• Allometry;
  • conservation;
  • planning;
  • dispersal;
  • metapopulation;
  • simulation;
  • spatial


Designing reserve networks often requires a tradeoff between maximizing patch sizes to decrease local extinction rates and clustering patches to increase colonization rates. Here we use stochastic metapopulation models to evaluate how this tradeoff affects landscape-wide extinction risk for idealized terrestrial mammals with body sizes from 10 g to 100 kg. In simple two-patch networks, clustering patches decreases extinction risk only when inter-patch distances are within 0.5–1.25 times a species’ maximum observed dispersal distance. In an empirical landscape in which a fixed total area can be protected, this finding accurately predicts that, relative to a network that maximizes mean patch area, clustering patches most decreases extinction risk for intermediate-sized species. These results demonstrate that there is no globally optimal level of patch clustering that will best protect all species and highlight rules of thumb for reserve network design based on the interaction of species’ body size and landscape scale.