Dominance relationships among siamang males living in multimale groups

2015 ◽  
Vol 78 (3) ◽  
pp. 288-297 ◽  
Author(s):  
Luca Morino
Keyword(s):  
Dominance Relationships ◽  
Multimale Groups

scholarly journals Dominance relationships and coalitionary aggression against conspecifics in female carrion crows

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Benedikt Holtmann ◽  
Julia Buskas ◽  
Matthew Steele ◽  
Kristaps Solokovskis ◽  
Jochen B. W. Wolf
Keyword(s):  
Social Interactions ◽  
Social Environment ◽  
Social Rank ◽  
Social Benefits ◽  
Same Sex ◽  
The Third ◽  
Dominance Relationships ◽  
Dominant Individual ◽  
The Individual

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.

scholarly journals Studies on the Role of the are a Gene in the Regulation of Nitrogen Catabolism in Aspergillus nidulans

1975 ◽  
Vol 28 (3) ◽  
pp. 301 ◽  
Author(s):  
MJ Hynes
Keyword(s):  
Nitrogen Source ◽  
Aspergillus Nidulans ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Selection Methods ◽  
Growth Responses ◽  
Dominance Relationships ◽  
Regulatory Circuits ◽  
Specific Activities

Mutants of Apergillus nidulanswith lesions in a gene, areA (formerly called amdT), have been isolated by a variety of different selection methods. The areA mutants show a range of pleiotropic growth responses to a number of compounds as sole nitrogen sources, but are normal in utilization of carbon sources. The levels of two amidase enzymes as well as urease have been investigated in the mutants and have been shown to be affected by this gene. Most of the areA mutants have much lower amidase-specific activities when grown in ammonium-containing medium, compared with mycelium incubated in medium la9king a nitrogen source. Some of the areA. mutants do not show derepression of urease upon relief of ammonium repression. The dominance relationships of areA alleles have been investigated in� heterozygous diploids, and these studies lend support to the proposal that areA codes for a positively acting regulatory product. One of the new areA alleles is partially dominant to areA + and areA102. This may be a result of negative complementation or indicate that areA has an additional negative reiuIatory function. Investigation.of various amdR; areA double mutants has led to the conclusion that amdR and areA participate in independent regulatory circuits in the control of acetamide utilizatiol1. Studies on an amdRc; areA.double mutant indicate that areA is involved in derepression of acetamidase upon relief of ammo.nium repression.

Monopoly Regulation Under Relaxed Pareto Efficiency

2017 ◽  
Vol 5 (2) ◽  
pp. 162-176
Author(s):  
Ismail Saglam
Keyword(s):  
Marginal Cost ◽  
Regulatory Environment ◽  
Pareto Dominance ◽  
Incentive Compatible ◽  
Monopoly Regulation ◽  
Dominance Relationships ◽  
Ex Post ◽  
Ex Ante ◽  
Pareto Axiom ◽  
Set Of Points

Baron and Myerson (BM; 1982, Econometrica, 50(4), 911–930) propose an incentive-compatible, individually rational and ex ante socially optimal direct-revelation mechanism to regulate a monopolistic firm with unknown costs. Their mechanism is not ex post Pareto dominated by any other feasible direct-revelation mechanism. However, there also exist an uncountable number of feasible direct-revelation mechanisms that are not ex post Pareto dominated by the BM mechanism. To investigate whether the BM mechanism remains in the set of ex post undominated mechanisms when the Pareto axiom is slightly weakened, we introduce the ∈-Pareto dominance. This concept requires the relevant dominance relationships to hold in the support of the regulator’s beliefs everywhere except for a set of points of measure ∈, which can be arbitrarily small. We show that a modification of the BM mechanism which always equates the price to the marginal cost can ∈-Pareto dominate the BM mechanism at uncountably many regulatory environments, while it is never ∈-Pareto dominated by the BM mechanism at any regulatory environment.

Environmental influence on maturation and dominance relationships in the three-spined stickleback (Gasterosteus aculeatus L.): temperature competes with photoperiod for primacy

2009 ◽  
Vol 38 (4) ◽  
Author(s):  
Ewa Sokołowska ◽  
Ewa Kulczykowska
Keyword(s):  
High Temperature ◽  
Visual Information ◽  
Gasterosteus Aculeatus ◽  
Environmental Influence ◽  
Gonadal Development ◽  
Constant Darkness ◽  
Dominance Relationships ◽  
Final Maturation ◽  
Maturation Rate ◽  
Spawning Periods

Environmental influence on maturation and dominance relationships in the three-spined stickleback (In this study, the influence of a combination of different photoperiods and temperatures on the final maturation and social interactions in three-spined sticklebacks was investigated. Water temperature appears to be the principal signal affecting gonadal development and breeding activity of sticklebacks in pre-spawning and spawning periods. Males can mature independently of photoperiod and a stimulatory effect of high temperature is not diminished by light deprivation. On the other hand, low temperature can inhibit the development of secondary sexual characters in males exposed to long day or constant light. In females, lighting seems to be more decisive for complete maturation and the lack of light delays the maturation rate, even in high temperature. While kept under the same conditions, males mature quicker than females. The presence of light and visual information are crucial to establish the social position of individuals in the group. In light, a rigid social hierarchy with one dominant, sexually active male is observed. In constant darkness, however, several males in the group demonstrate every sign of sexual activity.

FEMALE DOMINANCE RELATIONSHIPS AMONG CAPTIVE WESTERN LOWLAND GORILLAS: COMPARISONS WITH THE WILD

Behaviour ◽  
1999 ◽  
Vol 136 (10-11) ◽  
pp. 1283-1310 ◽  
Author(s):  
Joan Lockard ◽  
Jennifer Scott
Keyword(s):  
Natural Habitat ◽  
High Energy ◽  
Gorilla Gorilla ◽  
Female Dominance ◽  
Primate Species ◽  
Dominance Hierarchies ◽  
Mountain Gorillas ◽  
Dominance Relationships ◽  
Western Lowland Gorillas ◽  
Lowland Gorillas

AbstractFemale dominance relationships were studied among three family groups of western lowland gorillas (Gorilla gorilla gorilla) housed in large enclosures at Howletts Wild Animal Park, in Kent, England. In common with gorillas in their natural habitat, the Howletts gorillas forage throughout the day on low nutrient foods. However, the latter differ, at least from mountain gorillas (Gorilla gorilla beringei), in that they also have relatively frequent access to high nutrient, high energy novel food items which are patchily distributed in time and space, and defendable. It was predicted that, despite these differences, the Howletts females would resemble mountain gorillas in forming adult female dominance hierarchies (determined from supplant interactions) in which older females that have lived in the group the longest are dominant to younger females, more recent to the group. The comparison was made with mountain gorillas as they are the only gorilla subspecies for which such data exist for wild-living populations. As predicted, an age/tenure-based dominance hierarchy was found to be the case for those groups at Howletts where there was considerable variation between the females' ages and length of group tenure. As gorillas and chimpanzees resemble more closely each other in forming age/tenure-based dominance hierarchies than they do other female-transfer primate species, it is proposed that the gorilla-chimpanzee pattern may have common phylogenetic origins. In addition, the order of progression of gorillas into their indoor living quarters appears to be a good indicator of supplant-dominance relationships among adult group members. It was also found that, despite being removed from their natural habitat, dominant males in captivity still lead their groups during group travel in the same manner that do males in the wild: either at the head, or bringing up the rear. Though primate social behaviour may be flexible depending on immediate context and life history variables, this flexibility may well remain within evolutionarily defined parameters, leading to species-typical patterns in general social interactions.

scholarly journals Dominance relationships in a family pack of captive arctic wolves (Canis lupus arctos): the influence of competition for food, age and sex

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2707 ◽  
Author(s):  
Simona Cafazzo ◽  
Martina Lazzaroni ◽  
Sarah Marshall-Pescini
Keyword(s):  
Quantitative Methods ◽  
Social Dynamics ◽  
Dominance Relationships ◽  
The Social ◽  
Systematic Methodology ◽  
The Hierarchical Structure ◽  
Competition For Food ◽  
Linear Hierarchies ◽  
Feeding Context ◽  
Age And Sex

BackgroundDominance is one of the most pervasive concepts in the study of wolf social behaviour but recently its validity has been questioned. For some authors, the bonds between members of wolf families are better described as parent-offspring relationships and the concept of dominance should be used just to evaluate the social dynamics of non-familial captive pack members (e.g., Mech & Cluff, 2010). However, there is a dearth of studies investigating dominance relationships and its correlates in wolf family packs.MethodsHere, we applied a combination of the most commonly used quantitative methods to evaluate the dominance relationships in a captive family pack of 19 Arctic wolves.ResultsWe found a significant linear and completely transitive hierarchy based on the direction of submissive behaviours and found that dominance relationships were not influenced by the competitive contexts (feeding vs. non-feeding context). A significant linear hierarchy also emerges amongst siblings once the breeding pair (the two top-ranking individuals) is removed from analyses. Furthermore, results suggest that wolves may use greeting behaviour as a formal signal of subordination. Whereas older wolves were mostly dominant over younger ones, no clear effect of sex was found. However, frequency of agonistic (submissive, dominant and aggressive) behaviours was higher between female–female and male–male dyads than female–male dyads and sex-separated linear hierarchies showed a stronger linearity than the mixed one. Furthermore, dominance status was conveyed through different behavioural categories during intra-sexual and inter-sexual interactions.DiscussionCurrent results highlight the importance of applying a systematic methodology considering the individuals’ age and sex when evaluating the hierarchical structure of a social group. Moreover, they confirm the validity of the concept of dominance relationships in describing the social bonds within a family pack of captive wolves.

scholarly journals A Mating Selection Based on Modified Strengthened Dominance Relation for NSGA-III

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2837
Author(s):  
Saykat Dutta ◽  
Sri Srinivasa Raju M ◽  
Rammohan Mallipeddi ◽  
Kedar Nath Das ◽  
Dong-Gyu Lee
Keyword(s):  
Pareto Front ◽  
State Of The Art ◽  
Weight Vector ◽  
Dominance Relation ◽  
Additional Parameter ◽  
Pareto Dominance ◽  
Environmental Selection ◽  
Dominance Relationships ◽  
Test Suites ◽  
Selection Of

In multi/many-objective evolutionary algorithms (MOEAs), to alleviate the degraded convergence pressure of Pareto dominance with the increase in the number of objectives, numerous modified dominance relationships were proposed. Recently, the strengthened dominance relation (SDR) has been proposed, where the dominance area of a solution is determined by convergence degree and niche size (θ¯). Later, in controlled SDR (CSDR), θ¯ and an additional parameter (k) associated with the convergence degree are dynamically adjusted depending on the iteration count. Depending on the problem characteristics and the distribution of the current population, different situations require different values of k, rendering the linear reduction of k based on the generation count ineffective. This is because a particular value of k is expected to bias the dominance relationship towards a particular region on the Pareto front (PF). In addition, due to the same reason, using SDR or CSDR in the environmental selection cannot preserve the diversity of solutions required to cover the entire PF. Therefore, we propose an MOEA, referred to as NSGA-III*, where (1) a modified SDR (MSDR)-based mating selection with an adaptive ensemble of parameter k would prioritize parents from specific sections of the PF depending on k, and (2) the traditional weight vector and non-dominated sorting-based environmental selection of NSGA-III would protect the solutions corresponding to the entire PF. The performance of NSGA-III* is favourably compared with state-of-the-art MOEAs on DTLZ and WFG test suites with up to 10 objectives.

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