fugitive species (opportunist species) A species typical of unstable or periodically extreme environments, e.g. deserts or ephemeral ponds, and characterized by a strong dispersal ability. Such organisms are typically smaller than equilibrium species and have shorter life cycles. Hence initially they can colonize an area rapidly during a favourable period, though in the longer term they may lose out in competition with equilibrium species.

fugitive species(opportunist species) A species typical of unstable or periodically extreme environments, e.g. deserts or ephemeral ponds, and characterized by a strong dispersal ability. Such organisms are typically smaller than equilibrium species and have shorter life cycles. Hence initially they can colonize an area rapidly during a favourable period, though in the longer term they may lose out in competition with equilibrium species.

fugitive species A species that is able to coexist with a competitively superior species due to its better dispersal capabilities. The fugitive species is quicker to exploit any vacant patches in the environment that become available (for example due to a fire or storm), colonizing and reproducing before the more competitive species occupies the patch and excludes it. For example, the sea palm (Postelsia palmaeformis, a brown alga) colonizes bare patches in mussel beds off the northwestern coast of the USA. When a patch is created by wave action, the alga attaches itself to the bare rock, only to be gradually excluded as the surrounding mussels encroach. Although it is eventually driven from each site, the fugitive alga can coexist with the mussels provided sufficient bare patches become available.