Turning the threat of hybridization into an asset for conserving wild species by backcrossing

Captive breeding programs working to avoid the loss of threatened wild species are often working with a limited gene pool of founder individuals which can only be increased with difficulty. As usually hybridization with common species is seen as a threat to rare species, this commentary proposes the hybridization and recurrent backcrossing of common species with rare ones to turn this threat into an asset. After several generations of backcrossing, the backcrossed individuals would be virtually indistinguishable from the rare species, therefore performing the same ecosystem functions. This commentary presents where common species can be backcrossed with rare species to obtain an animal which is essentially and functionally the rare, threatened species to preserve biodiversity. To do so without threatening the rare species, surplus or non-reproducing males of the rare species must be used on females of common species, and only the female crossbred offspring reproduced. By further backcrossing the crossbred females to pure rare males, the offspring becomes indistinguishable from purebred individuals.