Frequency Of Agonistic Behaviour Research Articles

Factors affecting captive female giraffe stress response: Male presence, small enclosure, and low temperature.

To improve animal welfare based on suitable social housing conditions, it is important to understand the factors that trigger high-stress responses. Wild giraffes live in a fission-fusion society and males and females are rarely in the same herd for a long period. The captive condition of belonging to a herd with the same individuals for months or years is uncommon in nature. To understand the effect of male presence on female stress levels, fecal glucocorticoid metabolite (fGCM) levels and social interactions in two captive female giraffes were investigated. Additionally, the effect of enclosure size and temperature on fGCM level and social interactions were examined. The results showed no significant difference in the fGCM levels of females based on male presence. The frequency of agonistic behavior by the dominant female toward the subordinate female was significantly increased when a male was present. The subordinate female was significantly less likely to approach the dominant female and showed decreased affiliative and agonistic interactions toward the dominant female when a male was present. The frequencies of agonistic interactions between females were higher in the small enclosure regardless of male presence. Low temperature triggered higher fGCM levels and increased agonistic interaction in an aged female. The findings of this study suggest that these multiple factors should be considered individually to promote the welfare of captive giraffes.

Aspects of social behaviour and reproduction in the wild rabbit – Implications for rabbit breeding?

Further knowledge on aspects of social behaviour in the wild rabbit (Oryctolagus cuniculus), including the link to reproduction, could possibly point to new ways to improve housing and breeding conditions in rabbit farming. In this review, I present some results of our long-term study on a 2-hectare field enclosure population of wild rabbits (University of Bayreuth, Germany), exploring group-level and individual-level differences in agonistic behaviour of females and their potential associations with reproductive traits, including offspring survival. The frequency of agonistic behaviour in which females were involved, increased with increasing group size, and was lower in groups with a more heterogeneous age structure. At the individual level, reproducing females were involved in more agonistic interactions when groupmates gave birth and thus built their burrows and nests at around the same time, and higher-ranking mothers were particularly aggressive when other females approached close to their nursery burrows. Associations between females’ social environment and reproduction were evident, as the numbers of litters and offspring per female were lower at higher female densities, high-ranking females produced more offspring and had a lower offspring mortality than low-ranking ones, and cases of infanticide were lower in more stable groups, which we quantified by the more heterogeneous age structure of the females’ rank hierarchy in such groups. Furthermore, perinatal offspring mortality was increased in females with a delayed burrow and nest building activity, i.e. does that dug their nursery burrow and built their nest only during the last 24 h pre-partum, possibly driven by the more unfavourable social environment experienced by such females. Most importantly, our studies highlight the importance of the presence of litter siblings in improving an individual’s social environment, which resulted in an earlier onset of breeding in such females. Higher levels of positive social interactions with litter siblings were also associated with lower stress hormone (corticosterone) levels and with a better health status in terms of lower loads with an intestinal nematode. These findings on ameliorating effects of litter sibling presence in growing rabbits as well as in reproducing females may be a promising starting point worth further exploration in the context of group housing of domestic rabbits.

Effect of adult male sterilization on the behavior and social associations of a feral polygynous ungulate: the horse

Castration is commonly used to control the behavior of companion animals and livestock, yet there have been few longitudinal studies of its effects. Despite the ubiquity of this surgery in ridden horses, the effects of castration (termed gelding in horses) have rarely been examined in a reproductive population. We tested effects of gelding on maintenance and social behaviors of individuals pre- and post-gelding, and in comparison to intact control adult males (2 to >16 years old) in both harem and bachelor status, we then tested how gelding affected association with mares (i.e., maintenance of a harem group) compared to intact controls, and any effects on bachelor social associations. We further explored any effects on foaling rate to assess potential impacts on population growth rate. We conducted this study over four years (2017–2020) at two Herd Management Areas (HMAs) in western Utah, USA: Conger and Frisco. We conducted demographic observations year round at both HMAs to record survival and foaling rate. We additionally recorded behavioral observations at Conger HMA. In December 2017, 27 adult males from Conger (42% of adult males in the population) were gelded and returned to the range with their social groups. Due to pre-treatment observations we were able to compare stallions of known status pre- and post-treatment (harem or bachelor), as well as gelded and intact males. We had no morbidity or mortality related to the gelding surgery and all males maintained good body condition throughout the study. There was no effect of gelding on maintenance behaviors (feeding, moving, and standing). There was no effect of gelding on frequency of agonistic behavior, and a non-significant tendency for less reproductive behavior in geldings; geldings showed more affiliative and less marking behavior. Age class and/or social status were better predictors of behavior than gelding. Over time fewer geldings maintained a harem, and their harem size declined during the study. Horses that were bachelors when gelded tended to remain as bachelors, whereas intact bachelors of the same cohort mostly attained a harem. Foaling rate at Conger was reduced in the year following treatment, but then returned to pre-treatment levels. From a welfare perspective gelding is safe to use in feral horses and has minimal effects on horse behavior and social interactions in a reproductive herd. Effectiveness for population growth control would likely require a larger proportion of males in the population to be castrated for longer-term effects on foaling rate.

Environmental Enrichment for Pig welfare during Transport

ABSTRACT This study aimed to assess the effects of environmental enrichment for pigs during transportation in different phases of their productive cycle. Two trials were conducted, the first during transportation of pigs from the piglet production unit (PPU) to the nursery (n = 250) and the second during the transportation of nonhuman animals from the finishing unit (FU) to the slaughterhouse (n = 120). This work was an observational study with five environmental enrichments: Control – no enrichment; object – use of enrichment objects in the truck; aroma – use of lavender aroma in the truck; music – music in the truck; and vehicle sound. Animal behavior during transportation, respiratory rate, skin surface temperature, and skin lesion score were assessed. Piglets from the treatment music had the lowest frequency of agonistic behaviors during transportation from the farrowing to the nursery and lower skin temperature after transportation. Piglets from the control had the highest respiratory rate prior to transportation. Pigs familiarized with vehicle noises spent most of their time lying during the trip to the slaughterhouse. The creation of a familiar environment to pigs seems promising in enhancing animal well-being during transportation.

Ewes behavioural and physiological reactions to the odour of fox (Lycalopex gymnocercus) and wild boar (Sus scrofa) faeces

Predation of sheep is a production problem that deserves the studies of how this prey species detects and react to predators. In this context, this study determined the behavioural and physiological responses of ewes exposed to the odour of predators’ faeces as fox (Lycalopex gymnocercus) and wild boar (Sus scrofa). Four experimental treatments were applied to 48 Corriedale sheep (12 ewes each): fox faeces (FFO), wild boar faeces (WBFO), unknown sheep wool (SWOC) and no odour (NOC). All ewes were evaluated in a behavioural test for 5 min and then rectal temperature was measured, and a series of blood samples were obtained to determine cortisol concentration, glycaemia, total protein, albumin and globulin. The frequency of kicking the ground, turning their head, going back and stillness behaviours increased significantly in FFO in comparison with NOC (p = 0.01; p < 0.0001; p = 0.005 and p = 0.002, respectively) and kicking the ground and turning the head compared with SWOC (p = 0.03 and p < 0.001 respectively). The FFO group spent significantly more time turning the head and going back than NOC (p < 0.001 and p = 0.01 respectively) and SWOC (p = 0.002 and p = 0.05). For ewes evaluated with WBFO, kicking the ground, turning their head, going back and remaining still occurred significantly more times than with NOC (p = 0.008; p = 0.005; p = 0.01 and p = 0.003), and kicking the ground, turning their head and remaining still occurred significantly more times than with SWOC (p = 0.02; p = 0.02 and p = 0.05). Furthermore, WBFO group spent significantly less time still (p = 0.01) and more time turning their head and going back (p = 0.001 and p = 0.02, respectively) than NOC, that spent significantly more time turning their head than SWOC (p = 0.006). Rectal temperature and haematological variables were not affected by treatments. The increase in the frequency of agonistic behaviours and duration of locomotion behaviours in ewes treated with predators’ faeces, allow us to conclude that ewes respond to fox and wild boar’s faeces exposure with a similar aversive behavioural repertoire. Also, ewes displayed some physiological responses although these responses cannot be attributed to the odour of predators.

The effect of deep straw versus cubicle housing on behaviour during the dry period in Holstein cows

The present observational study assessed the effect of deep straw bedding compared to cubicles during the dry period on lying-, feeding- and agonistic behaviour in Holstein cows. A total of 74 primi- (heifers) and multiparous cows were moved either onto deep straw bedding (DS) or into cubicle housing (CS) 4 wk before the expected calving date and were observed for 21 consecutive days. Throughout the 21 d lying time and the number of lying bouts were recorded using automated accelerometers while feeding time, the number of feeder visits and feed intake was recorded using automatic feed bins. All variables were averaged by week. The transition time from lying to standing was obtained by averaging five randomly selected standing up events on d 7 prior to the actual calving date while the number of failed standing attempts was obtained by following the cows standing up bouts throughout all of d 7 prior to the actual calving date. The frequency of agonistic behaviour was obtained from 7 h of continuous video recordings on d 21 and 7 (or 8) before the actual calving date. Lying time was not affected by treatment but DS cows had a higher number of lying bouts and a shorter transition time between lying and standing compared to CS cows. Primiparous cows had a higher number of lying bouts compared to multiparous cows. There were no treatment differences in feeding behaviour but multiparous cows spent more time feeding and increased their feed intake more across weeks compared to primiparous cows. Cows housed in DS initiated more agonistic behaviour compared to CS cows at d 7 (or 8) before calving while no difference between treatments was seen at 21 d before calving. These results suggest that deep straw bedding facilitates the transition between lying and standing but may increase agonistic behaviour.

Hierarchical structure and the influence of individual attributes in the captive squirrel monkey (Saimiri collinsi)

The dominance structure of primate social groups varies widely. In addition to the groups' composition, intrinsic attributes such as sex, body size and life experience are important factors that can affect hierarchical dominance relations. All primates are social animals, and the social environment has a direct influence on the physiological conditions of vital systems such as immunological, reproductive and cardiovascular systems. In this study, we analyze the hierarchical structure of Saimiri collinsi in captivity, including the hierarchical structure type, the influence of individual intrinsic characteristics (sex, age, weight and origin-born in captivity or in the wild) based on the prior-attributes model, the relation between agonistic behavior frequency and hierarchical position, and hierarchy steepness, which represents the dominance gradient. We found that the group order was characterized by a partial hierarchy: a dominance position could be occupied by more than one individual simultaneously, including individuals of both sexes. Intrinsic characteristics had no influence on hierarchical structure, with the exception of the male in the highest hierarchical position, which had a markedly larger body than all other group members. Thus, the prior-attributes model did not apply to hierarchical formation of S. collinsi in captivity. Only the frequency of agonistic behavior of males correlated with their hierarchical position, and they differed from all other group members in their more aggressive behavior. The steepness between adjacent positions along the dominance gradient was significant only between the dominant male and the next individual in the group, with a smooth gradient between the other positions in the rank. As the access to resources is directly related to hierarchical dominance, a smooth dominance gradient is to be expected in species that form very large groups, such as wild Saimiri populations.

Influence of seasonality and stimulus of oestrous does in bucks’ aggressiveness

Aggressiveness is directly related to testosterone concentration, which varies with seasons and in response to female stimulation. The aim was to determine if the frequency and pattern of agonistic interactions between bucks varies seasonally and in response to oestrous female stimulation. In the first study we characterized the pattern of agonistic interactions during feeding throughout a whole year in groups of Iberian ibex bucks; and in the second study, we determined the influence of oestrous does on the frequencies of agonistic behaviours between Gabon bucks in different seasons. In Iberian ibex bucks, the frequency of agonistic behaviours was maximum in summer and testosterone concentration in late autumn. In Gabon bucks, total agonistic interactions increased in bucks stimulated by females in late summer and autumn. In late autumn there were more interactions without physical contact in stimulated than in isolated bucks. Aggressiveness in bucks varied along the year, but the seasonal pattern was related to the context in which behaviours were recorded. Stimulation with oestrous females induced an increase of aggressiveness during the breeding season. At least in the conditions of these studies, testosterone concentrations seemed not to be the main influence on the frequency in which aggressive behaviour was displayed.

Pair formation, home range, and spatial variation in density, size and social status in blotched foxface Siganus unimaculatus on an Okinawan coral reef.

The present study examined pair formation, spatial pattern of home range and spatial variation in density, size and social status of blotched foxface Siganus unimaculatus (family Siganidae) on an Okinawan coral reef. Of 32 pairs sampled for sexing, 31 (96.9%) were heterosexual and showed size-assortative pairing. Developed ovaries were found in April and July, whereas oocytes were immature in August, September and February. Heterosexual pairing was found in both reproductive and non-reproductive periods. Home range size tended to be positively related to fork length (FL). The degree of home range overlap for same size class pairs was smaller than that for different size class pairs. The intraspecific behavior when two pairs approached each other was categorized as ‘attack,’ ‘agonistic display’ and ‘no interactions,’ and the frequency of agonistic behaviors (“attack” or “agonistic display”) was significantly greater than “no interactions.” Underwater observations at a seagrass bed, a rocky reef flat and a sheltered reef slope revealed that the mean FL was significantly smaller at the sheltered reef slope (4–13 cm) than at the rocky reef flat (>13 cm). No individuals were found in the seagrass bed. Most individuals less than 6 cm FL were solitary, whereas most individuals over 7 cm FL were paired. Density was significantly greater on the sheltered reef slope than on the rocky reef flat.

Subcutaneous dye injection for marking and identification of individual adult zebrafish (Danio rerio) in behavioral studies

The zebrafish is increasingly utilized in behavioral brain research, as it offers a useful compromise between system complexity and practical simplicity. However, a potential drawback of this species in behavioral research is that individuals are difficult to distinguish. Here we describe a simple marking procedure, subcutaneous injection of color dyes, that may alleviate this problem. The procedure allowed us to successfully mark zebrafish and distinguish them for a period of more than 30 days, which is sufficiently long for most behavioral paradigms developed for this species. In addition, we also provide data suggesting that the injection-based marking does not significantly alter social interaction, as defined by the frequency of agonistic behaviors within shoals.

Measuring mating competition correctly: available evidence supports operational sex ratio theory

AbstractCentral to sexual selection theory is the question of when individuals should compete for mates. Theory predicts that the sex ratio of ready-to-mate individuals (operational sex ratio; OSR) affects male and female mating competition. In accordance with this, the strength of mating competition, measured by agonistic behaviors and courtship displays, has been found to co-vary with the OSR in field populations of several species. However, laboratory experiments have often produced results that seemingly contradict OSR theory, especially for courtship behavior. We argue that this may be because experiments typically measure frequencies of competitive behaviors. Frequencies of courtship and agonistic behavior are not only affected by the level of mating competition, but also by the number of potential mates or competitors encountered. In contrast, the propensity to behave competitively at a given encounter represents a behavioral response, and thus directly reflects mating competition. We show in 2 simple models that 1) courtship frequency can be expected to respond differently from courtship propensity to changes in OSR and 2) an increase in frequency of agonistic behaviors could occur even if the propensity is not affected by the OSR. In a meta-analysis of studies on courtship competition, we show that frequency measures produced largely opposite results to propensity measures, as predicted by our model. Moreover, courtship propensity increased when the OSR became more biased toward competitors. This presents strong evidence that the OSR affects competition, in the form of courtship, as predicted by OSR theory.

Social Environment and Agonistic Interactions: Strategies in a Small Social Mammal

In group-living species, the development of agonistic interactions among conspecifics may be affected by socio-ecological factors, such as size and composition of social group, and availability of nests and food. We analysed the importance of size and composition of social groups on agonistic interactions among males in the Southern mountain cavy (Microcavia australis). We made behavioural observations in four social groups of different size and composition. We recorded two types of agonistic interactions: agonistic displays and direct agonistic behaviours; both types increased in the breeding season. A social group composed of a high number of males was associated with high frequency of agonistic displays. Direct agonistic behaviours were also influenced by the interaction of season and number of males per social group and number of females per social group. Agonistic interactions were also recorded among males of different socials groups in the breeding season. Agonistic displays were most frequent among males of the same social group, whereas direct agonistic behaviours were most common among males of different social groups. These results suggest that social factors affect agonistic interactions among males of Southern mountain cavy and that in a conflict situation, males develop different strategies, such as increased frequency of agonistic behaviours in breeding season and intragroup cooperation for defence of oestrous females.

Mating group composition influences somatic costs and activity in rutting dominant male reindeer (Rangifer tarandus)

In polygynous species, males devote considerable effort to reproduction during the rut. Both the number of females in the mating group and the ratio of sexually mature males to sexually mature females [adult sex ratio (ASR)] are expected to affect the amount of effort a male devotes to reproductive activities. We predicted the reproductive effort of dominant male reindeer, measured as relative mass loss, proportions of active reproductive behaviors, and frequencies of agonistic behaviors would (1) increase with an increasing number of females in the mating group and eventually level off, and (2) exhibit a dome shape with respect to ASR in the mating group. We tested these predictions using 12 years of data collected from semi-domesticated reindeer in northern Finland. We found a positive relationship between relative mass loss and the mean number of females in the mating group for mature, but not young males. The relationship between the proportion of active reproductive behaviors performed by mature males and the mean number of females in the group was quadratic while agonistic behaviors of mature males increased with the increasing female group size. We also found that active reproductive behaviors decreased with a rising mating group ASR for mature males; whereas, young males performed more agonistic behaviors as group ASR increased. Our results point to age-specific patterns of mass loss and activity during the mating season. They also indicate that both the number of females and ASR in the mating group are important factors in determining the level of reproductive effort of dominant male reindeer.

Relationship between milk cortisol concentration and the behavioral characteristics of postpartum cows introduced to a new group

The objective of this study was to examine the relationship between milk cortisol concentration (MC) and behavioral responses to stress. As a stress response, the behaviors of 37 postpartum cows were observed when they were introduced into a new group. Milk samples for MC measurement and milk trait data were collected on the test day every 2 months after calving. The best linear unbiased prediction (BLUP) was estimated from each behavioral and milk trait data. Behavioral BLUP data were subjected to principal component (PC) analysis and three PCs were extracted. The first PC, with large loadings for eating and allogrooming, was positively correlated with milk yield. Therefore, individual differences in behaviors closely related with PC1 would have been unconsciously paid a lot of attention in terms of productivity. However, the second PC, with large loadings for drinking and self-grooming, uncorrelated with any milk traits, had a negative correlation with MC. The third PC, with large loadings for exploring, fighting and the frequency of agonistic behavior, was uncorrelated with all traits. Both PC2 and PC3 were independent of productivity, and individual differences in behaviors related with these PCs may be scarcely considered.

Levels of social tolerance between snow volesChionomys nivalis during over-wintering periods

We examined winter social behaviour of the snow voleChionomys nivalis Martins, 1842, a rock-dwelling microtine found principally in high-mountain biotopes. We conducted dyadic encounters among wild-caughtC. nivalis to determine patterns of intraspecific tolerance and the degree of aggressiveness between and within sexes during wintering periods. Our data show a high frequency of agonistic behaviours in all social encounters. Male pairs spent less time being aggressive than female pairs but more time in investigative behaviours. In contrast, the intensity of aggression displayed during interactions was significantly higher in male-male encounters than in female-female encounters, with an intermediate level of aggression in male-female encounters. The low degree of social tolerance found seems to be in agreement with the available data on the social organization of this species and further suggests that individuals may not spatially associate during over-wintering periods. Although both males and females were socially intolerant, the different patterns observed between the sexes may underlie different strategies.

Territorial behavior of Bearded Vultures in response to Griffon Vultures

Griffon Vultures (Gyps fulvus) are responsible for most cases of usurpation of nests of Bearded Vultures (Gypaetus barbatus). However, little is known about how both species interact during reproduction. We studied territorial behaviour during the breeding season in four Bearded Vulture pairs in the eastern Pyrenees of northeastern Spain. Frequency of agonistic behavior was positively correlated with Griffon Vulture colony size. However, no significantly higher frequency of aggressive interactions was found that suggested actual competition for nest sites between these species. Nonetheless, Bearded Vulture pairs maintained a continuous defence of the area immediately surrounding their nests throughout the breeding season. Our data suggest that the Bearded Vulture's territorial behavior was more closely associated with defence of breeding space than with specific defence of actual nest sites.

Individual recognition in the Damaraland mole‐rat, Cryptomys damarensis (Rodentia: Bathyergidae)

Conspecific recognition was investigated in the eusocial and subterranean Damaraland mole-rat Cryptomys damarensis. This species out-breeds and is xenophobic. Differences in the frequency of agonistic behaviours between male–male pairs were used as an indication of recognition. Focal males were tested with familiar, unfamiliar, and foreign conspecifics. Males directed significantly more aggression towards unfamiliar colony mates and foreign conspecifics than towards familiar colony mates. This happened even though both focal and test animals retained contact with their natal colonies and, therefore, any group cue. Furthermore, when male–male pairs were returned to their natal colonies they continued directing aggression towards each other but not towards the rest of the colony. These results suggest that the Damaraland mole-rat uses individually distinct cues rather than kin-specific cues based on genetic relatedness.

Individual recognition in the Damaraland mole-rat, Cryptomys damarensis (Rodentia: Bathyergidae)

Conspecific recognition was investigated in the eusocial and subterranean Damaraland mole-rat Cryptomys damarensis. This species out-breeds and is xenophobic. Differences in the frequency of agonistic behaviours between male–male pairs were used as an indication of recognition. Focal males were tested with familiar, unfamiliar, and foreign conspecifics. Males directed significantly more aggression towards unfamiliar colony mates and foreign conspecifics than towards familiar colony mates. This happened even though both focal and test animals retained contact with their natal colonies and, therefore, any group cue. Furthermore, when male–male pairs were returned to their natal colonies they continued directing aggression towards each other but not towards the rest of the colony. These results suggest that the Damaraland mole-rat uses individually distinct cues rather than kin-specific cues based on genetic relatedness.

Mother — Offspring Conflict in the Saharan Arrui, Ammotragus lervia sahariensis: Relation to Weaning and Mother's Sexual Activity

AbstractBehavioural conflict between mother and offspring was investigated in a captive population of the Saharan arrui (Ammotragus lervia sahariensis, Artiodactyla: Bovidae). The frequency of agonistic behaviours (mother's aggressiveness and calf's retreats) and unsuccessful suckling attempts, Hinde's proximity index and the distances between mother and calf have been analysed in relation to weaning and sexual activity of the mother. Mothers that conceive in the following mating season accelerate the weaning process of their current offspring; furthermore, high‐ranking females wean their male calves earlier. Behavioural conflict occurs during the resumption of the mother's sexual activity; however, no conflict appears to happen during weaning.

Social interactions in N'dama cows during periods of idling and supplementary feeding post-grazing

Thirty N'dama cows were observed post-grazing, during periods of idling (NF) and periods of supplementary feeding (F), over a 1-year period to determine the frequency and pattern of social interactions during 1 h each of feeding and idling. Agonistic interactions (butting, threatening and avoidance) were 1.4 times higher ( P<0.01) in the F than the NF. In contrast, amicable behaviours (rubbing, sniffing and grooming) were significantly ( P<0.05) higher in the NF than F. The frequency of agonistic interactions was highest during the first 30 min of the F when feed was available. There was no trend in the frequency of either agonistic or amicable behaviours during the NF. During the first 15 min of the F, animals initiated no amicable behaviours, but thereafter amicable behaviours sharply increased until the end of the period. Season (dry and rainy) had no influence on frequency of agonistic behaviours but grooming, and thus all amicable behaviours combined, were significantly ( P<0.05) higher in the rainy rather than dry season. As butting areas, animals preferred the sides (39–42%) and rear of companion animals (25–28%). Social dominance was highly correlated with liveweight ( r=0.828−0.884) and age ( r=0.664−0.754); this was not linear, and tended to be complex. High-ranking animals initiated most, but received few, agonistic interactions. Agonistic interactions were generally between animals close in rank or with subordinates. There was no significant ( P>0.05) relationship between number of animals dominated and amicable behaviours initiated or received.