Figure 3. Average probability of finding a metapopulation size above 50, 100 or 250 individuals as a function of the length of the zoo cluster radial distance (upper row), average number of zoos where the species is found as a function of the radial distance (middle row) and ratio between the probability of finding the metapopulation and the radial distance (lower row) for each taxonomic class of terrestrial vertebrates.

When the ratio is highest, we obtain the optimal radial distance between zoos and the optimal probability of finding a metapopulation size above the threshold. This is, at that ratio the probability of finding the metapopulation is highest with respect to the zoo cluster radial distance. For display purposes all ratios were multiplied by 1,000.