Bonobos are capable of passing the mirror-recognition test for self-awareness. They communicate primarily through vocal means, although the meanings of their vocalizations are not currently known. However, most humans do understand their facial expressions and some of their natural hand gestures, such as their invitation to play. Two Bonobos at the Great Ape Trust, Kanzi and Panbanisha, have been taught how to communicate using a keyboard labeled with lexigrams (geometric symbols) and they can respond to spoken sentences. Kanzi's vocabulary consists of more than 500 English words and he has comprehension of around 3,000 spoken English words. Some, such as philosopher and bioethicist Peter Singer, argue that these results qualify them for the "rights to survival and life," rights that humans theoretically accord to all persons.
There are instances in which non-human primates have been reported to have expressed joy. One study analyzed and recorded sounds made by human babies and Bonobos when they were tickled. It found although the Bonobo's laugh was a higher frequency, the laugh followed a similar spectrographic pattern to human babies.
The San Diego Zoo has done a good job making the Zoo accessible to visitors with disabilities. The venues are ramped or there are elevators to high areas. Restrooms were large.