Dr Katie Fawcett, from the Grace Center, says it’s also “essential” for an animal to form social relationships to be considered for release into the wild – which is the ultimate goal for Jojo’s keepers.

The bonds between gorillas – what we would call friendship – is key to their society, adds Dr Robin Morrison from the University of Zurich, who studies the social lives of mountain gorillas. In one recent study, she discovered that female mountain gorillas would seek out females they knew, even if they hadn’t seen them for many years, when joining a group.

And she says a big part of a gorilla’s normal social life is “just sitting together quietly sharing space”.

But Jojo has never been given the opportunity to sit quietly with another gorilla.

No one knows how Jojo will react to a companion. Moving an animal from an accredited zoo would be a decision for an international committee and based on genetics, health and the animals’ personalities and compatibility.

Any introduction to another animal would be done very carefully – perhaps giving them an object that smells of the other before they see each other.

These slow, cautious ape introductions do happen – when an animal moves from one zoo group to another, for example. Forrester has contacted a number of accredited zoos to explore the possibility of doing this for Jojo. But those discussions have fizzled out with no sign of progress.

The problem, she says, is “there aren’t clear processes in place to do these kinds of trans-locations”.