Sjors has become quite old, because on average chimpanzees living in captivity live to be about 50 years old. DierenPark Amersfoort therefore calls 56 years “a very good age for a chimpanzee”. Because of her advanced age, the caretakers had been keeping an extra close eye on her health for a long time. Because pain relief was no longer sufficient, it was decided to put the animal to sleep.