Fig. 8: Worker navigation within module gradient fields.
From: Two simple movement mechanisms for spatial division of labour in social insects
Panels (a–d) illustrate the direction-dependent modulation of turning behaviour within the gradient field for an example focal module (the nurse module of the same L. acervorum colony as shown in Fig. 7). a, b Calculating the gradient field. a Module score map for the focal module. b The focal module gradient field, derived from local spatial regressions on the site scores. The blow-up shows a transect across the border. Arrow heading and length indicate respectively the field direction and steepness. c, d Relative turn angles for residents (in this example, nurses) and non-residents heading down- and up-gradient in the field of the focal (nurse) module. Blow-ups in (c): residents heading down-gradient in the field of their primary module (\({\bar{\theta }}_{i,s,{M}_{i}}^{down}\)) exhibit larger turn angles than the average worker heading down-gradient at the same site in the same field (\({\bar{\theta }}_{s,{M}_{i}}^{down}\)), and so generally have positive relative turn angles (i.e., are less likely than average to leave the focal module). Blow-ups in d: residents heading up-gradient (\({\bar{\theta }}_{i,s,{M}_{i}}^{up}\)) exhibit smaller turn angles than the average worker (\({\bar{\theta }}_{s,{M}_{i}}^{up}\)) and so generally have negative relative turn angles (i.e, are more likely to enter the focal module). e–h Relative turn angles for workers heading down- or up-gradient (red & blue respectively) of their primary module, as a function of the gradient field steepness. All modules and all workers were included in this analysis. Points & error bars represent grand means and standard errors, calculated from the 50 colony means. Shaded areas represent the 95% confidence intervals after Bonferroni corrections. The dashed line represents the null expectation that residents and non-residents behave in the same way when approaching the module border. All analyses based on n = 613100 sites, and n = 12494 workers, drawn from n = 50 colonies. Source data are provided as a source data file.
