The video below just might bring tears to your eyes. Meet Mama, a 59 year old chimpanzee. She used to be the oldest chimp, and a matriarch of the world renowned chimp colony of the Royal Burgers Zoo in Arnhem, the Netherlands.
Jan Van Hooff is the emeritus professor of behavioral biology at Utrecht University and co-founder of the Burgers colony. The man has known Mama since 1972.
The chimp got very sick towards the end of her life and was refusing to eat, drink, and even acknowledge the zoo staff. But things changed when she spotted Jan in her enclosure. He visited her the week before she died of old age in April of 2016.