DOI: 10.5061/dryad.69p8cz93x
title: Group and individual social network metrics are robust to changes in resource distribution in experimental populations of forked fungus beetles

description: Social interactions drive many important ecological and evolutionary
 processes. It is therefore essential to understand the intrinsic and
 extrinsic factors that underlie social patterns. A central tenet of the
 field of behavioral ecology is the expectation that the distribution of
 resources shapes patterns of social interactions. We combined experimental
 manipulations with social network analyses to ask how patterns of resource
 distribution influence complex social interactions. We experimentally
 manipulated the distribution of an essential food and reproductive
 resource in semi-natural populations of forked fungus beetles
 (Bolitotherus cornutus). We aggregated resources into discrete clumps in
 half of the populations and evenly dispersed resources in the other half.
 We then observed social interactions between individually marked beetles.
 Half-way through the experiment, we reversed the resource distribution in
 each population, allowing us to control any demographic or behavioral
 differences between our experimental populations. At the end of the
 experiment, we compared individual and group social network
 characteristics between the two resource distribution treatments. We found
 a statistically significant but quantitatively small effect of resource
 distribution on individual social network position and detected no effect
 on group social network structure. Individual connectivity (individual
 strength) and individual cliquishness (local clustering coefficient)
 increased in environments with clumped resources, but this difference
 explained very little of the variance in individual social network
 position. Individual centrality (individual betweenness) and measures of
 overall social structure (network density, average shortest path length,
 and global clustering coefficient) did not differ between environments
 with dramatically different distributions of resources. Our results
 illustrate that the resource environment, despite being fundamental to our
 understanding of social systems, does not always play a central role in
 shaping social interactions. Instead, our results suggests that sex
 differences and temporally fluctuating environmental conditions may be
 more important in determining patterns of social interactions.
description: These data describe patterns of social interaction in 12
 experimental populations of <em>Bolitotherus cornutus</em>.
 Each population experienced both a clumped and an even distribution of
 bracket fungi resources over two different three-week observation periods
 (i.e. the resource distribution was switched between observation periods).
 Social interactions were defined as individuals in close proximity (within
 5cm) of one another and were collected through scan sampling three times a
 day. Behavioral datasets were error-checked to remove all unidentifiable
 beetles and all impossible or partially recorded interactions. Weigthed
 individual and group social network metrics were calcualted from observed
 social interactions using the simple ratio index. Network density was
 calculated in the R package sna. All other weighted social network metrics
 were calculated in the R package tnet.
description: These data are organized into two different datasets:
 "IndividSN.csv" and "groupSN.csv". Variable names for
 each dataset are described in the attached readme file
 "README_Costello.txt". Briefly, "IndividSN.csv" lists
 weighted individual social network metrics for each individual forked
 fungus beetle during each observation period. Beetles with one or no
 social partners have undefined local clustering coefficients (variable
 "am"). "groupSN.csv" lists weighted group social
 network metrics for each experimental population of forked fungus beetles
 during each observation period.