Fig. 5. Diagrammatic representation of six territories (A, B, C, D, E, and F), showing two dispersals (solid lines) and four dispersal opportunities (solid and dotted lines). A and C are termed dispersal origins and B and D are destinations (vacancies). B and D are defined as vacancies because dispersers moved into them from elsewhere. Note that territories E and F, although present in the population, would not be involved in the simulation because they contain neither dispersers nor vacancies, nor potential dispersers subsequently lost.