While Penny (Dr. Patterson) is away on travel, visiting family members, Koko is keenly aware of how long she will be gone and when she will return. In fact, when Penny called the Foundation the other day to say hello to Koko, Koko immediately pulled out the calendar to remind everyone when she was due back.
So the answer to your question is: yes, gorillas do really miss people when they leave them; which is just one of the reasons why we try to make really gpod decisions when hiring new gorilla caregivers and researchers.
