Avian Expert Articles

Inside Dr. Pepperberg’s Lab: Yes, Our Birds Mean What They Say

Griffin the African grey parrot standing on a table and giving a "look"
An old picture of a “grumpy Griffin,” to give you an idea of the kind of looks we get when our behavior is not what he would consider satisfactory.

The most common question I get at events like parties, when I tell people that I train parrots to communicate with humans in English, is, “But do they really understand what they are saying?”

I have 40-plus years of data and probably over a hundred publications to demonstrate that such is indeed the case. Sometimes, however, it is the anecdote — the once-in-a-blue-moon, not-possible-to-reproduce, I-can’t-believe-that-just-happened-incident — that transforms the general public into believers. These incidents can never hold up to scientific scrutiny, and at most can be the impetus to begin a serious scientific study, but they are consistently interesting and valuable.

Alex Chimes In

It is always exciting when the incident does lead to a series of experiments. Such was the case when we were training Griffin to respond to auditory numbers — sets of clicks. At the time, we made sure that the inter-click intervals were of random lengths and that the lengths of the sounds constituting the clicks were also random so that Griffin could not merely respond to the amount of sound or stimulus duration, but rather had to attend to the exact number.

We were working with “two,” and Griffin simply was not interested. I had clicked twice, asked, “How many?” and Griffin ignored me. I started over: “Griffin, pay attention! Listen! (two clicks) How many?” Again, Griffin continued to preen. Behind me, Alex, from his cage, piped up with a very clear FOUR. I told him he was wrong, that the answer was TWO, and gave Griffin one more chance. Alex then very clearly produced SIH (his label at the time for “six”).

DUH…I realized that Alex was adding the clicks! We quickly designed a study, based on work my colleague Sally Boysen had done with her apes (Boysen & Berntson, 1989), and showed that Alex could indeed sum small quantities of objects, and then Arabic numerals (Pepperberg, 2006, 2012).

Without any training, Alex also transferred his use of the label “none” from indicating a lack of similarity or difference in a pair of objects to the absence of a specific quantity. The details are in Pepperberg & Gordon (2005); basically, he manipulated me into asking him to identify a null set — so that he could use “none”— and that led to our study of his understanding of a zero-like concept.

Choosing What To Follow Up

Sometimes we intended to follow up on an incident, as with Alex’s famous, untrained, and very unexpected spelling out of N-U-T during a demonstration of what was supposed to be a simple identification of sound-letter associations (Pepperberg, 2008). Unfortunately, we never got around to testing him on other possible combinations.

And sometimes the incident is definitely something that we do not care to replicate, as when a student forgot to give Athena fresh water one morning…and she very clearly and, apparently intentionally, uttered WATER. Water deprivation is clearly a situation that we certainly do not want to happen in our lab deliberately! Athena has never again said WATER, even when she is trying to get us to do something like extend her shower. She had, however, made her point.

Griffin Makes His Thoughts Clear

Recently, Griffin added to our anecdote list. Suzanne, our long-time lab manager, who is also a post-doctoral fellow with us this year, was giving the birds a break from sessions. She had Griffin on one hand, was tickling his head with the other, but wasn’t giving him her full attention as she was also trying to read a journal article. Griffin kept saying TICKLE; she would stop reading briefly, completely attend to his needs for a short while, then go back to reading. He kept repeating his request. After a few such repetitions, he blurted out an extremely loud PAPER while he reached over, grabbed the article, threw it to the floor, and then stared at her directly and demanded TICKLE! It was quite clear what he thought of her behavior!

As I said at the outset, I’ve spent over 40 years collecting data and publishing papers to convince my scientific colleagues that my parrots really do have symbolic reference. Formally, the definition is that it “involves semantic and pragmatic use of noniconic symbols — be they auditory/vocal, manual, or lexical — to stand for (but not be limited to) items such as physical objects and their attributes, various concepts, relations among these items and concepts, actions that can be done to or with these items, and comments about these items (e.g., relating to past/ future/hypothetical issues).” (Pepperberg, 2021).

But sometimes it is the simple anecdote that helps people understand the intelligence of these parrots.


Semantic: Involving the meanings of symbols

Pragmatic: Involving practical use

Noniconic: An arbitrary relationship. For example, an iconic representation of a dog by a child is the use of the term “bowwow”; noniconic representations are the labels “dog,” “chien,” etc. that have nothing canine-like about them

Lexical: Generally refers to something written


Boysen, S. T., & Berntson, G. G. (1989). Numerical competence in a chimpanzee (Pan troglodytes). Journal of Comparative Psychology, 103, 23–31.

Pepperberg, I. M. (2006). Grey parrot (Psittacus erithacus) numerical abilities: addition and further experiments on a zero-like concept. Journal of Comparative Psychology, 120, 1–11.

Pepperberg, I.M. (2008). Alex & Me. New York: Harper-Collins.

Pepperberg, I. M. (2012). Further evidence for addition and numerical competence by a Grey parrot (Psittacus erithacus). Animal Cognition, 15, 711–717.

Pepperberg, I.M. (2021). Nonhuman and nonhuman-human communication: Some issues and questions. Frontiers in Psychology, 12:647841. Doi: 103389/fpsyg.2021.647841.

Pepperberg, I. M., & Gordon, J. D. (2005). Numerical comprehension by a Grey parrot (Psittacus erithacus), including a zero-like concept. Journal of Comparative Psychology, 119, 197–209.

One thought on “Inside Dr. Pepperberg’s Lab: Yes, Our Birds Mean What They Say

  1. Thanks a lot, Dr. Pepperberg. Your contribution helps keeping calm while your bird is acting like a human. Ciàula, my European Goldfinch, used to ignore the Christmas tree I had recently bought and placed into his living space: he never flew into it or inspected it. One night, coming home after training, I turned on the light. Ciàula was sleeping on the cage roof. He got awaked and scared by the light and flew around agitated. I got upset, as he was sleeping in the wrong place again. I do not like to avoid turning on the light because he is sleeping. I got upset and I loudly said, “I have bought this Christmas tree just for you and you have been simply ignoring it. Why don’t you sleep there instead?” Ciàula gives me short but very intense gaze. He then flies into the tree and sleeps there. I was shocked. I could not open my mouth again. He kept sleeping there for a week. Afterwards, he started to sleep again wherever he wanted.
    Some considerations: Humans need years of training before they can master a language. I bought Ciàula in November at a Danish avian market. He reacted this way in December, one month later. I speak to him in German.

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