Captive breeding Captive breeding is the process of breeding rare or endangered species in human controlled environments with restricted settings, such as wildlife reserves, zoos, and other conservation facilities. Captive breeding is meant to save species from extinction and so stabilise the population of the species that it will not disappear. This technique has worked for many species for some time, with probably the oldest known such instances of captive mating being attributed to menageries of European and Asian rulers, an example being the
Père David's deer. However, captive breeding techniques are usually difficult to implement for such highly mobile species as some migratory birds (e.g. cranes) and fishes (e.g.
hilsa). Additionally, if the captive breeding population is too small, then inbreeding may occur due to a reduced
gene pool and reduce
resistance. In 1981, the
Association of Zoos and Aquariums (AZA) created a
Species Survival Plan (SSP) to help preserve specific endangered and threatened species through captive breeding. With over 450 SSP Plans, some endangered species are covered by the AZA with plans to cover population management goals and recommendations for breeding for a diverse and healthy population, created by Taxon Advisory Groups. These programs are commonly created as a last resort effort. SSP Programs regularly participate in species recovery, veterinary care for wildlife disease outbreaks, and some other wildlife conservation efforts. The AZA's Species Survival Plan also has breeding and transfer programs, both within and outside of AZA – certified zoos and aquariums. Some animals that are part of SSP programs are
giant pandas, lowland gorillas, and
California condors.
Private farming Whereas poaching substantially reduces endangered animal populations, legal, for-profit, private farming does the opposite. It has substantially increased the populations of the southern
black rhinoceros and southern
white rhinoceros. Richard Emslie, a scientific officer at the IUCN, said of such programs, "Effective law enforcement has become much easier now that the animals are largely privately owned... We have been able to bring local communities into conservation programs. There are increasingly strong economic incentives attached to looking after rhinos rather than simply poaching: from Eco-tourism or selling them on for a profit. So many owners are keeping them secure. The private sector has been key to helping our work." Conservation experts view the effect of China's
turtle farming on the wild turtle populations of China and
South-Eastern Asia– many of which are endangered– as "poorly understood". Although they commend the gradual replacement of turtles caught wild with
farm-raised turtles in the marketplace– the percentage of farm-raised individuals in the "visible" trade grew from around 30% in 2000 to around 70% in 2007– they worry that many wild animals are caught to provide farmers with breeding stock. The conservation expert Peter Paul van Dijk noted that turtle farmers often believe that animals caught wild are superior breeding stock. Turtle farmers may, therefore, seek and catch the last remaining wild specimens of some endangered turtle species.
Conservation baselines and proposed paradigm shifts Some scientists have proposed that redefining the baseline for assessing recovery of an endangered species may be necessary as a last resort in the face of extinction, as the increased flexibility provides more realistic recovery goals in the face of extinction. This strategy, however, needs to be pursued with significant care and is typically not considered before attempting recovery within the natural range when possible, due to carrying additional risks and potential unintended consequences.
American bald eagle Once on the brink of extinction in the contiguous United States with only 417 known nesting pairs in 1963 due to pesticide use and habitat destruction, the
bald eagle population has made a remarkable recovery. By 2020, the number of nesting pairs had surged to 71,400. Major strategies employed to help raise populations included the provision of eaglets from stable regions to more threatened regions, and major land purchases to act as sanctuaries for the eagles. Thanks to habitat protection, legal protection, and DDT ban efforts, the bald eagle was removed from the list of threatened and endangered species.
Gray wolf Starting in 1995 and 1996, 31
gray wolves from
western Canada were relocated to
Yellowstone, where they were temporarily kept in acclimation pens before being released into the wild. This careful reintroduction aimed to restore a key predator to the ecosystem, which had profound effects on the park's wildlife dynamics. After being nearly eradicated in the lower 48 states by the early 20th century, reintroduction and protective measures have allowed their populations to rebound significantly. By 2017, gray wolves were delisted in
Montana,
Idaho, and
Wyoming, indicating a recovery to a point where they were no longer considered endangered in these areas.
Channel Island fox Beginning in 1999, the
Channel Islands National Park launched an ambitious recovery program for the
island fox, incorporating several strategies: captive breeding and reintroduction, removal of predatory golden eagles, re-establishment of bald eagles, and eradication of non-native ungulates. The
U.S. Department of the Interior officially recognized the recovery as the fastest for any Endangered Species Act-listed mammal in the U.S., announcing the delisting of three island fox subspecies in 2016. This recovery, from near extinction in the late 1990s to robust populations by the mid-2010s, underscores the power of partnership-driven conservation.
Purple Emperor butterfly The
Purple Emperor, native to the UK, has seen a significant comeback in recent years, expanding from southern England to a large portion of the British Isles. Conservation groups have aided this process through the planting of
goat willows in many forests, an important food source for the butterfly larvae. The territorial nature of the species makes this process more complicated, requiring many willow trees be planted over a large area, but groups such as Butterfly Conservation have made the recovery process possible. == Gallery ==