Mama, a 59-year-old chimpanzee at the Burgers Royal Zoo in the Netherlands, was suffering from a lengthy and terrible disease.

It was April 2016, and the monkey, a long-time zoo fixture, was snubbing every spoonful of food provided to her. She curled up into a ball instead.

Jan van Hooff, a Dutch scientist and an old friend of hers, paid her a visit. He met Mama in 1972 and the two developed a strong friendship throughout the years.

Mom recognized an old acquaintance and squealed with delight, according to a video posted on YouTube. The patient, who has ignored all of her carers’ gestures, extends her hands. She smiles, yells, and clings to the man fiercely.

In the video’s description, Van Hooff says, “Her reaction was highly emotional and painful.” Animals have long been found to have emotional attachments as least as strong as humans, from whales and dolphins to monkeys and octopuses.

But there was something else about their reunion: a sort of reminiscence between two long-lost pals.

Perhaps it was just a light that Mom needed to see as she approached the end of her life. She passed just a week after her buddy paid her a visit.