Figure 1. Simplified illustration of the Voronoi-like field generation process.

Here, a 101×101 unit arena is populated with 50 field seeds that are randomly placed on unit cells (a). The nearest seed is calculated for all the cells within the arena (with random allocation if several seeds are equally closest). If a cell possesses at least one neighbour that does not share its nearest seed, it is designated an ‘edge’ cell, whereas cells where all four neighbours share the same nearest seed are designated ‘field’ cells: (b) shows black edge and white field cells for the field seeds given in (a). To calculate wild edge cell availability nest sites are randomly placed on edge cells, and the numbers of edge and field cells are tallied within a given foraging radius of the nest (the area within the grey circle in c).