At the beginning of the 20th century scientist already knew at least four subspecies of chimpanzees exist. Until recently, however, no scientific techniques existed which could exactly determine to which subspecies a certain individual animal belonged. Especially zoo animals in the third or fourth generation could not be determined accurately. With the development of new DNA-techniques and specifically developed scientific tests for chimpanzees, nowadays it is possible to determine accurately to which subspecies a chimpanzee belongs: not only in the wild, but also in zoos.
Working on a huge task with great determination
For more than ten years the team of Arnhem zoo biologist and great ape expert Tom de Jongh and his Danish colleagues Frands Carlsen and Christina Hvilsom (Zoo Copenhague) have been analysing DNA-results of more than 750 chimpansees in all zoos which are member of EAZA (European Association of Zoos and Aquaria).
Besides that, also DNA-data have been analysed of hundreds of chimpanzees in zoos which are not a member of EAZA. Together with his Danish colleagues he has started an extensive research process. First, DNA-samples have been collected in Afrika of all subspecies of chimpanzees.
Secondly, scientific tests have been developed and, in a process of years, consistently improved in order to be able to determine chimpanzee subspecies also in the case of zoo animals. Before the start of their research, already was known that many ‘founding fathers’ of the European zoo population had been shipped from Western Africa in the past.
Based on the extensive labour of Tom and his colleagues it has been decided to breed with the Western subspecies of chimpanzee in Europe, which outnumber all other subspecies in European zoos, alongside a modest European breeding programme for the Central subspecies. Based on these compulsory guideliness Royal Burgers’ Zoo sterilizes two chimpanzee males which do not belong for a full hundred percent to the Western subspecies on Tuesday 20th October 2015.