Figure 2.

Cluster selection and the use of buffer zones. Hypothetical buffer zones of 2.5 km radius (shown as blue discs) around villages (shown as blue dots) potentially allow for the establishment of multiple clusters on a single island (a). Buffer zones of 5 km radius, requiring villages to be at least 10 km apart, would prevent nearby villages from being in different intervention clusters (b). As a result, some villages (shown in orange) could be excluded from the study (c). Adapted from OpenStreetMap. Credit: © OpenStreetMap contributors.