I've just found the following article about London Zoo's gorilla "Mok"; hopefully others will find it of interest. (The article was first published in "The Archives of Natural History"; the journal of The Society for the History of Natural History.)
https://www.euppublishing.com/doi/full/10.3366/anh.2022.0754
https://www.euppublishing.com/doi/full/10.3366/anh.2022.0754