Kanzi: Bonobo or Pan paniscus , was born Oct 23, 1980.

Kanzi was born at the Yerkes Field Station to Lorel (mother) and Bosondjo. But Matata was interested in Kanzi from the moment of his birth and followed Lorel everywhere she went. Finally, approximately 30 minutes after delivery, Lorel appeared exhausted and laid down with Kanzi on her ventrum and began to doze off. Matata gently lifted Kanzi up, one hand and then one foot at time, until he was free of Lorel's body and in the air. She then quickly pressed Kanzi to her ventrum, before Lorel realized what had happened.

Lorel whimpered and followed Matata about, attempting to retrieve Kanzi, but to no avail, as Matata was the dominant individual within the group and Lorel could not take Kanzi from her without a fight. Bonobos try to avoid fights and it is unlikely, even though Matata was dominant, that she could have taken Kanzi by force from Lorel. Matata, being an experienced mother, never let down her guard until Kanzi himself decided that Matata was his mother, began nursing, and showed no interest in Lorel. After 3 days, Lorel ceased attempting to retrieve Kanzi.

Kanzi and Matata came to LRC when Kanzi was 6 months of age, and Kanzi was exposed to human caretakers from that point on. Between 6 months of age and 2.5 years, caretakers worked daily with Matata in lexigram training tasks. Kanzi, who was always with his mother during these training sessions, either ignored them completely or interfered with them in any manner that he could invent on the spur of the moment. He did not appear interested in learning lexigrams, though he liked the lights on the keyboard and often tried to chase the symbols as they appeared on the projectors above the keyboard. The experimenters found Matata's nearly imperceptible progress as well as Kanzi's clear disinterest quite discouraging. At this time, it appeared that bonobos were far less linguistically competent than their common chimpanzee relatives.

At 2.5 years of age, the Yerkes Center requested that Kanzi be weaned and that Matata be returned for a short sojourn to the field station to breed again with Bosondjo. Matata was given a drug to dry up her milk supply. She recognized quickly what was occurring and began, for the first time, occasionally to deny Kanzi access to the nipple. This made him extremely upset and resulted in screams and gestures toward his human companions to request their assistance in making his mother permit him to nurse. If these companions showed any empathy with Kanzi's predicament, he would vocally threaten Matata and sometimes even attempt to bite her. Kanzi was offered prepared milk formula during this period, but steadfastly refused.

Following the separation, which occurred without Kanzi's awareness, Kanzi searched the lab for 3 days attempting to locate his mother before finally settling down. He also, much to the experimenters' surprise, began to correctly employ nearly all of the 10 lexigrams that were on his mother's keyboard at that time. He didn't need to be taught these lexigrams, as he already knew them. Prior to the separation, however, Kanzi had given no evidence that he had even been attending to them, much less that he understood any sort of semantic connection between lexigrams and objects in his world. Even more striking than the fact that Kanzi knew the lexigrams was the fact that he also knew the spoken English words which the lexigrams represented. He could not speak the words, but when he heard them he could locate the lexigram, or printed symbol, that corresponded with the word.

This was truly unprecedented. No ape, or indeed nonhuman of any sort, had ever before been able to determine that a specific spoken word corresponded to either a picture or a printed symbol. The fact that he was not trained to do this, but acquired the skill even without the awareness of the experimenters who were focusing upon his mother's training, was unprecedented in the field of animal cognition.

Certainly Lana, Sherman or Austin could not do this, nor could they select real objects that corresponded to spoken words. Many visitors to the laboratory asserted that Sherman and Austin could understand spoken language. But carefully controlled tests, which eliminated contextual cues, inevitably proved that true speech comprehension was lacking.

Some parrots are reported to vocalize specific words upon being shown certain objects, but comprehending those same words has not been demonstrated for parrots, for any other species, or for any apes other than Kanzi, Panzee and Panbanisha. Listening to a word, then selecting the written or printed symbol for that word, is a form symbol-to-symbol transfer. Such symbol to symbol transfer was never before reported in any nonhuman species. The fact that Kanzi was able to accomplish this feat, without training and indeed even without awareness on the part of the experimenters rearing him, was truly remarkable and completely unanticipated.

Once it was understood that Kanzi needed no specific training to grasp the meaning of spoken words, or their written symbols, reward based training was completely abandoned. As additional symbols were added to his keyboard, they were used in conversation with Kanzi but he was not trained to associate them with specific objects. Instead, all symbols were employed in conversations with Kanzi, and every attempt was made to aide Kanzi in understanding the conversations. Sometimes this entailed accompanying words and lexigrams with gestures, with pictures, with video tape and, of course, with behavioral activities that made manifest the intentions which underlay the communications. Most such conversations centered around travel, finding food and playing. Kanzi's vocabulary steadily increased. Today it is well over 200 words productively and 500 words receptively.

Kanzi has been presented with a variety of carefully controlled tests which demonstrate his comprehension of speech. In these tests, spoken words are presented through headphones and Kanzi is requested to indicate either the real object, the photo, or the lexigram that the word represents. He is essentially 100% accurate on all words that are a part of his vocabulary at any given age. He is able to respond to speakers with accents of many varieties as well as to synthesized speech with only minimal decline in accuracy. Kanzi is the first ape to demonstrate real comprehension of spoken speech. This claim has been made for other apes, but comprehension in these apes has not been systematically tested or demonstrated in controlled tests. No apes, other than Kanzi, Panbanisha and Panzee have been shown to pass tests in which spoken English is presented through headphones and they are requested to select the written symbols that represent the spoken word as well as the object that represent the spoken word.

In addition to single words, Kanzi has demonstrated unequivocal understanding of thousands of novel spoken sentences with syntactically complex structures including embedded phrases, pronouns, case markers, and absent referents. His comprehension of spoken language is at least equivalent to that of a 2-1/2 year old child. Examples below illustrate test sentences given to Kanzi in a formal test (monograph). His comprehension of these different sentences illustrates his understanding of complex grammatical issues.

Kanzi's achievements are not limited to language, but include tool use and tool manufacturing as well. Kanzi is the first ape who can be said to have mastered truly the art of flaking or "knapping" stone. Kanzi began by hitting rocks together without regard for edge, stone structure or type. He used his brute strength, which is considerable, to produce small stone flakes, which he used to cut a string. With time, however, he began to recognize the characteristics of the stone, its shape and the importance of taking these factors into account while knapping. Consequently, strength was replaced by reflection and Kanzi has become an expert at the production of good flint cutting tools. He has not yet learned to modify his cutting tools if they dull, nor to produce tools that correspond to a pattern such as the hand axes produced by early humans, but he has demonstrated that stone tool manufacture is clearly within the competency of living apes.

Kanzi continued to participate in the daily language living environment from birth until 1998, at which time he elected to integrate himself into the social group of bonobos consisting of his mother, his siblings and another adult male, P-Suke. At this time he continues to serve as a subject in language studies, tool manufacturing investigations, studies of vocal communication and social behavior.