Network-structure curves and SRI distributions by season. Black curves show the number of Girvan-Newman clusters in the thresholded network (left y-axis). Gray bars show the fraction of dyads with the given SRI value (right y-axis). Red dots show the points at which the network-structure curves display slope changes at the significance level of 0.05 or below with the window size w = 0.2 (see Methods; exact P-values for this and other window sizes are shown in Additional file 8: Figure S7). While the majority of ties are weaker than 0.2 in both real and randomized data, the distribution has a long tail in real data but not in randomized data. Randomized network shows no ties above a threshold of 0.5, and a nearly level network structure curve up to this threshold with no significant slope changes. In contrast, observed networks for each season show peaked curves with significant changes in slope. Qmax remains above 0.6 for real data while for randomized data it peaks and falls sharply (see Additional file 9: Figure S8).
de Silva et al. BMC Ecology 2011 11:17 doi:10.1186/1472-6785-11-17