The IUCN Red List now includes 12,259 species threatened with extinction (falling into the Critically Endangered, Endangered or Vulnerable categories). However the only taxonomic groups, which have been comprehensively assessed, are the birds and mammals.
Global rate of species extinction +/- 27,000 species of animal and plant per annum. (Myers -1987-Beyond the Bars. Thorson.)
In a 1994 article Auckland zoos senior curator stated that it was unlikely that the zoos orang-utans or any of their offspring will ever be reintroduced into the wild. He further stated that in most cases captive breeding isn't about reintroduction and that a recent conservation assessment of captive orang-utans found these animals (once they become dependent on humans) were unadaptable.
He went on to say "The likelihood of captive orang-utan adapting fully to the wild is fairly small."
"They are such a social animal - they learn from watching their peers. Humans aren't able to provide a substitute for that type of thing. However the wild orang-utan has been found to be relatively secure at the moment."
The IUCN Red List
of threatened and endangered species ranks Orang-utan as Endangered
- a taxon is Endangered when it is facing a very high risk of extinction
in the wild in the near future. Sumatran Orang-utan are listed as Critically
Endangered - a taxon is Critically Endangered when it is facing an
extremely high risk of extinction in the wild in the immediate future.
(IUCN 2003. 2003 IUCN Red List of Threatened Species. <www.redlist.org>. Downloaded on 03 December 2003)
Captive Breeding Problems
Captive breeding programmes are expensive
The "conservation dollar" is shortchanged by zoos spending more for the viewing public than conservation. Shops, cafes, amenities, public relations sections, etc all bleed away resources.
Captive breeding programmes are inefficient
Concentrating on one species at a time in a captive setting, and failing to do anything to protect functioning ecosystems. Thus any "conservation value" can never realistically be applied to more than a tiny proportion of species.
Zoos (especially when dealing with large species) can not maintain genetically viable populations over time – hence all the problems associated with small populations in the wild exist are greatly magnified captive settings. There is also the danger that much of the work that has been done on conservation genetics has been done in conjunction with zoo populations.
Adaptation to artificial conditions.
Removing a species from its natural ecosystem can have serious problems as individuals will adapt to captive conditions. This is because there is selection for individuals that do well in captivity, but it has the consequence that certain characteristics of the species are lost. The characteristics that are selected for are often not those that will be most important in the wild
Some individuals also fail to learn key behaviours needed to survive in the wild, or learn behaviours that are harmful in the wild. Learned behaviours and responses are critical to an individuals survival in the wild - these are not available to captive breed species wh,o for example, can become habituated to humans, socially maladapted, unable to communicate within social groups, unable to identify and respond to threats.
Zoo animals and disease.
Captive bred animals may pose a threat to wild populations by introducing disease and may themselves be threatened by not having been exposed, and therefore not being resistant to, naturally occurring diseases.
Captive breeding programs require a long-term commitment so if breeding is successful there can be overproduction so that facilities cannot cope with the number of animals. If there are no release programs to use the “excess” individuals there are issues about what should be done with them. Within the zoo industry culling surplus individuals is seen as a viable management strategy. New Zealand Zoo Guidelines state that zoos are allowed to kill animals - "when births occur despite animals being on a controlled breeding
programme, i.e. unwanted pregnancies" or "when there is over-representation of a particular sex or genetic line" - there is no provision for regarding conservation status.