scholarly journals Experimental field evidence that out-group threats influence within-group behavior

2019 ◽  
Vol 30 (5) ◽  
pp. 1425-1435 ◽  
Author(s):  
Amy Morris-Drake ◽  
Charlotte Christensen ◽  
Julie M Kern ◽  
Andrew N Radford
Keyword(s):  
Group Behavior ◽  
Behavioral Changes ◽  
Experimental Investigations ◽  
Dominance Status ◽  
Group Interactions ◽  
Additional Information ◽  
Social Species ◽  
Field Evidence ◽  
Cooperatively Breeding ◽  
Group Members

Abstract In social species, conspecific outsiders present various threats to groups and their members. These out-group threats are predicted to affect subsequent within-group interactions (e.g., affiliation and aggression) and individual behavior (e.g., foraging and vigilance decisions). However, experimental investigations of such consequences are rare, especially in natural conditions. We used field-based call playbacks and fecal presentations on habituated wild dwarf mongooses (Helogale parvula)—a cooperatively breeding, territorial species—to examine postinteraction responses to the simulated threat of a rival group. Dwarf mongooses invested more in grooming of groupmates, foraged closer together, and more regularly acted as sentinels (a raised guard) after encountering indicators of rival-group presence compared to control conditions. These behavioral changes likely arise from greater anxiety and, in the case of increased vigilance, the need to seek additional information about the threat. The influence of an out-group threat lasted at least 1 h but individuals of different dominance status and sex responded similarly, potentially because all group members suffer costs if a contest with rivals is lost. Our results provide field-based experimental evidence from wild animals that out-group threats can influence within-group behavior and decision making, and suggest the need for greater consideration of the lasting impacts of social conflict.

scholarly journals Post-allogrooming reductions in self-directed behaviour are affected by role and status in the green woodhoopoe

2011 ◽  
Vol 8 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Andrew N. Radford
Keyword(s):  
Recent Work ◽  
Costs And Benefits ◽  
Dominance Status ◽  
Social Functions ◽  
Evolution Of Sociality ◽  
Wide Range ◽  
Cooperatively Breeding ◽  
Subordinate Group ◽  
Group Members ◽  
First Time

Allogrooming occurs in a wide range of species and can serve both hygienic and social functions. While the latter have long been thought to be underpinned by reductions in tension for recipients, recent work has suggested that donors may also benefit in this way. Here, I show that, in cooperatively breeding green woodhoopoes Phoeniculus purpureus , involvement in allogrooming is followed by a reduction in self-grooming by both recipients and donors, but that the former exhibit a greater decrease. Moreover, I demonstrate for the first time that the dominance status of the allogrooming participant is important, with subordinate group members reducing subsequent self-grooming to a greater extent than the dominant pair. If avian self-directed behaviour reflects current distress levels in the same way as found in various primates, my results would indicate that allogrooming benefits are not confined to mammals, and would have important implications both for accurate assessments of the true costs and benefits of affiliative behaviour and for our understanding of the evolution of sociality.

Group Progress of Community Elderly as Measured by Tape Recordings, Group Tempo and Group Evaluation

1980 ◽  
Vol 10 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Marcella Bakur Weiner ◽  
Comilda S. Weinstock
Keyword(s):  
Group Intervention ◽  
Behavioral Changes ◽  
Short Term ◽  
Community Based ◽  
Group Interactions ◽  
Group Evaluation ◽  
Group Members ◽  
Group Experience ◽  
Experimental Group

Community based geriatric outpatients (N:67) were involved in a 12-session group resocialization program conducted at a municipal hospital. Meetings were taped and records kept on all group interactions. Short-term behavioral changes in quality of group participation and evaluation of the group experience by the members are reported. Comparison is made between the two experimental groups led by a trained group leader who used group intervention techniques and two “talk” groups in which the leader played a non-intervention role. Results indicate that experimental group members showed changes toward more active problem-solving approaches over time and maintained a lively group tempo. “Talk” group members remained fixed at one level evidencing little change along with a depressed tempo during group sessions.

scholarly journals Experimental evidence that intruder and group member attributes affect outgroup defence and associated within-group interactions in a social fish

2019 ◽  
Vol 286 (1912) ◽  
pp. 20191261 ◽  
Author(s):  
Ines Braga Goncalves ◽  
Andrew N. Radford
Keyword(s):  
Experimental Evidence ◽  
Social Dynamics ◽  
Experimental Tests ◽  
Potential Contribution ◽  
Territorial Defence ◽  
Group Interactions ◽  
Social Species ◽  
Group Members ◽  
Female Specific ◽  
Group Member

In many social species, individuals communally defend resources from conspecific outsiders. Participation in defence and in associated within-group interactions, both during and after contests with outgroup rivals, is expected to vary between group members because the threat presented by different outsiders is not the same to each individual. However, experimental tests examining both the contributions to, and the consequences of, outgroup conflict for all group members are lacking. Using groups of the cichlid Neolamprologus pulcher , we simulated territorial intrusions by different-sized female rivals and altered the potential contribution of subordinate females to defence. Dominant females and subordinate females defended significantly more against size- and rank-matched intruders, while males displayed lower and less variable levels of defence. Large and small, but not intermediate-sized, intruders induced increased levels of within-group aggression during intrusions, which was targeted at the subordinate females. Preventing subordinate females from helping in territorial defence led to significant decreases in post-contest within-group and female-specific submissive and affiliative displays. Together, these results show that the defensive contributions of group members vary greatly depending both on their own traits and on intruder identity, and this variation has significant consequences for within-group social dynamics both during and in the aftermath of outgroup contests.

scholarly journals Proactive prosociality in a cooperatively breeding corvid, the azure-winged magpie ( Cyanopica cyana )

2016 ◽  
Vol 12 (10) ◽  
pp. 20160649 ◽  
Author(s):  
Lisa Horn ◽  
Clara Scheer ◽  
Thomas Bugnyar ◽  
Jorg J. M. Massen
Keyword(s):  
Cooperative Breeding ◽  
Cooperatively Breeding ◽  
Group Members ◽  
Over Time

One of the contemporary hypotheses concerning the evolution of human altruism is the cooperative breeding hypothesis (CBH) which has recently been tested in non-human primates. Using a similar paradigm, we investigated prosociality in a cooperatively breeding corvid, the azure-winged magpie. We found that the magpies delivered food to their group members at high rates, and unlike other corvids, they did so without any cues provided by others. In two control conditions, the magpies stopped participating over time, indicating that they learned to discriminate prosocial tests from controls. Azure-winged magpies are thus the first birds that experimentally show proactive prosociality. Our findings are in line with the CBH; however, additional corvid species need to be tested in this promising paradigm.

Experimental predator intrusions in a cooperative breeder reveal threat-dependent task partitioning

2020 ◽  
Vol 31 (6) ◽  
pp. 1369-1378 ◽  
Author(s):  
Dario Josi ◽  
Annika Freudiger ◽  
Michael Taborsky ◽  
Joachim G Frommen
Keyword(s):  
Behavioral Responses ◽  
Alloparental Care ◽  
Potential Threat ◽  
Antipredator Defense ◽  
Outside Options ◽  
Cooperatively Breeding ◽  
Indirect Fitness ◽  
Antipredator Behaviors ◽  
Group Members ◽  
Eusocial Animals

Abstract In cooperatively breeding species, nonbreeding individuals provide alloparental care and help in territory maintenance and defense. Antipredator behaviors of subordinates can enhance offspring survival, which may provide direct and indirect fitness benefits to all group members. Helping abilities and involved costs and benefits, risks, and outside options (e.g., breeding independently) usually diverge between group members, which calls for status-specific differentiated behavioral responses. Such role differentiation within groups may generate task-specific division of labor, as exemplified by eusocial animals. In vertebrates, little is known about such task differentiation among group members. We show how breeders and helpers of the cooperatively breeding cichlid Neolamprologus savoryi partition predator defense depending on intruder type and the presence of dependent young. In the field, we experimentally simulated intrusions by different fish species posing a risk either specifically to eggs, young, or adults. We used intrusions by harmless algae eaters as a control. Breeders defended most when dependent young were present, while helper investment hinged mainly on their body size and on the potential threat posed by the respective intruders. Breeders and helpers partitioned defense tasks primarily when dependent young were exposed to immediate risk, with breeders investing most in antipredator defense, while helpers increased guarding and care in the breeding chamber. Breeders’ defense likely benefits helpers as well, as it was especially enhanced in the treatment where helpers were also at risk. These findings illustrate that in a highly social fish different group members exhibit fine-tuned behavioral responses in dependence of ecological and reproductive parameter variation.

scholarly journals Cooperative rescue of a juvenile capuchin (Cebus imitator) from a Boa constrictor

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Katharine M. Jack ◽  
Michaela R. Brown ◽  
Margaret S. Buehler ◽  
Saul Cheves Hernadez ◽  
Nuria Ferrero Marín ◽  
...  
Keyword(s):  
Costa Rica ◽  
Adult Female ◽  
Significant Role ◽  
Group Behavior ◽  
Cooperative Group ◽  
Alpha Male ◽  
Play Session ◽  
Boa Constrictor ◽  
Group Members ◽  
And Behavior

Abstract The threat of predation by snakes is considered to have played a significant role in the evolution of primate sensory systems and behavior. However, we know relatively little about individual and group responses given the rarity of observed predation events. Here we report an observed (filmed) predation attempt by an adult Boa constrictor (~ 2 m) on a juvenile white-faced capuchin (Cebus imitator) in the Sector Santa Rosa of the Área de Conservación Guanacaste, Costa Rica. The snake caught the juvenile monkey on the ground during a terrestrial play session. When the victim screamed, the alpha male, alpha female, and another adult female ran to the scene, physically attacked the snake (with bites and hits), and pulled the victim to safety. Most group members participated in the vocal mobbing of the snake both during and after the attack. Based on the outcomes of this predation attempt and published reports of other B. constrictor attacks on primates, the coordinated efforts of ≥ 2 group members is needed for a successful rescue. This observation adds to our growing knowledge of cooperative group behavior and its importance in predator defense.

scholarly journals Parochial Versus Universal Cooperation: Introducing a Novel Economic Game of Within- and Between-Group Interaction

2019 ◽  
Vol 11 (1) ◽  
pp. 36-45 ◽  
Author(s):  
Hillie Aaldering ◽  
Robert Böhm
Keyword(s):  
Social Dominance ◽  
Social Dominance Orientation ◽  
Intergroup Conflict ◽  
Social Value Orientation ◽  
Group Interactions ◽  
Group Relations ◽  
Group Cooperation ◽  
Group Members ◽  
The Individual ◽  
Natural Groups

Engaging in personally costly within-group cooperation benefits one’s in-group members but also impacts other groups by benefiting, neglecting, or harming out-group members, leading to a range of potential consequences for between-group relations (e.g., collaboration vs. competition). We introduce the Intergroup Parochial and Universal Cooperation (IPUC) game to investigate the prevalence of the individual preferences underlying these different expressions of within-group cooperation: universalism, weak parochialism, and strong parochialism. In two online experiments with natural groups, we show that the IPUC has value beyond existing economic games in measuring these preferences separately. In a third experiment conducted in the lab, we show how dispositional measures traditionally associated with within- and between-group cooperation, that is, social value orientation, social dominance orientation, honesty-humility, and empathic concern, predict different preferences. Thus, the IPUC provides a tool to better understand within- and between-group interactions and to test interventions to overcome intergroup conflict.

scholarly journals Giving to versus Taking from In- and Out-Group Members

Games ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 57 ◽  
Author(s):  
Marius Alt ◽  
Carlo Gallier ◽  
Achim Schlüter ◽  
Katherine Nelson ◽  
Eva Anggraini
Keyword(s):  
Social Norms ◽  
Cultural Context ◽  
Group Identity ◽  
Dictator Game ◽  
The Other ◽  
Group Interactions ◽  
Minimal Group Paradigm ◽  
Group Identities ◽  
Group Members ◽  
Full Factorial

In this experiment, we test whether subjects’ responses to variations in the action set in a dictator game depends on induced group identities. The action set includes choices in which the dictator can either give money to or take money from the other player. As an extension to the anonymous setting, we introduce induced group identities using the minimal group paradigm. Based on a dictator game conducted with more than 300 students in Indonesia, we implement a full factorial design in order to analyze the framing of the action set in a varied cultural context and to examine varied prevalence of social norms given a group identity context. If group identity is not salient, we find that participants are slightly more generous when they have an opportunity to give to rather than to take from the recipient. However, when participants are matched with in-group members, this result is reversed and highly significant. The result of differing responses to framing effects in within-group interactions compared to a neutral setting are largely ascribed to the varied compliance with existing social norms.

Modeling, Experiment, and Fabrication of Micro-Grooved Heat Pipes: An Update

2007 ◽  
Vol 60 (3) ◽  
pp. 107-119 ◽  
Author(s):  
Balram Suman
Keyword(s):  
Heat Pipe ◽  
Heat Pipes ◽  
Sensitivity Analyses ◽  
Experimental Investigations ◽  
Future Research ◽  
Detailed Knowledge ◽  
Additional Information ◽  
Modeling Experiment ◽  
Transient Models ◽  
Work Done

The review presents an update of the work done in the micro heat pipe research and development, with an aim to give updated detailed knowledge to individuals new to the field, as well as to those already working in this area. Presented here is a summary of the recent advances in these devices occurring since the early 1990s. The following review describes the historical development of these devices, along with a review of the steady state and the transient models, sensitivity analyses, recent experimental investigations and fabrication techniques. The critical heat input, dryout length, fill charge, various heat pipe limitations and design have also been discussed in brief. Finally, future research and areas in which additional information is required are identified and delineated. This article has 204 references.

scholarly journals Conformity in the collective: differences in hunger affect individual and group behavior in a shoaling fish

2019 ◽  
Vol 30 (4) ◽  
pp. 968-974 ◽  
Author(s):  
Alexander D M Wilson ◽  
Alicia L J Burns ◽  
Emanuele Crosato ◽  
Joseph Lizier ◽  
Mikhail Prokopenko ◽  
...  
Keyword(s):  
Collective Behavior ◽  
Nearest Neighbor ◽  
Collective Motion ◽  
Internal State ◽  
Group Behavior ◽  
Fundamental Interest ◽  
Individual Level ◽  
Group Members ◽  
The Individual ◽  
Nearest Neighbor Distances

Abstract Animal groups are often composed of individuals that vary according to behavioral, morphological, and internal state parameters. Understanding the importance of such individual-level heterogeneity to the establishment and maintenance of coherent group responses is of fundamental interest in collective behavior. We examined the influence of hunger on the individual and collective behavior of groups of shoaling fish, x-ray tetras (Pristella maxillaris). Fish were assigned to one of two nutritional states, satiated or hungry, and then allocated to 5 treatments that represented different ratios of satiated to hungry individuals (8 hungry, 8 satiated, 4:4 hungry:satiated, 2:6 hungry:satiated, 6:2 hungry:satiated). Our data show that groups with a greater proportion of hungry fish swam faster and exhibited greater nearest neighbor distances. Within groups, however, there was no difference in the swimming speeds of hungry versus well-fed fish, suggesting that group members conform and adapt their swimming speed according to the overall composition of the group. We also found significant differences in mean group transfer entropy, suggesting stronger patterns of information flow in groups comprising all, or a majority of, hungry individuals. In contrast, we did not observe differences in polarization, a measure of group alignment, within groups across treatments. Taken together these results demonstrate that the nutritional state of animals within social groups impacts both individual and group behavior, and that members of heterogenous groups can adapt their behavior to facilitate coherent collective motion.

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