Agonistic Behaviour Patterns Research Articles

Behavioural and endocrine predictors of dominance and tolerance in female common marmosets, Callithrix jacchus

As a result of social subordination, female common marmosets undergo suppression of ovulation and inhibition of sexual behaviour. This study examined the possibility that subordination also results in decreased aggressiveness and increased submissiveness towards same-sex strangers. Thirty-two adult females were pre-assigned to eight mixed-sex social groups. The females' behavioural and adrenocortical responses to brief confrontations with each of three female strangers were assessed under two conditions: while subjects were pair-housed with a male and while they were living in established, mixed-sex groups. Only 22% of subjects threatened stimulus females in the heterosexual pairs condition, 47% submitted and 31% showed no agonism. These agonistic behaviour patterns reliably predicted whether a female would become dominant or subordinate in a mixed-sex group. When animals were housed in established social groups, both dominant and subordinate females either showed similar responses to stimulus animals as they did in the earlier condition or became somewhat less responsive. Plasma cortisol levels did not correlate with agonistic behaviour and were not elevated by stranger-encounter testing. Finally, in the first 10 days following group formation, subordinate females that had shown ovulatory cyclicity prior to group formation were significantly more likely to receive persistent aggression from their dominant female groupmate than subordinates that had been anovulatory. These results suggest that attainment of social status between female marmosets is closely related to pre-existing individual differences in agonistic behaviour, whereas tolerance between females depends upon ovarian function.

The effects of infant births on the sociosexual behavior and hormonal patterns of a cooperatively breeding primate (Cebuella pygmaea).

This study examined changes in the behavioral and hormonal patterns of cooperatively breeding pairs in a primate species with the passing of time and with specific reproductive events. We (1) compared patterns of sexual, agonistic, and affiliative behavior of newly paired pygmy marmosets with the same behavioral patterns immediately after the birth of their first set of infants; (2) determined if postpartum behavioral differences existed between pairs whose infants lived and those whose infants died; and (3) examined whether behavioral patterns changed over the course of ovarian cycles in parous pygmy marmosets as had been documented in nulliparous pairs. The behavior of pairs was recorded during daily half-hour focal samples for 60 days after pairing, and 30 or 60 days after the birth of infants for pairs whose litters died or lived, respectively. Daily urine samples from females during the study were analyzed for luteinizing hormone and pregnanediol glucuronide concentrations to determine dates of ovulation. The results indicated that males consistently altered their sexual behavior and olfactory monitoring of mates during periovulatory periods in the females' cycles both postpairing and postpartum, while similar rates of social and sexual behavior were maintained between the conditions. Sexual behavior occurred throughout the females' ovarian cycles. Peaks in sexual behavior during the periovulatory period in nulliparous pairs disappeared after the birth of infants. Pairs whose infants died showed higher rates of sexual behavior than pairs with surviving infants. Social and sexual behavior may function to maintain the relationship both during and outside of ovulation, especially with the loss of infants. © 1996 Wiley-Liss, Inc.

Behavioural expression of laying hens in aviaries and cages: Frequencies, time budgets and facility utilisation

1. We studied: behavioural frequencies and time budgets of behaviour patterns in non-beak-trimmed White Leghorn layers housed in cages (720 cm2/hen, 3 hens/cage), and in the Marielund, the Tiered Wire Floor (TWF), and the Laco-Volétage aviaries (17 hens/m2 ground area); individual variation in behaviour among aviary hens; spatial utilisation of the different types of aviary. 2. At 25, 40, and 60 weeks of age behaviour patterns of 114 focal animals were data logged. Each bird was observed for 10 min 4 times a day on three consecutive days. 3. The frequency of activity transitions and the activity level was highest in TWF, second highest in cages, and lowest in Laco-Volétage, suggested that Laco-Volétage hens were the calmest, whereas birds in cages and in TWF were more restless. Abnormal types of behaviour occurred most often in cages and TWF. The disadvantageous behaviour patterns shown by birds in TWF and cages imply that these environments were the least appropriate for this layer strain. 4. Pronounced individual variations in mobility and facility utilisation were found, both within and between the three aviaries. Resting levels were used twice as much (Laco-Volétage), and litter areas one third as much (Marielund), as that expected on a simple a proportionate basis. Most feather pecking was performed at resting levels and on feeding floors, whereas most agonistic behaviour patterns were observed on feeding floors and litter. 5. Measures to improve the aviaries are outlined.

Seasonal influences on rhesus monkey (Macaca mulatta) behavior

Seasonal differences in the behavior of 2.5- to 4.5-year-old female subjects and male subjects >2.5 years of age were studied in two rhesus monkey groups over a period of 6 years. The frequencies and durations of sexual acts and states were higher during the Fall in Georgia, USA, but were significant only with regard to female partners. Total time in social proximity, scores for proximity by partner without social interaction, nonspecific contact, grooming received, and noncontact forms of aggression with female partners were also higher in the Fall. Although more submission and agonistically ambiguous responses were received from female partners during the Fall, no seasonal pattern prevailed for responses performed. More contact aggression was directed to males in the Spring, and the pattern of agonistic behavior observed cannot be accounted for by males fighting over estrous females. Significantly more play was observed among subjects in the Fall, but the oldest males played more in the Spring. Some patterns, like huddling, were seen more in the Fall, but they may have been due to temperature differences. Seasonal differences in morphology and behavior cannot be attributed to a single variable, like temperature, level of gonadal hormones, or sexual competition, and may reflect a broader adaptation to seasonal variables.

Investigating equine ingestive, maternal, and sexual behavior in the field and in the laboratory

Some of the techniques that may be used to study social, reproductive, and ingestive behavior in horses are described in this paper. One of the aspects of equine social behavior is the dominance hierarchy or patterns of agonistic behavior. Paired or group feeding from a single food source may be used to determine dominance hierarchies quickly. Focal animal studies of undisturbed groups of horses may also be used; this method takes longer, but may reveal affiliative as well as agonistic relationships among the horses. Reproductive behavior includes flehmen, the functional significance of which can be determined using combinations of field observations of harem groups and laboratory studies of stallions exposed to female urine or feces in the absence of the donor mare. Ingestive behavior may include food, salt, or water intake. Direct and indirect measurements of intake can be made and used to answer questions regarding the ability of horses to control their energy intake when the diet is diluted, the effect of feral equids on the ecology of an area, and the abilities of horses to compensate for dehydration and hypovolemia.

Courtship and agonistic behavior in mouflon sheep

Although native to Corsica and Sardinia, mouflon sheep ( Ovis orientalis musimon) have been widely introduced to other areas, including the United States. This study examines the courtship and agonistic behavior of 2 captive mixed-sex herds in west-central Texas, U.S.A. These herds were observed in large enclosures on game ranches during the autumn of 1980. Inter- or intra-sexual interactions consisted of one or more repeated behavioral postures (i.e. low stretch, twist, foreleg kick, sniff rear, urination, flehmen, mount, horn threat, chest push, neck fighting, head butt, clash, horn rubbing, chase). Ninety-five male-male, 63 female-female and 155 male-female interactions were observed. Low intensity agonistic displays (with total number of occurrences in the interactions given in paren-theses) such as foreleg kicks (154) and twists (141) were most frequently seen in male-male interactions. Although head butting (96) was commonly observed in male-male encounters, clashes (52) were also prominent. In female-female agonistic interactions, an unexpectedly high frequency of head butts (99) were regularly exhibited. Agonistic and courtship behavior patterns such as twist (131) and flehmen (106) were prominent in the behavior of males toward females. Although males would occasionally head butt a female (22), they seemed to inhibit clashing in their interactions with the hornless females. In most cases, female-female interactions were initiated by head butts (46) and male-male encounters began with either a head butt (23) or twist (18). Male-female interactions showed more variation in the behaviors which initiated the encounter, but usually began with a twist (39), flehmen (29) or low stretch (20) by the male. The observations of mouflon in this study conformed well with previous reports of sheep behavior.

The relationship of agonistic and affiliative behavior patterns to cellular immune function among cynomolgus monkeys (Macaca fascicularis) living in unstable social groups.

Considerable recent interest has focused on the possibility that behavioral factors may influence immune competence, and hence, potentially, patterns of disease. We report here the relationship between the aggressive and affiliative behavior and the cellular immune responses of 30 adult male cynomolgus monkeys (Macaca fascicularis) living in small (n = 5) social groups whose members were periodically redistributed over 26 months. Animals also were subjected to behavioral observation, allowing them to be categorized as either high or low in aggressiveness and affiliation. At the end of the 26 months, lymphocyte proliferation tests were performed on blood samples from all monkeys, using both concanavalin A (ConA) and phytohemagglutinin (PHA) in concentrations of 1, 5, and 10 ug/ml. Two-by-two (Aggressiveness [high, low] X Affiliation [high, low]) analyses of variance performed on these data showed lymphocyte proliferation in response to both ConA and PHA to be greatest (at 1 ug/ml) among highly affiliative animals, albeit only if they were also low in aggressiveness (ConA: Affiliation x Aggression, P < 0.02; PHA: Affiliation x Aggression, P < 0.03). An additional finding was that natural killer cell activity (at an effector to target ratio of 100:1) was highest among highly affiliative animals, regardless of their aggressiveness (P < 0.05). These results indicate that immune competence may be enhanced among monkeys which, in response to a disrupted social environment, spend large amounts of time in affiliation with other animals. Social status, a phenomenon known to influence many aspects of nonhuman primate physiology, was unassociated with nonspecific lymphocyte blastogenesis or natural killer cell activity in this experiment.

Agonistic and grooming behavior of captive crowned lemurs (Lemur coronatus) during the breeding season

Captive breeding of rare and endangered prosimians may be enhanced by an increased understanding of all aspects of their seasonal mating behavior. In this study, the agonistic and grooming behaior of captiveL. coronatus were studied during their annual breeding season. Between October and March, selected aspects of agonistic and grooming behavior of four male-female groups were recorded. Males initiated significantly more allogrooming than females. The frequency of this behavior pattern increased significantly in the weeks of estrus. Females performed significantly more agonistic behavior patterns than males. The mean frequency of agonistic interactions decreased significantly during the breeding season. In successfully reproducing groups males showed much less agonism towards females, than they did in unsuccessful groups. Inter-specific comparisons demonstrated that the patterns of agonistic interactions during the breeding season are very different among closely related species of lemurids. The conclusions drawn from this study are that captive breeding of crowned lemurs may be enhanced by keeping permanent multi-male, multi-female groups.

Temporal and sequential patterns of agonistic behavior: effects of alcohol, anxiolytics and psychomotor stimulants

Social and agonistic interactions are composed of a range of species-typical acts, postures, displays and other communicative signals that follow characteristic patterns. Descriptive and analytic methods permit an assessment of the temporal and sequential features of highly probable patterns of agonistic interactions. Analysis of the intervals that separate consecutive attacks by a resident mouse or rat toward an intruder identifies bursts or epochs of attacks. Amphetamine (1.25, 2.5 mg/kg), but not diazepam or alcohol, alters the burst pattern of attack behavior. Higher doses of alcohol, but not diazepam, in either resident male rats or in lactating rats confronting an intruder, reduce the sequences of aggressive acts and postures with high transition probabilities as identified by lag sequential analysis. These results suggest that temporal and sequential patterning mechanisms may be differentially altered by amphetamine- and alcohol-type substances. These neural for many types of behavior.

Lack of effects of environmental changes on agonistic behaviour patterns in a stabilizing group of stumptailed macaques (Macaca arctoides)

To evaluate how constant the form of agonistic interactions in the event of environmental changes is, a group of 11 stumptailed macaques, formed shortly before the start of the study, was observed under the following spatial conditions: in 10 and 18 m2 cages, and in a 50,000 m2 woodland. Results showed that the frequency of agonistic interactions was little affected by spatial density; however, the number of participants involved in aggressive interactions increased in the cage. Formal biting, which presumably acts as a regulator of social tension, was less frequent in the park. Patterning of agonistic interactions was little affected by spatial density. Such “robustness” makes the form of aggression liable to be used as a potentially useful parameter in interspecific comparisons.

Agonistic behavior in preschool children: A comparison of same-sex versus opposite-sex interactions

Patterns of agonistic behavior in preschool children were examined in order to compare samesex and opposite-sex interactions. Observational reports were supplemented with videotape analysis to provide details concerning three separate measures of agonistic behavior: threats, attacks, and displacements. Significant differences were found in attacks, displacements, and in combined scores for the three measures. Two different explanations are offered: One explanation concerns the socialization of “sex-appropriate” behavior, and the other focuses on the development of dominance relationships in young children.

Determinants of social dominance in eastern gray squirrels ( Sciurus carolinensis): a quantitative assessment

This study, conducted from January 1979 to August 1981 at the Rachelwood Wildlife Research Preserve, Westmoreland County, Pennsylvania, U.S.A., examined the structure of the dominance hierarchy in a free-ranging population of eastern gray squirrels ( Sciurus carolinensis), using physical attributes and behavioural patterns correlated with social status for groups observed in arena trials. Multivariate statistical analyses (principal components and linear discriminant function analyses) of over 380 agonistic interactions indicated that the primary determinants of dominance were the animals' sex and age, and that the frequency of display of key agonistic behaviour patterns could predict an individual's age (i.e. dominance) status, with over 94% accuracy. Non-parametric analyses of variance (Kruskal-Wallis and Jonckheere-Terpstra procedures) showed that adults significantly out-ranked immatures of both sexes. No significant differences in status were found in comparisons between immature animals and among adults, although average rank consistently increased with age among adults. Within sex/age groups, weight of the animals did not significantly influence status. These results support those determinants of dominance proposed in several earlier studies of gray squirrel social behaviour and behavioural ecology.

Agonistic behavior patterns in mice with streptozotocin-induced diabetes mellitus

To examine the effects of the altered metabolic and hormonal state of diabetes mellitus on rodent social behavior, male Swiss Webster mice made diabetic with streptozotocin were tested in a resident-intruder encounter. Isolated diabetic and control mice were introduced as intruders into the home cages of aggression-trained resident mice. The encounters were videotaped and analyzed for frequencies and durations of agonistic behavior. Diabetic mice responded to the aggression of resident mice with significantly less investigation and aggression and significantly more static defense and escape behaviors than did control mice. Resident mice responded to less aggressive diabetic mice with more aggression and social investigation. Plasma corticosterone levels were significantly higher in diabetic mice compared to controls and positively correlated with submissive behavior in diabetic mice. These findings indicate that social behavior is altered in male diabetic mice and support the hypothesis that elevated pituitary-adrenal cortical activity and/or metabolic changes affect behavior in male diabetic mice.

Estrogen action in anterior and ventromedial hypothalamus and the modulation of heterosexual behavior in female golden hamsters

Changes in heterosexual patterns of agonistic, marking, and sexual behavior were examined in female hamsters over a three day period following implantation of either estrogen or cholesterol in the hypothalamus. Animals were habituated to large arenas that permit the display of a wide range of behavior. Estrogen implants located in the ventromedial (VMH) but not the anterior (AH) portion of the hypothalamus were effective in facilitating the occurrence of vaginal marking, over a two day estrogen priming period. During this two day period, the exhibition of agonistic behavioral patterns declined significantly. Systemic administration of progesterone elicited sexual receptivity in 75% of the females in the VMH group, in contrast to only 25% in the AH group. Females with hypothalamic implants of cholesterol remained unreceptive following progesterone injections. The results provide important information on the estrogen sites of action at the hypothalamus in mediating heterosexual interactions.

The social interaction between mother and offspring during weaning in German Shepherd dogs: Individual differences between mothers and their effects on offspring

Seventeen litters of German Shepherd dogs were observed for 5–7 days per week between 3 and 8 weeks post-partum. Social behaviour patterns, aggressive signals towards the puppies and nursing were quantified. Mothers were found to differ in the frequency of both social and aggressive behaviour. Nursing declined during the period, while both agonistic and grooming behaviour towards puppies increased until the 7th week. During Week 7, agonistic behaviour patterns were found to be significantly correlated to grooming behaviour patterns. Some of these behaviour traits were significantly correlated to the puppies performance on a puppy test given at the age of 8 weeks. It is suggested that the interaction between mother and offspring may facilitate the appearance of submission, and the effects on later trainability are discussed.

Androgen and Corticoid Levels in Blood and Body Extracts of High‐ and Low‐ranking Swordtail Males (Xiphophorus helleri) before and after Social Isolation

Abstract and SummaryThe two highest‐ and the two lowest‐ranking swordtail males were determined by the criterion of number of attacks directed at and received from every other male in their breeding tanks. The events were recorded until 50 bites were given (high‐ranking males) or received (low‐ranking males). 40 high‐ and 40 low‐ranking males were bled either after being socially isolates for 4 weeks or after reaching the target number. Androgen and corticoid concentrations both in their blood and their body extracts were measured by means of radioimmunoassay.Although the agonistic behaviour patterns and social experience of high‐ and low‐ranking males were totally different, the baseline hormonal states of the animals were indistinguishable both in body extracts and blood. Isolation led to decreased blood androgen and corticoid levels in high‐ and low‐ranking males. In the body extracts, only the corticoids were reduced. A significant correlation between blood and tissue concentrations was found only in the case of corticoids.I would suggest that the contradictory findings in the literature dealing with the relationship between hormones and dominance result from differences in experimental procedure.

Agonistic interactions during competition for different resources in captive European wild pigs ( Sus scrofa)

We observed a group of captive wild pigs to determine how agonistic encounters vary as a function of preceding activities and with the availability and distribution of resources. Data are presented supporting previous competition hypotheses. The frequency and intensity of encounters was highest during competition for resources that were limited and defendable. Activities associated with limited but undefendable resources were followed by fewer encounters which were of lower intensity. When unlimited and undefendable resources were involved, agonistic encounters were infrequent. Comparisons with earlier work show that patterns of agonistic behavior in groups of Sus scrofa, regardless of the environmental setting, are not simply related to the preceding activity per se, but are related systematically to the availability and distribution of resources associated with that activity. A short-term decrease in the tendency of one male to displace its rank neighbor, not encompassed by familiar notions of rank-neighbor relations, was discovered. A previously undescribed visual display used to prevent or inhibit aggression was observed.

Lead exposure and agonistic behavior of adult mice of two ages

Adult male Heterogeneous stock (HET) mice were exposed to a 0.5% lead acetate solution when they were either 65 or 330 days of age. Fifteen weeks later they were paired with same age (young or old) water control HET mice and tested for aggression. All pairs of younger mice fought and six out of eleven pairs of older mice exhibited agonistic behavior. Although not all pairs of mice which fought achieved dominance, when dominant/subordinate relationships were established, the younger adults exposed to lead typically were subordinate. In contrast, older adults exposed to lead were always dominant. Differences in agonistic behavior patterns also were noted, with younger adults displaying more frequent and longer bouts of fighting than the older mice.

PHARMACO-ETHOLOGICAL ANALYSIS OF AGONISTIC BEHAVIOR BETWEEN RESIDENT AND INTRUDER MICE: EFFECT OF ANTICHOLINERGIC DRUGS

The resident-Intruder paradigm was employed in order to evoke an agonistic behavior in mice. In this situation a resident male mouse has been cohabiting with a female for 5 weeks, and an intruder male mouse is introduced into the resident’s home cage. A species-specific pattern of agonistic behavior was observed in all mice. The significance of cholinergic mechanisms in the mediation of the agonistic behavior was evaluated by pharmacological manipulations. Drugs were administered to resident mice. Scopolamine hydrobromide (0.25, 0.50 and 0.75 mg/kg, i.p.) significantly suppressed the resident’s aggressive episodes (offensive sideways posture, tail rattling and attack biting) in a dose-dependent manner, whereas the peripheral anticholinergic drug methylscopolamine nitrate (0.25, 0.50 and 0.75 mg/kg, i.p.) was ineffective. On the other hand, the resident’s locomotor activity and rearing response were significantly increased after the administration of scopolamine hydrobromide. The evidence suggests that brain cholinoceptive mechanisms may participate in the regulation of intraspecies aggressive behavior. However, it appears that other nonspecific behavioral effects of scopolamine cannot be ruled out.

Pharmaco-ethological analysis of agonistic behavior between resident and intruder mice: effect of anticholinergic drugs.

The resident-intruder paradigm was employed in order to evoke an agonistic behavior in mice. In this situation a resident male mouse has been cohabiting with a female for 5 weeks, and an intruder male mouse is introduced into the resident's home cage. A species-specific pattern of agonistic behavior was observed in all mice. The significance of cholinergic mechanisms in the mediation of the agonistic behavior was evaluated by pharmacological manipulations. Drugs were administered to resident mice. Scopolamine hydrobromide (0.25, 0.50 and 0.75 mg/kg, i.p.) significantly suppressed the resident's aggressive episodes (offensive sideways posture, tail rattling and attack biting) in a dose-dependent manner, whereas the peripheral anticholinergic drug methylscopolamine nitrate (0.25, 0.50 and 0.75 mg/kg, i.p.) was ineffective. On the other hand, the resident's locomotor activity and rearing response were significantly increased after the administration of scopolamine hydrobromide. The evidence suggests that brain cholinoceptive mechanisms may participate in the regulation of intraspecies aggressive behavior. However, it appears that other nonspecific behavioral effects of scopolamine cannot be ruled out.