scholarly journals Social deprivation affects cooperative predator inspection in a cichlid fish

2015 ◽  
Vol 2 (3) ◽  
pp. 140451 ◽  
Author(s):  
Saskia Hesse ◽  
Jaime M. Anaya-Rojas ◽  
Joachim G. Frommen ◽  
Timo Thünken
Keyword(s):  
Social Skills ◽  
Predation Risk ◽  
Social Environment ◽  
Social Deprivation ◽  
Cichlid Fish ◽  
Group Living ◽  
Social Environments ◽  
Complex Behaviour ◽  
Predator Inspection ◽  
The Individual

The social environment individuals are exposed to during ontogeny shapes social skills and social competence in group-living animals. Consequently, social deprivation has serious effects on behaviour and development in animals but little is known about its impact on cooperation. In this study, we examined the effect of social environment on cooperative predator inspection. Predator inspection behaviour is a complex behaviour, which is present in a variety of shoaling fish species. Often, two fish leave the safety of the group and inspect a potentially dangerous predator in order to gather information about the current predation risk. As predator inspection is highly risky, it is prone to conflicts and cheating. However, cooperation among individuals may reduce the individual predation risk. We investigated this complex social behaviour in juveniles of the cichlid fish Pelvicachromis taeniatus that were reared in two different social environments throughout development. Fish reared in a group inspected more often than isolation-reared fish and were more likely to cooperate, i.e. they conducted conjoint inspection of a predator. By contrast, isolation-reared fish were more likely to perform a single inspection without a companion. These results suggest an impairment of cooperative behaviour in isolation-reared fish most probably due to lack of social experience and resulting in lowered social skills needed in coordinated behaviour.

scholarly journals Predation risk drives social complexity in cooperative breeders

2016 ◽  
Vol 113 (15) ◽  
pp. 4104-4109 ◽  
Author(s):  
Frank Groenewoud ◽  
Joachim Gerhard Frommen ◽  
Dario Josi ◽  
Hirokazu Tanaka ◽  
Arne Jungwirth ◽  
...  
Keyword(s):  
Social Organization ◽  
Predation Risk ◽  
Social Evolution ◽  
Social Complexity ◽  
Group Structure ◽  
Cichlid Fish ◽  
Group Living ◽  
Ecological Factors ◽  
Habitat Saturation ◽  
Shelter Construction

Predation risk is a major ecological factor selecting for group living. It is largely ignored, however, as an evolutionary driver of social complexity and cooperative breeding, which is attributed mainly to a combination of habitat saturation and enhanced relatedness levels. Social cichlids neither suffer from habitat saturation, nor are their groups composed primarily of relatives. This demands alternative ecological explanations for the evolution of advanced social organization. To address this question, we compared the ecology of eight populations of Neolamprologus pulcher, a cichlid fish arguably representing the pinnacle of social evolution in poikilothermic vertebrates. Results show that variation in social organization and behavior of these fish is primarily explained by predation risk and related ecological factors. Remarkably, ecology affects group structure more strongly than group size, with predation inversely affecting small and large group members. High predation and shelter limitation leads to groups containing few small but many large members, which is an effect enhanced at low population densities. Apparently, enhanced safety from predators by cooperative defense and shelter construction are the primary benefits of sociality. This finding suggests that predation risk can be fundamental for the transition toward complex social organization, which is generally undervalued.

scholarly journals Frequency-dependent physiological trade-offs between competing colour morphs

2007 ◽  
Vol 3 (5) ◽  
pp. 494-497 ◽  
Author(s):  
Sarah R Pryke ◽  
Lee B Astheimer ◽  
William A Buttemer ◽  
Simon C Griffith
Keyword(s):  
Social Environment ◽  
Stress Responses ◽  
High Stress ◽  
Social Environments ◽  
Frequency Dependent ◽  
Trade Offs ◽  
The Social ◽  
Gouldian Finch ◽  
The Individual ◽  
Colour Morphs

Evolutionary theory suggests that alternative colour morphs (i.e. genetically controlled phenotypes) may derive similar fitness under frequency-dependent selection. Here we experimentally demonstrate opposing effects of frequency-dependent social environments on plasma hormone levels (testosterone and corticosterone) and immune function between red- and black-headed male morphs of the Gouldian finch ( Erythrura gouldiae ). Red-headed males are highly sensitive to changes in the social environment, especially towards the relative density of their own aggressive morph, exhibiting high stress responses and immunosuppression in socially competitive environments. In contrast, the non-aggressive black-headed males follow a more passive strategy that appears to buffer them against social stresses. The differential effect of hormones on aggressive behaviour and immune performance reinforces the contrasting behavioural strategies employed by these colour morphs, and highlights the importance of the social environment in determining the individual basis of behavioural and physiological responses.

scholarly journals Individual behavioural traits not social context affects learning about novel objects in archerfish

2021 ◽  
Vol 75 (3) ◽  
Author(s):  
Nick A. R. Jones ◽  
Helen C. Spence-Jones ◽  
Mike Webster ◽  
Luke Rendell
Keyword(s):  
Social Context ◽  
Social Environment ◽  
Social Contexts ◽  
Negative Effects ◽  
Behavioural Phenotype ◽  
Social Species ◽  
The Social ◽  
Social Animals ◽  
Novel Objects ◽  
The Individual

Abstract Learning can enable rapid behavioural responses to changing conditions but can depend on the social context and behavioural phenotype of the individual. Learning rates have been linked to consistent individual differences in behavioural traits, especially in situations which require engaging with novelty, but the social environment can also play an important role. The presence of others can modulate the effects of individual behavioural traits and afford access to social information that can reduce the need for ‘risky’ asocial learning. Most studies of social effects on learning are focused on more social species; however, such factors can be important even for less-social animals, including non-grouping or facultatively social species which may still derive benefit from social conditions. Using archerfish, Toxotes chatareus, which exhibit high levels of intra-specific competition and do not show a strong preference for grouping, we explored the effect of social contexts on learning. Individually housed fish were assayed in an ‘open-field’ test and then trained to criterion in a task where fish learnt to shoot a novel cue for a food reward—with a conspecific neighbour visible either during training, outside of training or never (full, partial or no visible presence). Time to learn to shoot the novel cue differed across individuals but not across social context. This suggests that social context does not have a strong effect on learning in this non-obligatory social species; instead, it further highlights the importance that inter-individual variation in behavioural traits can have on learning. Significance statement Some individuals learn faster than others. Many factors can affect an animal’s learning rate—for example, its behavioural phenotype may make it more or less likely to engage with novel objects. The social environment can play a big role too—affecting learning directly and modifying the effects of an individual’s traits. Effects of social context on learning mostly come from highly social species, but recent research has focused on less-social animals. Archerfish display high intra-specific competition, and our study suggests that social context has no strong effect on their learning to shoot novel objects for rewards. Our results may have some relevance for social enrichment and welfare of this increasingly studied species, suggesting there are no negative effects of short- to medium-term isolation of this species—at least with regards to behavioural performance and learning tasks.

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.

Plastic territoriality in group-living chestnut-crowned babblers: roles of resource value, holding potential and predation risk

2015 ◽  
Vol 101 ◽  
pp. 155-168 ◽  
Author(s):  
Enrico Sorato ◽  
Philippa R. Gullett ◽  
Matthew J.S. Creasey ◽  
Simon C. Griffith ◽  
Andrew F. Russell
Keyword(s):  
Predation Risk ◽  
Group Living ◽  
Resource Value

Contradictions in a Totalitarian Society

1969 ◽  
Vol 39 ◽  
pp. 30-40
Author(s):  
Michael Lindsay
Keyword(s):  
Characteristic Feature ◽  
Social Environment ◽  
Policy Making ◽  
Communist System ◽  
The Individual ◽  
Unanimous Agreement

Some aspects of the Chinese People's Republic have been explained as reversions to traditional Chinese patterns. There are resemblances between the Chinese Communist ideal for society and the traditional Confucian ideal. Both assume that, in a properly ordered society, there should be universal acceptance of a true doctrine and universal agreement on what is right. Paul Linebarger, describing the Confucian ideal, wrote, “Government, once cheng ming has been set in motion, is not a policy making body. There is no question of policy, no room for disagreement, no alternative; what is right is apparent. … government needs only to administer for … the maintenance of the ideology. Once right views are established, no individual is entitled to think otherwise. … control of the individual will devolves upon persons making up his immediate social environment. …” One can compare this with the frequent Chinese Communist statements about the universal validity of Marxism-Leninism and the thought of Mao Tse-tung and the continually appearing assumption that a process of discussion must end with unanimous agreement on what is right. Also, control of the individual by persons in his immediate social environment is a characteristic feature of the Chinese Communist system.

Two Social Environments in a Working Day: Occupation and Spatial Segregation in Metropolitan Tel Aviv

10.1068/a3452 ◽  
2001 ◽  
Vol 33 (10) ◽  
pp. 1765-1784 ◽  
Author(s):  
Orna Blumen ◽  
Iris Zamir
Keyword(s):  
Social Environment ◽  
Spatial Segregation ◽  
Social Environments ◽  
Social Significance ◽  
Tel Aviv ◽  
Blue Collar Workers ◽  
The Social ◽  
White Collar Workers ◽  
Working Day ◽  
And Gender

The concepts of segregation and social distance have long been used to explain the social environment of stratified residential space. However, the social significance of occupation, though acknowledged, has rarely been applied spatially. In this study, we employed these three concepts to examine the social environment of the entire metropolitan employment space as defined by job location. Smallest space analysis was used to identify and compare the sociospatial segregation produced by workers' occupational distribution in employment and residential spheres. This empirical study focused on metropolitan Tel Aviv, Israel's largest urban area, using the latest available national census. Our findings show that the social milieu of employment differed from that of residence: blue-collar workers were segregated from white-collar workers; managers, clerks, and salespersons formed the core group; and gender and ethnic divisions characterised the sociospatial realm of employment. Overall, most employees changed their social environment when they went to work. The study indicates that spatial segregation, within each sphere and between the two spheres, is intrinsic to the capitalist – patriarchal order.

scholarly journals A test of male infanticide as a reproductive tactic in a cichlid fish

2017 ◽  
Vol 4 (3) ◽  
pp. 160891 ◽  
Author(s):  
Shagun Jindal ◽  
Aneesh P. H. Bose ◽  
Constance M. O'Connor ◽  
Sigal Balshine
Keyword(s):  
Cichlid Fish ◽  
Group Living ◽  
Laboratory Setting ◽  
Dominant Position ◽  
Egg Cannibalism ◽  
Cooperatively Breeding ◽  
Dominant Individual ◽  
Living Species ◽  
Reproductive Tactic ◽  
Relative Body Size

Infanticide and offspring cannibalism are taxonomically widespread phenomena. In some group-living species, a new dominant individual taking over a group can benefit from infanticide if doing so induces potential mates to become reproductively available sooner. Despite widespread observations of infanticide (i.e. egg cannibalism) among fishes, no study has investigated whether egg cannibalism occurs in fishes as a result of group takeovers, or how this type of cannibalism might be adaptive. Using the cooperatively breeding cichlid, Neolamprologus pulcher , we tested whether new unrelated males entering the dominant position in a social group were more likely to cannibalize eggs, and whether such cannibalism would shorten the interval until the female's next spawning. Females spawned again sooner if their broods were removed than if they were cared for. Egg cannibalism occurred frequently after a group takeover event, and was rarer if the original male remained with the group. While dominant breeder females were initially highly aggressive towards newcomer males that took over the group, the degree of resistance depended on relative body size differences between the new pair and, ultimately, female aggression did not prevent egg cannibalism. Egg cannibalism, however, did not shorten the duration until subsequent spawning, or increase fecundity during subsequent breeding in our laboratory setting. Our results show that infanticide as mediated through group takeovers is a taxonomically widespread behaviour.

scholarly journals INFLUENCE OF SEASON AND SOCIAL ENVIRONMENT ON THE REPRODUCTIVE-ENDOCRINE STATUS OF THE ADULT LANDRACE BOAR

1990 ◽  
Vol 70 (1) ◽  
pp. 121-128 ◽  
Author(s):  
V. L. TRUDEAU ◽  
L. M. SANFORD
Keyword(s):  
Social Environment ◽  
Late Summer ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Social Environments ◽  
Blood Samples ◽  
Testosterone Secretion ◽  
Endocrine Status ◽  
Reproductive Endocrine ◽  
Basal Concentration

Seasonal variations in LH, FSH, and testosterone secretion were investigated for adult Landrace boars housed in different social environments for 1 yr. Socially nonrestricted boars (n = 4) were penned adjacent to ovariectomized gilts that were hormonally brought into estrus every 2 wk, while socially restricted boars (n = 4) were kept in pens with solid walls. Mean hormone concentrations were determined from the assay of single AM and PM blood samples collected from the jugular vein by venipuncture once a month. In November, February, May and August, blood samples were collected serially over 12 h from jugular catheters for assessment of pulsatile LH and testosterone secretion, and the LH response to a GnRH injection (1 μg kg−1 body weight). Mean LH and testosterone concentrations were relatively high in all boars during the late summer and fall, and often were greater for the socially nonrestricted versus the restricted boars (group × month), P < 0.05) in the winter (December and January). Mean FSH concentration also varied with month (P < 0.05). Pulse analysis indicated that higher mean testosterone concentrations in November and August were the result of increases (month, P < 0.05) in testosterone-pulse frequency and basal concentration. Maximal mean LH concentration in August was associated with maximal (month, P < 0.05) LH-pulse amplitude and basal concentration. The amplitude of the LH peak following GnRH injection increased (P < 0.05) between November and May, and remained high in August. Key words: Gonadotropins, testosterone, blood, season, social environment, boar

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