The consistency of individual centrality across time and networks in wild vervet monkeys
Previous primate social network studies largely limited their focus to grooming and/or aggression networks, particularly among adult females. In addition, the consistency of individuals' network centrality across time and/or different networks has received little attention, despite this being critical for a global understanding of dynamic social structure. Here, we analyzed the grooming, aggression, and play social networks of a group of 26-28 wild vervet monkeys (Chlorocebus pygerythrus), including adults and juveniles, over two periods of 6 months. We collected data on grooming, play, and aggression using focal animal sampling with instantaneous recording and ad libitum sampling. We exami…
The effects of data collection and observation methods on uncertainty of social networks in wild primates
International audience; In social species, network centralities of group members shape social transmission and other social phenomena. Different factors have been found to influence the measurement of social networks, such as data collection and observation methods. In this study, we collected data on adults and juveniles and examined the effect of data collection method (ad libitum sampling vs. focal animal sampling) and observation method (interaction—grooming; play—vs. association—arm‐length; 2 m; 5 m proximities—) on social networks in wild vervet monkeys. First, we showed using a bootstrapping method, that uncertainty of ad libitum grooming and play matrices were lesser than uncertaint…
Simulated poaching affects global connectivity and efficiency in social networks of African savanna elephants-An exemplar of how human disturbance impacts group-living species
Selective harvest, such as poaching, impacts group-living animals directly through mortality of individuals with desirable traits, and indirectly by altering the structure of their social networks. Understanding the relationship between disturbance-induced, structural network changes and group performance in wild animals remains an outstanding problem. To address this problem, we evaluated the immediate effect of disturbance on group sociality in African savanna elephants—an example, group-living species threatened by poaching. Drawing on static association data from ten free-ranging groups, we constructed one empirically based, population-wide network and 100 virtual networks; performed a …
Hierarchical networks of food exchange in the black garden ant Lasius niger
In most eusocial insects, the division of labour results in relatively few individuals foraging for the entire colony. Thus, the survival of the colony depends on its efficiency in meeting the nutritional needs of all its members. Here, we characterise the network topology of a eusocial insect to understand the role and centrality of each caste in this network during the process of food dissemination. We constructed trophallaxis networks from 34 food-exchange experiments in black garden ants (Lasius niger). We tested the influence of brood and colony size on (i) global indices at the network level (i.e. efficiency, resilience, centralisation and modularity) and (ii) individual values (i.e. …
Null models for animal social network analysis and data collected via focal sampling: Pre‐network or node network permutation?
In social networks analysis, two different approaches have predominated in creating null models for hypothesis testing, namely pre‐network and node network permutation approaches. Although the pre‐network permutation approach appears more advantageous, its use has mainly been restricted to data on associations and sampling methods such as ‘group follows’. The pre‐network permutation approach has recently been adapted to data on interactions and the focal sampling method, but its performance in different scenarios has not been thoroughly explored. Here, we assessed the performance of the pre‐network and node network permutation approach in several simulated scenarios based on proneness to fa…
Network measures in animal social network analysis : Their strengths, limits, interpretations and uses
International audience; We provide an overview of the most commonly used social network measures in animal research for static networks or time‐aggregated networks. For each of these measures, we provide clear explanations as to what they measure, we describe their respective variants, we underline the necessity to consider these variants according to the research question addressed, and we indicate considerations that have not been taken so far. We provide a guideline indicating how to use them depending on the data collection protocol, the social system studied and the research question addressed. Finally, we inform about the existent gaps and remaining challenges in the use of several va…
Opposing Forces of Social Attraction and Social Avoidance Drive Network Modularity
SUMMARY: How interactions between individuals contribute to the emergence of complex societies is a major question in biology. Nonetheless, little remains known about how simple rules of social attraction (e.g. to information) and social avoidance (e.g. of disease) interact to shape sociality. We developed an individual-based model where individuals choose with whom to interact depending on the status of group mates (informed and/or infected). Statistical models indicate that the emergence of social structure depends on the cost/benefit trade-offs underlying the system. Critically, pressures that optimize social relationships – i.e. minimize risky connections while favouring those that maxi…
Mechanisms of reciprocity and diversity in social networks: a modeling and comparative approach
Individual-based computer models show that different mechanisms, proximity-based or emotional bookkeeping, can lead to reciprocation. By comparing social networks from different computer models with those of empirical data, we show that the models’ social networks bear limited resemblance with some features of the observed social networks. This indicates that additional social processes (third-party awareness) may be needed in these models to represent more accurately the social behavior and interaction patterns observed in group-living animals.
A multilevel statistical toolkit to study animal social networks: Animal Network Toolkit (ANT) R package
AbstractHow animals interact and develop social relationships regarding, individual attributes, sociodemographic and ecological pressures is of great interest. New methodologies, in particular Social Network Analysis, allow us to elucidate these types of questions. However, the different methodologies developed to that end and the speed at which they emerge make their use difficult. Moreover, the lack of communication between the different software developed to provide an answer to the same/different research questions is a source of confusion. The R package Animal Network Toolkit (ANT) was developed with the aim of implementing in one package the many different social network analysis tech…