Ex situ conservation of animals takes place mainly in zoos, wildlife parks and aquaria. Their main conservation role is captive breeding: building up the numbers of endangered species in safety, ideally so that they can be returned to the wild.Captive populations are often founded from a small number of animals, so genetic diversity is low and there is a risk of inbreeding (breeding between close relatives). Inbreeding increases the chance that offspring inherit two copies of a harmful recessive allele. To reduce this, zoos:
• keep a studbook, a record of every animal's ancestry, and use it to choose unrelated breeding pairs;
• exchange animals between zoos in different countries;
• use artificial insemination, IVF and embryo transfer, so that sperm or embryos can be moved instead of whole animals;
• store frozen sperm, eggs and embryos in a frozen zoo.Releasing captive-bred animals back into their natural habitat is called reintroduction. The Arabian oryx became extinct in the wild but survived in captivity and was reintroduced to Oman and other parts of the Middle East.Zoos also carry out research and educate the public. However, ex situ conservation has problems: some species will not breed in captivity, animals may lose natural behaviours such as hunting or avoiding predators, disease can spread in captivity, and it is expensive. Reintroduction fails if the original threats, such as habitat loss or poaching, have not been removed.
• keep a studbook, a record of every animal's ancestry, and use it to choose unrelated breeding pairs;
• exchange animals between zoos in different countries;
• use artificial insemination, IVF and embryo transfer, so that sperm or embryos can be moved instead of whole animals;
• store frozen sperm, eggs and embryos in a frozen zoo.Releasing captive-bred animals back into their natural habitat is called reintroduction. The Arabian oryx became extinct in the wild but survived in captivity and was reintroduced to Oman and other parts of the Middle East.Zoos also carry out research and educate the public. However, ex situ conservation has problems: some species will not breed in captivity, animals may lose natural behaviours such as hunting or avoiding predators, disease can spread in captivity, and it is expensive. Reintroduction fails if the original threats, such as habitat loss or poaching, have not been removed.