scholarly journals Novel competition test for food rewards reveals stable dominance status in adult male rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diana F. Costa ◽  
Marta A. Moita ◽  
Cristina Márquez

AbstractSocial hierarchy is a potent modulator of behavior, that is typically established through overt agonistic interactions between individuals in the group. Once established, social ranks are maintained through subtler interactions allowing the redirection of energy away from agonistic interactions towards other needs. The available tasks for assessing social rank in rats allow the study of the mechanisms by which social hierarches are formed in early phases but fail to assess the maintenance of established hierarchies between stable pairs of animals, which might rely on distinct neurobiological mechanisms. Here we present and validate a novel trial-based dominancy assay, the modified Food Competition test, where established social hierarchies can be identified in the home cage of non-food deprived pairs of male rats. In this task, we introduce a small conflict in the home cage, where access to a new feeder containing palatable pellets can only be gained by one animal at a time. We found that this subtle conflict triggered asymmetric social interactions and resulted in higher consumption of food by one of the animals in the pair, which reliably predicted hierarchy in other tests. Our findings reveal stable dominance status in pair-housed rats and provide a novel tool for the evaluation of established social hierarchies, the modified Food Competition test, that is robust and easy to implement.

2020 ◽  
Author(s):  
Diana F Costa ◽  
Marta A Moita ◽  
Cristina Márquez

ABSTRACTSocial hierarchy is a potent modulator of behavior in many species, including humans, that is typically established through overt agonistic interactions between individuals in the group. Once established, social ranks are maintained through subtler interactions allowing the redirection of energy away from agonistic interactions towards other needs. Most of the available tasks for assessing social rank in rodents allow the study of the mechanisms by which social hierarches are formed but fail to assess the maintenance of established hierarchies between stable pairs of animals, which might rely on distinct neurobiological mechanisms. Here we present and validate a novel trial-based dominancy assay, the modified Food Competition test, where established social hierarchies can be identified in the home cage of non-food deprived pairs of male rats. In this task, we introduce a small conflict in the home cage, where access to a new feeder containing palatable pellets can only be gained by one animal at a time. We found that this subtle conflict triggered asymmetric social interactions and resulted in higher consumption of food by one of the animals in the pair. To assess the reliability of the observed asymmetries as reflecting dominance relationships we investigated the behavior of same rat dyads in multiple social tasks adapted from social hierarchy studies. We found a positive correlation in dominance indices across most tests used. Our findings reveal stable dominance status in pair housed rats and provide a novel tool for the evaluation of established social hierarchies, the modified Food Competition test, that is robust and easy to implement, thus expanding the set of tasks available to study dominance in the lab.


2017 ◽  
Vol 26 (6) ◽  
pp. 526-531 ◽  
Author(s):  
Jon K. Maner

Dominance and prestige represent evolved strategies used to navigate social hierarchies. Dominance is a strategy through which people gain and maintain social rank by using coercion, intimidation, and power. Prestige is a strategy through which people gain and maintain social rank by displaying valued knowledge and skills and earning respect. The current article synthesizes recent lines of research documenting differences between dominance- versus prestige-oriented individuals, including personality traits and emotions, strategic behaviors deployed in social interactions, leadership strategies, and physiological correlates of both behaviors. The article also reviews effects that dominance versus prestige have on the functioning and well-being of social groups. The article also presents opportunities for future research and discusses links between dominance and prestige and the social psychological literature on power and status.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Benedikt Holtmann ◽  
Julia Buskas ◽  
Matthew Steele ◽  
Kristaps Solokovskis ◽  
Jochen B. W. Wolf

Abstract Cooperation is a prevailing feature of many animal systems. Coalitionary aggression, where a group of individuals engages in coordinated behaviour to the detriment of conspecific targets, is a form of cooperation involving complex social interactions. To date, evidence has been dominated by studies in humans and other primates with a clear bias towards studies of male-male coalitions. We here characterize coalitionary aggression behaviour in a group of female carrion crows consisting of recruitment, coordinated chase, and attack. The individual of highest social rank liaised with the second most dominant individual to engage in coordinated chase and attack of a lower ranked crow on several occasions. Despite active intervention by the third most highly ranked individual opposing the offenders, the attack finally resulted in the death of the victim. All individuals were unrelated, of the same sex, and naïve to the behaviour excluding kinship, reproduction, and social learning as possible drivers. Instead, the coalition may reflect a strategy of the dominant individual to secure long-term social benefits. Overall, the study provides evidence that members of the crow family engage in coordinated alliances directed against conspecifics as a possible means to manipulate their social environment.


1980 ◽  
Vol 58 (3) ◽  
pp. 461-463 ◽  
Author(s):  
R. E. Salter

Social interactions in walrus herds of mixed sex and age composition were recorded at a haul-out site on the east coast of Bathurst Island, N.W.T., during July–August 1977. Most walruses maintained body contact with at least one other walrus while hauled out on land; herds were usually circular in shape. Adult males, adult females, and immatures all displaced other walruses, and thus entered herds, by jabbing with the tusks. Dominance during agonistic interactions was related to relative tusk length and sex and age of interactants. Behaviour of walruses on land suggested an energetic advantage in mutual body contact, which would be maximized by occupation of interior positions within herds.


2018 ◽  
Vol 41 ◽  
pp. 13-18
Author(s):  
Olav Hogstad ◽  
Tore Slagsvold

The Willow Tit Poecile montanus is highly sedentary and breeding pairs remain in their exclusive areas throughout the year. During the winter, these areas are defended by small, non-kin flocks, formed as the roaming yearlings become sedentary and join adults during late summer and autumn. Once established, stable social hierarchies are maintained in these flocks during the winter. The winter flocks consist normally of the socially dominant adult mated pair and two mated juvenile pairs, one higher-ranked and one lower-ranked. Individually colour-ringed juvenile Willow Tits were followed over years in subalpine forest in Norway from ringing in the autumn till they disappeared. None of the lower ranked birds survived their first winter, whereas only 4 of 71 higher-ranked juvenile pairs disappeared during this time. Half of the 71 pairs survived their first winter, about 25 % survived two winters, 8.5% survived three winters, and 5.6% survived four winters. Survival was similar for males and females. Alpha pairs remained mated and defended their common territory across years. Maximum age as revealed by ringing showed one female became six years old and two males ringed as adults were at least nine years old when last observed. The main factor associated with survival was early flock establishment that led to a high rank position among the juvenile flock members. Body size seemed insignificant. Birds that survived their first winter either succeeded to establish as territory owners or they were forced into the role as floaters and probably perished.


2014 ◽  
Vol 14 (2) ◽  
pp. 365-375 ◽  
Author(s):  
Marcin T. Górecki ◽  
Natalia Dziwińska

Abstract The aim of this study was to recognize features determining social hierarchy in Wrzosówka Polska ewes kept indoors as well as to investigate their resting place and companionship preferences. Observations (156 hours in total) were carried out in a group of 22 ewes. The social rank of sheep was determined by their age, body weight and length of horns. Social position was positively correlated with aggressive behaviour performed and negatively with aggressive behaviour received. Use of space while resting was influenced by ewe social behaviour; aggressive individuals lied more often in attractive places, namely against walls and fodder troughs compared to other animals. In general, the ewes rested by having physical contact with animals of similar rank and aggressiveness. Kinship appeared not to be important in neighbour preference. As can be concluded, social interactions influenced the use of space and neighbourhood in ewes


Ranking ◽  
2019 ◽  
pp. 42-64
Author(s):  
Péter Érdi

This chapter studies how social ranking in humans emerged as the result of an evolutionary process. It starts with the story of the discovery of pecking order among chickens by a Norwegian boy. Both animals and humans need a healthy balance between cooperation and competition to ensure evolutionarily efficient strategies. The biological machinery behind social ranking is discussed. There are two distinct mechanisms for navigating the social ladder: dominance and prestige. Dominance, an evolutionarily older strategy, is based on the ability to intimidate other members in the group by physical size and strength. The group members don’t accept dominance-based social rank freely, only by coercion. Members of a colony fight, and the winners of these fights will be accepted as “dominants” and the losers as “subordinates.” The naturally formed hierarchy serves as a way to prevent superfluous fighting and injuries within a colony. Prestige, as a strategy, is evolutionarily younger and is based on skills and knowledge as appraised by the community. Prestige hierarchies are maintained by the consent of the community, without pressure being applied by particular members. The mechanisms of forming and maintaining social hierarchies are described. Social structures, both hierarchies and network organizations, are reviewed. Discussion of these structures is carried over to social and political history and the tension between democracy and authoritarianism.


2020 ◽  
Vol 87 (S1) ◽  
pp. 144-147
Author(s):  
Susanne Waiblinger ◽  
Kathrin Wagner ◽  
Edna Hillmann ◽  
Kerstin Barth

AbstractThe aim of the study reported in this Research Communication was to compare play behaviour and social interactions of dairy calves either separated from their mother and reared in a calf group (Artificial) or with access to their mother and the cow herd (cow-calf contact: Contact). Contact calves had access to a calf area and also to the cow barn where they could suckle their dam. Artificial calves were fed whole milk up to 16 kg per day via an automatic milk feeder and were only kept in the calf area. We observed the animals on 3 d during the first three months of life. Contact calves showed solitary play, consisting predominantly of locomotor play, for longer than Artificial calves and mainly in the cow barn. This indicates higher welfare in Contact calves. In addition, Artificial calves hardly experienced any agonistic interaction, while Contact calves both initiated and received agonistic interactions, which might contribute to the development of higher social competence.


2015 ◽  
Vol 11 (6) ◽  
pp. 20150307 ◽  
Author(s):  
Diego Astúa ◽  
Rafael A. Carvalho ◽  
Paula F. Maia ◽  
Arthur R. Magalhães ◽  
Diogo Loretto

The Didelphidae are considered solitary opossums with few social interactions, usually limited to mating-related or mother–pouch young interactions. Anecdotal reports suggest that additional interactions occur, including den sharing by a few individuals, usually siblings. Here, we report novel observations that indicate opossums are more social than previously thought. These include nest sharing by males and females of Marmosa paraguayana , Gracilinanus microtarsus and Marmosops incanus prior to the onset of the breeding season and without signs of sexual activity; this is taken to indicate early pair-bonding matching and cooperative nest building. We also recorded den sharing among recently weaned siblings of Didelphis aurita and Caluromys philander . In addition, we observed 13 individuals of Didelphis albiventris representing three age classes resting without agonistic interactions in a communal den. These are the first reports of gregarious behaviour involving so many individuals, which are either unrelated or represent siblings from at least two litters, already weaned, sharing the same den with three adults. Sociality in opossums is probably more complex than previously established, and field experimental designs combining the use of artificial nests with camera traps or telemetry may help to gauge the frequency and extent of these phenomena.


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