by Cassie Bakshani
Hanabi-ko, or Koko, as she was affectionately named, was a female western lowland gorilla born at San Francisco Zoo on July 4th 1971. She spent most of her life at the Gorilla Foundation in California and it was here that she died in her sleep on June 19th, 2018, at the age of 46.
Koko, an ambassador for her species, was instrumental in developing our understanding of cognition in great apes. In 1972, Stanford University graduate and developmental psychologist Francine Patterson began teaching one year old Koko American Sign Language. The infant gorilla was initially confused and reluctant, and would attempt to bite Francine when she moulded Koko’s hands into the correct configuration for a sign. However, after moving Koko away from the distractions of the zoo enclosure and introducing her to more isolated living quarters in a mobile trailer, Francine reported that Koko was acquiring new signs at a rate of one sign per month. By seven years old, it was estimated that Koko possessed a working vocabulary of approximately 375 signs. By the time of her death, she was able to understand more than 1,000 words.
Communicating in this way, Koko provided valuable insights into the minds of great apes, including their emotional capacity and information processing abilities. Researchers marvelled at her ability to express herself in a ‘humanlike’ manner, discussing her likes and dislikes using aspects of our own language and demonstrating empathy within interspecies relationships. Notably with an adopted kitten named All Ball, with whom she developed a close maternal bond, she displayed behaviours we associate with grieving upon learning of his death, signing the words ‘bad, sad, bad, frown, cry-frown, sad’.
Koko provided an example of how our closest living primate relatives rely on complex social interactions to navigate through daily life. Nevertheless, whilst scientists learnt a great deal from studying Koko, it is important to recognise the sacrifice she was required to make to her everyday existence purely to fulfil our scientific curiosity. The ethics associated with confining an intelligent animal in unnatural conditions are concerning, particularly, as in Koko’s case, where she was largely unable to communicate with others of her own kind, let alone in the social group-settings observed in wild gorilla families.
Koko’s impact will undoubtedly be long-lasting and it is my hope that we reflect on this experience and allow it to inform how we, as scientists, study animals in the future. We have a duty to ensure focus on not only our intellectual gain, but also on the physical and psychological wellbeing of these incredible animals.