Functional Vocalizations by an African Grey Parrot (Psittacus erithacus)


Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, U.S.A.


An African grey parrot, after 26 months of speech training, has acquired a verbal vocabulary consisting of three color adjectives, two phrases for describing shape, 9 nouns, and functional use of the word “no”. The parrot is capable of correctly combining these vocalizations so as to identify proficiently, request, and/or refuse more than 30 objects by means of verbal labels.