均存在显著差异,雄性多于雌性,年龄间按次数多少依次为:成年猴、亚成年猴、青年猴、少年猴;承受者在
性别间和年龄间差异均不显著。社会单元内与单元间攻击行为差异显著,前者多于后者。一雄多雌单元间的等
级高低依次为:长毛单元、白头单元、红头单元。基于单元内攻击行为较多,建议适当扩大投食场,给每只个
体分别投食,以减少因争食发生的攻击行为。     

An investigation of individual, age and sexual differences in the play of Rattus norvegicus (Mammalia: Rodentia)

Eight litters of Rattus norvegicus of the PVG/C hooded strain were observed in order to investigate the roles of individuality, sexuality and age in playful behaviour.
Three measures of social play, namely, initiations, numbers of play bouts and numbers of playful elements performed were all found to be positively correlated. The incidence of social and solitary play were also positively correlated so that a concept of "playfulness" appeared to be justifiable. Playfulness showed no correlation with the general level of non-playful locomotor activity.
Male rats were more playful than females but only minor sex-related differences were found to occur in the sequential organisation of play.
Older rats showed longer play bouts and a higher degree of temporal organisation. Considerable individual differences in playfulness were recorded and in single sex litters playful rats were found to play together.
The majority of opponents, in playfighting, alternated between the roles of attacker and defender.     

Apomorphine induced biting and fighting behaviour in reserpinized rats and an approach to the mechanism of action

Various patterns of aggressive behaviour have been induced by drugs. In the present study, the biting and the fighting responses were induced in rats by apomorphine alone, and reserpine plus apomorphine combination respectively, and these could be blocked completely by a dopamine receptor blocking agent. Dopamine, norepinephrine and clonidine given intraperitoneally or intraventricularly failed to induce these responses. Chemical agents known to increase the concentration of dopamine in the brain, induced the biting, but not the fighting response, whereas these behavioural patterns were more intense due to apomorphine in the rats pretreated with reserpine and dopamine or α-methyltyrosine and reserpine combinations. In amphetamine pretreated rats, apomorphine induced intense biting after 10 min and a few bouts of fighting after 30 min. It is suggested that (i) the receptors on which apomorphine acts may be called ‘Apomorphine Receptor’ rather than ‘Dopamine Receptor’, (ii) dopamine incompletely activates these receptors which are sensitised in the absence of catecholamines and induce a higher degree of stereotyped behaviour i.e. fighting, due to apomorphine.     

The ontogeny of sex differences in the behavior of patas monkeys

Many studies of sex differences in primates have been based on small experimental groups of peers in which only a limited range of social behavior could be expressed. In addition, the first few months of life are often the focus of such studies, with relatively little attention paid to older juveniles. In this study, 11 male and 9 female juvenile patas monkeys, living in a captive social group with all age-sex classes available, were observed between 1 and 4 years of age. A subset of seven patas monkeys was also observed between birth and 1 year of age. Here, we report the development of sex differences in independence, play, grooming, positioning behavior, and aggression over the juvenile period. Juvenile male patas monkeys played more and in longer bouts than females, but wrestling (rough-and-tumble play) was not more common among males. There were few differences in behaviors directed to male and female juveniles by other group members. Distinct differences emerged only in the behaviors of the juveniles themselves, with females being more active participants in social and aggressive interactions than males. In general, sex differences in patas monkeys show a mixture of patterns, some of which are predictive of adult sex differences and some of which appear to be specific to the particular demands of the juvenile period in this species     

Playful interactions in family groups of the common marmoset (Callithrix jacchus jacchus)

Play behaviour in six family groups of common marmosets (Callithrix jacchus jacchus) is described. Playful behaviour patterns comprised a distinct repertoire of behaviour and the patterns formed ordered sequences. The differences in the play of adults and offspring are described and analysed. Adult play was infrequent and most took the form of adult-offspring interactions; it contained fewer bouts of chasing and was less active, and adults elicited fewer bouts. No differences attributable to sex could be determined in the play of offspring and the only pattern that decreased with age was bouncing gait. Possible partner preferences were analysed, and it was found that marmoset twins showed an overall preference for playing with the twin. The vocalizations heard during bouts of play were recorded and analysed and their relationship to non-playful vocalization discussed; during bouts of play younger animals were found to vocalize to older animals. Marmoset play wrestling differed in form from aggressive wrestling, and patterns occurred during aggressive interactions which were not observed in play. The play of marmosets is discussed with regard to the socioecology of the species and compared to the play of other mammalian species.     

Decision making in grooming by Japanese macaques (Macaca fuscata)

I analyzed the temporal organization of individual Japanese macaques’ (Macaca fuscata) grooming sequences in 14 mothers and 13 offspring of different age/sex classes and 4 nonkin females. I hypothesized that preceding grooming affects subsequent grooming by the same individual. Grooming bouts were likely to be terminated as the bouts became longer when females groomed nonrelatives. Moreover, the duration of first bouts was longer than that of following bouts. These effects were also seen in grooming of mothers by their offspring > 1 year old and that of adult and adolescent female offspring by their mothers. In contrast, neither the duration of first bouts nor the number of preceding bouts had much effect on the occurrence or duration of subsequent bouts in any subject.     

A quantitative study of serum testosterone,sex accessory organ growth,and the development of intermale aggression in the mouse

Radioimmunoassay of serum testosterone (T) was used to characterize circulating T levels in mice from birth to sexual maturity. Until 25 days of age, serum T levels ranged from 1 to 4 ng/ml. A significant increase in T concentrations was observed in 30-day-old males, followed by a secondary rise in serum T between Days 45 and 50 of life. The latter increment was associated with the appearance of extreme individual variation in circulating T levels which was also observed in adult (120 days) males. The most rapid growth of accessory sex organs occurred between 30 and 50 days of age, the period preceding attainment of peak serum-T levels. The first incidence of intermale aggression coincided with a prepubertal rise in circulating T, but adult levels of fighting were present prior to the secondary increase in T observed between 45 and 50 days of age. Although animals involved in a fight did not differ with respect to weight of the accessory sex organs or serum T concentrations, the male that weighed more than his opponent usually won an encounter. Compared to males in encounters in which no fighting occurred, animals that won or lost an aggressive encounter showed significantly greater accessory sex organ development. While circulating T is required for the initiation and maintenance of intermale aggression, it is apparent that additional factors are related to the onset of fighting and the establishment of dominance/ subordinance relationships in mice.     

Effect of prenatal diazepam, phenobarbital, haloperidol and fluoxetine exposure on foot shock induced aggression in rats.

Different groups of pregnant rats were treated with diazepam (10 mg/kg), phenobarbital (10 mg/kg), haloperidol (0.1 mg/kg), fluoxetine (10 mg/kg) and vehicle (normal saline) intraperitoneally once a day during gestation days 13 to 21. After birth these pups were culled to 8 pups/dam and foster-nursed by lactating mothers for 3 weeks and were reared in colony cages thereafter. Sex and weight matched pairs of rat offsprings were subjected to foot shock induced aggression test at 8 weeks of age. Two parameters of aggressive behaviour were recorded namely, the latency to fight and total number of fighting bouts. The results indicate that prenatal exposure to diazepam, phenobarbital, haloperidol and fluoxetine caused significantly enhanced aggression in terms of number of fighting bouts.     

Ontogeny of social behavior of pups of laboratory rats genetically selected for activity level

In pups of Wistar laboratory rats genetically selected for high (+A) and low (-A) locomotor activity in an open field social behavior was tested in a situation of paired interactions in a novel environment. Tests were performed on postnatal Days 16, 19, 23, and 27. They consisted of four five-minute trials with 50 min, intertrial intervals. Duration of active contacts, passive contacts, mutual grooming, following (chasing), and playful fighting was recorded. In pups of the +A line total duration of all social interactions increased between Days 16 and 23, while in the -A pairs preweaning maximum in most types of social activities was achieved already on Day 16, after this day the time spent in mutual contacts decreased. Analysis of dynamics of social behavior over trials in the -A line showed the tendency to habituate, maximum duration of paired interactions appeared in the first trial contrary to +A groups, in which duration of social contacts tended to increase with repeated trials. In both lines, duration of following responses increased from Day 16 to Day 27. In +A pairs following often led to playful fighting, while in -A pairs fighting was practically absent. The experiment demonstrated that differences between lines +A and -A appeared in those social contacts which required higher energy expenditure and which realized themselves in the larger space of the testing box.     

Timing of presentation of an audience: aggressive priming and audience effects in male displays of Siamese fighting fish (Betta splendens)

Studies of animal communication often underestimate the presence of individuals other than the signaller-receiver dyad. Signalling interactions often occur in the presence of non-participating individuals (audiences); the effect of these individuals upon the dynamics of interactions has been called the audience effect. Recent studies of fighting fish Betta splendens have shown that the presence of a male audience can increase aggression during interactions. However, in many of these studies males were allowed to see the audience prior to the interaction, thus such pre-exposure may have facilitated aggressive behaviour (aggressive priming). Here we present results of two experiments designed to examine the relative importance of priming and audience effects on the dynamics of aggressive interactions. Males that were pre-exposed showed higher levels of aggression during subsequent interactions regardless of the presence or absence of an audience. When only one of the interactants had been pre-exposed to the audience, the non-exposed male showed similar increases in aggressive behaviour, i.e. matching the level of aggression showed by his opponent. Taken together these results suggest that aggressive priming may have resulted in an over-estimation of the audience effect in previous studies. The results still highlight the importance of social environment in determining the dynamics and outcomes of aggressive contests.     

Audience effect is context dependent in Siamese fighting fish, Betta splendens

Investigations of communication networks in animals have focusedprimarily on determining whether animals extract informationfrom peripheral contests (eavesdropping) or respond to the presenceof bystanders (audience effect). The possibility that an animal'sresponse to being watched might be context dependent, however,has been explored in far less detail. This study investigatedthe influence of two contexts, exposure to audiences of differentsexes and presence or absence of a nest, on the aggressive behaviorof interacting male Siamese fighting fish, Betta splendens.Males interacted in the presence (male, female) or absence ofan audience in three different nest conditions (0, 1, or 2 nests).Audience sex and territorial status influenced aggressive behaviorin the interacting males, but a strong audience x nest interactionalso was uncovered. Males were more aggressive when neithermale had a nest and a male audience was present than when afemale or no audience was present. Males also were more aggressivewhen only one male had a nest and a male audience was presentthan when a female or no audience was present. When both maleshad nests and a male audience was present, however, males wereless aggressive than when only one male or neither male hada nest. In sum, aggressive behavior was influenced by the interactionbetween audience and nest; neither nest nor audience alone wassufficient to explain the results. Male Siamese fighting fishalter their behavior based on both external cues, the sex ofthe audience, and internal cues, reproductive state and resourcepossession. Our results emphasize the importance of consideringaspects of an animal's environment when examining audience effectsand communication networks in general.     

Aggression in harlequin frogs: male-male competition and a possible conflict of interest between the sexes

Long-term field observations and experimental manipulations were made on a population of harlequin frogs, Atelopus varius, in Costa Rica to document seasonality of intra- and intersexual aggression, determine the function of aggression, and identify the factors that influence success in aggressive encounters. Both males and females defended portions of their home range and exhibited site fidelity. Males were more aggressive towards other males during the pre-breeding and breeding seasons, whereas females were more aggressive towards other females during the post-breeding season. For up to several months prior to oviposition, males attempted to amplex (clasp) females without courtship behaviour, while females chased males from their territories and attempted to dislodge males that amplexed them. In staged encounters the winner was usually the apparent resident, regardless of body size. Frogs from a high-density population were more aggressive than individuals from a low-density population. Subadult males were as aggressive and as likely to win encounters as adult males. The function of aggression seemed to be related to the bizarre reproductives behaviour observed in these frogs. There seemed to be male-male competition for mates, as the operational sex ratio strongly favoured males, oviposition was asynchronous, and amplexus lasted for at least several weeks. Female-female aggression may have been related to defence of foraging or shelter sites, but aggression towards males was likely to be an attempt to thwart unwanted amplexus.     

The Behavioral Ecology of Libellula luctuosa (Burmeister) (Anisoptera: Libellulidae): I. Temporal Changes in the Population Density and the Effects on Male Territorial Behavior

A single population of a common pond dragonfly, Libellula luctuosa, was studied at a site where the density of males increased dramatically during the breeding season. Early in the summer one active male was found on each territory on the pond. Satellite males were only occasionally found on the territories. Later in the season the number of males per territory increased so that two or more males simultaneously defended on many of the territories, and several satellite males occupied each of the territories. The number and rate of female visitations per day did not change over the summer. These factors resulted in a change in the operational sex ratio with variations in male density. Male behavior was also altered with increasing population density. As male density increased, males were less likely to be seen perching on their territories and more likely to be seen performing aggressive acts such as chasing nearby territorial males and chasing intruders. At high male density, the duration of territorial behaviors was shorter than at low male density. Thus, the percent of a time budget spent in any one activity did not change despite the change in number of males present. Male activity in L. luctuosa is not strictly determined by the opportunity for aggression. Costs of aggression associated with territoriality are minimized by maintaining flexible territorial behaviors.     

Deferred agonistic behavior in a long-lived scincid lizard Eumeces laticeps

Summary A laboratory experiment with the broad-headed skink (Eumeces laticeps) involving staged agonistic encounters demonstrates that larger males have an advantage over smaller ones in agonistic bouts. Field data on head wounds produced by intraspecific fighting during the breeding season show a much higher frequency of new wounds among males over 100 mm in snout-vent-length than in smaller males. The significant difference in new-wound frequency strongly suggests avoidance of fights by the small males, which is corroborated by laboratory and field observations. Access by males to reproductively active females depends on the ability to defeat other males in aggressive contests virtually always involving head biting if the males are of nearly equal size. Because the probability of winning agonistic encounters increases with size, young males avoid fights with older males. Aggressive contests with larger males and reproductive attempts other than courtship in the absence of larger males are deferred.Aggressive behavior in E. laticeps may be employed in direct defense of females, but might also be expressed in defense of specific sites and/or territories. In the laboratory, males in their home cages were significantly more likely to win encounters with males of similar size than were males fighting in the home cages of opponents. This suggests that encounter site could be important in determining encounter outcome and that field study of possible site defense or territoriality is needed.     

Detailed analysis of fighting in polecats (Mustelidae) using ciné film

The phenomenon of fighting was investigated under laboratory conditions using polecats ( Mustela putorius, M. furo and interspecific hybrids). Diadic interactions between male polecats were recorded on 16 mm cine film in an unfamiliar area of 16 m², one individual having been introduced ten minutes before its opponent.
The behaviour patterns involved in fighting are described and their frequencies of occurrence, duration and average bout lengths specified. Biting, which occupied 41% of the animal's time in fighting, and attacking, which made up 27% of the bouts of behaviour, were the most important actions involved in fighting. Polecats most commonly bite their opponent's neck and bites in this region were the longest in duration. Success in gaining a bite was influenced by the opponent's behaviour at the time of the attack.
Polecats fight when one individual bites its opponent and the opponent retaliates by biting; bite was shown to be the commonest response to being bitten. The length of a fight appears to be determined by the levels of motivation to bite of the two opponents, while biting and being bitten operate as a positive feed back mechanism. The fight terminates when the more aggressive opponent ceases to make spontaneous attacks. The reasons why one individual wins a fight are that it consistently spends more time than its opponent in biting, it persists for longer in making spontaneous attacks and its method of attacking is more efficient.     

Is the parallel walk between competing male fallow deer, Dama dama, a lateral display of individual quality?

During competitive encounters protagonists are expected to use signals of individual quality particularly if there is a risk of injury or death. Lateral presentation of body profile, by which information regarding phenotypic characteristics associated with individual quality are displayed, may represent such a strategy. During aggressive interactions, male fallow deer frequently engage in parallel walking which is assumed to represent a mutual display of quality, as mediated by exposure of the maximal profile of the body or antlers. We examined the context and role of the parallel walk during competitive encounters to investigate whether there was evidence that dyads of competing males were assessing differences in phenotypic characteristics. There was no evidence to support the hypotheses that the parallel walk is a lateral display of body size or weaponry or that its use is associated with a reduced level of escalated or risky behaviours during fighting. Total time spent fighting was not shorter when a parallel walk was present than when there was no parallel walk. The parallel walk was highly associated with fighting and it was more likely to be initiated by the subsequent loser. Furthermore, parallel walking frequently followed bouts of fighting and as such may represent a strategy that permits an animal the opportunity to decide whether to continue fighting. Parallel walking was also associated with a failure to resolve contests in favour of one animal indicating that it may be a means of withdrawing from further fighting without incurring a loss in dominance status. Copyright 2003 Published by Elsevier Science Ltd on behalf of The Association for the Study of Animal Behaviour.      

Assessing the role of color cues and people's beliefs about color-flavor associations on the discrimination of the flavor of sugar-coated chocolates

We report 2 experiments designed to investigate the effect of people's prior beliefs concerning specific color-flavor associations on their ability to discriminate the flavor of colored sugar-coated chocolate sweets. The participants in our study judged whether pairs of Smarties had the same flavor or not. In our first experiment, the participants either performed the task with their eyes open or else while wearing a blindfold to eliminate any visual cues. We used pairs of Smarties that either did or did not differ in flavor. In making a sighted comparison between red and green Smarties, the participants were more likely to judge them as tasting the same if they believed all non-orange Smarties to be identical in flavor and as different in flavor if they did not hold such a belief. The ability of our participants to discriminate orange Smarties from the red and green Smarties was unaffected by their prior belief that orange Smarties taste different. In a second experiment, participants' ratings of their certainty of there being a difference in flavor between a red and an orange Smartie that either tasted the same or different were affected by their prior beliefs-those participants who expected a difference were more likely to report a difference than those without any such prior expectation. Taken together, these results demonstrate that people's expectations concerning color-flavor associations can modulate their flavor discrimination responses, even for a familiar food product such as Smarties.     

Play in chimpanzees of the Arnhem Zoo: Self-serving compromises

In a colony of 25 chimpanzees maintained at Arnhem (The Netherlands), play behavior was studied for four months, yielding 1,651 play bouts involving the 11 oldest immature chimpanzees on which detailed data were collected during 88 focal animal samples of 30 min each. Play frequency and object play were negatively correlated with increasing age. These findings potentially reflect changing motivations during development and increasingly perfected skills. Like-aged partners were preferred play partners and older partners initiated play more frequently, probably because younger individuals feared rough responses by older immatures and waited until the latter initiated play bouts in a self-handicapped manner. Moreover, play was frequently interrupted by short breaks. This, in conjunction with the preference for like-aged partners, may be mechanisms to achieve and maintain compromises between the play partners' different interests in social play (which e.g. depend on sex and physical development) and to minimize the risk to being cheated. Males played significantly more often than females and played more chasing games. Male-male play was over-represented whereas female-female play was underrepresented. These facts potentially foreshadow sex differences in (wild) maturing chimpanzees, where males engage in more agonistic conflicts and tend to build coalitions.     

Male competition is disruptive to courtship in the Pacific blue‐eye

The present study examined the effects of competition on male courtship in the Pacific blue‐eye Pseudomugil signifer , a species of fish where females have previously been shown to use courtship, but not male fighting prowess, as an important mate choice cue. Courtship bouts directed to a stimulus female were shortest when two males were allowed to freely interact (contact treatment) and longest when there was only one male (non‐interaction). Courtship length in trials where one of two males was confined to a clear cylinder (visual) was intermediate between the other two treatments. Courtship in visual and contact treatments was constantly disrupted. The percentage of interrupted courtships was higher for the contact compared to visual treatment where aggressive interactions were also longer in duration and took place more frequently. Within contact trials, dominant males courted longer than subordinates despite both males experiencing comparable rates of courtship disruption. These results suggest that male‐male competition can have important implications for adaptive female choice particularly in circumstances where the benefits being sought by females are unrelated to male fighting ability.     

Reproductive strategies of Atlantic salmon: ecology and evolution

Atlantic salmon (Salmo solar, Salmonidae) show a diversity of life history, behavioural and morphological adaptations for reproduction which have evolved as an outcome of competition to maximize reproductive success. Reproductive traits of females have been shaped principally by natural selection for offspring production and survival, those of males by sexual selection for access to matings. Female Atlantic salmon invest approximately six times more energy in offspring production (i.e. gonads) than males and face an important trade-off between number and size of eggs to produce that will maximize the number of surviving offspring. Timing of breeding and the construction of nests appear adapted to increase offspring survival. The most important determinant of female breeding success is body size because it affords high fecundity, access to breeding territories and decreased probability of nest destruction. Asynchronous female spawning and the male ability to spawn rapidly and repeatedly results in male-biased operational sex ratios that generate intense male competition for mates. This has likely been responsible for the evolution of elaborate male secondary sexual characters associated with fighting and status signalling. Furthermore, it has given rise, through frequency-dependent selection, to two alternative male breeding phenotypes: (1) large, anadromous males; and (2) small, mature male parr. Anadromous males invest heavily in behavioural activity on the spawning grounds, searching and fighting for mates and courting them, with body size being an important determinant of their breeding success. This behavioural activity carries a heavy cost, as anadromous males have significantly reduced survival relative to females. In contrast, mature male parr invest proportionally more in testes for sperm competition and attempt to sneak access to matings. While this behaviour also carries costs in terms of subsequent growth and survival, male parr are more likely to breed again, either prior to or following a migration to sea, than anadromous males. While knowledge about the breeding of Atlantic salmon is detailed, we are only beginning to understand the ultimate causes and/or functional significances of their reproductive strategies. Predictive models of the life history variation are developing, focusing on the need for empirical study and testing of life history and reproductive patterns.