[3] The rescue effect is remarkably important in areas where the persistence of a species is threatened because of the increasing rates of habitat destruction and fragmentation.
This is a clear example, of how the reduction or elimination of interpatch movement and consequently the lack of the rescue effect, is directly related with the abundance and patch occupancy of a species.
This is particularly true in species that represent early stages in insular taxon cycles and are characterized by species-area curves of shallow slope.
[1] Another common principle relating both with the rescue effect and the previously commented insular biogeography is the dispersal capabilities of a species.
[1] A reduction in the fitness (biology) of a population is a direct consequence of its low diversity which is dependent on the expression of deleterious recessive alleles.
This means that immigrants make a positive contribution to fitness over and above the demographic effects of simply adding more individuals, by bringing novel alleles to the population.
[12] This means that if an environmental phenomena diminishes the distributions or abundances of many populations over a large geographical area at the same time, the probabilities of a rescue effect are very low.