Reintroduction of species

Species reintroduction is the deliberate release of a species into the wild, from captivity or other places where the organism is capable of survival. The goal of species reintroduction is to establish a healthy, genetically diverse , self-sustaining population in the area where it was exterminated, or to increase an existing population . Species that may be eligible for reintroduction are usually endangered in the wild. However, reintroduction of a species can also be used for pest control ; for example, wolves are reintroduced into the wild to curb overpopulation of deer. Because reintroduction can involve the return of native species to places where they have been exterminated, some prefer the term ” recovery “.

For millennia, humans have reintroduced species for pest and food control. However, the practice of reintroduction for conservation is much younger, dating back to the 20th century.

There are many approaches to reintroducing species. The optimal strategy will depend on the biology of the organism. The first question to be addressed when starting reintroduction of a species is whether to source individuals in situ, from wild populations, or ex situ, such as from captivity in a zoo or botanical garden.

In situ sources for restoration include moving individuals from an existing wild population to a new location where the species has previously been extirpated. Ideally, populations should be obtained in situ whenever possible because of the many risks associated with reintroducing organisms from captive populations back into the wild. To ensure that reintroduced populations have the best chance of survival and reproduction, individuals should come from populations that genetically and ecologically resemble the recipient population. Generally, sampling from populations with similar environmental conditions to the reintroduction site maximizes the chance that reintroduced individuals will adapt well to the habitat of the reintroduction site.

One factor affecting in situ sourcing is at what life stage the organisms are to be collected, transported, and reintroduced. For example, in the case of plants, it is often best to transport them as seeds, as they have the best chance of surviving translocation at this stage. However, some plants are difficult to grow as seeds and may need to be translocated into juveniles or adults.

In situations where in situ collection of individuals is not possible, such as for rare and endangered species where too few individuals exist in the wild, ex situ collection is possible . Ex situ collection methods allow for the storage of individuals with high reintroduction potential. Examples of storage include germplasm stored in seed banks, sperm and egg banks, cryopreservation and tissue culture. Methods that allow storage of large numbers of individuals also aim to maximize genetic diversity. Stored materials usually have a long shelf life, but some species lose viability when stored as seeds. Tissue culture and cryopreservation methods have only been perfected for a few species.