scholarly journals Female vervet monkeys fine-tune decisions on tolerance versus conflict in a communication network

2017 ◽  
Vol 284 (1867) ◽  
pp. 20171922 ◽  
Author(s):  
Christèle Borgeaud ◽  
Alessandra Schnider ◽  
Michael Krützen ◽  
Redouan Bshary
Keyword(s):  
Driving Force ◽  
Significant Interaction ◽  
Group Living ◽  
Third Party ◽  
Vervet Monkeys ◽  
Social Strategies ◽  
Trade Off ◽  
Social Species ◽  
Social Opportunities ◽  
Fine Tune

Group living promotes opportunities for both cooperation and competition. Selection on the ability to cope with such opposing social opportunities has been proposed as a driving force in the evolution of large brains in primates and other social species. However, we still know little about the degree of complexity involved in such social strategies. Here, we report advanced social strategies in wild vervet monkeys. Building on recent experimental evidence that subordinate females trade grooming for tolerance from higher-ranking individuals during foraging activities, we show that the audience composition strongly affects this trade. First, tolerance was lower if the audience contained individuals that outranked the subordinate partner, independently of audience size and kinship relationships. Second, we found a significant interaction between previous grooming and relative rank of bystanders: dominant subjects valued recent grooming by subordinates while intermediate ranked subjects valued the option to aggress subordinate partners in the presence of a dominant audience. Aggressors were also more likely to emit coalition recruitment calls if the audience contained individuals that outranked the subordinate partner. In conclusion, vervet monkeys include both recent grooming and knowledge about third-party relationships to make complex decisions when trading grooming for tolerance, leading to a finely balanced trade-off between reciprocation and opportunities to reinforce rank relationships.

scholarly journals Non-random associations in group housed rats (Rattus norvegicus)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Leanne Proops ◽  
Camille A. Troisi ◽  
Tanja K. Kleinhappel ◽  
Teresa Romero
Keyword(s):  
Network Analysis ◽  
Empirical Evidence ◽  
Rattus Norvegicus ◽  
Dominance Hierarchy ◽  
Group Living ◽  
Ecological Factors ◽  
Limited Evidence ◽  
Rat Strains ◽  
Social Species ◽  
Over Time

AbstractEcological factors, such as predation, have traditionally been used to explain sociability. However, it is increasingly recognised that individuals within a group do not associate randomly, and that these non-random associations can generate fitness advantages. The majority of the empirical evidence on differentiated associations in group-living mammals, however, comes from a limited number of taxa and we still know very little about their occurrence and characteristics in some highly social species, such as rats (Rattus spp.). Here, using network analysis, we quantified association patterns in four groups of male fancy rats. We found that the associations between rats were not randomly distributed and that most individuals had significantly more preferred/avoided associates than expected by random. We also found that these preferences can be stable over time, and that they were not influenced by individuals’ rank position in the dominance hierarchy. Our findings are consistent with work in other mammals, but contrast with the limited evidence available for other rat strains. While further studies in groups with different demographic composition are warranted to confirm our findings, the occurrence of differentiated associations in all male groups of rats have important implications for the management and welfare of captive rat populations.

Enhancement of Gripping Efficiency of Miniature Gripper Applying Elastic Buckling Phenomenon by Constraining Deformation

2008 ◽  
Author(s):  
H. Ando ◽  
Y. Takami ◽  
N. Muramatsu
Keyword(s):  
Elastic Deformation ◽  
Driving Force ◽  
Experimental Results ◽  
Elastic Buckling ◽  
Trade Off ◽  
Gripping Force

This paper discusses the enhancement of gripping efficiency of a gripping mechanism for miniature grippers. This gripping mechanism employs a displacement enlarging mechanism utilizing an elastic buckling of the flexible gripping fingers. Miniature grippers have been realized by the flexible gripping fingers acting as the displacement enlarging mechanism. However, there is a trade-off relation between the enlarged displacement and gripping force of the gripping mechanism. For this reason, the enhancement of gripping efficiency of the gripping mechanism has been experimentally attempted by constraining an elastic deformation of the flexible gripping fingers. The flexible gripping fingers are largely deformed due to elastic buckling after gripping an object. This elastic deformation is constrained by supports. Experiments have been conducted for some different cases of placement of the supports. The driving force, driving displacement and gripping force of the gripping mechanism have been measured. From experimental results, it has been confirmed that the enhancement of gripping efficiency of the gripping mechanism is feasible by controlling deformation of the flexible fingers passively.

scholarly journals Third-Party Ranks Knowledge in Wild Vervet Monkeys (Chlorocebus aethiops pygerythrus)

PLoS ONE ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. e58562 ◽  
Author(s):  
Christèle Borgeaud ◽  
Erica van de Waal ◽  
Redouan Bshary
Keyword(s):  
Third Party ◽  
Vervet Monkeys ◽  
Chlorocebus Aethiops

scholarly journals The effects of familiarity and social hierarchy on group membership decisions in a social fish

2009 ◽  
Vol 6 (3) ◽  
pp. 301-303 ◽  
Author(s):  
Lyndon A. Jordan ◽  
Marian Y. L. Wong ◽  
Sigal S. Balshine
Keyword(s):  
Life History ◽  
Decision Process ◽  
Group Membership ◽  
Social Rank ◽  
Group Living ◽  
Social Hierarchy ◽  
Trade Off ◽  
The Social ◽  
Potential Benefits ◽  
Complex Decision

Members of animal groups face a trade-off between the benefits of remaining with a familiar group and the potential benefits of dispersing into a new group. Here, we examined the group membership decisions of Neolamprologus pulcher , a group-living cichlid. We found that subordinate helpers showed a preference for joining familiar groups, but when choosing between two unfamiliar groups, helpers did not preferentially join groups that maximized their social rank. Rather, helpers preferred groups containing larger, more dominant individuals, despite receiving significantly more aggression within these groups, possibly owing to increased protection from predation in such groups. These results suggest a complex decision process in N. pulcher when choosing among groups, dependent not only on familiarity but also on the social and life-history consequences of joining new groups.

Sampling rainfall events: a novel approach to generate large correlated samples

2012 ◽  
Vol 44 (2) ◽  
pp. 351-361 ◽  
Author(s):  
Siao Sun ◽  
Soon-Thiam Khu ◽  
Slobodan Djordjević
Keyword(s):  
Computational Efficiency ◽  
Driving Force ◽  
Group Method ◽  
Marginal Distributions ◽  
Rainfall Events ◽  
Trade Off ◽  
Large Group ◽  
Efficient Generation ◽  
Novel Approach ◽  
Novel Method

It is essential that the correlation between variables is considered properly when using sampling-based methods. Modeling rainfall events is of great interest because the rainfall is usually the major driving force of hydrosystems. A novel method for generating correlated samples is introduced providing that the marginal distributions of variables as well as their correlations between them are known. The basic idea of the method is to adjust the correlations between samples by rearranging the positions inside marginal samples after each marginal sample is generated according to its distribution. The group method is developed in order to facilitate an efficient generation of correlated samples of large sizes. The theoretical precision associated with the group method is derived. There is a trade off between the computational efficiency of the algorithm and the precision that can be achieved when using different numbers of groups. The method is successfully applied to two cases of rainfall sample generation problems. The effectiveness of the group method is studied. Large group numbers are recommended in practical use as the samples distribute more broadly regardless of computational efficiency.

Strategic and tactical fighting decisions in cichlid fishes with divergent social systems

Behaviour ◽  
2014 ◽  
Vol 151 (1) ◽  
pp. 47-71 ◽  
Author(s):  
Kristina Hick ◽  
Adam R. Reddon ◽  
Constance M. O’Connor ◽  
Sigal Balshine
Keyword(s):  
Social Systems ◽  
Cichlid Fish ◽  
Group Living ◽  
Social Situation ◽  
Closely Related Species ◽  
Social Species ◽  
Hierarchy Formation ◽  
Trade Offs ◽  
The Social ◽  
Contest Behaviour

The costs and benefits of engaging in a contest will differ depending on the social situation of the individuals involved. Therefore, understanding contest behaviour can help to elucidate the trade-offs of living in differing social systems and shed light on the evolution of social behaviour. In the current study, we compared contest behaviour in two closely related species of Lamprologine cichlid fish. Neolamprologus pulcher and Telmatochromis temporalis are both pair-breeding cichlids, but N. pulcher are highly social, group-living fish, while T. temporalis display no grouping behaviour. To examine how competition varies by species, sex and familiarity, we staged same-sex conspecific contests over a shelter, a resource that is highly valued by both species, where contestants were either familiar or unfamiliar to one another. When we examined tactical and strategic components of these contests, we found that the highly social species had shorter contests and engaged in fewer costly aggressive acts than did the non-social species. Individuals of the highly social species were also more likely to resolve conflicts through the use of submissive displays, while individuals of the non-social species were more likely to flee from conflict. Familiarity increased the use of submissive displays in the highly social species but not in the less social species. Our findings suggest that conflict resolution behaviour and dominance hierarchy formation are fundamentally linked to the evolution of complex social systems.

scholarly journals Solitary bees reduce investment in communication compared with their social relatives

2017 ◽  
Vol 114 (25) ◽  
pp. 6569-6574 ◽  
Author(s):  
Bernadette Wittwer ◽  
Abraham Hefetz ◽  
Tovit Simon ◽  
Li E. K. Murphy ◽  
Mark A. Elgar ◽  
...  
Keyword(s):  
Social Behavior ◽  
Communication Systems ◽  
Group Membership ◽  
Group Living ◽  
Signal Perception ◽  
Eusocial Insects ◽  
Social Species ◽  
Solitary Living ◽  
Social Animals ◽  
Signal Production

Social animals must communicate to define group membership and coordinate social organization. For social insects, communication is predominantly mediated through chemical signals, and as social complexity increases, so does the requirement for a greater diversity of signals. This relationship is particularly true for advanced eusocial insects, including ants, bees, and wasps, whose chemical communication systems have been well-characterized. However, we know surprisingly little about how these communication systems evolve during the transition between solitary and group living. Here, we demonstrate that the sensory systems associated with signal perception are evolutionarily labile. In particular, we show that differences in signal production and perception are tightly associated with changes in social behavior in halictid bees. Our results suggest that social species require a greater investment in communication than their solitary counterparts and that species that have reverted from eusociality to solitary living have repeatedly reduced investment in these potentially costly sensory perception systems.

Am I Too Rich?: Determining Limits for Gas Composition to Ensure Crack Arrest in an Existing Pipeline

2016 ◽  
Author(s):  
Robert M. Andrews ◽  
Michael Smith
Keyword(s):  
Driving Force ◽  
Probabilistic Approach ◽  
Crack Arrest ◽  
General Purpose ◽  
The Body ◽  
Third Party ◽  
Gas Composition ◽  
Original Design ◽  
Crack Driving Force ◽  
Wide Range

Fracture control studies for new gas transmission pipelines usually produce a specified minimum Charpy energy, often including “correction factors”, which will ensure that a crack will arrest in the body of the pipe. The basic pipeline parameters such as pressure, pipe grade, diameter and wall thickness will be fixed early in design, and the reservoir and process engineering design will set limits on the extremes of the gas composition. The inverse case, where the gas composition in an existing pipeline is to be changed from the original design basis, is more challenging. Changes in composition can arise from ageing of the reservoir supplying a pipeline, or opportunities for the operator to generate additional revenue from 3rd party access. Sales gas specification limits for general purpose natural gas transmission often have broad limits, which can be met by a wide range of compositions. As a wide range of gas compositions can give the same crack driving force, determining the composition limits is a “many to one” problem without a unique solution. This paper describes the derivation of an envelope of richer gas compositions which gave an acceptable probability of crack arrest in an existing pipeline which had originally been designed for a very lean gas mixture. Hence it was necessary to limit the amount of rich third party gas to ensure that the crack driving force did not increase sufficiently to propagate a long running fracture. Manufacturing test data for the linepipe were used with the EPRG probabilistic approach to derive a characteristic Charpy energy which would achieve a 95% probability of crack arrest in 5 joints or fewer. After “uncorrecting” the high Charpy energy, the value was used with the Battelle Two Curve model to analyse a range of gas compositions and derive an envelope of acceptable compositions. Sensitivity studies were carried out to assess the effects of increasing the temperature and of expanding the limits for nitrogen and carbon dioxide beyond the initial assumptions. It is concluded that for a specific case it will be possible to solve the inverse problem and produce composition limits which will allow increased flexibility of operation whilst maintaining safety.

scholarly journals Changes in social cohesion in a long-lived species under a perturbation regime

2019 ◽  
Author(s):  
M. Genovart ◽  
O. Gimenez ◽  
A. Bertolero ◽  
R. Choquet ◽  
D. Oro ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Social Cohesion ◽  
Group Living ◽  
Social Bonding ◽  
World Population ◽  
List Type ◽  
Social Species ◽  
The Social ◽  
Capture Recapture ◽  
A Site

AbstractUnderstanding the behaviour of a population under perturbations is crucial and can help to mitigate the effects of global change. Sociality can influence the dynamics of behavioural processes and plays an important role on populations’ resilience. However little is known about the effects of perturbations on the social cohesion of group-living animals.To explore the strength of social cohesion and its dynamics under perturbations, we studied an ecological system involving a colonial, long-lived species living in a site experiencing a shift to a perturbed regime. This regime, caused by the invasion of predators, led this colony to hold from 70% to only 3% of the total world population in only one decade. Because birds breed aggregated in discrete and annually changing patches within large colonies, we could disentangle whether annual aggregation was random or resulted from social bonding among individuals. Our goals were 1) to uncover if there was any long-term social bonding between individuals and 2) to examine whether the perturbation regime affected social cohesion.We explored social cohesion by means of contingency tables and, within the Social Network Analysis framework, by modeling interdependencies among observations using additive and multiplicative effects (AME) and accounted for missing data. We analysed 25 years of monitoring with an individual capture-recapture database of more than 3,500 individuals.We showed that social bonding occurs over years in this species. We additionally show that social bonding strongly decreased after the perturbation regime. We propose that sociality and individual behavioural heterogeneity have been playing a major role driving dispersal and thus population dynamics over the study period.Perturbations may lead not only to changes in individuals’ behaviours and fitness but also to a change in populations’ social cohesion. The demographic consequences of the breaking down of social bonds are still not well understood, but they can be critical for population dynamics of social species. Further studies considering individual heterogeneity, sociality and different types of perturbations should be carried out to improve our understanding on the resilience of social species.

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