Fighting patterns in young coyotes: Initiation,escalation, and assessment

The fighting patterns of young coyotes were studied and 2,350 fights were analyzed. Our results can be summarized as follows: 1) No major injuries were sustained by any of the infants, even in unritualized bouts. 2) In pairs, there was no relationship between social rank and the proportion of fights that were initiated by either animal. 3) Dominant animals were more likely than subordinate individuals to escalate first (perform the first unprovoked dangerous move) during short interactions and to escalate and then subsequently win short fights. 4) Highest-ranking (alpha) individuals in litters did not fight the most. 5) Alpha individuals initiated 73% of the fights in which they partook. Alpha coyotes initiated and then won 86% of the contests that they initiated. 6) For fourth-ranking coyotes in litters, there was a perfect positive correlation between the proportion of times that they initiated fights and the proportion of times that they initiated and then won encounters. They initiated interactions least with the first- to third-ranking animals. 7) Alpha and fourth-ranking animals escalated about the same proportion of the time, but alpha coyotes escalated and then won a greater proportion of fights. 8) Both alpha and fourth-ranking animals initiated and then escalated the greatest proportion of time with individuals nearest in rank, with whom they may have experienced the greatest difficulty in assessing relative social standing. 9) Our data suggested that individuals, especially in litters, were able to make pre-fight assessments but that they were not perfect with respect to this ability. During-fight assessments appeared to be easier to make, using escalation to test an opponent.     

Maternal aggression toward infanticidal males of different social status in wild house mice (Mus musculus domesticus)

Maternal aggression was examined in wild female mice (Mus musculus domesticus) derived from animals trapped in Alberta, Canada. Lactating females were tested for their behavior toward intruder males during the time of postpartum estrus while housed in a two-cage apparatus containing a defensible nest area. Prior to being used as intruders, sexually naive males were screened for their behavior toward a newborn pup (83% exhibited infanticide). Only infanticidal males were then housed in pairs and allowed to establish a dominance hierarchy. Dominance status was further verified by a urine marking test. The dominant and subordinate infanticidal males were then placed into a lactating female's cage and observed for 1 hr. The test was terminated immediately when a male began to attack the pups. Lactating females attacked the males in both groups, but subordinate males received more intense attacks than dominant males. Dominant males elicited significantly more fear/defense behavior than subordinate intruders. All of the dominant males and only one submissive male attacked the pups. Females were thus successful in blocking infanticide only by infanticidal subordinate males. Since females do not persist in attacking males with high fighting ability, one function of maternal aggression could be to assess the fighting, and resource holding, potential of a future mate. © 1994 Wiley-Liss, Inc.     

Some subordinates are more equal than others: Play fihgting amongst adult subordinate male rats

Adult male rats living together form dominance relationships, with one dominant and the remainder adopting subordinate roles. In previous studies, it was shown that in adult male pairs, the subordinate rat initiates more playful contacts and retains a more juvenile response to the playful contacts by the dominant. In this experiment, triads were used to examine the play between subordinate males. The subordinates directed fewer playful contacts to each other than to the dominant rat, and there was a symmetrical play relationship between the subordinates. After the dominant was removed from the colony, one subordinate became the dominant. Playful interactions amongst these pairs increased, with the subordiante intiating more playful contacts than the dominant. Furthermore, from a similarly low frequency of juvenile-type response to playful contact to each other when in triads, the subordinate in the dyads increased its frequency of juvenile responses to the dominant partner. This supports the hypothesis that the playful behavior of subordinate male rats towards the dominant is an adaptive response, playful behavior of subordinate male rats towards the dominant is an adaptive response, serving a “friendship maintenance” function. Finally, when in triads, one subordinate was more playful with the dominant than the other subordinate. It was the least playful subordinate that was the most likely to become the dominant. This sugests that within a colony, not all subordinates are the same. © 1993 Wiley-Liss, Inc.     

Effects of male social status on reproductive success and on behavior in mice (Mus musculus)

Differences in reproduction as well as in behavior in the presence of females were evaluated according to dominant and subordinate male rank in albino mice, in the temporary absence of each male's antagonist. Dominant males reproduced more successfully than subordinate males. Subordinate males were generally inactive, except for displacement activities, during the first 15 min they were exposed to female partners. These findings suggest that mechanisms other than male-male interference or mating order may be operating or influencing behavior and reproductive results.     

Social dominance and individual aggressiveness

Male rats exhibiting high, moderate, or low levels of offensive aggressive behavior in interactions with intruders in their home cage were grouped in mixed-sex colonies with 1 male of each aggression-level group in each colony. Agonistic interactions measured 1, 2, 3, 7, 14, 21, and 22 days after colony formation indicated that highly aggressive males on pretests continued to be more aggressive, becoming the dominant colony male in five of seven colonies and attacking intruders more often than less aggressive males. In the two remaining colonies the moderately aggressive male became dominant. This relationship, which was consistent over a number of indices, including offensive and defensive behaviors, and wound counts and wound sites, was seen even when a substantial weight differential favored the less aggressive animal. Dominance relationships were rapidly established and within-group fighting declined significantly over the 21-day test period. Pretest offensive levels also influenced the behavior of subordinates, with high or moderately aggressive subordinates showing more defense in interactions with dominants and receiving more wounds than did low-aggression subordinates. Dominant males also showed more defense in interacting with those subordinates which had been more aggressive during pretests. This pattern of results suggests that aggression level of the subordinate as well as the dominant may be an important factor determining the intensity of agonistic interactions in male rats.     

Anybody can be a boss but only certain people make good subordinates: behavioral impacts of striving for dominance and dominance aversion

The present study investigated whether people in assigned subordinate or dominant roles differ in their dominance behavior according to whether they initially wanted a subordinate or a dominant role. Sixty-six females and 72 males interacted twice for 8 mins in same-gender dyads. Prior to the interaction, participants could indicate whether they preferred to take a subordinate or a dominant role. Roles were then assigned randomly. Both interactions were videotaped and later coded for perceived dominance and speaking time. Results showed that for assigned subordinates, those who initially wanted to be in the dominant position were perceived as more dominant and behaved more dominantly than those who initially wanted to be in the subordinate role. For assigned high-dominance people, there was no difference in perceived dominance and behavioral dominance between those who initially wanted the dominant versus subordinate position.     

Dominance and social information use in a lizard

There is mounting evidence that social learning is not just restricted to group-living animals, but also occurs in species with a wide range of social systems. However, we still have a poor understanding of the factors driving individual differences in social information use. We investigated the effects of relative dominance on social information use in the eastern water skink (Eulamprus quoyii), a species with age-dependent social learning. We used staged contests to establish dominant–subordinate relationships in pairs of lizards and tested whether observers use social information to more quickly solve both an association and reversal learning task in situations where the demonstrator was either dominant or subordinate. Surprisingly, we found no evidence of social information use, irrespective of relative dominance between observer and demonstrator. However, dominant lizards learnt at a faster rate than subordinate lizards in the associative learning task, although there were no significant differences in the reversal task. In light of previous work in this species, we suggest that age may be a more important driver of social information use because demonstrators and observers in our study were closely size-matched and were likely to be of similar age.     

The introduction of a group of alien mice (Mus musculus L.) into hierarchically organized groups of five male mice

Groups of 3 male or female Mus musculus were introduced into hierarchically organized colonies of 5 male mice for a period of 8 days. The colonies were of 2 kinds; high-level aggressive (HLA), which had been set up 3 days prior to the introduction of the aliens, and low-level aggressive (LLA), which had been established for 21 days before strangers were introduced. Both males and anestrous females were attacked, but males were attacked 5 times more frequently than females. In HLA colonies most of the attacks on the aliens were by the dominant; in LLA colonies there was no difference in the behavior of dominant and subordinate mice toward strangers. Both aggression toward aliens and intracolony aggression declined over the 8 day experimental period. In HLA colonies the dominant mouse mounted females 5 times more frequently than did either his subordinates or male mice in the LLA colonies. In HLA colonies aliens huddled with subordinates to form a single colony with 1 dominant and 7 subordinates. In LLA colonies alien males remained as a discrete group spatially separated in the cage. Female aliens were incorporated into the main colony. In all cases dominant male mice made more attacks on aliens as compared with familiar mice.     

Selective approach to a male and subsequent receptivity to mounting comprise mate‐choice behavior of female mice1

Abstract: To ensure the effectiveness of the mate‐choice behavior of female house mice (Mus domesticus), we observed them in two different situations that involved restriction of the area of movement of the male mice. In Experiment 1, we observed 12 trios consisting of two male mice and an estrous female placed in a chamber in which none of the animals was restricted during the 6‐h test. It was found that the female was more receptive to the male that had ejaculated with it first. Additionally, when the female initiated the mating event by approaching the male, the lordosis quotient was higher than that when the male initiated the mating event. In Experiment 2, a female was able to visit two males that were prevented from getting out of small boxes. As a result of the 3‐h observation of 10 cases, it was found that the females were more receptive to the dominant male. The intromission ratio of the dominant male was also higher than that of the subordinate male. The behavioral roles of female mice in mating interactions and their adaptive validity are discussed.     

Juvenilized play fighting in subordinate male rats

As pairs of male juvenile sibling rats that are housed together become sexually mature, they develop a dominance-subordinance relationship. These dominance relationships appear to be reflected in the play fighting of the pairmates both as juveniles and as young adults, in that the seemingly subordinate partner initiates more playful attacks at both ages. However, as adults, even though it is the subordinate that initiates more playful attacks, it is the subordinate that is pinned on his back by the partner most often. Dominant pairmates were found to switch to defensive patterns typically found in adult males. In contrast, the subordinates, when contacted on the nape, were more likely to retain the juvenile pattern of turning over to supine. Therefore, the subordinate pairmate of an adult pair of male siblings both initiates more playful attacks and defends itself in a more juvenile manner than its dominant partner, and this leads to it being pinned more frequently. This pattern of behavior by subordinate rats is suggested to function as a friendship maintenance mechanism permitting co-existence in multimale colonies.     

Playful defensive responses in adult male rats depend on the status of the unfamiliar opponent

Adult male rats reared as pairmates from weaning were tested in a neutral arena with both members of another pair (one at a time). The unfamiliar pairs were found to engage in play fighting, although they were more likely to escalate the encounter into serious fighting than were pairs of familiar rats. Based on their within‐home pair behavior, each pairmate was designated as a dominant or a subordinate. When the test encounters between unfamiliar males were analyzed with regard to whether the pairings consisted of two dominants, two subordinates, or a mixed pair, the pattern of play fighting was found to be attenuated. Both dominants and subordinates were more likely to initiate playful encounters, to respond defensively during these encounters, and to do so using adult‐typical tactics of defense when paired with an unfamiliar rat that was dominant in its home cage. The mechanisms by which the home status of unfamiliar male rats can be identified by another male are discussed, particularly with regard to the role that play fighting may serve for this function. It is concluded that the data support the hypothesis that play fighting can be used by adult rats for social testing, which in this case seems to involve ascertaining the opponent's fighting capability. Aggr. Behav. 25:141–152, 1999. © 1999 Wiley‐Liss, Inc.     

Leading a conspecific away from food in ravens (<Emphasis Type="Italic">Corvus corax</Emphasis>)?

Active misleading of conspecifics has been described as a social strategy mainly for primates. Here we report a raven leading a competitor away from food in a social foraging task. Four individuals had to search and compete for hidden food at color-marked clusters of artificial food caches. At the beginning of the experiment, a subordinate male found and exploited the majority of the food. As a result, the dominant male displaced him from the already opened boxes. The subordinate male then developed a pattern, when the loss of reward to the dominant got high, of moving to unrewarded clusters and opening boxes there. This diversion often led the dominant to approach those unrewarded clusters and the subordinate then had a head start for exploiting the rewarded boxes. Subsequently, however, the dominant male learned not to follow the subordinate to unrewarded clusters and eventually started searching for the reward himself. These interactions between the two males illustrate the ravens' potential for deceptively manipulating conspecifics. We discuss under which circumstances ravens might use this capacity.     

Agonistic onset marks emotional changes and dispersal propensity in wild house mouse males (Mus domesticus)

The authors investigated implications of agonistic onset for anxiety and dispersive motivation in maturing wild house mouse males (Mus domesticus). Laboratory-kept fraternal pairs either developed agonistic dominance or stayed amicable during their first 2 months of life, when the authors assessed open-field behavior and dispersal propensity. State anxiety was lower in amicable than agonistic males and higher in subordinate than dominant ones. During subsequent dispersal trials, 1 dominant and 1 amicable male from 2 fraternal pairs were concomitantly introduced into seminatural enclosures containing 3 females. One male invariably became territorial. The defeated males, if previously dominant, dispersed at significantly higher rates than if previously amicable. The authors conclude that agonistic onset during development represents an adaptive behavioral switch from a submissive-philopatric to agonistic-dispersive coping strategy.     

Visible homonyms are ambiguous, subliminal homonyms are not: a close look at priming

Homonyms, i.e. ambiguous words like ‘score’, have different meanings in different contexts. Previous research indicates that all potential meanings of a homonym are first accessed in parallel before one of the meanings is selected in a competitive race. If these processes are automatic, these processes of selection should even be observed when homonyms are shown subliminally. This study measured the time course of subliminal and supraliminal priming by homonyms with a frequent (dominant) and a rare (subordinate) meaning in a neutral context, using a lexical decision task. In the subliminal condition, priming across prime-target asynchronies ranging from 100 ms to 1.5 s indicated that the dominant meaning of homonyms was facilitated and the subordinate meaning was inhibited. This indicates that selection of meaning was much faster with subliminal presentation than with supraliminal presentation. Awareness of a prime might decelerate an otherwise rapid selection process.     

归类优势与基本水平效应的再探讨

类别特异性分数是预测归类优势的有效指标。实验1考察该分数能否预测基本水平归类优势, 结果：分数较高的表现归类优势。实验2检验有归类优势的下位类别的分数, 结果：它们都有较高分数, 同时发现下位类别的特异性可以影响分数。实验3探讨相同的基本水平与特异性不同的下位组合的归类表现, 结果：下位特异性低就表现基本水平归类优势, 高则相反。据此提出“经验说”, 分数高低与人们在经验中对各层次类别形成的表征特异性程度相关。     

Fighting and playfighting in captive adolescent chimpanzees

Most young non-human primates spend a great deal of time playing alone or with conspecifics. Despite numerous studies on social play, its adaptive functions remain unclear. A longitudinal study comparing social interactions preceding and following rank reversals among four captive adolescent chimpanzees (Pan troglodytes schweinfurtii) suggests that social play during their adolescent period functioned in establishing and maintaining the dominance rank within dyads, without interventions from allies. Interventions were less frequent in rough-and-tumble play than in real fighting. Within dyads of competing chimpanzees, rough play was more frequent than gentle play. Both types of play were correlated with reciprocal aggression between competitors, and most play bouts terminated in truly aggressive conflict. Dominant individuals seemed to be responsible for maintaining play activity, by responding playfully to threats and aggression of contestants. In addition, dominant individuals more often initiated play encounters with their subordinates when the dominance relationships were clear, but subordinate individuals also initiated play sequences when they challenged the dominant's rank. The adaptive value and mechanisms of rough-and-tumble play are discussed in the context of adolescence. © 1994 Wiley-Liss, Inc.     

Conditions necessary to the establishment of mating dominance by the male hamster

We tested whether establishment of a dominance hierarchy among four males will ensure the dominant male preferential mating access to a single female. Establishment of the dominance hierarchy in the absence of a female did not result in any competitive mating advantage for the dominant male in terms of mating priority or total number of intromissions. However, establishment of the dominance hierarchy in the presence of a female, with interactions between the males and female occurring throughout the 4-day estrous cycle prior to the female becoming receptive resulted in the dominant male having a clear mating priority. Under these conditions the dominant male achieved more intromissions than the three subordinate males combined. Thus, male dominance status can affect mating success; however, it appears that interaction with the female as well as with other males prior to the onset of receptivity by the female is essential for assurance of a clear mating priority.     

A Taste for Justice: Unpacking Identity Politics in a Nascent Democracy

This article examines attention to justice cues in the novel context of the nascent democracy of Tanzania. Using secondary national survey data, we illustrate Tanzanian citizens' attention to justice cues. We then test two competing hypotheses about the impact of religious identity on attention to justice cues. The first hypothesized model, based on System Justification Theory, predicts that subordinate group members (Muslims) will stay more loyal than dominant group members (Christians) to their government due to a decreased attention to justice cues. The second hypothesized model, based on the relational model of procedural justice, predicts that subordinate group members (Muslims) will dissent more than dominant group members (Christians) from their government due to an increased attention to justice cues. Multiple regression and mediational analyses indicate support for the procedural justice framework, with trust in the dominant political party mediating the relationship between process satisfaction and party identification. Implications for political and psychological theorizing about democratic processes will be discussed.     

Contest experience and body size affect different types of contest decisions

This study examined the relative importance of contest experience and size differences to behavioral decisions over the course of contests. Using a mangrove rivulus fish, Kryptolebias marmoratus, we showed that although contest experience and size differences jointly determined contest outcomes, they affected contestants’ interactions at different stages of contests. Contest experience affected behavioral decisions at earlier stages of contests, including the tendency and latency to launch attacks, the tendency to escalate contests into mutual attacks and the outcome of non-escalated contests. Once contests were escalated into mutual attacks, the degree of size difference affected the fish’s persistence in escalation and chance of winning, but contest experience did not. These results support the hypothesis that contest experience modifies individuals’ estimation of their fighting ability rather than their actual strength. Furthermore, (1) in contests between two naïve contestants, more than 60 % of fish that were 2–3 mm smaller than their opponent escalated the contest to physical fights, even though their larger opponents eventually won 92 % of escalated fights and (2) fish with a losing experience were very likely to retreat in the face of an opponent 2–3 mm smaller than them without escalating. The result that a 2–3 mm size advantage could not offset the influence of a losing experience on the tendency to escalate suggests that, as well as depending on body size, the fish’s physical strength is influenced by other factors which require further investigation.     

Effects of prior agonistic experience on risk assessment and approach behavior evoked by familiar or unfamiliar conspecific odors

Risk assessment and appetitive behaviors in response to familiar and unfamiliar conspecific odors were measured in mice rendered dominant or subordinate by a series of resident-intruder encounters. Subordinate mice showed elevated levels of risk assessment in response to the odors of both familiar dominant and unfamiliar males. These behaviors were almost totally absent among dominant males exposed to familiar subordinate or unfamiliar male odors. Subordinate mice showed a marginally significant elevation in latencies to approach familiar, but not unfamiliar, dominant odors. Dominant and subordinate mice spent comparable amounts of time in the cage area containing familiar antagonist odors, however, and the durations of subordinates were mildly elevated, rather than decreased, when unfamiliar conspecific odors were present. There were no group differences in any of the appetitive behaviors. These findings suggest that apparent preferences for conspecific odors may arise from quantitatively and/or qualitatively differing emotional states. The inclusion of risk assessment measures is suggested to be a useful adjunct for studies of olfactory preference/rejection. © 1994 Wiley-Liss, Inc.