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News/Education: :Sep. 10, 2008
Listening to Zoos about the Requirements for Great Ape ZEST

Koko signs with Penny
Dr. Penny Patterson and Koko converse
Gorillas and other great apes in captive environments deserve our most sensitive care — both because they exhibit a high level of emotional and intellectual awareness, and because they face an increasing threat of extinction in the wild.

Zoological institutions recognize this, and hold themselves to elevated standards of care and management for great apes. They have developed sophisticated behavioral enrichment techniques to mitigate stress and provide physically and mentally stimulating environments, and employ training techniques such as operant conditioning to ameliorate potentially difficult medical matters and to introduce preventative health and wellness routines.

Ground-breaking developments in great ape behavioral enrichment and training are thus of the utmost interest to great ape management teams, because they can lead to enhanced health, greater contentment and increased reproduction of endangered gorillas, chimpanzees, bonobos and orangutans.

To offer advanced capabilities to zoological and sanctuary teams working with great apes, the Gorilla Foundation has developed a gestural training tool that optimizes care through enhanced two-way, sign language-based communication. This tool, called ZEST (Zoo Enrichment Signing Technology), leverages over three decades of scientific experience in the process and progress of teaching sign language to gorillas Koko and Michael through Project Koko, and supplies a multimedia tutorial and database for teaching basic signs (American Sign Language/ASL) to any great ape in a captive environment.

In an effort to develop ZEST for potential worldwide use, we are requesting feedback from zoo and sanctuary keepers, curators and behavioral management directors—and we will continue to listen carefully to what they have to say about how this tool might best meet the needs of their institutions.

What we've learned so far, in speaking with zoo personnel, is that for ZEST to be successful as a zoological training tool, it must meet a few basic requirements. Above all, it must be effective at improving great ape care. The training must also be easy to learn and apply behind the scenes, without requiring too much time in a zoo keeper's busy schedule. And, of course, curators need to know that ZEST is based on sound scientific data, with the capability for most great apes to learn and utilize sign language clearly established in advance. We address these requirements via the following set of frequently asked questions:

  1. How will ZEST improve great ape care?
2. How easy will it be for zoo keepers to learn?
3. How easy will it be for great apes to learn?
4. Is it really meaningful communication, or just imitation?
5. When will ZEST be ready for trial at zoos and sanctuaries?
6. Is there a cost for implementing ZEST?
7. How can I learn more about ZEST, or influence its development?

1. How will ZEST improve great ape care?

pain chart
Koko points to a level 3 (out of 10) on her pain chart

During the past 35 years, working with gorillas Koko, Michael and Ndume, we have found that the two-way communication afforded by teaching even "basic" signs to gorillas significantly improves the ability to care for them. And others who have taught sign language to chimpanzees, bonobos and orangutans, have had similar experiences (see, eg, Fouts, Savage-Rumbaugh and Miles).

The most notable benefit of ZEST in a zoological setting is the aid to medical evaluation and care. By developing a pathway to convey simple yet important bits of information regarding health and welfare issues (diet, illness, pain, etc.), zoo keepers and medical personnel can work more effectively toward the highest level of care for great apes in captivity.

“Welfare” vocabulary can be minimal and still have a powerful impact on preventative, diagnostic and curative care. We are even able to use a Pain Chart, which combines signs and symbols to better understand levels of discomfort, allowing us to address pain management strategies with great specificity and increasing the success and safety of treatment.

It is important to note that, as quality of care for captive-held great apes continues to improve, zoos and sanctuaries are providing support for longer-living apes. Thus, both apes and their caregivers are
confronting new challenges associated with age-related illness. ZEST can play a valuable role in longevity through keen medical insight and good quality of life.

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Dr. Penny Patterson and Koko converse

At the Gorilla Foundation we focus on the science of teaching sign language to gorillas, but we are also motivated by the emotional benefits to both the gorillas and their caregivers. Since language is intellectually and emotionally stimulating, it acts as a natural form of behavioral enrichment.

But we also find that by using a
shared communication system, which gives expression to the gorillas’ needs and desires, we expand their choices and allow them to be more involved in selecting foods and activities. The caregivers enjoy the advantages of being able to make and meet detailed requests, which results in mutual and intrinsic enrichment for both gorilla and human.

2. How easy will it be for zoo keepers to learn?   (top of page)

Some basic starting signs to learn and teach

ZEST makes it easy for keepers to quickly learn a basic set of ASL signs by providing a multimedia tutorial page for each sign—a video clip of Dr. Penny Patterson and an associate demonstrating the sign and a description of how the sign is formally done, along with a photo of Koko illustrating the sign and an explanation of how the apes’ adaptation may differ slightly from the formal form, usually due to the size and dexterity limitations of ape hands.

Koko's vocabulary is subdivided into small subsets, such as Essential Signs, Health-Related Signs, Food-Related Signs, etc. A keeper can use the standard sets as a guide, selecting words most appropriate for their needs to create a personalized vocabulary. There are also video examples of the signs being used in real-life conversations with Koko. This system gives keepers quick access to whatever they need to learn, and can be used to refresh knowledge of signs they've previously studied. An average person should be able to learn a dozen signs in a week or two; however, a lot of communication can take place with even just a few signs—consider the power of the three words eat, drink and more for managing great ape meals.

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Penny and caregiver Darlene demonstrate "Drink"

After learning a few signs, the keeper will begin teaching those signs to participating great apes. That's where the tutorial aspect of ZEST becomes important. There are several ways to teach basic signs to captive great apes—all of them are illustrated and demonstrated in the tutorial and all of them can be done within the keeper’s regular routine. The only additional step involves taking a few daily notes and entering them in the computer to track and aid progress. Each training session can take place in as little as 15 minutes per day. After a small "basic care vocabulary" has been established (5-20 signs), there may be a reduction in the keeper’s time requirements, as the learned signs can now be integrated into other behavioral training activities.

Note that ape sign learning can be facilitated by modeling the "learning process" itself — say, by having one keeper teach a sign to another in front of the apes — so that the apes view learning signs as a valuable activity.

3. How easy will it be for great apes to learn?   (top of page)

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San Francisco Zoo gorillas gesturing [J. Tanner]

Great apes are gestural by nature, so the idea and process of gesturing with arms and hands does not have to be learned; it appears to be genetically built into their behavior. Great apes have been observed to use natural (untaught) gestures of their own to communicate with each other.

For example, in a study by Dr. Joanne Tanner, gorillas at the San Francisco Zoo were observed to use dozens
of natural gestures consistently, persistently and frequently over a period of seven years, This and other studies suggest that great apes already have a sign language of their own. So, teaching them our particular form of sign language (ASL) is not a monumental task. It is a matter of recognizing their gestures and assimilating our gestures into their own communication repertoire. They, in turn, will recognize the benefits of utilizing the new gestures to obtain desired items and behaviors from us (which enhances behavioral enrichment) and as a means to respond to our requests (which enhances training).

Koko learned her first few signs in less than two weeks when she was a year old. There was then a burst of learning many new signs when Koko was between 3 and 4 years old (similar to human language development) and currently, at age 37, Koko employs over 1000 ASL signs. Michael was exposed to ASL when he was about three years old. He eventually learned and utilized over 500 ASL signs. Ndume came to the Foundation at 10 years old and is now a full-grown silverback. He has picked up several care-related signs by simply watching Koko and Michael and their caregivers. Ndume has used a variety of untaught signs and compound signs. For example, when Ndume was present during a malfunctioning of our audio recording equipment, he commented: "Fake listen." He must have learned these signs by observation. This exemplifies the ability of adult apes to learn, understand and utilize sign language.
Our experience also attests to the power of even the smallest vocabulary, as long as it is shared.

Koko signs with Penny
Penny models the sign for "Food" to baby Koko

The main difference between the way Koko learned ASL, and the way zoo gorillas will learn has to do with the fact that most keepers work with some level of protected contact. Since Koko had to be human-reared (after separation from her mother when Koko became ill), Dr. Patterson was able to touch her and use "hand-molding" to teach her initial signs.

Nevertheless, many of Koko's subsequent signs were learned through "modeling" — simply demonstrating the sign for her in the right context, and repeating it with her and other caregivers in appropriate circumstances (not necessarily "training sessions").

The "modeling" technique can be used in any environment, and with a little repetition, the gorilla (or chimp, et al) will often pick up the sign very rapidly and start using it both spontaneously and accurately, though they may need occasional correction via re-modeling. Simply pointing to the appropriate body part for the sign is also an effective teaching tool.

Interestingly, we have found that simultaneously signing and speaking facilitates faster learning. Since great apes seem capable of comprehending a lot of spoken words (automatically) in captive settings, this builds on that foundation. However, once a sign is learned, speaking becomes optional.

4. Is it really meaningful communication, or just imitation?  (top of page)

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Koko's asks to be let into the yard to meet Ndume.

ZEST steps beyond traditional operant conditioning as imitation gives rise to comprehension. Koko and Michael started with the basic signs for eat, drink and more, and then branched out to learn other signs relevant to their daily routines, environment and social group. Because Koko and Michael began generalizing their acquired signs spontaneously and accurately very early in the process (i.e., in months not years), it became clear that they were not simply imitating, but using the signs as a true form of language.

Koko and Michael have used signs
creatively, to make up stories, synthesize new signs, tell jokes, deliver insults, comment on the past and future, and to express emotional reactions to what was going on around themall with grammatical consistency and personal flair. Our data includes thousands of examples of meaningful sign language exchanges between the gorillas and their caregivers. Shown here are just a few:

In the video clip above (right), Koko asks Penny to open the gate and let her into the outdoor enclosure so that she can meet Ndume (her self-chosen mate) for the first time.

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Michael recounts a memory about his mother.

In the video at left, gorilla Michael responds to the question: "Tell me about your mother?" by recounting a story that appears to describe his mother being killed by poachers in Africa, an event which we have good reason to believe he witnessed as an infant.

And in the video clip below left, Koko expresses her frustration when Dr. Patterson doesn't understand one of her new signs. Situations like this create an excellent opportunity for further communication and mutual learning.

Such illustrations suggest that sign language communication between keepers and great apes can be meaningful, interesting, functional, educational, engaging, enriching and in some cases critically important.

Also, of possible long-term importance is the potential for offspring of sign-conversant great apes to learn sign from their parents, as well as from signing humans in their environment. This process could result in enhanced learning and improved care for the youngsters.

While we do not have direct evidence of cultural transmission with Koko since she has not yet had a baby, the passing on of language to the next generation has already been witnessed with the sign-conversant chimpanzee, Washoe (see Friends of Washoe) and Koko has indicated her readiness to teach signs to a baby by practicing with great ape dolls (see video below right).

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Koko is frustrated when she's not understood.

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Koko molds her Orangutan doll to sign "drink"

For additional scientific documentation, information or training results, see our bibliography or email us at zest@koko.org.

5. When will ZEST be ready for trial with great apes at zoos and sanctuaries?  (top of page)

ZEST Multimedia Look-Up of the Sign for "Apple"

Before making ZEST available on a broad scale, we are looking to establish a few closely managed partnerships with zoos or sanctuaries. These flagship teams will receive special attention from Gorilla Foundation staff, and their needs will be accommodated quickly and thoroughly.

Aside from the aforementioned benefits to apes and keepers, there are scientific opportunities for the first teams that explore ZEST in a zoological setting, including new great ape behavioral studies and the subsequent publishing of results, utilizing our secure database.

ZEST is currently available as a prototype at the Gorilla Foundation. It has an expanding multimedia sign language dictionary, culled from Koko's 1,000 word vocabulary, associated video examples and a mechanism for targeting and tracking the development of a basic sign language and natural gesture vocabulary for each great ape, keeper and organization involved. However, still needed is additional testing, user-interface smoothing and extended reporting features to make it easier to evaluate progress.

If you're interested in being an early ZEST partner, please contact us at zest@koko.org.

6. Is there a cost for implementing ZEST?   (top of page)

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Koko and Penny interact through the mesh

ZEST is still in the prototype stage and selected partners will be allowed to try it and receive extensive support from the Gorilla Foundation, free of charge. We have not set a price yet for ZEST, but any future cost will depend on how many additional features and developers are required to maintain the program to the satisfaction of the zoological community.

The video at left illustrates a
n interaction between Koko and Dr. Penny Patterson, as filmed through the mesh of her indoor enclosure. It reveals the simple joy of being able to communicate across interspecies boundaries. Learning sign language, when accompanied by spoken English, often leads to increased comprehension of the latter, which means that communication involving both words and gestures begins to emerge naturally.

We conclude that, by adding ZEST to zoological training protocol with a minimal time
investment, behavioral enrichment is taken to a higher level, and zoo keepers and medical personnel can enjoy tangible science-based results, which greatly enhance the care and ease of management for great apes.

7. How can I learn more about ZEST, or influence its development?   (top of page)

We would like to keep an open and on-going dialogue about ZEST, so encourage zoo keepers, curators, behavioral managers and other great ape caregivers to email additional questions or concerns to Gary Stanley at zest@koko.org. We appreciate your feedback, and welcome partnership inquiries.

This article was written collaboratively by Gary Stanley (left), Director of Educational and Information Technology at the Gorilla Foundation and Brooke Bessesen (right), naturalist, award-winning children's author-illustrator, and a zoo CVT (certified veterinary technician). Gary is the principal developer of ZEST, and Brooke assisted in garnering preliminary feedback from the zoo community to assure that ZEST is as useful as possible to that community and its resident great apes.

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