Cognitive and communicative abilities of Grey parrots☆
Introduction
This paper presents a brief summary of almost 30 years of study of the cognitive and communicative activities of Grey parrots. Much of this work has involved direct contact amongst myself, my students and individual birds, most notably my oldest subject Alex, and describes the cognitive development of each individual. For this reason this paper departs from conventional practice in scientific writing and makes regular use of personal nouns and pronouns (e.g. Alex and I) for the good reason that this format makes the paper easier to read. It has become clear from this work that Alex exhibits cognitive capacities comparable to those of marine mammals, apes and sometimes 4–6-year-old children (Pepperberg, 1999). Using English vocalizations, Alex labels 50 different objects, 7 colors, 5 shapes and quantities up to and including six. He combines these labels to identify, request, refuse, categorize and quantify about 100 different objects. He has functional use of phrases such as “Come here”, “I want X” and “Wanna go Y” where X and Y are, respectively, appropriate object or location labels. He has concepts of category, bigger/smaller, same/different, absence and quantity; some of these will be discussed in detail below. Of particular interest is that his abilities are inferred not from operant tasks common in animal research, but from vocal responses to vocal questions; that is, he demonstrates intriguing communicative parallels with young humans, despite his phylogenetic distance. Younger birds have begun to replicate Alex's results. It is unlikely that I taught Alex and other parrots these abilities de novo, which suggests that their achievements derive from existent cognitive and neurological architectures. Although this work has interest on its own merit for researchers in psychology, biology, neurobiology, anthropology, linguistics and other scientific disciplines, the data also have implications for the treatment of psittacines in captive situations such as zoos or as human companion animals.
Section snippets
Animals and housing
The subjects of my studies have been several male Grey parrots (Psittacus erithacus). (Note: Their sex has been a matter of chance, as Greys are sexually monomorphic and were not tested until after their acquisition.) The oldest, Alex, was acquired in 1977 when he was approximately 1 year old; he is still a research subject. Alo was acquired at 7 months, in 1991, and was in the laboratory until early 1995. Kyaaro, acquired at about 3 months, also in 1991, remained in the laboratory until 2001.
Results of M/R training
As noted above, Alex has acquired several complex cognitive concepts. He not only produces various English labels, but also understands their use and the numerous questions we pose. He is not responding by rote to objects in his environment. So, for example, I can show him a particular object and ask him “What color?” (green), “What shape?” (four-corner), “What matter?” (wood) and “What toy?” (block). He could not respond appropriately unless he comprehended the labels for, and the concepts of,
Unexpected similarities between primates and parrots
Other unexpected similarities exist for birds and primates with respect to the development of communicative competence. These parallels involve behavior for which underlying mechanisms may suggest a commonality in brain structure and/or information processing. I discuss two studies: combinatory learning and phonological processing.
Overall conclusions
A key message of this paper, presented within the context of a symposium on Animal Sentience, is to encourage an awareness of, and a sensitivity to, the abilities of non-humans, particularly non-primate and non-mammalian subjects. For far too long, animals in general, and birds in particular, have been denigrated and treated merely as creatures of instinct rather than sentient, intelligent beings. The data presented here and elsewhere (see Pepperberg, 1999) demonstrate that many species of
References (38)
- et al.
Do bird possess homologues of mammalian primary visual, somatosensory and motor cortices?
TINS
(2000) - et al.
Allospecific vocal learning by Grey parrots (Psittacus erithacus): a failure of videotaped instruction under certain conditions
Behav. Proc.
(1998) Children's understanding of counting
Cognition
(1990)Understanding the link between joint attention and language
- et al.
Representing quantity beyond whole numbers: some, none and part
Can. J. Expt’l Psychol.
(2000) Uber das Unterscheidungsvermögen unbenannter Anzahlen bei Papageien
Z. Tierpsychol.
(1952)A First Language
(1973)Children's Counting and Concepts of Number
(1988)- et al.
Specifying the relation between novel and known: input affects the acquisition of novel color terms
Child Dev.
(1996) - et al.
Male zebra finches and Bengalese finches emit directed songs to the video images of conspecific females projected onto a TFT display
Zool. Sci.
(1999)
Strategies used to combine seriated cups by chimpanzees (Pan troglodytes), bonobos (Pan paniscus), and capuchins (Cebus apella)
J. Comp. Psychol.
The ability of birds to ‘count’
Bull. Anim. Behav. Soc.
Thinking without words
Sixteen- and 24-month olds’ use of mutual exclusivity as a default assumption in second-label learning
Dev. Psychol.
Versuche zur Frage des “Zähl”-Vermögens an einem Graupapagei und Vergleichsversuche an Menschen
Z. Tierpsychol.
A comparative approach to vocal learning: song development in white-crowned sparrows
J. Comp. Physiol. Psychol.
A comparative study of human and Grey parrot phonation: acoustic and articulatory correlates of stop consonants
JASA
Acquisition of the same/different concept by an African Grey Parrot (Psittacus erithacus): learning with respect to color, shape, and material
Anim. Learn. Behav.
Evidence for conceptual quantitative abilities in the African Grey Parrot: labeling of cardinal sets
Ethology
Cited by (61)
Neurobiology of numerical learning
2024, Neuroscience and Biobehavioral ReviewsNeural evidence for referential understanding of object words in dogs
2024, Current BiologyComputational benefits of structural plasticity, illustrated in songbirds
2022, Neuroscience and Biobehavioral ReviewsCitation Excerpt :Many species of birds, including starlings, crows and parrots, have been found to maintain complex social organization among colonies of thousands (and more) of subjects (Boucherie et al., 2019; Downing et al., 2020), relying at least partly on vocal communication. Finally, parrots display cognitive abilities that we have until now considered unique to humans and other primates (conceptual representation, combinatory learning, counting (Pepperberg, 2006)) and magpies can recognize themselves in a mirror (Prior et al., 2008), a skill thought to require a representation of oneself and only sparsely present in mammals. Altogether, the similar cognitive abilities of birds compared to mammals suggest that similar constraints apply to the organization of their nervous system to optimize their behavior.
Disentangling feedforward versus feedback processing in numerosity representation
2021, CortexCitation Excerpt :Approximate numerical magnitude – or simply numerosity – represents a fundamental attribute of a visual scene (e.g., Anobile, Cicchini, & Burr, 2016). Humans, as well as many other animal species, are thought to possess a natural sense of number that allows them to rapidly estimate the approximate number of objects in a visual scene (Agrillo, Dadda, Serena, & Bisazza, 2008; Dehaene, 2011; Gallistel & Gelman, 1992; Pepperberg, 2006; Piantadosi & Cantlon, 2017; Rugani, Vallortigara, Priftis, & Regolin, 2015). This sense of number appears to be phylogenetically ancient, and ontologically innate, as human newborns are able to discriminate the numerosity of different sets shortly after birth (Izard, Sann, Spelke, & Streri, 2009; Xu, 2003; Xu & Spelke, 2000).
Looking for more food or more people? Task context influences basic numerosity perception
2019, CortexCitation Excerpt :That said, modern theories of numerical cognition posit that our approximate numerical abilities have deep ontogenetic and phylogenetic roots (e.g., Dehaene, 2011; Gelman & Cordes, 2001). This idea is empirically supported by studies demonstrating that this number sense is widespread across animal species (Agrillo, Dadda, Serena, & Bisazza, 2008; Pepperberg, 2006; Piantadosi & Cantlon, 2017; Rugani, Vallortigara, Priftis, & Regolin, 2015) and present from birth in human newborns (Izard, Sann, Spelke, & Streri, 2009; Xu & Spelke, 2000; Xu, 2003). One crucial question, however, is whether numerosity is processed by a dedicated perceptual system independently from other non-numerical magnitude dimensions, or whether and to what extent other continuous visual cues are used to derive the representation of numerosity.
How environmental enrichment affects behavioral and glucocorticoid responses in captive blue-and-yellow macaws (Ara ararauna)
2018, Applied Animal Behaviour ScienceCitation Excerpt :Birds, especially parrots, have high cognitive abilities and need stimulation to maintain proper neural function. Studies have shown that the cognitive ability of Gray parrots (Psittacus erithacus) is comparable to marine mammals and young children, and the communicative competence is equivalent to many primates due to the similarity in brain structure and information processing (Pepperberg, 2006). In a recent study, Olkowicz et al. (2016) found that the brains of many bird species show a higher number and density of neurons than brains of similarly sized mammals.
- ☆
This paper is part of the special issue entitled Sentience in Animals, Guest Edited by Dr. John Webster.