Part of the show Captive breeding
Last week, the 2nd to last to last wild born Spix’s Macaw died. The 40 year old
• According to the International Union for Conservation of Nature's Red List, around 17,000 species are listed as threatened with extinction. This is largely due to habitat loss and hunting.
• Captive breeding programs within zoos aim to protect the most endangered species from going extinct. Some of these will, eventually, re-release animals into the wild.
• The first success story was in the 1960s, when a captive breeding program allowed the Arabian oryx to be re-released after being hunted to extinction.
• More recently, golden-lion tamarins have been re-released in Brazil after a successful breeding programme, and their numbers are slowly rebounding.
• For a population to be healthy, whether captive or in the wild, it is important it is genetically diverse.
• When animals mate, the offspring receive one set of genes from the mother and one from the father. Usually, if one gene in a pair is defective it doesn’t affect the animal.
• If, however, the parents are closely related, it is more likely the offspring will receive two copies of the defective gene, which can lower its survival chances. This is known as inbreeding.
• As a population becomes less genetically diverse, it is also more likely that a single illness could wipe out the whole group.
• Each zoo only holds a few individuals of each species, so they have to work together to
• Groups such as the European Association of Zoos and Aquaria (or EAZA) carefully manage captive populations to ensure they are as genetically diverse as possible.
• Their animals don’t ‘belong’ to a zoo, but are on loan from the EAZA, meaning they can be moved around in the way that most benefits the population as a whole.
• This reduces the need to take animals from the wild and, hopefully, leads to healthy and diverse populations.