Distribution map of Norway rats in the Falkland Islands. Islands with rats (red points) appear in clusters. We hypothesize that rats are able to move between islands that are geographically close. Islands without rats (blue points) are typically farther from the mainland (East and West Falkland). Islands were assigned to geographic sectors based on their location: islands closer to West Falkland are in the western sector, while islands closer to East Falkland are in the eastern sector.