The release was the first of its kind to use VHF-GPS store-on-board ARGOS tracking collars to monitor the progress of the chimpanzees. The ARGOS system emits GPS points to satellites downloadable via the internet. It is also only the second time that rehabilitated chimpanzees have been released back into the wild in an area where other wild chimpanzees live.

Dr Tatyana Humle from the University of Kent is the scientific advisor to the project, which is being carried out by the Chimpanzee Conservation Centre in the Haut Niger National Park, Guinea, West Africa. This centre is one of 14 Pan African Sanctuary Alliance (PASA)-accredited sanctuaries caring for chimpanzee victims of the pet and bush meat trade.

Six males and six females between eight and 20 years old were released in June 2008. Over two years after the release, nine chimpanzees remain free-living with two males and three females forming a group at the original release site. Two of these females gave birth to healthy offspring and another female successfully integrated into a wild chimpanzee community.

The release presented a number of challenges for researchers including finding a suitable release area, assessing its overlap with the home range of other wild chimpanzees to minimize competition and the risk of aggression, and ensuring the chimpanzees' ability to survive independently of human assistance.

The GPS points stored on the collars allowed researchers to monitor the chimpanzees' behaviour including their habitat use, day travel range and association patterns. The ARGOS system also facilitated several rescue missions to retrieve chimpanzees when they strayed too far from the protected release site.

The release project has brought significant conservation benefits to the local area. Environmental education and awareness raising programs have been established in and around the park, illegal logging activities have stalled and illegal hunting and fishing activities have been reduced.

Other sanctuaries and conservation centres are set to benefit significantly from the project's pioneering use of new technology.

Dr Humle, from the University's School of Anthropology and Conservation, said: 'This release demonstrates that under special circumstances the release of wild-born adult chimpanzees of both sexes is a viable strategy, which can also function as an effective conservation tool.

'The lessons learnt and the experience gained so far will benefit other sanctuaries that are also considering the option of releasing suitable candidates in the future. We still have much to learn about how rehabilitation, pre- and post-release procedures, and monitoring protocols impact release success. We can only hope that increased collaboration among academics, conservationists and sanctuaries will help bridge these gaps.'

Note: If no author is given, the source is cited instead.

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