scholarly journals Investment in chemical signalling glands facilitates the evolution of sociality in lizards

2021 ◽  
Vol 288 (1945) ◽  
pp. 20202438
Author(s):  
Simon Baeckens ◽  
Martin J. Whiting
Keyword(s):  
Information Transfer ◽  
Social Conflict ◽  
Group Living ◽  
Comparative Approach ◽  
Lizard Species ◽  
Chemical Signalling ◽  
Social Grouping ◽  
Evolution Of Sociality ◽  
Group Members ◽  
Epidermal Glands

The evolution of sociality and traits that correlate with, or predict, sociality, have been the focus of considerable recent study. In order to reduce the social conflict that ultimately comes with group living, and foster social tolerance, individuals need reliable information about group members and potential rivals. Chemical signals are one such source of information and are widely used in many animal taxa, including lizards. Here, we take a phylogenetic comparative approach to test the hypothesis that social grouping correlates with investment in chemical signalling. We used the presence of epidermal glands as a proxy of chemical investment and considered social grouping as the occurrence of social groups containing both adults and juveniles. Based on a dataset of 911 lizard species, our models strongly supported correlated evolution between social grouping and chemical signalling glands. The rate of transition towards social grouping from a background of ‘epidermal glands present’ was an order of a magnitude higher than from a background of ‘no epidermal glands’. Our results highlight the potential importance of chemical signalling during the evolution of sociality and the need for more focused studies on the role of chemical communication in facilitating information transfer about individual and group identity, and ameliorating social conflict.

scholarly journals Dorsal raphe oxytocin receptors regulate the neurobehavioral consequences of social touch

2019 ◽  
Author(s):  
Z.A. Grieb ◽  
E.G. Ford ◽  
F.P. Manfredsson ◽  
J.S. Lonstein
Keyword(s):  
Cortical Plasticity ◽  
Coping Behavior ◽  
Group Living ◽  
Dorsal Raphe ◽  
Social Touch ◽  
Oxytocin Receptors ◽  
Tactile Cues ◽  
Group Members ◽  
New Mother ◽  
Dorsal Raphé

SummaryProsocial interactions are essential for group-living animals and are regulated by tactile cues shared among the group members. Neurobiological mechanisms through which social touch influences prosociality and related affective behaviors are relatively unknown. Using the evolutionarily ancient mother-young dyad as a model, we hypothesized that neurobehavioral consequences of social touch involves an interaction between central oxytocin (released during social touch) and serotonin (regulating affect and neuroplasticity). New mother rats showed upregulation of numerous aspects of the oxytocin system in the midbrain dorsal raphe (DR; source of forebrain serotonin) compared to non-maternal females. Preventing this upregulation by OTR knockdown in the maternal DR elicited infanticide, reduced nursing, increased aggression, and decreased active coping behavior. OTR knockdown also decreased serotonin-immunoreactive fibers, and increased neuroplasticity-restricting perineuronal nets, in the primary somatosensory cortex. Thus, oxytocin signaling in the DR regulates mechanisms involved in serotonin-induced cortical plasticity, which refines the tactile processing underlying prosocial behaviors.

scholarly journals Fitness of breeders in social Damaraland mole-rats is independent of group size

2021 ◽  
Author(s):  
Jack Thorley ◽  
Hanna Bensch ◽  
Kyle Finn ◽  
Tim Clutton-Brock ◽  
Markus Zöttl
Keyword(s):  
Reproductive Success ◽  
Group Size ◽  
Survival Rates ◽  
Group Living ◽  
Adult Survival ◽  
High Survival ◽  
Successful Reproduction ◽  
Related Group ◽  
Group Members ◽  
Using Data

Damaraland mole-rats (Fukomys damarensis) are usually viewed as an obligatorily group living eusocial species in which successful reproduction is dependent on reproductive altruism of closely related group members. However, the reproductive ecology of social mole-rats in their natural environment remains poorly understood and it is unclear to what extent successful reproduction is dependent on assistance from other group members. Using data from a 7-year field study of marked individuals, we show that, after dispersal from their natal group, individuals typically settled alone in new burrow systems where they enjoyed high survival rates, and often remained in good body condition for several years before finding a mate. Unlike most other eusocial or singular cooperative breeders, we found that Damaraland mole-rats reproduced successfully in pairs without helpers and experimentally formed pairs had the same reproductive success as larger established groups. Overall there was only a weak increase in reproductive success with increasing group size and no effect of group size on adult survival rates across the population. Juveniles in large groups grew faster early in life but their growth rates declined subsequently so that they eventually plateaued at a lower maximum body mass than juveniles from small groups. Taken together, our data suggest that the fitness benefits of group living to breeders are small and we suggest that extended philopatry in Damaraland mole-rats has evolved because of the high costs and constraints of dispersal rather than because of strong indirect benefits accrued through cooperative behaviour.

scholarly journals Social fluidity mobilizes contagion in human and animal populations

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Ewan Colman ◽  
Vittoria Colizza ◽  
Ephraim M Hanks ◽  
David P Hughes ◽  
Shweta Bansal
Keyword(s):  
Social Bonds ◽  
Group Living ◽  
Basic Reproductive Number ◽  
Reproductive Number ◽  
Frequency Dependent ◽  
Density Dependent ◽  
Gregarious Behavior ◽  
Animal Populations ◽  
Group Members ◽  
Social Fluidity

Humans and other group-living animals tend to distribute their social effort disproportionately. Individuals predominantly interact with a small number of close companions while maintaining weaker social bonds with less familiar group members. By incorporating this behavior into a mathematical model, we find that a single parameter, which we refer to as social fluidity, controls the rate of social mixing within the group. Large values of social fluidity correspond to gregarious behavior, whereas small values signify the existence of persistent bonds between individuals. We compare the social fluidity of 13 species by applying the model to empirical human and animal social interaction data. To investigate how social behavior influences the likelihood of an epidemic outbreak, we derive an analytical expression of the relationship between social fluidity and the basic reproductive number of an infectious disease. For species that form more stable social bonds, the model describes frequency-dependent transmission that is sensitive to changes in social fluidity. As social fluidity increases, animal-disease systems become increasingly density-dependent. Finally, we demonstrate that social fluidity is a stronger predictor of disease outcomes than both group size and connectivity, and it provides an integrated framework for both density-dependent and frequency-dependent transmission.

When and why do sit-and-wait social spiders disperse?

2019 ◽  
Vol 66 (1-2) ◽  
pp. 15-25
Author(s):  
Bharat Parthasarathy ◽  
Hema Somanathan
Keyword(s):  
Information Transfer ◽  
Spatial Scales ◽  
Structured Populations ◽  
Social Spiders ◽  
Intrinsic Factors ◽  
Area Of Interest ◽  
Evolution Of Sociality ◽  
Dispersal Distances ◽  
Complex Relationships ◽  
Living Organisms

Abstract Dispersal is inherent to all living organisms. Sit-and-wait predators such as social spiders, with their sedentary lifestyles, present an intriguing and underexplored case to examine the proximate and ultimate reasons for dispersal. Though a reduction in dispersal tendencies must accompany the evolution of sociality in spiders, a fraction of the colony may disperse in groups or individually in many species. Such group or solitary dispersal by female social spiders in specific life stages, can lead to colony fission or colony foundation. Males move between colonies, however, there are no direct estimations of male dispersal distances for any species. The structured populations and high inbreeding within colonies suggest that dispersal events occur over limited spatial scales and may be mediated by extrinsic and intrinsic factors. Future studies exploring complex relationships between environmental variables, phenotypes of individuals, colony state and dispersal are advocated. Another area of interest is probing the dispersal process itself to understand the mechanisms of information transfer between individuals at the onset of dispersal. This involves designing studies to examine how break-away groups reach a consensus on when to disperse and where to go.

scholarly journals Parrots do not show inequity aversion

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Anastasia Krasheninnikova ◽  
Désirée Brucks ◽  
Nina Buffenoir ◽  
Dániel Rivas Blanco ◽  
Delphine Soulet ◽  
...  
Keyword(s):  
Mammalian Species ◽  
Inequity Aversion ◽  
Comparative Approach ◽  
Cooperative Interactions ◽  
Unequal Treatment ◽  
Token Exchange ◽  
Group Members ◽  
Parrot Species ◽  
High Condition

Abstract Inequity aversion, the negative reaction to unequal treatment, is considered a mechanism for stabilizing cooperative interactions between non-kin group members. However, this might only be adaptive for species that switch cooperative partners. Utilizing a comparative approach, inequity aversion has been assessed in many mammalian species and recently also in corvids and one parrot species, kea, revealing mixed results. To broaden our knowledge about the phylogenetic distribution of inequity aversion, we tested four parrot species in the token exchange paradigm. We varied the quality of rewards delivered to dyads of birds, as well as the effort required to obtain a reward. Blue-headed macaws and African grey parrots showed no reaction to being rewarded unequally. The bigger macaws were less willing to exchange tokens in the “unequal” condition compared to the “equal high” condition in which both birds obtained high quality rewards, but a closer examination of the results and the findings from the control conditions reveal that inequity aversion does not account for it. None of the species responded to inequity in terms of effort. Parrots may not exhibit inequity aversion due to interdependence on their life-long partner and the high costs associated with finding a new partner.

White-winged vampire bats (Diaemus youngi) exchange contact calls

2009 ◽  
Vol 87 (7) ◽  
pp. 604-608 ◽  
Author(s):  
G. G. Carter ◽  
M. B. Fenton ◽  
P. A. Faure
Keyword(s):  
Group Living ◽  
Social Contact ◽  
Social Calls ◽  
Equal Distance ◽  
Antiphonal Calling ◽  
Vampire Bats ◽  
Contact Calls ◽  
Living Species ◽  
Group Members ◽  
Vampire Bat

Temporally precise vocal exchanges, termed “antiphonal calling”, might allow pair or group members to maintain social contact with greater efficiency than when calling independently. The white-winged vampire bat ( Diaemus youngi (Jentink, 1893)) is a group-living species that produces social calls in antiphonal exchanges. Because white-winged vampire bats can use social calls to discriminate conspecifics, we suspect that one function of these vocal exchanges is to allow group members to know who is where. Here, we tested the prediction that antiphonal calling by groups of white-winged vampire bats increases when the spatial positions of conspecifics change. We recorded social calls from groups of four individually caged bats in total darkness, with each bat located in the corner of a 4 m × 4 m room. During test trials, we shifted the spatial positions of caged bats to new positions. During control trials, caged bats were displaced an equal distance but were returned to their original positions. We found that both the number of social calls and the proportion of antiphonal exchanges were greater during test trials than during control trials. These results suggest that white-winged vampire bats use antiphonal exchanges of social calls to monitor the spatial positions of conspecifics.

Chemical cues and group association preferences in a subsocial cockroach, Panesthia australis

2009 ◽  
Vol 57 (6) ◽  
pp. 385 ◽  
Author(s):  
Zacariah D. Billingham ◽  
David G. Chapple ◽  
Paul Sunnucks ◽  
Bob B. M. Wong
Keyword(s):  
Chemical Cues ◽  
Social Systems ◽  
Group Living ◽  
Social Recognition ◽  
Restricted Gene Flow ◽  
Diverse Range ◽  
Living Species ◽  
Group Members ◽  
Wood Boring

An ability to recognise and discriminate between group and non-group members is essential for most group-living species. Several different sensory modalities may be utilised for social recognition, the most notable of which is olfaction. Among insects, members of the order Blattodea (cockroaches, termites) exhibit a diverse range of social systems and provide an excellent model for examining the role of chemical communication in group discrimination. We experimentally tested the importance of chemical cues in the association preferences of the subsocial Australian wood-boring cockroach, Panesthia australis. Using a series of dichotomous choice trials, we found that individuals preferred conspecific odour cues over those of an unscented peatmoss control. We then gave cockroaches a choice between the odour cues of cockroaches from different logs, and found that they did not exhibit a preference for the cues of individuals from their own log versus those from different logs within the same locality. However, cockroaches exhibited a strong preference for cues taken from individuals from a geographically distant population. Our findings suggest that P. australis engages in group discrimination, and that patterns of association may reflect an underlying preference for unfamiliar and/or genetically dissimilar individuals in a species encumbered by restricted gene flow.

Collective behaviour of wild Asian elephants in risky situations: how do social groups cross roads?

Behaviour ◽  
2017 ◽  
Vol 154 (12) ◽  
pp. 1215-1237 ◽  
Author(s):  
Kaori Mizuno ◽  
Nachiketha Sharma ◽  
Gen’ichi Idani ◽  
Raman Sukumar
Keyword(s):  
National Park ◽  
Group Living ◽  
Age Classes ◽  
Asian Elephants ◽  
The Road ◽  
Traffic Characteristics ◽  
Group Members ◽  
On The Road ◽  
Free Ranging ◽  
Road Crossing

Among group-living animals, some members may derive benefit by following the decisions of other members. Free-ranging wild Asian elephants in Mudumalai National Park, southern India, must often cross roads and can be disturbed by vehicles. We assessed if measures of road and traffic characteristics serve as indicators of risk, and compared behaviours of different age classes during road-crossing events. More individuals displayed excitable behaviour on wider roads. A larger number of adults entered the road first, which is considered the most dangerous position, compared with immature elephants. Immature individuals tended to move ahead of others on the road, suggesting that it is more important for immature individuals to follow adults at the beginning of a crossing than to follow along for the entire crossing. These findings may suggest that less experienced group members derive benefit by following the decisions of experienced ones under risky situations.

scholarly journals Adaptation and the genetics of social behaviour

2009 ◽  
Vol 364 (1533) ◽  
pp. 3209-3216 ◽  
Author(s):  
Laurent Keller
Keyword(s):  
Social Behaviour ◽  
Social Evolution ◽  
Division Of Labour ◽  
Chemical Signalling ◽  
Insect Societies ◽  
Genetic Mechanisms ◽  
Selective Forces ◽  
Group Members ◽  
Reproductive Division Of Labour ◽  
Reproductive Division

In recent years much progress has been made towards understanding the selective forces involved in the evolution of social behaviour including conflicts over reproduction among group members. Here, I argue that an important additional step necessary for advancing our understanding of the resolution of potential conflicts within insect societies is to consider the genetics of the behaviours involved. First, I discuss how epigenetic modifications of behaviour may affect conflict resolution within groups. Second, I review known natural polymorphisms of social organization to demonstrate that a lack of consideration of the genetic mechanisms involved may lead to erroneous explanations of the adaptive significance of behaviour. Third, I suggest that, on the basis of recent genetic studies of sexual conflict in Drosophila , it is necessary to reconsider the possibility of within-group manipulation by means of chemical substances (i.e. pheromones). Fourth, I address the issue of direct versus indirect genetic effects, which is of particular importance for the study of behaviour in social groups. Fifth, I discuss the issue of how a genetic influence on dominance hierarchies and reproductive division of labour can have secondary effects, for example in the evolution of promiscuity. Finally, because the same sets of genes (e.g. those implicated in chemical signalling and the responses that are triggered) may be used even in species as divergent as ants, cooperative breeding birds and primates, an integration of genetic mechanisms into the field of social evolution may also provide unifying ideas.

Larger lizards live longer in the group-living Egernia stokesii

2016 ◽  
Vol 64 (3) ◽  
pp. 182 ◽  
Author(s):  
S. K. Pearson ◽  
S. S. Godfrey ◽  
C. M. Bull ◽  
M. G. Gardner
Keyword(s):  
Site Fidelity ◽  
Group Living ◽  
Space Use ◽  
Limited Attention ◽  
Field Surveys ◽  
Evolution Of Sociality ◽  
Short Period ◽  
Recent Attention ◽  
Egernia Stokesii

Animal space use has implications for gene flow, disease dynamics, mating systems and the evolution of sociality. Given recent attention to sociality in reptiles, lizards are an important group for expanding our understanding of animal space use. Lizard space use is commonly investigated within one population over a short period and limited attention has been given to potential predictors of site fidelity. This study evaluated site fidelity in three populations of group-living Egernia stokesii (gidgee skink) between two field surveys separated by almost a decade. Of 43 recaptured lizards, 28 (65%) occupied their original space, and 15 (36%) of those shared their space with the same other lizard or lizards in both surveys. This confirmed long-term site and social bond fidelity in E. stokesii. We found that larger lizards were more likely to be recaptured. Neither body size, individual genetic heterozygosity, nor the availability of refuges strongly predicted whether lizards were recaptured in the same or a different place. The reasons why some lizards stayed in the same space while others moved are yet to be resolved.

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