In 1971, the director of Burgers´ Zoo, Antoon van Hoof, and his brother Jan, an ethologist, decided to create a one hectare outdoor island for about 25 chimpanzees. A unique way of keeping chimps in those days. This environment provided great opportunity for behavioural researchers to observe social interaction in a large group of chimpanzees. Since the opening in 1971, the chimpanzees have been observed by numerous researchers. A number of animals in the group are already very old as you can see in the video. In nature, chimpanzees’ life expectancy generally does not exceed forty years, but in Burgers’ Zoo several animals in the group are already in their fifties. When it is colder than 10 ºC, the chimpanzees prefer to stay in the heated indoor enclosure, where they can be observed as well. There’s an observation booth that appears at the end of the video in the right top corner.

In Arnhem they mimic the natural situation, with several adult males in the group. The chimp colony in Burger’s Zoo was and still is a great success, and it became an example of how to keep chimpanzees in captivity, for many zoos all over the world.