other individuals familiar from earlier in life when foraging, but select for partners that are 38 unfamiliar during mate choice. We found no effect of either personality or dominance on 39 foraging associations or mate choice. Our study shows how using social network analysis can 40 increase our understanding of the drivers behind population structure (in our case kin 41 selection and inbreeding avoidance). Moreover, our study demonstrates that social networks 42 can be largely determined by long-term processes, in particular early-life familiarity. Flack et al. 2006; Lusseau et al. 2011; Hirsch et al. 2012; Madden et al. 2012 based on earlier findings in this species (Choudhury & Black 1994; Black & Owen 1995). 90We had no a priori expectations in respect of dominance or boldness (Schuett et al. 2010). and Sons, 't Zand, the Netherlands) and after the experiments geese were returned to the 115 breeding farm. were circa two years of age. Two weeks before, the geese were separated into two single-sex 120 flocks, allowing the study of sex-specific factors that may contribute to association 121 preferences while avoiding any confounding inter-sexual interactions. We thus performed our 122 observations on one group consisting of all males, and one group consisting of all females. were seen together out of the total number of times those individuals were observed, thereby 141 controlling for inter-individual differences in the total number of sightings. SRI tends to be a Statistical analysis 227To analyse our data we developed a novel node-label permutation test with general(ized) 228 linear models fitted to linearized similarity / dissimilarity matrices. We used the SRI matrix as unscrambled general linear models, the residuals were visually inspected for normality. The 236 columns were scrambled in the same order as the rows to maintain the inherent properties of 237 the matrix which prevents impossible matrices being generated. We refer to this method as 238 MRMPA (Multiple Regression Matrix-Permutation using AIC). Scrambling was repeated 239 10,000 times. We fitted separate models for females and males. To calculate the effect sizes 240 and standard errors of the variables in the models we linearized the matrices and extracted a 255To analyse the determinants of mate choice we used the (binary) mate pair matrix as 256 the dependent variable and fitted as independent variables the familiarity matrix, the genetic 257 relatedness matrix and the boldness distance matrix. The significance of each independent 258 variable was calculated using a similar procedure as described above (MRMPA) but with two 265This was repeated 10,000 times, after which we calculated the mean estimate and the mean females having relatively few strong and many weak connections (Fig. 2a, Appendix 1). 286Female geese associated significantly more with individuals from the same familiarity group 287 (MRMPA: P < 0.0001, Table 1, Fig. 3a, 4). A strong, highly significant association was found 288 between genetic relatedness and associatio...

In group-living species, decisions made by individuals may result in collective behaviours. A central question in understanding collective behaviours is how individual variation in phenotype affects collective behaviours. However, how the personality of individuals affects collective decisions in groups remains poorly understood. Here, we investigated the role of boldness on the decision-making process in different-sized groups of barnacle geese. Naive barnacle geese, differing in boldness score, were introduced in a labyrinth in groups with either one or three informed demonstrators. The demonstrators possessed information about the route through the labyrinth. In pairs, the probability of choosing a route prior to the informed demonstrator increased with increasing boldness score: bolder individuals decided more often for themselves where to go compared with shyer individuals, whereas shyer individuals waited more often for the demonstrators to decide and followed this information. In groups of four individuals, however, there was no effect of boldness on decision-making, suggesting that individual differences were less important with increasing group size. Our experimental results show that personality is important in collective decisions in pairs of barnacle geese, and suggest that bolder individuals have a greater influence over the outcome of decisions in groups.

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