Reintroduction of species to sites where they have become extinct and reinforcement of severely depleted populations have become essential tools in rewilding and ecosystem restoration initiatives.
The Arabian Oryx became Extinct in the Wild in the 1970s. It was reintroduced into Oman in 1982, marking the first time a large mammal had been successfully restored to the wild. This operation set the pattern for further releases of that species at other sites in the Arabian Peninsula, and for similar initiatives involving other antelope species elsewhere.
IUCN has developed standard guidelines on reintroductions and other conservation translocations https://portals.iucn.org/library/efiles/documents/2013-009.pdf
The IUCN SSC Conservation Translocation Specialist Group provides expertise and advice on all aspects of animal and plant reintroductions https://iucn-ctsg.org/