Attack and defense in conspecific fighting in tree shrews (Tupaia belangeri)

Principles of conspecific defense have been analyzed for rodents, in which specific target sites for biting by attackers on defenders serve as an important determinant of the actions involved in both attacker and defender behavior. In an effort to determine the generality of these principles, attack and defensive behaviors and target sites for biting attack were evaluated in a nonrodent species, the tree shrew (Tupaia belangeri). Brief daily and repeated conspecific dyadic encounters between adult, socially experienced males (dominants, attackers), and adult, socially naive males (subordinates, defenders) that had been transferred into the territory of the dominants, produced a polarization of attack and defense. The dominant males showed chase, chase attack, jump attack, and biting behaviors, while the subordinates displayed flight and freezing. The vast majority of bites, as well as wounds and bruises, were on the subordinates’ backs. These patterns are very similar to those previously found in rats and mice and suggest that the organization of fighting, with targets of biting (or other painful) attack serving as an important determinant of both attacker (dominant) and defender (subordinate) behavior, may show considerable generality across nonrodent as well as rodent species. Although relatively few wounds were found after 28 days of repeated and daily encounters, the subordinate tree shrews show a variety of behavioral, neuroendocrine, and central nervous changes, indicating that they are stressed by these encounters per se. Aggr. Behav. 27:139–148, 2001. © 2001 Wiley‐Liss, Inc.     

Targets and tactics of agonistic and precopulatory behavior in montane and prairie voles: Their relationship to juvenile play-fighting

Play-fighting by juvenile montane and prairie voles involves attack and defense of the head, neck and shoulders. Since during play animals typically borrow behavior patterns from other functional contexts, two adult behavioral contexts were compared to juvenile play-fighting. These were serious fighting and sexual encounters. During serious fighting in a resident-intruder paradigm, most bites are directed at the rump and lower flanks. During sexual encounters, especially in precopulatory behavior, the head, neck and shoulders are gently contacted. Therefore, play-fighting by juveniles would appear to involve attack and defense of areas of the body contacted in adult precopulatory behavior, not adult fighting. Furthermore, the species-specific differences in juvenile play-fighting were also found to be matched by species-specific differences in precopulatory behavior. In both playful and precopulatory encounters, montane voles contacted the head and used upright defensive behaviors more often than prairie voles. In contrast, prairie voles made mutual contact more often and were more likely to rotate to supine in defense of contact to the nape and head. These findings support our hypothesis that juvenile play-fighting in muroid rodents involves the precocial expression of precopulatory, not agonistic behavior.     

Analysis of the targets and tactics of conspecific attack and predatory attack in northern grasshopper mice onychomys leucogaster

Comparisons of tactics of fighting between species are often difficult to make since the body targets attacked may differ. Thus it becomes difficult to assess whether differences in fighting tactics are due to species-specific differences in the tactics themselves or due to the different targets attacked. A solution to this problem is to analyse the tactics of a species that attacks different targets under different circumstances. In this way, differences in tactics can be more readily attributed to differences in targets. In this study, resident male northern grasshopper mice (Onychomys leucogaster) were tested against intruding male conspecifics and against laboratory mice (Mus musculus domesticus). Conspecifics were mainly bitten on the lower dorsum, whereas prey were bitten and killed by bites to the nape of the neck. Therefore, it was possible to analyze the tactics of attack by grasshopper mice when attacking different body targets. For example, in order to defend the lower dorsum and the nape, both intruding conspecifics and prey adopted an upright defensive posture. Resident grasshopper mice used the lateral attack tactic to gain access to the lower flanks but not the nape. This illustrates that the lateral attack tactic is not merely a tactic suitable for overcoming the upright defense tactic, but is used in this context only when the target attacked is on the opponent's posterior dorsum. Such withinpecies comparison enables the identification of the contextual rules which govern the use of fighting tactics. © 1992 Wiley-Liss, Inc.     

Lateral display as a combat tactic in richardson's ground squirrel Spermophilus richardsonii

During fighting, adult ground squirrels frequently face each other laterally, arch the back, and piloerect the tail. In a diurnal species, such distinctive visual cues seem consistent with the suggestion that the lateral display serves a communicatory function. However, a detailed analysis of videotaped sequences of free-living Richardson's ground squirrels from two consecutive mating seasons suggested that the lateral maneuver has a functional role in combat. Because most agonistic encounters involve chasing, the rump is the principal body area bitten. When stationary, however, the opponent's rump is bypassed, and bites are targeted at the shoulders. Defensively, a hip thrust is used to block such attacks to the shoulder by pushing the opponent's head away. Offensively, the lateral maneuver is used to push against the opponent, providing a vantage point from which to lunge at the opponent's shoulders. In addition, the defender can launch counterattacks at the side of the head. The lateral orientation provides the attacker with a means of evading such attacks, by swerving laterally away. In some encounters, both the offensive and defensive variations of the lateral maneuver were used by both opponents, often simultaneously. Therefore, irrespective of the signalling function of the lateral display, much of its occurrence during combat can be explained in terms of its role as a combat tactic. © 1996 Wiley-Liss, Inc.     

Play-fighting differs from serious fighting in both target of attack and tactics of fighting in the laboratory rat Rattus norvegicus

Play-fighting is often difficult to differentiate from inhibited or immature serious fighting because both may utilize many of the same behavior patterns. In the rat the two behaviors involve different targets of attack. During play-fighting, snout or oral contact is directed at the opponent's nape of the neck, whereas during serious fighting, male residents mostly direct their bites at the intruder's rump. Although similar to those used in serious fighting, the behavior patterns used during play-fighting are modified to achieve the different targets of attack. Even though the tactics of attack and defense appear more adult-like with increasing age, the playful targets persist well into adulthood.     

Sexual and aggressive play fighting of sibling Richardson’s ground squirrels

Play fighting in many species of squirrels can involve sexual play and aggressive play, both of which can lead to wrestling which appears superficially similar. Such convergence can make scoring of the relative frequencies of these two types of play difficult and can lead to the mistaken conclusion that they grade into one another. In this study, both staged laboratory encounters between sibling pairs and spontaneous encounters between siblings in free‐living litters of Richardson’s ground squirrels (Spermophilus richardsonii) were videotaped. Frame‐by‐frame analyses using the Eshkol‐Wachman Movement Notation were employed to record the correlated movements of attack and defense by the partners and to reveal the body areas targeted during each play bout. Whereas sexual play was organized around access to the rump, aggressive play was organized around the shoulders. Although in most cases the defender’s tactics blocked access to the respective target, when contact did occur, it involved mounting in sexual play and nosing or biting in aggressive play. Eighty‐six percent of play fights could be unambiguously categorized as either sexual or aggressive play. Of these, the majority (?80%) involved sexual play. The sex of the participants did not affect the frequency of aggressive play, but in sexual play, males initiated more attacks than females. Once initiated, each form of play fighting remained distinct—if a bout began as sexual play, it would end as sexual play. Furthermore, a counterattack following sexual play was significantly more likely to be sexual than aggressive, and vice versa for counterattacks following aggressive play. Therefore, all the evidence suggested that the two forms of play fighting were not intermixed in Richardson’s ground squirrels. Aggr. Behav. 27:323–337, 2001. © 2001 Wiley‐Liss, Inc.     

Prospective information for pass decisional behavior in rugby union

Decision-making requires the perception of relevant information variables that emerge from the player–environment interaction. The purpose of the present article is to empirically assess whether players’ decisional behavior about which type of pass to make is influenced by the spatio-temporal variable tau. Time series positional data of rugby players were analyzed from video footage taken in real match scenarios. The tau of the distance motion gap between attacker and defender was calculated, along with the duration of the next pass. Results revealed that the initial tau value predicted 64% of the variance found in pass duration. A qualitative distinction of tau dynamics between two periods of the approach between the attacker and the defender was also observed. We argue that the time-to-contact between the attacker and the defender may yield information about future pass possibilities. Additionally, the informational fields constraining attacker–defender interaction may be viewed as a convergent channeling of possibilities towards a single pass solution.     

Posture-related affordances guide attacks in basketball

Objectives

The purpose of this study was to investigate the decision made by the attacker to drive to the left or right of the defender.

Method

Participants were 32 novice and intermediate basketball players who were assigned the role of attacker or defender in a one-on-one subphase. We manipulated the defender’s posture and measured both the postures of defenders and attackers and the ensuing decision on drive direction.

Results

As hypothesized, the posture of defenders guided the decision behavior of the attacker. Both novice and intermediate attackers made the same affordance-based decision by driving to the side of the defender’s most advanced foot, but only when the distance between attacker and defender was small. Moreover, novice attackers conveyed postural information regarding their upcoming drive direction while intermediate attackers were better able to conceal this information.

Conclusions

These results lend further support to the notion of information-based control of interpersonal actions in sport contexts.     

Different levels of complexity in the play-fighting by muroid rodents appear to result from different levels of intensity of attack and defense

Play-fighting in deer mice, Peromyscus maniculatus bairdii, prairie voles, Microtus ochrogaster, and montane voles, M. Montanus, was compared to that of laboratory rats, Rattus norvegicus. Play in rats appears more complex for two reasons: 1) more of the playful contacts elicit defensive behaviors, and 2) more of these defenses lead to counterattacks, and hence, role reversals between attackers and defenders. Neither high levels of defense, as shown by montane voles, nor high levels of counterattack, as shown by prairie voles, produce rat-like play-fighting. This only occurs when high rates of defense involving turning to face the attacker and counterattack are combined, as in rats. These two components are rarely combined together by deer mice, and so this species rarely exhibits rat-like play-fighting. Furthermore, playful counterattack appears to arise from playful attack, and not from an escalation of defense. These data suggest that the more complex forms of social play, such as play-fighting, have evolved, in part, via the escalation of defense in response to playful attack.     

A comparative study of rodent ultrasonic vocalizations during copulation

The temporal patterning of ultrasonic vocalizations (USVs) during copulation was recorded for male-female pairs of Djungarian hamsters (Phodopus campbelli), prairie voles (Microtus ochrogaster), and montane voles (Microtus montanus). Each species appears to utilize a single major frequency band for USVs, centered around 31 kHz for the vole species and 71 kHz for hamsters. Djungarian hamsters exhibited low rates of USVs prior to introduction of the female and following ejaculation, but a high USV rate during periods of copulatory activity. Both vole species called at high rates during all stages of the copulatory sequence, although calling rates decreased following ejaculation. Anesthetization trials, where one pair member was awake and the other anesthesized, suggest that it is the male of each species that produces most USVs. The results were compared with six other muroid species for which data on the temporal patterning of USVs during copulation are available. These data extend our knowledge of the patterning of USVs during copulatory behavior and suggest the need for additional comparative investigations.     

Targets of attack and defense in play-fighting of the Djungarian hamster Phodopus campbelli: Links to fighting and sex

Analysis of the body targets attacked and defended during play-fighting by juvenile Djungarian hamsters Phodopus campbelli revealed that about 70% of all attacks were directed at the mouth. If successfully contacted, the mouth was briefly licked and nuzzled. The remaining playful attacks were gentle bites directed at the rump, and to a lesser extent, the top of the head. During serious fighting the top of the head and the rump are targets of attack, whereas the mouth is not. Licking and nuzzling the mouth was found to be a behavior performed by adult males at the beginning of sexual encounters. Therefore, play-fighting in juvenile hamsters cannot be thought of merely as a form of “mock fighting” since the principal target is seemingly sexual, not agonistic. The data also show that of the sexual body targets contacted, adult females are more likely to defend the mouth. In this way it is suggested that targets attacked and defended during juvenile play-fighting are derived from adult contexts in which such targets are defended. This hypothesis accounts for the prevalence of agonistic targets in the play-fighting of many species, and may provide a rationale for classifying those amicable targets that are competed for during play-fighting.     

Differences in affiliative behavior, pair bonding, and vaginal cytology in two species of vole (Microtus ochrogaster and M. montanus)

Prairie voles (Microtus ochrogaster) and montane voles (M. montanus) display marked differences in social organization in the field. Trios of 1 male and 2 females were studied in a large enclosure for a 10-day period. Prairie voles spent 59% of the observation time in side-by-side contact, whereas montane voles spent only 7% of the time in contact. Vaginal smears indicated female-female suppression of estrus in prairie voles; female montane voles appeared to cycle in the presence of males. Male prairie voles preferentially paired and nested with 1 of the females, and vaginal estrus generally followed pair formation by 2 days. Male montane voles did not spend time preferentially with either female, even after mating. These results suggest that the contrasting mating systems of these species result from differences in the propensity for affiliative behavior and social bonding rather than from mate availability or female receptivity.     

Targets and tactics: The analysis of moment-to-moment decision making in animal combat

Even though injury and death are more common consequences of fighting among animals than once believed, they are still relatively infrequent. Modern evolutionary models of animal combat have emphasized that given the threat of retaliation, animals only escalate to more injurious fighting if the benefits outweigh the costs, and then only if threat and bluff fail to achieve the goal. Such models stress the role of communication as to whether animals decide to escalate or not. An alternative view is that failure to produce injury or death arises from the neutralization of one animal's attack by another's defense. That is, attack and defense end in a stalemate that may be misinterpreted by outside observers as an absence of injury producing behavior. As attack typically involves the biting or striking of specific body targets, movements and postures occurring during combat need to be analyzed with respect to their role in gaining or averting such contact. For example, in the combat of muroid rodents the attacker targets the lower dorsum and flanks (low threshold) or face (high threshold), whereas a defender may defensively launch counterstrikes against the attacker's face. Two combat tactics (supine defense and lateral attack) typically present in the fighting of muroid rodents are analyzed in detail to illustrate how targets constrain the movements of combatants. Such a functional analysis of combat assumes that the movements and postures performed are related to their role in the attack and defense of targets. Deviations from such a strict functional interpretation reveal some of the other factors that may constrain the combatants' behavior. For example, body morphology and the aggressiveness of the opponent are shown to be important in deciding the type of combat tactic to use and how it is performed. Finally, movements and postures that are neutral or even counterproductive for attack and defense may be revealed as communicatory. This approach provides a means of analyzing behavior during the "heat of combat" that is typically not dealt with in traditional evolutionary models. Aggr. Behav. 23:107–129, 1997.© 1997 Wiley-Liss, Inc.     

Estrus induction in four species of voles (Microtus).

Male-induced estrus was examined in montane (Microtus montanus), meadow (M. pennsylvanicus), prairie (M. ochrogaster), and pine (M. pinetorum) voles. Duration of male contact needed for receptivity, effects of parity, and vaginal cytology were assessed. Among nulliparous females, montane voles attained receptivity with less male contact than prairie voles. Meadow and pine voles showed very low receptivity rates. Among parous females, montane and meadow voles did not differ in duration of male contact needed for receptivity and required less than prairie voles. Overall, parous females had higher receptivity rates than nulliparous females. When isolated from males, prairie and pine voles had more leukocytes and fewer cornified cells in vaginal smears than montane or meadow voles. Species differences in estrus induction are discussed in relation to species differences in social organization.     

Interpersonal Pattern Dynamics and Adaptive Behavior in Multiagent Neurobiological Systems: Conceptual Model and Data

ABSTRACT

Ecological dynamics characterizes adaptive behavior as an emergent, self-organizing property of interpersonal interactions in complex social systems. The authors conceptualize and investigate constraints on dynamics of decisions and actions in the multiagent system of team sports. They studied coadaptive interpersonal dynamics in rugby union to model potential control parameter and collective variable relations in attacker–defender dyads. A videogrammetry analysis revealed how some agents generated fluctuations by adapting displacement velocity to create phase transitions and destabilize dyadic subsystems near the try line. Agent interpersonal dynamics exhibited characteristics of chaotic attractors and informational constraints of rugby union boxed dyadic systems into a low dimensional attractor. Data suggests that decisions and actions of agents in sports teams may be characterized as emergent, self-organizing properties, governed by laws of dynamical systems at the ecological scale. Further research needs to generalize this conceptual model of adaptive behavior in performance to other multiagent populations.     

Creativity Under Attack: How People’s Role in Competitive Conflict Shapes Their Creative Idea Generation

Although creativity is helpful if not needed to deal with conflicts, research on the effects of conflict on creativity shows inconsistent findings. In this study, the possibility that effects may depend on people’s role in conflict was considered. Whether, when, and why assuming the role of attacker or defender in conflict affects creative idea generation was therefore investigated. The prediction was tested if attackers are more creative than defenders. In addition, control over the situation as a moderating variable and anxiety as a mediator were considered. Participants (n = 115, M_age = 22.06, SD_age = 2.75, 83 women) were recruited in Amsterdam, the Netherlands, and were randomly assigned to an attacker, defender, or role control condition. Controllability over the situation was manipulated within-subjects and anxiety and creativity were measured during 2 rounds of idea generation. Results revealed no differences in creative performance and anxiety between defenders and attackers and that defenders generated a greater number of ideas than people in the role control condition. Exploratory analyses further revealed that attackers and defenders generated a greater number of aggressive ideas. Finally, attackers and defenders experienced more anxiety, but increased anxiety did not account for observed differences in the number of (aggressive) ideas. The effect of controllability could not be investigated due to a failed manipulation. Limitations and implications are discussed.     

Eficacia de tácticas de influencia en la intención de conducta proambiental

This paper analyzes the effectiveness of social influence tactics based on both psychological (commitment/consistency), and cultural principles (identitarian, conspicuous, statutory), for favoring the intention of pro-environmental behavior. An experimental study was conducted using a 2×5 factorial design, where the variables were the type of influence tactics manipulated by discourse in each experimental group and gender. The dependent variable measured the intention of pro-environmental behavior related to reducing waste, wasteful or unnecessary expense of water, gas and electricity at home. The effectiveness of the tactics for favoring the intention of pro-environmental behavior is verified, and significant differences are found between males and females in messages based on principles of coherence and conspicuous consumption.     

Functions of the vibrissae in the defensive and aggressive behavior of the rat

Removal of mystacial vibrissae for strange rats placed in an established rat colony produced reliable decrements in defensive boxing for these animals, and corresponding increases in freezing. In a subsequent experiment, removal of the vibrissae of the attacking colony males did not change the attack behavior of the vibrissectomized animals. These results indicate that the vibrissae are involved in defensive boxing behavior, but play no essential role in the elicitation or maintenance of conspecific attack in the rat.     

Agonistic versus amicable targets of attack and defense: Consequences for the origin,function, and descriptive classification of play-fighting

Play-fighting appears to involve the behavior patterns of attack and defense otherwise seen in serious fighting. The degree of similarity, however, depends on the body targets attacked and defended during these forms of fighting. For many taxa, including diverse mammalian families and some birds, the same targets are attacked and defended during both play-fighting and serious fighting. However, for several species of muroid rodents, the targets of play-fighting are not the same as those of serious fighting. In these cases, the tactics of attack and defense are also different. It is argued that for these muroid species the playful targets have arisen from amicable behavior (e.g., social investigation, greeting, allogrooming) rather than, as appears to be the case in so many other taxa, from agonistic behavior. These data strongly suggest that “play-fighting” has evolved from different precursors in different taxa and thus has multiple origins. Furthermore, these data have an important bearing on the universal applicability of many of the suggested functions of play-fighting and also on how such behavior is to be described and classified.     

Identification of the possible origin of the body target that differentiates play fighting from serious fighting in syrian golden hamsters (Mesocricetus auratus)

Play fighting in the Syrian Golden hamster Mesocricetus auratus can be distinguished from serious fighting by the targets attacked in each case. In play fighting, the animals attack and defend the cheeks and cheek pouches, whereas in serious fighting they attack and defend the rump and lower flanks. Since play typically involves the use of behaviors borrowed from other functional contexts, this paper investigates the origin of the cheek target during play fighting. Comparison of resident-intruder serious fighting with awake and anesthetized intruders does not reveal the cheek to be an inhibited target for serious attack. Similarly, analysis of social investigation and allog-rooming, while revealing the ears to be important targets, do not show the cheeks to be targets in these behaviors. Sniffing, licking, and nibbling of the cheek area appear to occur mainly during sexual encounters by males. This area, seemingly a sexual target, may be the one utilized during play fighting.